148 results on '"Han Bin Oh"'
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2. New free radical-initiated peptide sequencing (FRIPS) mass spectrometry reagent with high conjugation efficiency enabling single-step peptide sequencing
- Author
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Sang Tak Lee, Hyemi Park, Inae Jang, Choong Sik Lee, Bongjin Moon, and Han Bin Oh
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Medicine ,Science - Abstract
Abstract A newly designed TEMPO-FRIPS reagent, 4-(2,2,6,6-tetramethylpiperidine-1-oxyl) methyl benzyl succinic acid N-hydroxysuccinimide ester or p-TEMPO–Bn–Sc–NHS, was synthesized to achieve single-step free radical-initiated peptide sequencing mass spectrometry (FRIPS MS) for a number of model peptides, including phosphopeptides. The p-TEMPO–Bn–Sc–NHS reagent was conjugated to target peptides, and the resulting peptides were subjected to collisional activation. The peptide backbone dissociation behaviors of the MS/MS and MS3 experiments were monitored in positive ion mode. Fragment ions were observed even at the single-step thermal activation of the p-TEMPO–Bn–Sc–peptides, showing mainly a-/x- and c-/z-type fragments and neutral loss ions. This confirms that radical-driven peptide backbone dissociations occurred with the p-TEMPO–Bn–Sc–peptides. Compared to the previous version of the TEMPO reagent, i.e., o-TEMPO–Bz–C(O)–NHS, the newly designed p-TEMPO–Bn–Sc–NHS has better conjugation efficiency for the target peptides owing to its improved structural flexibility and solubility in the experimental reagents. An energetic interpretation using the survival fraction as a function of applied normalized collision energy (NCE) ascertained the difference in the thermal activation between p-TEMPO–Bn–Sc– and o-TEMPO–Bz–C(O)– radical initiators. This study clearly demonstrates that the application of the p-TEMPO–Bn–Sc– radical initiator can improve the duty cycle, and this FRIPS MS approach has the potential to be implemented in proteomics studies, including phosphoproteomics.
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- 2022
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3. Unveiling host–guest–solvent interactions in solution by identifying highly unstable host–guest configurations in thermal non-equilibrium gas phase
- Author
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Hyoju Choi, Young-Ho Oh, Soojin Park, Sung-Sik Lee, Han Bin Oh, and Sungyul Lee
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Medicine ,Science - Abstract
Abstract We propose a novel scheme of examining the host–guest–solvent interactions in solution from their gas phase structures. By adopting the permethylated β-cyclodextrin (perm β-CD)–protonated L-Lysine non-covalent complex as a prototypical system, we present the infrared multiple photon dissociation (IRMPD) spectrum of the gas phase complex produced by electrospray ionization technique. In order to elucidate the structure of perm β-CD)/LysH+ complex in the gas phase, we carry out quantum chemical calculations to assign the two strong peaks at 3,340 and 3,560 cm−1 in the IRMPD spectrum, finding that the carboxyl forms loose hydrogen bonding with the perm β-CD, whereas the ammonium group of L-Lysine is away from the perm β-CD unit. By simulating the structures of perm β-CD/H+/L-Lysine complex in solution using the supramolecule/continuum model, we find that the extremely unstable gas phase structure corresponds to the most stable conformer in solution.
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- 2022
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4. Development and Validation of a Solvent-Free Headspace GC-MS Method for the Screening of Benzyl Chloride in Pharmaceutical Products
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Eunchae Song, Chanhong Min, Eunjae Kim, Sang Beom Han, Yong-Moon Lee, Kwang-Hyeon Liu, Jongki Hong, and Han Bin Oh
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benzyl chloride ,cinnarizine ,ICH M7 ,impurity ,solvent-free HS-GC/MS ,Biochemistry ,QD415-436 - Abstract
This study presents a solvent-free headspace gas chromatography–mass spectrometry (SF-HS-GC/MS) method for robustly screening benzyl chloride, a mutagenic carcinogen, impurities in active pharmaceutical ingredients (APIs) and drug products. The SF-HS-GC/MS method simplifies analysis by eliminating solvent use, reducing matrix interference. Optimized headspace parameters include incubation temperature, time, and sample amount. Validation, aligned with Q2(R1) ICH guidelines and ICH M7 recommendations, covers selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, system suitability, and robustness. Employing a DB-5MS column (30 m × 0.25 mm, 0.25 µm) with solvent-free split injection, the method’s calibration curve (0.05–5 μg/g) exhibits a strong correlation (>0.9998). The LOQ was 0.1 μg/g, with precision (%CV) consistently
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- 2023
- Full Text
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5. Quantitative proteomic profiling of Cervicovaginal fluid from pregnant women with term and preterm birth
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Young Eun Kim, Kwonseong Kim, Han Bin Oh, Sung Ki Lee, and Dukjin Kang
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Cervicovaginal fluid ,Preterm birth ,Quantitative proteomics ,Cytology ,QH573-671 - Abstract
Abstract Background Preterm birth (PTB) is one of major causes of perinatal mortality and neonatal morbidity, but knowledge of its complex etiology is still limited. Here we present cervicovaginal fluid (CVF) protein profiles of pregnant women who subsequently delivered at spontaneous preterm or term, aiming to identify differentially expressed CVF proteins in PTB and term birth. Methods The CVF proteome of women who sequentially delivered at preterm and term was analyzed using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional nanoflow liquid chromatography-tandem mass spectrometry (2D-nLC-MS/MS). We compared the CVF proteome of PTB (n = 5) and control subjects (term birth, n = 7) using pooled control CVF (term birth, n = 20) as spike-in standard. Results We identified 1294 CVF proteins, of which 605 were newly identified proteins. Of 990 proteins quantified in both PTB and term birth, 52 proteins were significantly up/down-regulated in PTB compared to term birth. The differentially expressed proteins were functionally associated to immune response, endopeptidase inhibitors and structural constituent of cytoskeleton. Finally, we confirm the down-regulation of SERPINB7 (a serine-type protease inhibitor) in PTB compared to control by Western blot. Conclusions Taken together, our study provide quantitative CVF proteome profiles of pregnant women who ultimately delivered at preterm and term. These promising results could help to improve the understanding of PTB etiology and to discover biomarkers for asymptomatic PTB.
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- 2021
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6. Author Correction: New free radical-initiated peptide sequencing (FRIPS) mass spectrometry reagent with high conjugation efficiency enabling single-step peptide sequencing
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Sang Tak Lee, Hyemi Park, Inae Jang, Choong Sik Lee, Bongjin Moon, and Han Bin Oh
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Medicine ,Science - Published
- 2023
- Full Text
- View/download PDF
7. Characteristics of the Molecular Weight of Polyhexamethylene Guanidine (PHMG) Used as a Household Humidifier Disinfectant
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Dong-Uk Park, Kee Won Yang, Jiwon Kim, Ju-Hyun Park, So-Yeon Lee, Kyung Ehi Zoh, Jung-Hwan Kwon, Soyoung Park, and Han Bin Oh
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humidifier-disinfectant-associated lung injury (HDLI) ,polyhexamethylene guanidine (PHMG) ,oligomer ,molecular mass ,polymerization ,number-average molecular weight (Mn) ,Organic chemistry ,QD241-441 - Abstract
(1) Background: Household humidifier disinfectant (HD) brands containing polyhexamethylene guanidine (PHMG) have been found to cause the most HD-associated lung injuries (HDLIs) in the Republic of Korea. Nevertheless, no study has attempted to characterize the potential association of the health effects, including HDLI, with the physicochemical properties of PHMG dissolved in different HD brands. This study aimed to characterize the molecular weight (MW) distribution, the number-average molecular weight (Mn), the weight-average molecular weight (Mw), and the structural types of PHMG used in HD products. (2) Methods: Quantitative measurements were made using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF MS). The Mn, Mw, and MW distributions were compared among various HD products. (3) Results: The mean Mn and Mw were 542.4 g/mol (range: 403.0–692.2 g/mol) and 560.7 g/mol (range: 424.0–714.70 g/mol), respectively. The degree of PHMG oligomerization ranged from 3 to 7. The MW distribution of PHMG indicated oligomeric compounds regardless of the HD brands. (4) Conclusions: Based on the molecular weight distribution, the average molecular weight of PHMG, and the degree of polymerization, the PHMG collected from HDLI victims could be regarded as an oligomer. PHMG, as used in household humidifiers, should not be exempted from toxic chemical registration as a polymer. Further study is necessary to examine the association of PHMG oligomeric compounds and respiratory health effects, including HDLI.
- Published
- 2021
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8. Characteristics of Exposure to Chloromethylisothiazolinone (CMIT) and Methylisothiazolinone (MIT) among Humidifier Disinfectant-Associated Lung Injury (HDLI) Patients in South Korea
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Dong-Uk Park, Seon-Kyung Park, Jiwon Kim, Jihoon Park, Seung-Hun Ryu, Ju-Hyun Park, So-Yeon Lee, Han Bin Oh, Sungkyoon Kim, Kyung Ehi Zoh, Soyoung Park, and Jung-Hwan Kwon
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humidifier disinfectant-associated lung injury (HDLI) ,humidifier disinfectant (HD) ,chloromethylisothiazolinone (CMIT) ,methylisothiazolinone (MIT) ,inhalation exposure ,patient ,Organic chemistry ,QD241-441 - Abstract
This study aimed to quantify both chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) dissolved in different product brands and to characterize the exposure to these chemicals among humidifier disinfectant-associated lung injury (HDLI) patients. Both CMIT and MIT dissolved in different humidifier disinfectant (HD) products were quantified using gas chromatography–mass spectrometry. The inhalation level of CMIT and MIT was estimated based on HD-associated factors as reported by HDLI patients. A total of eleven HD products marketed until the end of 2011 were found to contain CMIT and/or MIT. The level of combined CMIT and/or MIT dissolved in these HD products ranged from 12 to 353 ppm. The level varied among HD products and the year of manufacture. The average inhalation levels were estimated to be 7.5, 4.1, and 3.2 μg/m3 for the definite, probable, and possible groups, respectively. If probable and possible groups were collapsed together, the inhalation level of the collapsed group was significantly different from that of the definite group (p < 0.001). All HDLI patients responded as having used HD not only while sleeping, but also as having a humidifier treated with HD within close proximity every day in insufficiently ventilated spaces. These HD use characteristics of patients may be directly/indirectly linked to the HDLI development.
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- 2020
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9. Noncovalent Complexes of Cyclodextrin with Small Organic Molecules: Applications and Insights into Host–Guest Interactions in the Gas Phase and Condensed Phase
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Jae-ung Lee, Sung-Sik Lee, Sungyul Lee, and Han Bin Oh
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cyclodextrin ,host–guest chemistry ,mass spectrometry ,ion mobility spectroscopy ,IRMPD spectroscopy ,DFT calculation ,Organic chemistry ,QD241-441 - Abstract
Cyclodextrins (CDs) have drawn a lot of attention from the scientific communities as a model system for host–guest chemistry and also due to its variety of applications in the pharmaceutical, cosmetic, food, textile, separation science, and essential oil industries. The formation of the inclusion complexes enables these applications in the condensed phases, which have been confirmed by nuclear magnetic resonance (NMR) spectroscopy, X-ray crystallography, and other methodologies. The advent of soft ionization techniques that can transfer the solution-phase noncovalent complexes to the gas phase has allowed for extensive examination of these complexes and provides valuable insight into the principles governing the formation of gaseous noncovalent complexes. As for the CDs’ host–guest chemistry in the gas phase, there has been a controversial issue as to whether noncovalent complexes are inclusion conformers reflecting the solution-phase structure of the complex or not. In this review, the basic principles governing CD’s host–guest complex formation will be described. Applications and structures of CDs in the condensed phases will also be presented. More importantly, the experimental and theoretical evidence supporting the two opposing views for the CD–guest structures in the gas phase will be intensively reviewed. These include data obtained via mass spectrometry, ion mobility measurements, infrared multiphoton dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations.
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- 2020
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10. Properties of Polyhexamethylene Guanidine (PHMG) Associated with Fatal Lung Injury in Korea
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Dong-Uk Park, Jihoon Park, Kee Won Yang, Ju-Hyun Park, Jung-Hwan Kwon, and Han Bin Oh
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humidifier disinfectant-associated lung injury ,PHMG ,oligomer ,molecular mass ,polymerization ,Organic chemistry ,QD241-441 - Abstract
The use of humidifier disinfectant (HD) has been determined to be associated with lung injuries (HDLI) in Korea. Although HD brands containing polyhexamethylene guanidine (PHMG) oligomers have been found to cause more HDLI compared to brands containing other disinfectants, the physicochemical properties of PHMG have been poorly defined. We aimed to quantify the PHMG dissolved in HD brands, characterize the number-average (Mn) and weight-average (Mw) molecular masses, and identify the polymerization degree of PHMG. Analysis of the PHMG oligomers was performed using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) operated in positive-ion reflectron mode. Eight brands of HD containing PHMG were identified. The PHMG concentrations in these brands ranged from 160 to 37,200 ppm (mean = 3100.9 ppm). Concentration was a significant variable among and within HD brands. The degree of PHMG oligomerization fell within the range of two to four. The averages of Mn and Mw were 517.2 g/mol (range: 422–613 g/mol) and 537.3 g/mol (range: 441.0–678.0 g/mol), respectively. Based on the average molecular weight and the degree of polymerization, the PHMG examined here could be regarded as oligomers, which may be associated with the highest proportion of HDLI being caused by PHMG.
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- 2020
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11. Untargeted Metabolomics and Steroid Signatures in Urine of Male Pattern Baldness Patients after Finasteride Treatment for a Year
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Yu Ra Lee, Eunju Im, Haksoon Kim, Bark Lynn Lew, Woo-Young Sim, Jeongae Lee, Han Bin Oh, Ki Jung Paeng, Jongki Hong, and Bong Chul Chung
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male pattern baldness ,liquid chromatography-tandem mass spectrometry ,androgens ,estrogen ,finasteride ,Microbiology ,QR1-502 - Abstract
Male pattern baldness (MPB) has been associated with dihydrotestosterone (DHT) expression. Finasteride treats MPB by inhibiting 5-alpha reductase and blocking DHT production. In this study, we aimed to identify metabolic differences in urinary metabolomics profiles between MPB patients after a one-year treatment with finasteride and healthy controls. Untargeted and targeted metabolomics profiling was performed using liquid chromatography-mass spectrometry (LC-MS). We hypothesized that there would be changes in overall metabolite concentrations, especially steroids, in the urine of hair loss patients treated with finasteride and normal subjects. Untargeted analysis indicated differences in steroid hormone biosynthesis. Therefore, we conducted targeted profiling for steroid hormone biosynthesis to identify potential biomarkers, especially androgens and estrogens. Our study confirmed the differences in the concentration of urinary androgens and estrogens between healthy controls and MPB patients. Moreover, the effect of finasteride was confirmed by the DHT/T ratio in urine samples of MPB patients. Our metabolomics approach provided insight into the physiological alterations in MPB patients who have been treated with finasteride for a year and provided evidence for the association of finasteride and estrogen levels. Through a targeted approach, our results suggest that urinary estrogens must be studied in relation to MPB and post-finasteride syndrome.
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- 2020
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12. Examination of Various Metal Ion Sources for Reducing Nonspecific Zinc finger−Zn2+ Complex Formation in ESI Mass Spectrometry
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Soojin Park, Sunhee Park, Joo Yeon Oh, Sang Yun Han, Kyubong Jo, and Han Bin Oh
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Zinc finger ,Zinc ion ,Electrospray ionization ,Tartrate ,Noncovalent complexes ,Analytical chemistry ,QD71-142 - Abstract
The formation of zinc finger peptide−Zn2+ complexes in electrospray ionization mass spectrometry (ESI-MS) was examined using three different metal ion sources: ZnCl2, Zn(CH3COO)2, and Zn(OOC(CHOH)2COO). For the four zinc finger peptides (Sp1-1, Sp1-3, CF2II-4, and CF2II-6) that bind only a single Zn2+ in the native condition, electrospray of apo-zinc finger in solution containing ZnCl2 or Zn(CH3COO)2 resulted in the formation of zinc finger−Zn2+ complexes with multiple zinc ions. This result suggests the formation of nonspecific zinc finger−Zn2+ complexes. Zn(tartrate), Zn(OOC(CHOH)2COO),mainly produced specific zinc finger−Zn2+ complexes with a single zinc ion. This study clearly indicates that tartrate is an excellent counter ion in ESI-MS studies of zinc finger−Zn2+ complexes, which prevents the formation of nonspecific zinc finger−Zn2+ complexes.
- Published
- 2012
13. An anomalous dissociation of protonated cluster ions of DNA guanine-cytosine base-pair
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Han Bin Oh, Sung-Chan Jo, Sang Yun Han, and Yeonmi Seong
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Pronton affinity ,Collisional dissociation ,Proton transfer ,Guanine ,Cytosine ,Analytical chemistry ,QD71-142 - Abstract
In the collisionally-activated dissociation of the proton-bound cluster ions of DNA base guanine (G) and cytosine (C), G••H+••C, the abundance of [CH+] ions was found to be higher than that of [GH+] despite the fact that G has a higher proton affinity than C. This unexpected observation seems to demonstrate another example that the simple kinetic method scheme does not work. We suggest that a kinetic factor or detailed dynamics governing the proton transfer and dissociation should be carefully considered in the applications of the kinetic method to the proton affinity measurements.
- Published
- 2011
14. Machine Learning Liquid Chromatography Retention Time Prediction Model Augments the Dansylation Strategy for Metabolite Analysis of Urine Samples
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Eunwoo Choi, Won Jun Yoo, Hwa-yong Jang, Tae-Young Kim, Sung Ki Lee, and Han Bin Oh
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- 2023
15. Revealing Unknown Controlled Substances and New Psychoactive Substances Using High-Resolution LC–MS-MS Machine Learning Models and the Hybrid Similarity Search Algorithm
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SungIll Suh, Sang Tak Lee, Han Bin Oh, Bum Jun Ko, and So Yeon Lee
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Computer science ,Health, Toxicology and Mutagenesis ,Nearest neighbor search ,Toxicology ,Barcode ,Machine learning ,computer.software_genre ,Methcathinone ,Analytical Chemistry ,law.invention ,Machine Learning ,Software ,Artificial Intelligence ,Tandem Mass Spectrometry ,law ,medicine ,Environmental Chemistry ,Psychotropic Drugs ,Chemical Health and Safety ,Controlled Substances ,Artificial neural network ,business.industry ,Reproducibility of Results ,Support vector machine ,Statistical classification ,Test set ,Artificial intelligence ,business ,Algorithm ,computer ,Algorithms ,Chromatography, Liquid ,medicine.drug - Abstract
High-resolution liquid chromatography–tandem mass spectrometry (LC--MS-MS)-based machine learning models are constructed to address the analytical challenge of identifying unknown controlled substances and new psychoactive substances (NPSs). Using a training set composed of 770 LC–MS-MS barcode spectra (with binary entries 0 or 1) obtained generally by high-resolution mass spectrometers, three classification machine learning models were generated and evaluated. The three models are artificial neural network (ANN), support vector machine (SVM) and k-nearest neighbor (k-NN) models. In these models, controlled substances and NPSs were classified into 13 subgroups (benzylpiperazine, opiate, benzodiazepine, amphetamine, cocaine, methcathinone, classical cannabinoid, fentanyl, 2C series, indazole carbonyl compound, indole carbonyl compound, phencyclidine and others). Using 193 LC–MS-MS barcode spectra as an external test set, accuracy of the ANN, SVM and k-NN models were evaluated as 72.5%, 90.0% and 94.3%, respectively. Also, the hybrid similarity search (HSS) algorithm was evaluated to examine whether this algorithm can successfully identify unknown controlled substances and NPSs whose data are unavailable in the database. When only 24 representative LC–MS-MS spectra of controlled substances and NPSs were selectively included in the database, it was found that HSS can successfully identify compounds with high reliability. The machine learning models and HSS algorithms are incorporated into our home-coded artificial intelligence screener for narcotic drugs and psychotropic substances standalone software that is equipped with a graphic user interface. The use of this software allows unknown controlled substances and NPSs to be identified in a convenient manner.
- Published
- 2021
16. Influence of mobile phase composition on the analytical sensitivity of LC–ESI–MS/MS for the concurrent analysis of bisphenols, parabens, chlorophenols, benzophenones, and alkylphenols
- Author
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Kang Mi Lee, Sang Moon Han, Hyeon-Jeong Lee, Minsik Kang, Tae Young Jeong, Junghyun Son, Hophil Min, Sangwon Cha, Han Bin Oh, Won Keun Oh, and Jaeick Lee
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Biochemistry ,General Environmental Science - Published
- 2023
17. TEMPO-Assisted Free-Radical-Initiated Peptide Sequencing Mass Spectrometry for Ubiquitin Ions: An Insight on the Gas-Phase Conformations
- Author
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Jae-ung Lee, Sang Tak Lee, Chae Ri Park, Bongjin Moon, Hugh I. Kim, and Han Bin Oh
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Cyclic N-Oxides ,Models, Molecular ,Free Radicals ,Structural Biology ,Sequence Analysis, Protein ,Tandem Mass Spectrometry ,Ubiquitin ,Spectroscopy - Abstract
TEMPO ((2,2,6,6-tetramethylpiperidine-1-yl)oxyl)-assisted free-radical-initiated peptide sequencing mass spectrometry (FRIPS MS) is applied to the top-down tandem mass spectrometry of guanidinated ubiquitin (UB(Gu)) ions, i.e.
- Published
- 2022
18. Influence of Mobile Phase Composition on Analytical Sensitivity of Lc–Esi–Ms/Ms for the Concurrent Analysis of Bisphenols, Parabens, Chlorophenols, Benzophenones, and Alkylphenols
- Author
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Kang Mi Lee, Sang Moon Han, Hyeon-Jeong Lee, Minsik Kang, Tae Young Jeong, Junghyun Son, Hophil Min, Sangwon Cha, Han Bin Oh, Won Keun Oh, and Jaeick Lee
- Published
- 2022
19. Characteristics of the Molecular Weight of Polyhexamethylene Guanidine (PHMG) Used as a Household Humidifier Disinfectant
- Author
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Soyoung Park, Kyung Ehi Zoh, Jung Hwan Kwon, So-Yeon Lee, Ju-Hyun Park, Dong-Uk Park, Han Bin Oh, Jiwon Kim, and Kee Won Yang
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number-average molecular weight (Mn) ,Disinfectant ,Pharmaceutical Science ,molecular mass ,010501 environmental sciences ,Degree of polymerization ,Guanidines ,01 natural sciences ,Oligomer ,Article ,Humidifiers ,oligomer ,Analytical Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,QD241-441 ,0302 clinical medicine ,Republic of Korea ,Drug Discovery ,Humans ,Physical and Theoretical Chemistry ,Respiratory health ,0105 earth and related environmental sciences ,Molecular mass ,Organic Chemistry ,weight-average molecular weight (Mw) ,Lung Injury ,Toxic chemical ,Molecular Weight ,030228 respiratory system ,chemistry ,Polyhexamethylene guanidine ,humidifier-disinfectant-associated lung injury (HDLI) ,Chemistry (miscellaneous) ,polymerization ,Molecular Medicine ,Molar mass distribution ,polyhexamethylene guanidine (PHMG) ,Disinfectants ,Nuclear chemistry - Abstract
(1) Background: Household humidifier disinfectant (HD) brands containing polyhexamethylene guanidine (PHMG) have been found to cause the most HD-associated lung injuries (HDLIs) in the Republic of Korea. Nevertheless, no study has attempted to characterize the potential association of the health effects, including HDLI, with the physicochemical properties of PHMG dissolved in different HD brands. This study aimed to characterize the molecular weight (MW) distribution, the number-average molecular weight (Mn), the weight-average molecular weight (Mw), and the structural types of PHMG used in HD products. (2) Methods: Quantitative measurements were made using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF MS). The Mn, Mw, and MW distributions were compared among various HD products. (3) Results: The mean Mn and Mw were 542.4 g/mol (range: 403.0–692.2 g/mol) and 560.7 g/mol (range: 424.0–714.70 g/mol), respectively. The degree of PHMG oligomerization ranged from 3 to 7. The MW distribution of PHMG indicated oligomeric compounds regardless of the HD brands. (4) Conclusions: Based on the molecular weight distribution, the average molecular weight of PHMG, and the degree of polymerization, the PHMG collected from HDLI victims could be regarded as an oligomer. PHMG, as used in household humidifiers, should not be exempted from toxic chemical registration as a polymer. Further study is necessary to examine the association of PHMG oligomeric compounds and respiratory health effects, including HDLI.
- Published
- 2021
- Full Text
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20. Liposome leakage and increased cellular permeability induced by guanidine-based oligomers: effects of liposome composition on liposome leakage and human lung epithelial barrier permeability
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Yeonjeong Ha, Ga Eun Kim, Yerim Koo, Han Bin Oh, Jung Hwan Kwon, Seon-Kyung Park, and Ha Ryong Kim
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A549 cell ,Liposome ,chemistry.chemical_compound ,Membrane ,chemistry ,Polyhexamethylene guanidine ,General Chemical Engineering ,Biophysics ,General Chemistry ,Lipid bilayer ,Guanidine ,Oligomer ,Barrier function - Abstract
Over the decades, guanidine-based oligomer groups have been one of the most widely used antimicrobial agents. Reportedly, these cationic oligomers cause serious damage to microorganisms but have low toxicity to humans. However, public concerns regarding the guanidine group have rapidly grown after the fatal misuse of these oligomers as humidifier disinfectants, which resulted in thousands of fatalities in South Korea. Herein, we investigated liposome leakage and cellular permeability changes caused by polyhexamethylene guanidine (PHMG) and polyhexamethylene biguanide (PHMB), both representative guanidine-based oligomers. The leakage of zwitterionic liposomes, induced by cationic oligomers, was more extensive than that of negative liposomes, indicating that oligomer adsorption onto lipid head groups via electrostatic interaction cannot fully explain the induced lipid membrane damage. Furthermore, lipid packing parameters, including intrinsic curvature, cholesterol content, and lipid phases, affected liposome leakage, particularly for PHMG. Cellular permeability tests were performed using an A549 cell monolayer model and a respiratory 3D tissue model, revealing that PHMG and PHMB damaged cell membranes and reduced cell barrier function. Furthermore, liposome leakage induced by PHMG and PHMB was higher in human lung surfactant-mimicking liposomes than that observed in Escherichia coli-mimicking liposomes. These results indicated that human cells are susceptible to guanidine-based oligomers. Considering that the interaction of oligomers and cell membranes is a major mechanism of toxicity initiation, this study provides crucial insights into the action of these disinfectants on mammalian cells.
- Published
- 2021
21. A solvent-free headspace GC/MS method for sensitive screening of N-nitrosodimethylamine in drug products
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Seoungchul Park, Yong-Moon Lee, Jongki Hong, Kwang Hyun Liu, Hee Soo Pyo, Do Hee Lee, Han Bin Oh, Jeongmi Lee, Su Hyeon Hwang, and Sang Beom Han
- Subjects
Drug ,General Chemical Engineering ,media_common.quotation_subject ,010501 environmental sciences ,Mass spectrometry ,Ranitidine ,01 natural sciences ,Gas Chromatography-Mass Spectrometry ,Analytical Chemistry ,Dimethylnitrosamine ,chemistry.chemical_compound ,N-Nitrosodimethylamine ,medicine ,0105 earth and related environmental sciences ,media_common ,Detection limit ,Active ingredient ,Solvent free ,Chromatography ,010401 analytical chemistry ,General Engineering ,0104 chemical sciences ,chemistry ,Pharmaceutical Preparations ,Solvents ,Gas chromatography–mass spectrometry ,Nizatidine ,medicine.drug - Abstract
A solvent-free headspace gas chromatography-mass spectrometry (SF-HS-GC/MS) method was developed and validated for screening N-nitrosodimethylamine (NDMA) in various active pharmaceutical ingredients (APIs) and drug products. Experimental parameters such as incubation temperature, incubation time, and sample volume in solvent-free headspace conditions were optimized. The developed SF-HS-GC/MS method was validated in terms of linearity, limit of quantification (LOQ), precision, and accuracy. The results indicated excellent linearity from 5 to 500 ng g-1 with correlation coefficients higher than 0.9999. The LOQ of this method was 5 ng g-1 and matrix effects ranged from 0.97 to 1.11. The accuracy ranged from 92.77 to 106.54% and the precision RSDs were below 5.94%. No significant matrix effect was observed for any of the drug products. Also, artefactual NDMA formation in ranitidine, nizatidine, and metformin was investigated under HS conditions. Adjusted (mild) SF-HS conditions were suggested for precise quantification of NDMA in positive drug products by GC/MS. The present SF-HS-GC/MS method is a promising tool for the screening and determination of toxic NDMA in APIs and drug products.
- Published
- 2021
22. Effect of carbon nanomaterial dimension on the functional activity and degeneration of neurons
- Author
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Hong Nam Kim, Nu Ri Lim, Han Bin Oh, Seongchan Kim, Ki Hun Kim, Hyojin Lee, Il-Joo Cho, Kyeong Seob Hwang, and Jongbaeg Kim
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Neurons ,Programmed cell death ,Mechanism (biology) ,Chemistry ,Biophysics ,Bioengineering ,Human brain ,Degeneration (medical) ,Carbon ,Cell biology ,Nanostructures ,Biomaterials ,Neurotransmitter secretion ,medicine.anatomical_structure ,Mechanics of Materials ,Ceramics and Composites ,medicine ,Humans ,Nanoparticles ,Neuron ,Function (biology) ,Calcium signaling - Abstract
Despite growing concerns regarding the threat of airborne nanoparticle-mediated brain degeneration, the underlying pathological mechanisms remain unclear. Carbon nanomaterials, the main components of airborne nanoparticles, have multi-dimensional structures. Therefore, the dimensional effect of carbon-based nanomaterials on the regulation of neural function in brain disorders requires additional clarification. Herein, we report the interaction between zero-to three-dimensional carbon nanostructures and the amyloid-beta protein, which can either activate or interrupt neuronal functions, depending on the dimension of the carbon nanostructures. The carbon nanomaterials induced significant cellular activation by short-term exposure, while prolonged exposure eventually caused neuronal cell death. Such dimension-dependent activation or degeneration was more evident in the higher-dimension carbon nanomaterials, as confirmed by the increases in neurotransmitter secretion and synapse-related protein levels to more than five times at 72 h of monitoring and calcium signaling in the neurons. The inclusion of amyloid-beta proteins ameliorated the cytotoxic effects of carbon nanomaterials in higher-dimensional carbon nanomaterials by regulating 333 genes. We found that the ɑ-synuclein gene is the key factor in carbon-induced abnormal neuronal function. Therefore, through biological analyses and in vitro feasibility studies, this new insight may contribute toward understanding the pathological mechanism and finding a new target for therapy in human brain pathologies.
- Published
- 2021
23. LC–MS/MS Software for Screening Unknown Erectile Dysfunction Drugs and Analogues: Artificial Neural Network Classification, Peak-Count Scoring, Simple Similarity Search, and Hybrid Similarity Search Algorithms
- Author
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Jongki Hong, Jung-Min Lee, Bongjin Moon, Han Bin Oh, Inae Jang, Beom Hee Kim, and Jae-Ung Lee
- Subjects
Male ,Nearest neighbor search ,Drug Evaluation, Preclinical ,010402 general chemistry ,Proof of Concept Study ,01 natural sciences ,Analytical Chemistry ,Software ,Erectile Dysfunction ,Tandem Mass Spectrometry ,Search algorithm ,Lc ms ms ,Humans ,Molecular Structure ,Artificial neural network ,Chemistry ,business.industry ,010401 analytical chemistry ,Pattern recognition ,0104 chemical sciences ,Identifier ,Urological Agents ,Neural Networks, Computer ,Artificial intelligence ,business ,Classifier (UML) ,Chromatography, Liquid - Abstract
Screening and identifying unknown erectile dysfunction (ED) drugs and analogues, which are often illicitly added to health supplements, is a challenging analytical task. The analytical technique most commonly used for this purpose, liquid chromatography-tandem mass spectrometry (LC-MS/MS), is based on the strategy of searching the LC-MS/MS spectra of target compounds against database spectra. However, such a strategy cannot be applied to unknown ED drugs and analogues. To overcome this dilemma, we have constructed a standalone software named AI-SIDA (artificial intelligence screener of illicit drugs and analogues). AI-SIDA consists of three layers: LC-MS/MS viewer, AI classifier, and Identifier. In the second AI classifier layer, an artificial neural network (ANN) classification model, which was constructed by training 149 LC-MS/MS spectra (including 27 sildenafil-type, 6 vardenafil-type, 11 tadalafil-type ED drugs/analogues and other 105 compounds), is included to classify the LC-MS/MS spectra of the query compound into four categories: i.e., sildenafil, vardenafil, and tadalafil families and non-ED compounds. This ANN model was found to show 100% classification accuracy for the 187 LC-MS/MS modeling and test data sets. In the third Identifier layer, three search algorithms (pick-count scoring, simple similarity search, and hybrid similarity search) are implemented. In particular, the hybrid similarity search was found to be very powerful in identifying unknown ED drugs/analogues with a single modification from the library ED drugs/analogues. Altogether, the AI-SIDA software provides a very useful and powerful platform for screening unknown ED drugs and analogues.
- Published
- 2019
24. Development of Triglyceride Certified Reference Materials in Human Frozen Serum Using Isotope Dilution‐Liquid Chromatography–Tandem Mass Spectrometry
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Sun Young Lee, Tae-Young Kim, Jongki Hong, Kwonseong Kim, Hyun Soo Kwon, Young Eun Kim, Ji-Seon Jeong, Han Bin Oh, Dukjin Kang, and Ki-Young Kim
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chemistry.chemical_compound ,Chromatography ,Certified reference materials ,Triglyceride ,Chemistry ,Liquid chromatography–mass spectrometry ,General Chemistry ,Isotope dilution - Published
- 2019
25. Quantitative MALDI-TOF mass spectrometric analysis of biocidal polyhexamethylene guanidine (PHMG) oligomers in consumer products
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Yunha Ju, Bongjin Moon, Choong Sik Lee, Myungjun Park, Insu Song, Jung eun Bae, Jung Hwan Kwon, Jung-Min Lee, and Han Bin Oh
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Chromatography ,Chemistry ,010401 analytical chemistry ,010402 general chemistry ,Condensed Matter Physics ,Mass spectrometry ,01 natural sciences ,0104 chemical sciences ,Matrix (chemical analysis) ,Matrix-assisted laser desorption/ionization ,chemistry.chemical_compound ,Polyhexamethylene guanidine ,Ionic liquid ,Molar mass distribution ,Solid phase extraction ,Physical and Theoretical Chemistry ,Instrumentation ,Quantitative analysis (chemistry) ,Spectroscopy - Abstract
In Korea, biocides, which were used for sterilizing household humidifiers, caused a large number of casualties. The biocides used were either guanidine-containing oligomers, such as polyhexamethylene guanidine (PHMG), or thiazolinone-based small molecules such as methylisothiazolinone/methylchloroisothiazolinone (MIT/CMIT). For the guanidine-containing oligomers, a quantitative analysis method has not yet been developed, as the quantification of the oligomers is very challenging due to their polydispersed molecular weight distribution. In this paper, we describe a new MALDI-TOF mass spectrometry (MS)-based quantitative analysis method for the PHMG oligomers contained in wet wipe products. Quantification was made using internal standard 13C labeled PHMG oligomers that were custom synthesized. To get rid of matrix molecules, for example, polyethylene glycols (PEGs), included in the wet wipes, solid phase extraction (SPE) with an MCX SPE cartridge was carried out. In addition, an ionic liquid matrix (ILM) of 1-methylimadazolium α-cyano-4-hydroxycinnamate (1-MeIm-CHCA) was used to improve the reproducibility of the MALDI-TOF MS measurements. This new quantitative analysis method was validated, and good linearity was obtained in the calibration plot. This approach is expected to be equally applicable to other guanidine-containing oligomers, such as polyhexamethylene biguanide (PHMB) and oligo-(2-(2-ethoxy)-ethoxyethyl)-guanidinium-chloride (PGH) as well as to other consumer products.
- Published
- 2019
26. Comprehensive screening of multiclass illegal adulterants in herbal supplements and Spice-type drugs using specific MS/MS fragmentations by UHPLC-Q/TOF-MS
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Jisu Hur, Jongki Hong, Wonwoong Lee, Hyun Ji Kim, Han Bin Oh, Ji Hyun Lee, Do Hee Lee, Yong Moon Lee, and Beom Hee Kim
- Subjects
Uhplc q tof ms ,Chromatography ,Chemistry ,Formic acid ,General Chemical Engineering ,010401 analytical chemistry ,General Engineering ,Phenethylamines ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Carbonyl group ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,Synthetic cannabinoids ,medicine ,Gradient elution ,Amine gas treating ,0210 nano-technology ,Herbal supplement ,medicine.drug - Abstract
In this study, a comprehensive screening method for 98 multi-class illegal adulterants (19 NSAIDS, 31 weight loss drugs, 35 psychotropic substances, and 13 cannabinoids) in dietary supplements and Spice drugs was suggested by UHPLC-Q/TOF-MS. After effective application of pH controlled liquid–liquid extraction from herbal supplements and Spice-type drugs, a broad range of 98 adulterants was successfully separated within 15 min on 1.7 μm fused-core C18 particles in a 100 × 2.1 mm column with gradient elution (mobile phase A: 0.1% formic acid in water; B: 0.1% formic acid in acetonitrile) and sensitively detected at sub-ng g−1 levels by ESI in positive ion mode. From the MS/MS spectra of illegal adulterants, certain common ions were observed to reflect their structural characteristics: m/z 117 for phenethylamines, m/z 155 and 144 for synthetic cannabinoids, m/z 165 and 199 for opioid analogues and m/z 125 and 158 for sibutramine analogues. Specific neutral molecule loss fragments were also observed: H2O, NH3, or CO respectively for hydroxyl, amine, or carbonyl group containing adulterants. Phenylamide, C7H4O3S, or C2H3NO molecule loss fragmentations were observed for heterocyclic compounds. Based on these specific fragmentations, extracted common ion chromatograms (ECICs) and neutral loss scans (NLSs) were effectively applied for rapid screening of illegal adulterants in herbal supplements and Spice-type drugs. The developed method can serve as a promising screening tool for confirmation and determination of illegal adulterants in various types of supplements, thus ensuring public safety.
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- 2019
27. Rapid screening of sulfonamides in dietary supplements based on extracted common ion chromatogram and neutral loss scan by LC-Q/TOF-mass spectrometry
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Beom Hee Kim, Han Bin Oh, Nam-Yong Ki, Jongki Hong, Bongjin Moon, Jisu Hur, and Kyung Ho Kim
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030309 nutrition & dietetics ,Calibration curve ,lcsh:TX341-641 ,Mass spectrometry ,01 natural sciences ,Mass Spectrometry ,03 medical and health sciences ,chemistry.chemical_compound ,medicine ,Hypoglycemic Agents ,Diuretics ,Chromatography, High Pressure Liquid ,Pharmacology ,Detection limit ,Sulfonamides ,0303 health sciences ,Aqueous solution ,Chromatography ,Chemistry ,Solid Phase Extraction ,010401 analytical chemistry ,Sulfonamide (medicine) ,Extraction (chemistry) ,lcsh:RM1-950 ,0104 chemical sciences ,lcsh:Therapeutics. Pharmacology ,Dietary Supplements ,Time-of-flight mass spectrometry ,Drug Contamination ,Ammonium acetate ,lcsh:Nutrition. Foods and food supply ,Food Science ,medicine.drug - Abstract
There is an increasing amount of dietary supplements that are adulterated with diuretics and anti-diabetic drugs; this has become a global problem due to the wide distribution of dietary supplements and the serious negative health effects of the adulterants. In this study, a rapid screening method was developed for detection and confirmation of 35 sulfonamides in supplements by ultra-high performance liquid chromatography quadrupole/time of flight mass spectrometry. For effective extraction of sulfonamides from dietary supplements, four extraction protocols including HLB and WAX solid-phase extraction, Quick Easy Cheap Effective Rugged and Safe method, and pH-controlled liquid–liquid extraction were evaluated, and pH-controlled liquid–liquid extraction method was shown to be the most effective with high recovery efficiency and low matrix effect. Rapid separation of 35 sulfonamides was achieved with the UHPLC C18 column (150 × 2.1 mm, 1.7 um) within 7 min using ammonium acetate aqueous solution (pH 8) and acetonitrile as the mobile phase. From the MS/MS spectra of sulfonamides, common ions (m/z 77.9650 [SO2N]- and m/z 79.9812 [SO2NH2]-) and neutral molecule loss fragments (HCl and SO2) were observed according to their structural characteristics. Extracted common ion chromatograms and neutral loss scan of these characteristic fragments could effectively apply for rapid screening of sulfonamides in various types of supplements. A reduced mass tolerance window of ±5 ppm was useful for detecting targeted and untargeted sulfonamides and could avoid false positive and false negative results. Overall calibration curves within dynamic range for all targets were shown to be linear with a correlation coefficient R2 > 0.995 and limits of detection ranged from 0.04 to 11.18 ng/g for all sulfonamides. The established method was successfully applied for screening and confirmation of sulfonamides in various supplements. The developed method will be helpful for the identification of sulfonamide diuretics and anti-diabetics in dietary supplements, promoting public health and consumer safety. Keywords: Sulfonamides, Dietary supplements, UHPLC-Q/TOF-MS, Extracted common ion chromatogram, Neutral loss scan
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- 2019
28. Enhanced Incorporation of Gaseous CO2 to Succinate by a Recombinant Escherichia coli W3110
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Gwangro You, Soohyun Park, Hyeonsoo Kim, Jinwon Lee, Han Bin Oh, Jun Hee Han, and Sukhyeong Cho
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0106 biological sciences ,0303 health sciences ,Recombinant escherichia coli ,biology ,Chemistry ,Biomedical Engineering ,Bioengineering ,01 natural sciences ,Applied Microbiology and Biotechnology ,Metabolic engineering ,03 medical and health sciences ,chemistry.chemical_compound ,Biochemistry ,010608 biotechnology ,Carbonic anhydrase ,Carbon source ,Carbon dioxide ,biology.protein ,Citrate synthase ,Industrial and production engineering ,Phosphoenolpyruvate carboxylase ,030304 developmental biology ,Biotechnology - Abstract
Carbon dioxide (CO2) emissions are related to global warming. However, CO2 can be used as an abundant and cheap carbon source for production of valuable chemicals using carbon capture and storage technology. Here, the genes related to carbon flux toward pyruvate biosynthesis in E. coli were deleted to enhance the incorporation of CO2 for succinate production. The codonoptimized carbonic anhydrase gene (SP(-)HCCA) derived from Hahella chejuensis KCTC 2396 and the phosphoenolpyruvate carboxylase gene (ppc) of E. coli W3110 were co-overexpressed to enhance carbon flux toward oxaloacetate synthesis in E. coli. Finally, we constructed SGJS134, which shows the highest production of succinate derived from CO2 compared with other strains. SGJS134 produced approximately 6.5 mM succinate from CO2 and yielded approximately 13.0 mM succinate per dry cell weight. These results may be useful for enhancing the incorporation of CO2 for succinate production in E. coli. Additionally, the metabolic engineering method used in this study will propose the potential of E. coli to convert CO2 to valuable chemicals.
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- 2018
29. 8 th Asia–Oceania Mass Spectrometry Conference (AOMSC)
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Jentaie Shiea, Ivan K. Chu, K. W. Michael Siu, Han Bin Oh, P. B. Armentrout, Yoshinao Wada, Newman Siu-Kwan Sze, Richard A. J. O'Hair, and Guibin Jiang
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Chemistry ,Environmental chemistry ,Mass spectrometry ,Spectroscopy - Published
- 2021
30. Quantitative proteomic profiling of Cervicovaginal fluid from pregnant women with term and preterm birth
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Dukjin Kang, Young Eun Kim, Sung Ki Lee, Han Bin Oh, and Kwonseong Kim
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medicine.diagnostic_test ,integumentary system ,Proteomic Profiling ,business.industry ,lcsh:Cytology ,Research ,Quantitative proteomics ,Preterm birth ,Proteomics ,Biochemistry ,Asymptomatic ,Andrology ,Western blot ,Proteome ,medicine ,Etiology ,Term Birth ,Cervicovaginal fluid ,medicine.symptom ,lcsh:QH573-671 ,business ,Molecular Biology - Abstract
Background Preterm birth (PTB) is one of major causes of perinatal mortality and neonatal morbidity, but knowledge of its complex etiology is still limited. Here we present cervicovaginal fluid (CVF) protein profiles of pregnant women who subsequently delivered at spontaneous preterm or term, aiming to identify differentially expressed CVF proteins in PTB and term birth. Methods The CVF proteome of women who sequentially delivered at preterm and term was analyzed using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional nanoflow liquid chromatography-tandem mass spectrometry (2D-nLC-MS/MS). We compared the CVF proteome of PTB (n = 5) and control subjects (term birth, n = 7) using pooled control CVF (term birth, n = 20) as spike-in standard. Results We identified 1294 CVF proteins, of which 605 were newly identified proteins. Of 990 proteins quantified in both PTB and term birth, 52 proteins were significantly up/down-regulated in PTB compared to term birth. The differentially expressed proteins were functionally associated to immune response, endopeptidase inhibitors and structural constituent of cytoskeleton. Finally, we confirm the down-regulation of SERPINB7 (a serine-type protease inhibitor) in PTB compared to control by Western blot. Conclusions Taken together, our study provide quantitative CVF proteome profiles of pregnant women who ultimately delivered at preterm and term. These promising results could help to improve the understanding of PTB etiology and to discover biomarkers for asymptomatic PTB.
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- 2021
31. Photo-Oxidative Protection of Chlorophyll a in C-Phycocyanin Aqueous Medium
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Seung-Yop Lee, Ji-Eun Hong, Hwa-Yong Jang, Bong Geun Chung, Han Bin Oh, Jae Hyun Lim, and Tae Yoon Kim
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0301 basic medicine ,Chlorophyll a ,chlorophyll a ,Physiology ,Clinical Biochemistry ,antioxidant activity ,Atmospheric-pressure chemical ionization ,Mass spectrometry ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Phycocyanin ,Photodegradation ,Spectroscopy ,Molecular Biology ,lcsh:RM1-950 ,Cell Biology ,Malondialdehyde ,Decomposition ,phycocyanin ,030104 developmental biology ,lcsh:Therapeutics. Pharmacology ,chemistry ,030220 oncology & carcinogenesis ,cytotoxicity ,photodegradation ,Nuclear chemistry - Abstract
In this study, potential protection of chlorophyll a from illumination and oxidation-induced decomposition has been examined using C-phycocyanin (C-PC) aqueous medium. Photo-oxidation resistance of chlorophyll a was monitored in various aqueous media using ultraviolet-visible spectroscopy and direct-infusion atmospheric pressure chemical ionization mass spectrometry analysis. The spectroscopy results showed that chlorophyll a in C-PC medium experienced the lowest rate of conversion to its derivatives, thus, it was demonstrated that chlorophyll a was mostly intact in the C-PC medium. Furthermore, the C-PC treated with chlorophyll a showed the lowest concentrations of malondialdehyde, and chlorophyll a in C-PC medium did not cause serious damage to human liver cells in vitro after intensive illumination. Therefore, we propose a new method of protecting chlorophyll a from photodegradation and oxidation using C-PC aqueous medium.
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- 2020
32. Characteristics of Exposure to Chloromethylisothiazolinone (CMIT) and Methylisothiazolinone (MIT) among Humidifier Disinfectant-Associated Lung Injury (HDLI) Patients in South Korea
- Author
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Kyung Ehi Zoh, Seung Hun Ryu, Jiwon Kim, Jihoon Park, So-Yeon Lee, Ju-Hyun Park, Seon Kyung Park, Han Bin Oh, Sungkyoon Kim, Soyoung Park, Dong-Uk Park, and Jung Hwan Kwon
- Subjects
Male ,Disinfectant ,Pharmaceutical Science ,010501 environmental sciences ,01 natural sciences ,Gastroenterology ,Humidifiers ,Analytical Chemistry ,chloromethylisothiazolinone (CMIT) ,chemistry.chemical_compound ,Limit of Detection ,Drug Discovery ,humidifier disinfectant-associated lung injury (HDLI) ,Child ,Lung ,Inhalation exposure ,Air Pollutants ,0303 health sciences ,methylisothiazolinone (MIT) ,Inhalation ,Lung Injury ,Middle Aged ,humidifier disinfectant (HD) ,inhalation exposure ,Chemistry (miscellaneous) ,Child, Preschool ,Molecular Medicine ,Female ,patient ,Adult ,medicine.medical_specialty ,Lung injury ,Article ,Gas Chromatography-Mass Spectrometry ,lcsh:QD241-441 ,03 medical and health sciences ,lcsh:Organic chemistry ,Methylisothiazolinone ,Internal medicine ,Republic of Korea ,medicine ,Humans ,Physical and Theoretical Chemistry ,030304 developmental biology ,0105 earth and related environmental sciences ,business.industry ,Organic Chemistry ,Infant ,Thiazoles ,chemistry ,business ,Disinfectants - Abstract
This study aimed to quantify both chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) dissolved in different product brands and to characterize the exposure to these chemicals among humidifier disinfectant-associated lung injury (HDLI) patients. Both CMIT and MIT dissolved in different humidifier disinfectant (HD) products were quantified using gas chromatography&ndash, mass spectrometry. The inhalation level of CMIT and MIT was estimated based on HD-associated factors as reported by HDLI patients. A total of eleven HD products marketed until the end of 2011 were found to contain CMIT and/or MIT. The level of combined CMIT and/or MIT dissolved in these HD products ranged from 12 to 353 ppm. The level varied among HD products and the year of manufacture. The average inhalation levels were estimated to be 7.5, 4.1, and 3.2 &mu, g/m3 for the definite, probable, and possible groups, respectively. If probable and possible groups were collapsed together, the inhalation level of the collapsed group was significantly different from that of the definite group (p <, 0.001). All HDLI patients responded as having used HD not only while sleeping, but also as having a humidifier treated with HD within close proximity every day in insufficiently ventilated spaces. These HD use characteristics of patients may be directly/indirectly linked to the HDLI development.
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- 2020
33. Inactivation of the β (1, 2)-xylosyltransferase and the α (1, 3)-fucosyltransferase gene in rice (Oryza sativa) by multiplex CRISPR/Cas9 strategy
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Seong-Ryong Kim, Jun-Hye Shin, Moon-Sik Yang, Hilal Begum, Han-Bin Oh, Jae-Wan Jung, Won-Kyung Lee, Chan-Hong Min, and Mi-Hwa Jang
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0106 biological sciences ,0301 basic medicine ,Fucosyltransferase ,Xylosyltransferase ,Plant Science ,Biology ,medicine.disease_cause ,01 natural sciences ,Frameshift mutation ,03 medical and health sciences ,Epitopes ,Polysaccharides ,medicine ,CRISPR ,Gene Silencing ,Pentosyltransferases ,Gene ,Plant Proteins ,Genetics ,Gene Editing ,Mutation ,Oryza sativa ,Cas9 ,food and beverages ,Oryza ,General Medicine ,Fucosyltransferases ,Plants, Genetically Modified ,030104 developmental biology ,biology.protein ,CRISPR-Cas Systems ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
CRISPR/Cas9-mediated OsXylT and OsFucT mutation caused the elimination of plant-specific β1,2-xylose and α1,3-fucose residues on glycoproteins in rice, which is the first report of OsXylT/OsFucT double KO mutation in rice. N-glycosylation pathway is the one of post-translational mechanism and is known as highly conserved in eukaryotes. However, the process for complex-N-glycan modification is different between mammals and plants. In plant-specific manner, β1,2-xylose and α1,3-fucose residues are transferred to N-glycan core structure on glycoproteins by β1,2-xylosyltransferase (β1,2-XylT) and α1,3-fucosyltransferase (α1,3-FucT), respectively. As an effort to use plants as a platform to produce biopharmaceuticals, the plant-specific N-glycan genes of rice (Oryza sativa), β1,2-xylT (OsXylT) and α1,3-FucT (OsFucT), were knocked out using multiplex CRISPR/Cas9 technology. The double knock-out lines were found to have frameshift mutations by INDELs. Both β1,2-xylose and α1,3-fucose residues in the lines were not detected in Western blot analysis. Consistently, there was no peak corresponding to the N-glycans in MALDI-TOF/MS analysis. Although α1,3-fucose and β1,2-xylose residues were not detected in the line, other plant-specific residues of β1,3-galactose and α1,4-fucose were detected. Thus, we suggest that each enzymes working on the process for complex N-glycan biosynthesis might independently act in rice, hence the double knock-out of both OsXylT and OsFucT might be not enough to humanize N-glycan structure in rice.
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- 2020
34. Biofilm development of Bacillus siamensis ATKU1 on pristine short chain low-density polyethylene: A case study on microbe-microplastics interaction
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Yerin Jung, Jung Hwan Kwon, Hanbyul Lee, Han Bin Oh, Han Young Woo, Jae Ung Lee, Abhrajyoti Tarafdar, and Ji Eun Jeong
- Subjects
Microplastics ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,Bacillus ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Bacillus siamensis ,chemistry.chemical_compound ,Environmental Chemistry ,Food science ,Waste Management and Disposal ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,Biofilm ,Polyethylene ,Biodegradation ,Pollution ,Bacterial strain ,Low-density polyethylene ,chemistry ,Biofilms ,Plastics - Abstract
A low-density polyethylene (LDPE) degrading bacterial strain (ATKU1) was isolated (99.86% similar with Bacillus siamensis KCTC 13613T) from a plastic dumping site to study interactions between microplastics (
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- 2020
35. Properties of Polyhexamethylene Guanidine (PHMG) Associated with Fatal Lung Injury in Korea
- Author
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Kee Won Yang, Han Bin Oh, Jihoon Park, Ju-Hyun Park, Jung Hwan Kwon, and Dong-Uk Park
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Pharmaceutical Science ,molecular mass ,010501 environmental sciences ,Lung injury ,Degree of polymerization ,010402 general chemistry ,01 natural sciences ,Oligomer ,Guanidines ,Article ,Humidifiers ,oligomer ,Analytical Chemistry ,lcsh:QD241-441 ,chemistry.chemical_compound ,lcsh:Organic chemistry ,Drug Discovery ,Republic of Korea ,Humans ,Physical and Theoretical Chemistry ,Lung ,0105 earth and related environmental sciences ,Chromatography ,Molecular mass ,Chemistry ,Organic Chemistry ,Lung Injury ,humidifier disinfectant-associated lung injury ,PHMG ,0104 chemical sciences ,Molecular Weight ,Polyhexamethylene guanidine ,Chemistry (miscellaneous) ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,polymerization ,Molecular Medicine ,Molar mass distribution ,Equipment Contamination ,Disinfectants - Abstract
The use of humidifier disinfectant (HD) has been determined to be associated with lung injuries (HDLI) in Korea. Although HD brands containing polyhexamethylene guanidine (PHMG) oligomers have been found to cause more HDLI compared to brands containing other disinfectants, the physicochemical properties of PHMG have been poorly defined. We aimed to quantify the PHMG dissolved in HD brands, characterize the number-average (Mn) and weight-average (Mw) molecular masses, and identify the polymerization degree of PHMG. Analysis of the PHMG oligomers was performed using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) operated in positive-ion reflectron mode. Eight brands of HD containing PHMG were identified. The PHMG concentrations in these brands ranged from 160 to 37,200 ppm (mean = 3100.9 ppm). Concentration was a significant variable among and within HD brands. The degree of PHMG oligomerization fell within the range of two to four. The averages of Mn and Mw were 517.2 g/mol (range: 422&ndash, 613 g/mol) and 537.3 g/mol (range: 441.0&ndash, 678.0 g/mol), respectively. Based on the average molecular weight and the degree of polymerization, the PHMG examined here could be regarded as oligomers, which may be associated with the highest proportion of HDLI being caused by PHMG.
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- 2020
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36. Abnormal behaviors in the calibration curves of liquid chromatography–tandem mass spectrometry occurring in the quantitative analysis of surfactants near critical micelle concentrations
- Author
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Lee Sang Tak, Jung Hwan Kwon, Han Bin Oh, and Hyeri Kim
- Subjects
Chromatography ,010405 organic chemistry ,Calibration curve ,Electrospray ionization ,010401 analytical chemistry ,Mass spectrometry ,01 natural sciences ,Micelle ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Liquid chromatography–mass spectrometry ,Critical micelle concentration ,Amphiphile ,Sodium dodecyl sulfate ,Spectroscopy - Abstract
Surfactants, including quaternary ammonium compounds, are widely used in daily life as part of consumer chemical products and, more recently, in the shale oil industry. Because of their unique amphiphilic properties, surfactants form micelles at concentrations above a certain threshold known as the critical micelle concentration (CMC). A previous electrospray ionization mass spectrometry studies conducted by Siuzdak et al. and others presented indirect evidence regarding micelle formation. Herein, we have used liquid chromatography-tandem mass spectrometry to explore how such micelle formations affect the quantitative analysis of surfactants. Results reveal abnormal behaviors in the calibration plots of a few selected anionic and cationic surfactants, such as sodium decyl sulfate (SDeS), sodium dodecyl sulfate (SDS), myristyltrimethylammonium bromide (MTAB), and benzyldimethyloctadecylammonium chloride (BAC-18). At concentrations close to the respective CMCs of these surfactants, the calibration plot for MTAB flattened, whereas the slopes of the calibration plots for SDeS, SDS, and BAC-18 suddenly changed. These abnormal behaviors can be related to micelle formation. From a practical perspective, the above observations suggest that in the quantitative analysis of surfactants, high micelle concentrations close to the CMC should be avoided to obtain accurate surfactant measurements.
- Published
- 2020
37. Untargeted Metabolomics and Steroid Signatures in Urine of Male Pattern Baldness Patients after Finasteride Treatment for a Year
- Author
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Jeongae Lee, Woo-Young Sim, Ki Jung Paeng, Han Bin Oh, Eunju Im, Bark Lynn Lew, Bong Chul Chung, Haksoon Kim, Yu Ra Lee, and Jongki Hong
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0301 basic medicine ,medicine.medical_specialty ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Metabolite ,Urinary system ,lcsh:QR1-502 ,Urine ,01 natural sciences ,Biochemistry ,Article ,lcsh:Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Internal medicine ,medicine ,estrogen ,liquid chromatography-tandem mass spectrometry ,Molecular Biology ,business.industry ,010401 analytical chemistry ,androgens ,medicine.disease ,0104 chemical sciences ,finasteride ,030104 developmental biology ,Endocrinology ,Hair loss ,chemistry ,Estrogen ,Dihydrotestosterone ,Finasteride ,male pattern baldness ,Male-pattern baldness ,business ,medicine.drug - Abstract
Male pattern baldness (MPB) has been associated with dihydrotestosterone (DHT) expression. Finasteride treats MPB by inhibiting 5-alpha reductase and blocking DHT production. In this study, we aimed to identify metabolic differences in urinary metabolomics profiles between MPB patients after a one-year treatment with finasteride and healthy controls. Untargeted and targeted metabolomics profiling was performed using liquid chromatography-mass spectrometry (LC-MS). We hypothesized that there would be changes in overall metabolite concentrations, especially steroids, in the urine of hair loss patients treated with finasteride and normal subjects. Untargeted analysis indicated differences in steroid hormone biosynthesis. Therefore, we conducted targeted profiling for steroid hormone biosynthesis to identify potential biomarkers, especially androgens and estrogens. Our study confirmed the differences in the concentration of urinary androgens and estrogens between healthy controls and MPB patients. Moreover, the effect of finasteride was confirmed by the DHT/T ratio in urine samples of MPB patients. Our metabolomics approach provided insight into the physiological alterations in MPB patients who have been treated with finasteride for a year and provided evidence for the association of finasteride and estrogen levels. Through a targeted approach, our results suggest that urinary estrogens must be studied in relation to MPB and post-finasteride syndrome.
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- 2020
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38. Reliable screening and classification of phosphodiesterase type 5 inhibitors in dietary supplements using gas chromatography / mass spectrometry combined with specific common ions
- Author
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Jongki Hong, Myung Eun Lee, Yong-Moon Lee, Hyun Ji Kim, Seongchul Park, Han Bin Oh, Beom Hee Kim, Wonwoong Lee, and Ji Hyun Lee
- Subjects
Time Factors ,Drug Evaluation, Preclinical ,Mass spectrometry ,Biochemistry ,Consumer safety ,Gas Chromatography-Mass Spectrometry ,Sildenafil Citrate ,Analytical Chemistry ,Tadalafil ,chemistry.chemical_compound ,Vardenafil Dihydrochloride ,Screening method ,medicine ,Derivatization ,Ions ,Chromatography ,Organic Chemistry ,Discriminant Analysis ,General Medicine ,Phosphodiesterase 5 Inhibitors ,Phosphodiesterase Type 5 Inhibitors ,chemistry ,Vardenafil ,Dietary Supplements ,sense organs ,Pharmacophore ,Gas chromatography–mass spectrometry ,medicine.drug - Abstract
Illegal dietary supplements adulterated with phosphodiesterase type 5 inhibitors (PDE-5i) are increasingly widely distributed through internet markets and underground routes. For this reason, it demands development of reliable screening methods to determine a wide range of PDE-5i drugs in various types of dietary supplements. Herein, we developed a screening method using gas chromatography-mass spectrometry (GC–MS) for simultaneous detection of 53 PDE-5i drugs in supplements. Common formulations (such as capsule, powder, pill, and tablet) of supplements with complicated matrices were treated by simple liquid–liquid extraction and trimethylsilyl (TMS) derivatization. With the aid of TMS derivatization, 53 PDE-5i drugs could be successfully separated and detected within 15 min, using a short microbore GC column (15 m). Moreover, owing to enhanced detection sensitivity and selectivity of PDE-5i TMS derivatives, 0.5 mg of sample was sufficient to screen and confirm targeted PDE-5i drugs. In this study, specific common ions according to structural characteristics of PDE-5i drugs were found under the electron ionization (EI) of their TMS derivatives. These specific common fragments could reflect the common pharmacophores for 4 classes of PDE-5i drugs (sildenafil, other sildenafil, vardenafil, and tadalafil analogues). Based on characteristic EI fragment ions, extracted common ion chromatograms (ECICs) and discriminant analysis (DA) were effectively used for reliable screening and classification of various types of PDE-5i drugs. Specific ECICs and DA using characteristic EI fragments here will aid in identification of newly emerging PDE-5i counterfeits in supplements. This study will be helpful to supervise illegal adulteration of PDE-5i drugs in dietary supplements to protect public health and consumer safety.
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- 2020
39. Graph theory-based reaction pathway searches and DFT calculations for the mechanism studies of free radical-initiated peptide sequencing mass spectrometry (FRIPS MS): a model gas-phase reaction of GGR tri-peptide
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Jae-Ung Lee, Yeonjoon Kim, Han Bin Oh, and Woo Youn Kim
- Subjects
Reaction mechanism ,Free Radicals ,Kinetics ,General Physics and Astronomy ,Peptide ,Molecular Dynamics Simulation ,010402 general chemistry ,Mass spectrometry ,01 natural sciences ,Mass Spectrometry ,Gas phase ,Cyclic N-Oxides ,Computational chemistry ,Sequence Analysis, Protein ,Amino Acid Sequence ,Physical and Theoretical Chemistry ,Density Functional Theory ,chemistry.chemical_classification ,Chemistry ,010401 analytical chemistry ,Graph theory ,0104 chemical sciences ,Peptide sequencing ,Thermodynamics ,Density functional theory ,Gases ,Oligopeptides - Abstract
Graph theory-based reaction pathway searches (ACE-Reaction program) and density functional theory calculations were performed to shed light on the mechanisms for the production of [an + H]+, xn+, yn+, zn+, and [yn + 2H]+ fragments formed in free radical-initiated peptide sequencing (FRIPS) mass spectrometry measurements of a small model system of glycine–glycine–arginine (GGR). In particular, the graph theory-based searches, which are rarely applied to gas-phase reaction studies, allowed us to investigate reaction mechanisms in an exhaustive manner without resorting to chemical intuition. As expected, radical-driven reaction pathways were favorable over charge-driven reaction pathways in terms of kinetics and thermodynamics. Charge- and radical-driven pathways for the formation of [yn + 2H]+ fragments were carefully compared, and it was revealed that the [yn + 2H]+ fragments observed in our FRIPS MS spectra originated from the radical-driven pathway, which is in contrast to the general expectation. The acquired understanding of the FRIPS fragmentation mechanism is expected to aid in the interpretation of FRIPS MS spectra. It should be emphasized that graph theory-based searches are powerful and effective methods for studying reaction mechanisms, including gas-phase reactions in mass spectrometry.
- Published
- 2020
40. GC–MS Method for the Quantitative Analysis of Limonene from Genetically Engineered<scp>Saccharomyces cerevisiae</scp>
- Author
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Sukhyeong Cho, Han Bin Oh, Jinwon Lee, Jeongmo Yang, and Minhee Son
- Subjects
0301 basic medicine ,Limonene ,Chromatography ,biology ,Genetically engineered ,Saccharomyces cerevisiae ,General Chemistry ,biology.organism_classification ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Gas chromatography–mass spectrometry ,Quantitative analysis (chemistry) - Published
- 2018
41. Multiresidue analysis of 85 persistent organic pollutants in small human serum samples by modified QuEChERS preparation with different ionization sources in mass spectrometry
- Author
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Han Bin Oh, Sang Beom Han, Ki Hun Kim, Joo Eun Lee, and Hosub Im
- Subjects
Atmospheric-pressure chemical ionization ,Acetates ,Mass spectrometry ,Quechers ,Biochemistry ,Gas Chromatography-Mass Spectrometry ,Analytical Chemistry ,Acetone ,Polybrominated diphenyl ethers ,Limit of Detection ,Tandem Mass Spectrometry ,Halogenated Diphenyl Ethers ,Hydrocarbons, Chlorinated ,Hexanes ,Humans ,Pesticides ,Electron ionization ,Detection limit ,Chromatography ,Chemistry ,Organic Chemistry ,Extraction (chemistry) ,General Medicine ,Polychlorinated Biphenyls ,Atmospheric Pressure ,Environmental Pollutants ,Female ,Gas chromatography - Abstract
In this study, a multiresidue analytical method was developed, validated, and applied for quantifying 85 persistent organic pollutants (POPs), including 38 polychlorinated biphenyls (PCBs), 23 polybrominated diphenyl ethers (PBDEs), and 24 organochlorine pesticides (OCPs) from 200 μL of human serum. A modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was applied to minimize the required sample amount and optimize various conditions including the extraction solvent and the number of extractions. The extraction efficiency was optimized using double extraction with an ethyl acetate/hexane/acetone mixture. Gas chromatography coupled with triple-quadrupole mass spectrometry was used for analysis, and two different ionization sources, electron impact ionization (EI) and atmospheric pressure chemical ionization (APCI), were used to compare their sensitivity. The APCI source employed soft ionization at atmospheric pressure, producing abundant molecular ion formation with minimal fragmentation, in contrast to extensive fragmentation caused by EI. Of the 85 POPs analyzed, 59 target compounds (69.4%) showed lower limits of detection that were two- to fifty-fold lower in APCI than those determined using EI. The developed method was validated for its detection limit (0.5-10 pg/mL for PCBs, 2-20 pg/mL for PBDEs, and 2-40 pg/mL for OCPs), precision (0.8%-34.3% of coefficient of variation), recovery (49.6%-77.1%), matrix effect (46.7%-156.9%), and accuracy (81.2%-113.1% for PCBs, 85.8%-112.2% for PBDEs, and 55.2%-113.9% for OCPs). Its linearity was R2 > 0.99 for 84 compounds, and 96% average accuracy (for APCI) was obtained using the National Institute of Standards and Technology (NIST) standard reference materials (NIST 1957 and 1958). These ionization methods were compared by analyzing 25 real human serum samples. The observed species were 1.1-24.6 pg/mL of 28 PCBs, 2.5 pg/mL of BDE-47, and 6.5-195.1 pg/mL of 6 organochlorine pesticides (median concentration for each species), and only 11 compounds were detected with APCI owing to its enhanced sensitivity.
- Published
- 2019
42. Microbial production of uracil by an isolated Methylobacterium sp. WJ4 using methanol
- Author
-
Han Bin Oh, Yuhyun Kwon, Jinwon Lee, Byung-Keun Oh, Sangwoo Kim, Soohyun Park, Insu Song, and Wangjun Lee
- Subjects
0301 basic medicine ,Bioengineering ,Raw material ,Applied Microbiology and Biotechnology ,Biochemistry ,Biotechnological process ,03 medical and health sciences ,chemistry.chemical_compound ,RNA, Ribosomal, 16S ,Republic of Korea ,heterocyclic compounds ,Uracil ,Phylogeny ,Soil Microbiology ,biology ,Chemistry ,Methanol ,biology.organism_classification ,Combinatorial chemistry ,Carbon ,Methylobacterium sp ,Kinetics ,RNA, Bacterial ,Methylobacterium ,030104 developmental biology ,Genes, Bacterial ,Metabolic Networks and Pathways ,Bacteria ,Biotechnology - Abstract
In this study, we report the production of uracil from methanol by an isolated methylotrophic bacterium, Methylobacterium sp. WJ4. The use of methanol as alternative carbon feedstock is attractive option in biotechnology. As a feedstock of biotechnological processes, methanol has distinct advantages over methane. This is not only due to physical and chemical considerations, but also to the properties of the pertinent organisms. Besides, with a wide array of biological activities and synthetic accessibility, uracil is considered as privileged structures in drug discovery. Uracil analogues have been applied to treatments of patients with cancer or viral infections. In this respect, it is meaningful to produce uracil using methanol. The effect of process parameters and methanol concentration for uracil production were investigated and optimized. Uracil production was remarkably increased to 5.76mgg cell dry weight-1 in optimized condition. The results were significant for further understanding of methylotrophic bacteria on uracil production.
- Published
- 2018
43. Ionization of Gas-Phase Polycyclic Aromatic Hydrocarbons in Electrospray Ionization Coupled with Gas Chromatography
- Author
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Han Bin Oh, Eun Sook Jeong, Sang Beom Han, Sangwon Cha, Eunju Cha, Sunghwan Kim, Jaeick Lee, and Junghyun Son
- Subjects
Analyte ,Chromatography ,Chemistry ,Electrospray ionization ,010401 analytical chemistry ,technology, industry, and agriculture ,Protonation ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Gas phase ,Ion ,Ionization ,Gas chromatography ,0105 earth and related environmental sciences - Abstract
Herein, gas-phase polycyclic aromatic hydrocarbons (PAHs) as nonpolar compounds were ionized to protonated molecular ions [M + H]+ without radical cations and simultaneously analyzed using gas chromatography (GC)/electrospray ionization (ESI)-tandem mass spectrometry (MS/MS). The ionization profile, dissociation, and sensitivity were first investigated to understand the significant behavior of gas-phase PAHs under ESI. The formation of protonated molecular ions of PAHs was distinguished according to the analyte phase and ESI spray solvents. The protonated PAHs exhibited characteristic dissociations, such as H-loss, H2-loss, and acetylene-loss, via competition of internal energy. In addition, GC/ESI-MS/MS resulted in relatively lower concentration levels (better sensitivity) for the limits-of-detection (LODs) of PAHs than liquid chromatography (LC)/ESI-MS/MS, and it seems to result from the characteristic ionization mechanism of the gas-phase analyte under ESI. Furthermore, the LODs of gas-phase PAHs depen...
- Published
- 2018
44. Chiral differentiation of <scp>d</scp>- and <scp>l</scp>-isoleucine using permethylated β-cyclodextrin: infrared multiple photon dissociation spectroscopy, ion-mobility mass spectrometry, and DFT calculations
- Author
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Hyun Hee L. Lee, Sungyul Lee, Soojin Park, Han Bin Oh, Ju Hyeon Oh, Byeong Ki Min, Xianglei Kong, Hugh I. Kim, Jae-Ung Lee, Yin Hong, and Sung-Sik Lee
- Subjects
Chemistry ,Infrared ,Electrospray ionization ,010401 analytical chemistry ,General Physics and Astronomy ,Protonation ,010402 general chemistry ,01 natural sciences ,Dissociation (chemistry) ,0104 chemical sciences ,Physical chemistry ,Density functional theory ,Infrared multiphoton dissociation ,Physical and Theoretical Chemistry ,Spectroscopy ,Conformational isomerism - Abstract
Chiral differentiation of protonated isoleucine (Ile) using permethylated β-cyclodextrin (perCD) in the gas-phase was studied using infrared multiple photon dissociation (IRMPD) spectroscopy, ion-mobility, and density functional theory (DFT) calculations. The gaseous protonated non-covalent complexes of perCD and d-Ile or l-Ile produced by electrospray ionization were interrogated by laser pulses in the wavenumber region of 2650 to 3800 cm-1. The IRMPD spectra showed remarkably different IR spectral features for the d-Ile or l-Ile and perCD non-covalent complexes. However, drift-tube ion-mobility experiments provided only a small difference in their collision cross-sections, and thus a limited separation of the d- and l-Ile complexes. DFT calculations revealed that the chiral distinction of the d- and l-complexes by IRMPD spectroscopy resulted from local interactions of the protonated Ile with perCD. Furthermore, the theoretical results showed that the IR absorption spectra of higher energy conformers (by ∼13.7 kcal mol-1) matched best with the experimentally observed IRMPD spectra. These conformers are speculated to be formed from kinetic-trapping of the solution-phase conformers. This study demonstrated that IRMPD spectroscopy provides an excellent platform for differentiating the subtle chiral difference of a small amino acid in a cyclodextrin-complexation environment; however, drift-tube ion-mobility did not have sufficient resolution to distinguish the chiral difference.
- Published
- 2018
45. Fragmentation Pathways of Tadalafil and Its Analogues in Electrospray Ionization Tandem Mass Spectrometry
- Author
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Han Bin Oh, Bongjin Moon, Jongki Hong, and Jung-Min Lee
- Subjects
Chromatography ,Fragmentation (mass spectrometry) ,Chemistry ,Electrospray ionization ,010401 analytical chemistry ,General Chemistry ,010402 general chemistry ,Tandem mass spectrometry ,01 natural sciences ,0104 chemical sciences - Published
- 2017
46. 28108 Untargeted metabolomics and steroid signatures in urine of male pattern baldness patients after finasteride treatment for a year
- Author
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Min-Jeong Kang, Woo-Young Sim, Jeongae Lee, Han Bin Oh, Ki Jung Paeng, Ji-Hoon Lim, Bark Lynn Lew, Haksoon Kim, Yu Ra Lee, Soon Hyo Kwon, and Eunju Im
- Subjects
business.industry ,medicine.medical_treatment ,Physiology ,Dermatology ,Urine ,medicine.disease ,Steroid ,chemistry.chemical_compound ,Untargeted metabolomics ,chemistry ,Finasteride ,Medicine ,Male-pattern baldness ,business - Published
- 2021
47. Prediction of liquid chromatography retention times of erectile dysfunction drugs and analogues using chemometric approaches
- Author
-
Jongki Hong, Hye Kyung Park, Han Bin Oh, Jin Young Kim, and Jung-Min Lee
- Subjects
Chromatography ,010405 organic chemistry ,Chemistry ,010401 analytical chemistry ,Clinical Biochemistry ,Pharmaceutical Science ,medicine.disease ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,Chemometrics ,Erectile dysfunction ,Liquid chromatography–mass spectrometry ,medicine ,Retention time - Abstract
A chemometric model, which utilizes quantitative structure–retention relationships, has been developed for predicting liquid chromatography retention times (RTs) of 41 erectile dysfunction (ED) dru...
- Published
- 2017
48. Application of paper EWOD (electrowetting-on-dielectrics) chip: Protein tryptic digestion and its detection using MALDI-TOF mass spectrometry
- Author
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Kwanwoo Shin, Inae Jang, Han Bin Oh, Oh-Sun Kwon, Hyojin Ko, Heedo Chae, Jae Hwan Lee, Sunkyung Choi, Seunghwi Paek, Gwangro You, and Hyunji Lee
- Subjects
Chromatography ,Protein digestion ,Chemistry ,Disulfide bond reduction ,010401 analytical chemistry ,Biomedical Engineering ,Bioengineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,MALDI-TOF Mass Spectrometry ,Mass spectrometry ,Chip ,01 natural sciences ,0104 chemical sciences ,Digestion (alchemy) ,Electrowetting ,Electrical and Electronic Engineering ,0210 nano-technology ,Biotechnology - Abstract
A paper-based open EWOD chip was used for protein tryptic digestion, and the resulting peptides were analyzed using MALDI-TOF mass spectrometry to identify the proteins. Although on-chip protein digestion was previously demonstrated on a glass-based EWOD platform, this is the first report to show that a paper-based EWOD can also be used for protein digestion and further analysis by mass spectrometry. A number of protein digestion processes, i.e., disulfide bond reduction, alkylation, buffering, and tryptic digestion, can be successfully conducted on the paper-based EWOD chip. Furthermore, a “Y”-shaped junction design was shown to be effective in successfully manipulating a droplet for protein digestion. A paper-based EWOD platform offers a cheap and versatile avenue for biological applications.
- Published
- 2017
49. Reliable screening and confirmation of 156 multi-class illegal adulterants in dietary supplements based on extracted common ion chromatograms by ultra-high-performance liquid chromatography-quadrupole/time of flight-mass spectrometry
- Author
-
Bongjin Moon, Sung-Kwan Park, Jongki Hong, Wonwoong Lee, Hee Seung Seo, Na-Hyun Park, Han Bin Oh, Sun Young Baek, Jung Ah Do, Eun Hye Kim, and Nam Yong Ki
- Subjects
Accuracy and precision ,Analytical chemistry ,010402 general chemistry ,Mass spectrometry ,Tandem mass spectrometry ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,Ion ,Limit of Detection ,Tandem Mass Spectrometry ,Quadrupole time of flight ,Chromatography, High Pressure Liquid ,Detection limit ,Chromatography ,Chemistry ,010401 analytical chemistry ,Organic Chemistry ,Extraction (chemistry) ,Reproducibility of Results ,General Medicine ,0104 chemical sciences ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Dietary Supplements ,Linear Models ,Ultra high performance ,Drug Contamination - Abstract
An analytical method for the reliable screening and confirmation of 156 illegal drugs (58 erectile dysfunction drugs, 49 synthetic steroids, 26 anabolic steroids, and 23 anti-histamine drugs) in supplementary diets using ultra-high-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) was developed. Various types of supplements (liquid, capsule, powder, pill and tablet) with complicated matrices were pretreated by simple liquid-liquid extraction. The wide scope of 156 target compounds was effectively determined within 15min in the positive ion mode, detecting the compounds at a sub-ppb level. Their MS/MS spectra were preferentially investigated to find diagnostic common ions according to the structural similarity of diverse adulterants. For the rapid screening of multiple classes of the target adulterants, extracted common ion chromatograms (ECICs) based on specific fragments of similar molecular moieties were attempted. A database including the elemental compositions, retention times, and MS/MS spectra was built for the confirmation of adulterants. The established method was validated in terms of the linearity, limits of detection (LOD), precision, and accuracy. The linear correlation coefficient and limit of detection ranged from 0.9880 to 1 and from 0.02 to 16.04ng/mL, respectively. The precision and accuracy of intra- and inter-day experiments for the spiked samples at the range of 0.2 and 16.0ng/mL were from 0.16 to 13.50% and 0.19-11.48%, respectively, with relative standard deviation. Mean recoveries ranged from 81.6 to 124.7%, and relative standard deviation was less than 9.20%. The screening and confirmation method demonstrated the usefulness of UHPLC-Q/TOF-MS combined with ECICs as a promising approach for the analysis of multi-class adulterants. Finally, the established method was successfully applied for the monitoring of several types of dietary supplements in routine analysis.
- Published
- 2017
50. Increased incorporation of gaseous CO 2 into succinate by Escherichia coli overexpressing carbonic anhydrase and phosphoenolpyruvate carboxylase genes
- Author
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Han Bin Oh, Jae-Ung Lee, Sukhyeong Cho, Hyeonsoo Kim, Seung Pil Pack, Jinwon Lee, and Soohyun Park
- Subjects
0106 biological sciences ,0301 basic medicine ,biology ,Bioengineering ,General Medicine ,PEP group translocation ,medicine.disease_cause ,01 natural sciences ,Applied Microbiology and Biotechnology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Biochemistry ,chemistry ,010608 biotechnology ,Carbonic anhydrase ,Lactate dehydrogenase ,biology.protein ,medicine ,Citrate synthase ,Phosphoenolpyruvate carboxylase ,Phosphoenolpyruvate carboxykinase ,Escherichia coli ,Pyruvate kinase ,Biotechnology - Abstract
Carbon dioxide (CO2) is an abundant and cheap carbon source that is partly responsible for global warming in the atmosphere. The objective of this study was to construct a recombinant E. coli strain that can show enhanced production of succinate derived from CO2. In this study, we confirmed the enhancement of utilization by analyzing succinate containing one carbon-13 (13C) derived from 13CO2. Firstly, the carbonic anhydrase gene (SP(-)HCCA) derived from Hahella chejuensis KCTC 2396 was over-expressed to enhance carbon flux toward bicarbonate ion (HCO3-) synthesis in E. coli. The phosphoenolpyruvate carboxylase gene (ppc) was over-expressed to enhance the production of oxaloacetate by enhancing the carbon flux. Compared with the control strain, the percentage of the succinate containing one 13C (succinate119) to total succinate was enhanced by approximately 2.80-fold and the amount of succinate119 also increased by approximately 4.09-fold in SGJS120. Secondly, the lactate dehydrogenase gene (ldhA) was deleted to re-direct the utilization of the carbon source from glucose to enhance succinate production in SGJS120. However, ldhA deletion did not increase CO2 utilization in SJGS120. Finally, the phosphotransferase system gene (ptsG) and pyruvate kinase F gene (pykF) were deleted to increase the amount of phosphoenolpyruvate (PEP). SGJS126 (pykF deletion strain) showed the highest increase, which was 6.05-fold higher than the control strain. From the results, SP(-)HCCA overexpression and pykF deletion may be useful for enhancing CO2 utilization in E. coli. Additionally, engineered strains showed the potential to reduce the cost of succinate production by using an industrially cheaper carbon source such as CO2 and converting CO2 to a valuable chemical.
- Published
- 2017
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