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This article discusses the synthesis and characterization of 3-triazinyl-7-aminocoumarins, which are important compounds with various applications. The authors explore different synthetic approaches and find that a C–H/C–H cross-coupling method using heptafluorobutyric acid as a catalyst is a more straightforward and environmentally-friendly approach. They optimize the reaction conditions and identify the best conditions for synthesis. The article also provides detailed information on the physical and chemical properties of various compounds, including their spectroscopic data and yields. Supporting information is available online. [Extracted from the article]

In this paper, a simple and efficient high‐performance liquid chromatography method was established to analyze the chemical composition fingerprint of Centellae Herba (CHA) and determine five triterpenoid active components in CHA, namely, asiaticoside B (AB), madecassoside, asiaticoside, madecasic acid, and asiaticoic acid. The separation of the compounds was carried out on an XD‐C18 column (250 mm × 4.6 mm, 5 µm), the wavelength of the ultraviolet detector was set to 205 nm, and the mobile phase was composed of acetonitrile −0.05% phosphoric acid, 2 mmol/L β‐cyclodextrin aqueous solution, and gradient elution at the flow rate of 1.0 mL/min. A general chromatographic fingerprint consisting of 20 characteristic peaks of 18 batches of CHA samples was established, and the samples were classified and evaluated by similarity analysis, hierarchical cluster analysis, and principal component analysis combined with multivariate econometric analysis. In quantitative analysis, all calibration curves showed good linear regression in the test range (r > 0.999), the average recovery was 96.12%–104.63%, and the relative standard deviations of repeatability and stability were less than 2.00%. The results show that the method is accurate and effective and can be used for the comprehensive quality control of CHA. [ABSTRACT FROM AUTHOR]

In this study, a combination approach involving macroporous resin (MR) column chromatography and gradient countercurrent chromatography (CCC) was employed to enrich and purify bufadienolides from the roots and rhizomes of Helleborus thibetanus Franch. Initially, a D101 MR‐packed column chromatography was utilized for fractionation and enrichment of the bufadienolides, which were effectively eluted from the column using a 60% ethanol solution. CCC was subsequently introduced to separate the enriched product using the ethyl acetate/n‐butanol/water (EBuWat, 4:1:5, v/v) and EBuWat (5:0:5, v/v) solvent systems in a gradient elution mode. As results, five bufadienolides, including 6.1 mg of hellebrigenin‐3‐O‐β‐D‐glucoside (1), 2.2 mg of tigencaoside A (2), 8.3 mg of deglucohellebrin (3), 3.5 mg of 14 β‐hydroxy‐3β‐[β‐D‐glucopyranosyl‐(1→6)‐(β‐D‐glucopyranosyl)oxy]‐5α‐bufa‐20,22‐dienolide (4), and 3.0 mg of 14β‐hydroxy‐3β‐[(β‐D‐glucopyranosyl)oxy]‐5α‐bufa‐20,22‐dienolide (5), were effectively separated from 300 mg of the enriched product. The respective high‐performance liquid chromatography purities were as follows: 95.2%, 75.8%, 85.7%, 82.3%, and 92.8%. This study provides valuable insights for the efficient enrichment and separation of bufadienolides from Helleborus thibetanus Franch. [ABSTRACT FROM AUTHOR]

Itampolin A, a natural brominated tyrosine alkaloid isolated from the sponge Iotrochota purpurea, has been shown to have good inhibitory effects in lung cancer cells as a p38α inhibitor. A simple, sensitive, and reliable ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) method has been established, validated, and applied to the study of the pharmacokinetics and tissue distribution of itampolin A following intragastric and intravenous administration. Itampolin A and theophylline (internal standard, IS) were extracted by the simple protein precipitation technique using methanol as the precipitating solvent. Chromatographic separation was achieved by using the optimized mobile phase of a 0.1% formic acid aqueous solution and acetonitrile in the gradient elution mode. Itampolin A and IS were detected and quantified using positive electrospray ionization in the multiple reaction monitoring mode with transitions of m/z 863.9 → 569.1 for itampolin A and m/z 181.1 → 124.1 for IS, respectively. The assay exhibited a linear dynamic range of 1–1600 ng/mL for itampolin A in biological samples and the low limit of quantification was 1 ng/mL. Non-compartmental pharmacokinetic parameters indicated that itampolin A was well-absorbed into the systemic circulation and rapidly eliminated after administration. The apparent distribution volume of itampolin A was much higher after intragastric administration than that after intravenous administration. A tissue distribution study showed that itampolin A could be detected in different tissues and maintained a high concentration in the lung, which provided a material basis for its effective application in lung cancer. The pharmacokinetic process and tissue distribution characteristics of imtapolin A were expounded in this study, which can provide beneficial information for the further research and clinical application of itampolin A. [ABSTRACT FROM AUTHOR]

With the escalating demand for Astragalus polysaccharides products developed from Radix Astragali (RA), the necessity for quality control of polysaccharides in RA has become increasingly urgent. In this study, a specific method for the simultaneous determination of seven monosaccharides in polysaccharides extracted from Radix Astragali (RA) has been developed and validated using ultra-performance liquid chromatography equipped with an ultraviolet detector (UHPLC-UV) for the first time. The 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatizations were separated on a C18 column (Waters ACQUITYTM, Milfor, MA, USA, 1.8 µm, 2.1 × 100 mm) using gradient elution with a binary system of 5 mm ammonium formate (0.1% formic acid)-acetonitrile for 24 min. Additionally, seven monosaccharides showed good linear relationships (R2, 0.9971–0.9995), adequate precision (RSD < 4.21%), and high recoveries (RSD < 4.70%). The established method was used to analyze 109 batches of RA. Results showed that the Astragalus polysaccharides (APSs) mainly consist of mannose (Man), rhamnose (Rha), glucose (Glu), galactose (Gal), arabinose (Ara), xylose (Xyl); and fucose (Fuc); however, their composition was different among RA samples from different growth patterns, species, growth years, and origins, and the growth mode of RA and the age of wild-simulated RA can be accurately distinguished by principal component analysis (PCA). In addition, the immunological activity of APSs were also evaluated jointly by measurement of the NO release with RAW264.7, with the results showing that APSs have a promoting effect on the release of NO and exhibit a significant correlation with Man, Glu, Xyl, and Fuc contents. Accordingly, the new established monosaccharides analytical method and APS-immune activity determination in this study can provide a reference for quality evaluation and the establishment of quality standards for RA. [ABSTRACT FROM AUTHOR]

SIPI6398 is a novel anti-schizophrenia agent with a new mechanism of action and demonstrates better target selectivity and safety compared to its competitors. However, few in vivo studies on the pharmacokinetics and bioavailability of SIPI6398 have been performed. A rapid and simple ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach was developed for accurate quantification of SIPI6398 in rat plasma. A simple protein precipitation of acetonitrile-methanol (9 : 1, v/v) was used to treat plasma. Chromatography was performed on a UPLC HSS T3 column (50 mm × 2.1 mm, 1.8 μm) at a flow rate of 0.4 ml/min. The mobile phase consisted of acetonitrile-water (with 0.1% formic acid) and gradient elution was used, and the elution time was 4 minutes. Quantitative analysis was performed using electrospray ionization (ESI) in positive ion detection mode with multiple reaction monitoring (MRM) mode. To evaluate the pharmacokinetics and bioavailability, SIPI6398 was administered to rats in two different ways: oral (4 mg/kg) and intravenous (2 mg/kg) administration. The calibration curve for the UPLC-MS/MS approach shows excellent linearity in the range of 1–2000 ng/mL with an r value above 0.99. The precision, accuracy, recovery, matrix effect, and stability results all meet the criteria established for biological analytical methods. The UPLC-MS/MS method was successfully applied it to pharmacokinetics study of SIPI6398. The bioavailability of SIPI6398 was calculated to be 13.2%. These studies have the potential to contribute towards a more comprehensive comprehension of the pharmacokinetics and bioavailability of SIPI6398. [ABSTRACT FROM AUTHOR]

This study designed to characterize major forced degradation products of Olmesartan Medoxomil (OM) and to perform genotoxicity profiling using acid, base, and hydrogen peroxide‐induced stress degradation studies. The isolation of degradation products was conducted on flash chromatography using FlashPure ECOFLEX C18 4 g column with gradient elution and diode array detection‐based fraction collection, and characterized by mass spectrometry. Three impurities (impurity‐1, 2, and 3) were identified with respective m/z values of 447.213, 461.229, and 463.208. The genotoxic potential of impurities was assessed by in silico prediction, and in vitro comet assay using HEK cells. The extent of DNA damage was analyzed using Comet Assay IV imaging software. For impurity‐1, head and tail lengths and their respective total intensities were significantly (p<0.001) larger than those of dimethyl sulfoxide (solvent) control and comparable to positive control. Other parameters such as mean grey level and total area of comet were statistically significant as compared with the solvent and positive controls. Overall, impurity‐1 was a possible genotoxic impurity and a known major degradation product in OM tablet dosage form. In silico prediction also revealed impurity‐1 as toxicity class 3, whilst impurities 2 and 3 were of toxicity class 4. [ABSTRACT FROM AUTHOR]

The objective of this study was to create a liquid chromatographic method that could accurately and simultaneously quantify the amount of Quercetin, Berberine, and Phytosterol present in lyophilized liposome used to treat metabolic syndrome. To achieve this goal, the team utilized a Shim‐pack GIST C8 column with a gradient elution of 0.1% (V/V) triethylamine buffer: acetonitrile at 30°C. They analyzed the phytoconstituents using an eluent flow rate of 1 mL/min and ultraviolet detection at 205 nm. The method was linear within a range of 25–77 μg/mL, which had excellent correlation coefficients (R2) of 0.9998, 0.9998, and 0.9996 for Quercetin, Berberine, and Phytosterol, respectively. The %RSD for precision and robustness of the method were also less than 2%, and the recovery values for Quercetin, Berberine, and Phytosterol were 99.5%, 100.5%, and 99.8%, respectively. The assay values of were found to be 100.2%, 101.6%, and 100.5% for Quercetin, Berberine, and Phytosterol, loaded lyophilized liposomes, respectively. As a result, this specific, accurate, and precise method can be employed for the routine analysis of Quercetin, Berberine, and Phytosterols in QC laboratories. [ABSTRACT FROM AUTHOR]

A pinanamine‐based analog, (1R,2R,3R,5S)‐N‐((3‐cyclopropylthiophen‐2‐yl)methyl)‐2,6,6‐trimethylbicyclo[3.1.1]heptan‐3‐amine (M090) was synthesized and demonstrated with anti‐influenza activity to overcome the multi‐drug resistance. Herein, a rapid and robust liquid chromatography‐tandem mass spectrometry method was developed and validated to quantify M090 in rat plasma. With simple protein precipitation by methanol, the separation of M090 was performed on a Waters BEH‐C18 column (2.1 × 100 mm, 1.7 μm) by gradient elution at 0.4 mL/min with mobile phases consisting of water containing 0.1 % formic acid (phase A) and methanol (phase B). M090 and clenbuterol (internal standard) were detected using multiple reaction monitoring in positive electrospray ionization mode with transitions of m/z 290.3→137.0 and m/z 277.0→203.0, respectively. The method was validated over a linear range of 1.0–2400 ng/mL with a regression coefficient of 0.9974 and no endogenous interference. The intra‐ and inter‐batch precisions were within 8.29% and accuracy ranged from 100.3% to 108.1% for M090. The validated method was utilized to evaluate the in vitro metabolic stability and in vivo pharmacokinetics of M090 in rats. [ABSTRACT FROM AUTHOR]

Chromatographic modeling software packages are valuable tools during method optimization steps. These are well established for reversed‐phase applications utilizing retention time (RT) prediction to optimize separations and receive robust methods, which is of high interest for the analysis of pharmaceuticals. In contrast to liquid chromatography, the knowledge of RT prediction in supercritical fluid chromatography is limited to a manageable number of studies. This study uses the software DryLab to predict the RTs of the peptides bacitracin (Bac), colistin, tyrothricin (Tyro), and insulin analogs. Gradient time, column temperature, and the ternary composition (terC) of carbon dioxide, methanol (MeOH), and acetonitrile (ACN) in the gradient elution are varied in a feasibility approach using a neutral (Viridis BEH) and an amino‐derivatized aromatic (Torus 2‐PIC) stationary phase. In the second part, chromatographic optimization is performed in silico through gradient adjustments to optimize the separation of the fingerprint of Bac. The final gradient method utilizes a Viridis BEH column (100 × 3.0 mm, 1.7 μm), carbon dioxide, and a modifier consisting of ACN/MeOH/water/methanesulfonic acid (60:40:2:0.1, v:v:v:v). In addition, changes in the retention order of Tyro compounds with the proportion of the terC in combination with a Torus Diol column are investigated. [ABSTRACT FROM AUTHOR]

Background An eco-friendly analytical technique was developed with the intention of preserving the environment by using green chemistry principles. Pemetrexed is a folate analogue indicated for the treatment of advanced lung cancer. Objective Development of a green stability-indicating HPLC method for the quantification of pemetrexed ditromethamine (PDT) impurities in Active Pharmaceutical Ingredient (API) and parenteral dosage form. Methods Chromatographic separation was achieved using a Zorbax SB C18 column (150 mm × 4.6 mm i.d. 3.5 µ particle size) with perchlorate buffer (pH 3.0 ± 0.1, 50 mM) as mobile phase A and acetonitrile–perchlorate (90 + 10, v/v) buffer as mobile phase B at a flow rate of 0.8 mL/min with a column temperature of 40°C ± 0.5°C. All analytes were well resolved by gradient elution with a total run time of 75 min. The UV detection wavelength was 230 nm. Results The RP-HPLC method is capable of resolving all the degradation and process impurities for PDT API and parenteral dosage form. The related compounds method was validated in accordance with International conference on harmonization (ICH) Q2(R1) and United states of Pharmacopoeia (USP) <1225> guidelines, and found to be accurate, specific, precise, linear, robust and stability-indicating. The precision and intermediate results were <5% CV for all the impurities. The accuracy for all the impurities was found to be between 90 and 110%. The linearity of regression co-efficient values for all the impurities were found to be more than 0.999. Conclusion The proposed related compounds method is found suitable for the determination of process and degradation impurities of commercial formulations, stability samples in QC analysis for PDT API, and drug product. Highlights The developed liquid chromatographic method greenness and eco-friendliness were assessed using the green analytical procedure index (GAPI) and the analytical greenness (AGREE) tool, and found to be green. A PDT detoxification procedure was also developed to reduce environmental pollution. [ABSTRACT FROM AUTHOR]

Yupingfeng granules (YPFG) is commonly used in the treatment of immunological diseases, inflammations, and pulmonary diseases. Several studies have found that chromones, flavones, and saponins were the major bioactive compounds of YPFG. However, few studies have reported accurate quantification methods of these compounds. This study aimed to establish a simple and rapid method by using liquid chromatography–tandem mass spectrometry (LC–MS/MS) to determine 15 bioactive compounds in YPFG. The experimental parameters including extraction methods, extraction solvents, extraction time, solid–liquid ratio, and LC–MS/MS condition were optimized. The linearity, precision, repeatability, stability, and recovery of the established method were evaluated. The contents of 15 bioactive compounds in seven batches of YPFG samples were analyzed by the established method and the results were compared with the values determined by HPLC. The optimal extraction condition was to extract 0.1 g of YPFG by ultrasound with 50 mL 50% ethanol for 30 min. A Waters ACQUITY UPLCBEH C18 column using the 0.1% formic acid water solution and acetonitrile as mobile phase with a gradient elution was applied to the chromatographic separation. The linearity, precision, repeatability, stability, and recovery of the method were within acceptable ranges. Compared with HPLC analysis methods in Chinese Pharmacopoeia and literature, the established method was faster, simpler, more accurate, and more reliable. The method of simultaneous determination of 15 components in YPFG by LC–MS might provide a basis for the study of the bioactive compounds and the improvement of the quality standard of YPFG. [ABSTRACT FROM AUTHOR]

Therapeutic drug monitoring is an important clinical testing of the drugs to monitor their concentrations in plasma in order to guarantee their optimal impact, and to avoid any side effects resulting from drug-drug interactions. A green reversed-phase high-performance liquid chromatographic method using a photodiode array detector (RP-HPLC-PDA) was developed for the simultaneous determination of three carbapenem antibiotics (Imipenem, ertapenem, and meropenem) with the co-formulated drug (cilastatin) and contraindicated drugs (probenecid and warfarin) in spiked human plasma. The separation was achieved at 25 °C using a gradient elution of a mixture of mobile phase A: methanol and mobile phase B: phosphate buffer (pH 3.0). The photodiode array detector was adjusted at 220 nm. Bioanalytical method validation was carried out as per the FDA guidelines, and the method showed good linearity ranges for the six drugs that included their Cmax levels along with low limits of quantification. Based on the results, the method was found to be accurate and precise; with high % recovery and good % RSD, respectively. The method was successfully applied to spiked human plasma, signifying a good potential to be implemented in future TDM studies of these drugs when co-administered together. [ABSTRACT FROM AUTHOR]

Previous research has evaluated the extent to which cocaine and other drugs were detectable on currency in the USA. The literature was in agreement that the majority of bills exhibited some degree of contamination. With the increase of fentanyl in the illicit drug supply, this study was designed to evaluate the extent that fentanyl, cocaine, methamphetamine and other substances were present on circulating currency in 2022. A quantitative assay using liquid chromatography–triple quadrupole mass spectrometry was developed and validated to detect six analytes: fentanyl, 4-anilino- N -phenethylpiperidine, acetylfentanyl, benzylfentanyl, cocaine and methamphetamine. One-dollar bills were collected from 13 cities across the country. Sample preparation consisted of soaking the bills in methanol followed by liquid–liquid extraction. Chromatographic separation was achieved using a C18 analytical column and gradient elution with ammonium formate in water (5 mM, pH 3) and 0.1% formic acid in acetonitrile. The quantitative working range for this assay was 0.1 μg to 1.0 μg per bill (equivalent to 1 ng/mL to 100 ng/mL of extract). Fentanyl was detected on the majority (63%) of samples, with 61% of samples having ≥0.1 μg of fentanyl and 4% of samples having ≥1.0 μg. Cocaine and methamphetamine were detected on 100% and 98% of bills, respectively, typically in amounts >1.0 μg. The remaining fentanyl-related substances were detected in 15% of samples in amounts no >0.69 μg per bill and exclusively in the presence of fentanyl. Unsurprisingly, areas of the country with higher incidence of fentanyl use yielded higher frequency of contaminated bills and higher concentrations. Human exposure to drugs on currency is unlikely to have any significant impacts toxicologically or pharmacologically; however, our research findings suggest that paper currency could serve as a useful substrate for surveillance of drug trends regionally, nationally and/or internationally. [ABSTRACT FROM AUTHOR]

[Objectives] An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for simultaneous determination of 26 antibiotics in the water around landfills. [Methods] After an HLB solid-phase extraction column was activated, and a water sample, which was adjusted with phosphoric acid to a pH of (2±0.5) and added with 500 mg of disodium EDTA, was loaded, and 5 ml of water and 20% methanol water was added for washing. Next, 10 ml of elution solution was added for elution, and the collected eluate was evaporated under reduced pressure at 40 °C to near dryness, and 1 ml of reconstitution solution was added to a constant volume. An ACQUITY UPLC BEH C18 (100 mm ×2.1 mm, 2.6 µm) chromatographic column was adopted for LC separation by gradient elution with 0.1% formic acid aqueous solution-acetonitrile as the mobile phase. For MS detection, the MRM mode was adopted for collection, and the positive and negative ion modes were switched for simultaneous determination, and the internal standard method was used for quantification. [Results] The correlation coefficient R2 was greater than 0.99 in the linear range of each target substance. The limits of detection ranged from 0. 15 to 3.00 ng/L, and the limits of quantitation were between 0.80 and 10.00 ng/L, and the recoveries ranged from 77.9% to 104.85%. [Conclusions] The method has high sensitivity, good accuracy and strong practical value. [ABSTRACT FROM AUTHOR]

Strychnos nux‐vomica (S.N) also known as poisonous nut, Dog button, Kuchla whose seeds and barks have various components that are used in folklore and traditional medicines in different countries. Stem bark of SN is collected from local area and extracted using chloroform by soxhlation process and isolated the phytoconstituents from the chloroform extract using column chromatography method by gradient elution technique. Six compounds are isolated from the column out of which four compounds are found to be novel from the S.N. Obtained phytoconstituents are checked for in silico studies using reverse docking process with the help of Schrodinger software and the docking score indicates that the phytoconstituents are found to have very good antidiabetic action. [ABSTRACT FROM AUTHOR]

Folic acid (FA) is easily photodegraded to yield 6‐formylpterin and pterin‐6‐carboxylic acid, which can generate reactive oxygen species and result in the formation of oxidized guanine derivatives such as 8‐hydroxy‐2′‐deoxyguanosine and 8‐hydroxy‐guanosine. In this study, we developed a simple, rapid, and sensitive liquid chromatography‐tandem mass spectrometry strategy for the simultaneous determination of FA photolysis products and oxidized guanine derivatives in plasma samples. Chromatographic separation was performed on a Waters HSS T3 column (2.1 × 100 mm, 5.0 μm) with gradient elution at a flow rate of 0.25 mL/min. Plasma samples were first pretreated with 1% formic acid, followed by protein precipitation with methanol. The developed method showed good linear relationships between 1 and 2000 ng/mL (r2 > 0.99). The intra‐ and inter‐day precisions ranged from 2.6% to 7.5% and from 2.5% to 6.5%, respectively. Recoveries of the analytes were between 75.4% and 112.4% with the relative standard deviation < 9.1%. Finally, the method was applied to quantify FA photolysis products and oxidized guanine derivatives in rats with light and non‐light conditions. [ABSTRACT FROM AUTHOR]

A reverse phase high-performance liquid chromatography (HPLC) method has been developed for the quantification of a typical drug Dasatinib (DST) and its related impurities in pharmaceuticals. Kinetex C18 (4.6 × 150 mm, 5 μm) column was used in the chromatographic separations, using buffer (1.36 g of KH2PO4 in 1000 mL of water, pH = 7.8; adjusted with diluted KOH solution) with solvent as acetonitrile and mode of elution as the gradient. The flow rate is 0.9 mL/min, column oven temperature as 45°C and the overall gradient run time as 65 min. The developed method was found to produce symmetric and good separation between the process-related and degradation impurities. Method optimization is achieved with photodiode array at 305 nm over the concentration range of 0.5 mg/mL and degradation studies were carried out under acidic, alkaline, oxidative, photolytic and thermal conditions to demonstrate the stability indicating capability of the method. Two major impurities were found in forced degradation studies in the HPLC analysis, the unknown, acid degradants were enriched and isolated by preparative HPLC, then characterized through high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. The unknown acid degradation impurity was showing Exact Mass of 521.11, molecular formula C22H25Cl2N7O2S and its chemical name as 2-(5-chloro-6-(4-(2-hydroxyethyl) piperazin-1-yl)-2-methylpyrimidin-4-ylamino)-N-(2-chloro-6-methylphenyl) thiazole-5-carboxamide. Another impurity (oxidative degradant) found as known DST N-oxide Impurity-L and its chemical name as 4-(6-((5-((2-chloro-6-methylphenyl) carbamoyl) thiazol-2-yl) amino)-2-methylpyrimidin-4-yl)-1-(2-hydroxyethyl) piperazine 1-oxide. The analytical HPLC method was further validated as per ICH guidelines. [ABSTRACT FROM AUTHOR]

Many analytical methods are reported for simultaneous estimation of pharmaceutical dosages form. However, only a few are reproducible at an industrial scale. The proposed research aims to establish a technology transfer (TT) protocol between two laboratories (Lab-X, originator) with binary and (Lab-Y, receiver) with quaternary high-performance liquid chromatography (HPLC) system. Thus, utilizing reverse-phase HPLC (RP-HPLC), a robust, sensitive and repeatable analytical method has been developed, validated and TT between two laboratories for simultaneous estimation of Andrographolide (AG) and Paclitaxel (PTX). The method has been developed on a Phenomenex Luna C18 column (150 x 4.6, 5) sustained at 40°C and validated under the International Conference on Harmonisation (ICH) Q2 (R1) regulatory guideline and TT USP chapter 1224. The mobile phase consisted of MilliQ (pH = 3) and a combination of acetonitrile and methanol (1:1) in the ratio 50:50 with a flow rate of 0.45 mL/min, linear gradient elution in both labs. The AG and PTX were detected on the PDA detector at 224 and 227 nm wavelength with retention time of 4.5 ± 0.34 and 8.2 ± 0.02 min and limit of detection was found 0.028 ± 0.004 μg/mL, and 0.028 ± 0.0007 μg/mL, whereas limit of quantification as 0.086 ± 0.011 μg/mL and 0.088 ± 0.0014 μg/mL respectively in both labs. Throughout, this approach we have proved that proposed method is repeatable in both labs, and it can be used to quantify AG and PTX in developed pharmaceutical nano-formulations. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish an analytical method for the simultaneous detection of chloramphenicol, stilbenes, and resorcylic acid lactones. After enzymatic hydrolysis, pork samples were extracted by ethyl acetate. Two methods were used for purification: a C18 cartridge and immunoaffinity microextraction in a packed syringe. The samples were analyzed by UPLC–MS/MS on an Acquity UPLC® BEH C18 column with gradient elution. The methods were demonstrated to be suitable for the determination of chloramphenicol, stilbenes, and resorcylic acid lactones in pork. The SPE–UPLC–MS/MS had average recoveries of 42.4–97.1%. The intra-day and inter-day RSDs ranged from 6.1 to 16.9% and 3.7 to 18.4%, respectively. The IA–MPES–UPLC–MS/MS had average recoveries of 14.6–33.3%, and the intra-day and the inter-day RSDs ranged from 4.7 to 19.2% and 1.0 to 16.5%, respectively. Overall, the immunoaffinity microextraction in a packed syringe saves the organic reagent when balancing the C18 cartridge; thus, the dose of the organic reagent is less. However, the recovery of extraction by immunoaffinity microextraction in a packed syringe is less ideal. [ABSTRACT FROM AUTHOR]

Rationale: Secondary hypertension is often caused by activation of complex multi‐organ endocrine systems, while renin activity indicated by angiotensins (Angs), aldosterone (ALD) and cortisol (COR) in such systems are generally accepted as its diagnostic markers. As antibody‐based methods cannot offer comparable quantification for these biomarkers, a liquid chromatography (LC)–tandem mass spectrometry (MS/MS)‐based approach was developed to quantify them simultaneously and accurately. Methods: Five different beads for magnetic solid‐phase extraction (MSPE) were evaluated towards their enrichment efficiency for these biomarkers. An LC system with optimized elution gradient and a triple‐quadrupole MS with tuned parameters were coupled to quantitatively monitor the extracted analytes. The method performance was further examined such as linearity, precision, stability, recovery rate and matrix effect. Based on the developed method, the abundance of Ang II, ALD and COR in plasma was measured and the quantification was compared with that derived from commercial ELISA kits. Results: As compared with other MSPEs, Angs, ALD and COR were highly enriched by the HLB magnetic beads with satisfactory recoveries. These analytes were simultaneously quantified by LC/MS/MS and all the method parameters for quantification were well matched with the requirements of clinical testing. Comparison of the quantitative results derived from ELISA and LC/MS/MS exhibited that the two methods offered basically comparable values with Pearson r values at 0.896, 0.895 and 0.835, respectively. The stability test for plasma Angs at room temperature indicated that the abundance of Ang II was relatively stable within 3 h, whereas that of Ang I and Ang 1–7 was time‐dependently changed. Conclusions: Coupling of HLB beads and LC/MS/MS thus enables simultaneous quantification of a set of biomarkers related to secondary hypertension. [ABSTRACT FROM AUTHOR]

Supplementing fish oil is one of the strategies to reduce the risk of cardiovascular disease, the leading cause of death around the world. Contradictorily, fish oil may also contain trimethylamine-N-oxide, a recently emerged risk factor for cardiovascular disease, as well as one of its precursors, trimethylamine. A method suitable for routine quantification of trimethylamine-N-oxide and trimethylamine in fish oil with a quick and easy liquid extraction without derivatization has been developed. Liquid chromatography with tandem mass spectrometry detection was employed along with a zwitterionic hydrophilic interaction liquid chromatography column and a gradient elution with eluents containing 50 mmol/L of ammonium formate. An internal standard (triethylamine) was used for quantification by mass spectrometry with an external calibration. The assay proved high linearity in the ranges of 10 to 100 ng/mL and 100 to 1000 ng/mL for trimethylamine-N-oxide and trimethylamine, respectively. The lowest limit of quantification was determined to be 100 µg/kg for trimethylamine and 10 µg/kg for trimethylamine-N-oxide, with the limit of detection at 5 µg/kg and 0.25 µg/kg, respectively. Accuracy ranged from 106–119%. Precision was below 7% the relative standard deviation for both analytes. The method was successfully applied for the determination of trimethylamine-N-oxide and trimethylamine contents in nine commercially available liquid fish oils and three commercially available fish oil capsules, showing that trimethylamine and trimethylamine-N-oxide are not present in highly refined fish oils. [ABSTRACT FROM AUTHOR]

Plasma proteomics holds immense potential for clinical research and biomarker discovery, serving as a non-invasive "liquid biopsy" for tissue sampling. Mass spectrometry (MS)-based proteomics, thanks to improvement in speed and robustness, emerges as an ideal technology for exploring the plasma proteome for its unbiased and highly specific protein identification and quantification. Despite its potential, plasma proteomics is still a challenge due to the vast dynamic range of protein abundance, hindering the detection of less abundant proteins. Different approaches can help overcome this challenge. Conventional depletion methods face limitations in cost, throughput, accuracy, and off-target depletion. Nanoparticle-based enrichment shows promise in compressing dynamic range, but cost remains a constraint. Enrichment strategies for extracellular vesicles (EVs) can enhance plasma proteome coverage dramatically, but current methods are still too laborious for large series. Neat plasma remains popular for its cost-effectiveness, time efficiency, and low volume requirement. We used a test set of 33 plasma samples for all evaluations. Samples were digested using S-Trap and analyzed on Evosep One and nanoElute coupled to a timsTOF Pro using different elution gradients and ion mobility ranges. Data were mainly analyzed using library-free searches using DIA-NN. This study explores ways to improve proteome coverage in neat plasma both in MS data acquisition and MS data analysis. We demonstrate the value of sampling smaller hydrophilic peptides, increasing chromatographic separation, and using library-free searches. Additionally, we introduce the EV boost approach, that leverages on the extracellular vesicle fraction to enhance protein identification in neat plasma samples. Globally, our optimized analysis workflow allows the quantification of over 1000 proteins in neat plasma with a 24SPD throughput. We believe that these considerations can be of help independently of the LC–MS platform used. [ABSTRACT FROM AUTHOR]

Abri Herba (Jigucao) and Abri mollis Herba (Maojigucao) are derived from dried plants of Abrus cantoniensis Hance (Leguminosae) and Abrus mollis without pods. Abri Herba is commonly used in Jigucao tablets; Abri mollis Herba is usually used in Jigucao capsules and FufangJigucao capsules. Surprising, there are few reports focused on the quantitative control of these mentioned Jigucao related pharmaceuticals. This research endeavour has harnessed the formidable power of cutting‐edge ACQUITY UPLC technology to formulate a groundbreaking methodology for the simultaneous quantification of 10 target compounds in Jigucao capsules, Jigucao tablets and FufangJigucao capsules. The primary aim is to bolster quality control and precise identification within the realm of these pharmaceutical products. Separation was performed on an ACQUITY UPLC HSS T3 Column (2.1 × 100 mm, 1.8 μm), gradient elution was performed with 0.1% formic acid in water and acetonitrile. A column temperature of 40°C acts as our guiding compass, and DAD detection scans the spectral landscape in the wavelength range of 210–400 nm. The concentrations of the 10 target components can be used to identify Jigucao tablets, Jigucao capsules and FufangJigucao capsules through the art of chemometrics. The results showed that the established method for determination of 10 target compounds was accurate and reliable with good linearity (r ≥.9948) and satisfactory recoveries (82.91%–108.6%). The identification of the three Jigucao related pharmaceuticals can be performed using chemometrics based on the 10 target compounds. Thus, our study not only showcases a pioneering analytical approach but also unveils a new dimension in the identification of these pharmaceutical treasures. [ABSTRACT FROM AUTHOR]

Bopyeo-tang (BPT), comprising six medicinal plants, has been used for the treatment of respiratory diseases such as pulmonary fibrosis and chronic obstructive pulmonary disease. In this study, we developed and validated a quantitative method for the quality assessment of BPT using ultra-performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS). Eighteen marker compounds were separated on an Acquity UPLC BEH C18 reversed-phase column (2.1 mm × 100 mm, 1.7 μm) via gradient elution with a 0.1% aqueous formic acid–acetonitrile mobile phase. The multiple-reaction monitoring mode was used to improve analysis speed and accuracy. The coefficients of determination, limits of detection, and limits of quantitation of the 18 marker compounds were 0.9991–0.9996, 0.36–24.45 μg/L, and 1.07–73.35 μg/L, respectively. The recovery was 85.19–110.25%, and the relative standard deviation of precision was ≤9.01%. When applied to a typical BPT sample, the method revealed a range of concentrations from below the quantitative limit (one compound only) to a maximum of 3.20 mg/freeze-dried g. This method will be used for quality control of BPT preparations. [ABSTRACT FROM AUTHOR]

A simple quality by design aided stability indicating method was developed for quantification of sonidegib (SONI) and its process related impurities using on ultra‐performance liquid chromatography in bulk drug substance. AutoChrom and Design‐Expert software were used to predict physicochemical properties, draw Ionization graphs, and generate analytical target profile. SONI was subjected to forced degradation conditions, such as oxidative, acid hydrolysis, base hydrolysis, hydrolytic, thermal, and photolytic hydrolysis. All degradation products and process contaminants were separated using an Acquity Ethylene Bridged Hybrid C18 column in gradient elution mode with a mobile phase containing 0.02 M ammonium acetate buffer and acetonitrile: methanol (80:20 v/v). The predicted physicochemical properties are accurate and they facilitated for selection of robust conditions in development of chromatographic method with minimal trials. The developed method can be used for quantification of drug and its process related impurities in bulk drugs. [ABSTRACT FROM AUTHOR]

Taxifolin is a natural polyphenol belonging to the class of flavonoids. The structure of this compound is characterized by the presence of two chiral centers. The spheroidal form of taxifolin (TAXs) has emerged as a promising modification due to enhanced solubility, higher safety profile, and long-term release from solid dosage forms. The study's objective was to assess the diastereomeric content in TAXs and industrially produced samples of taxifolin. Considering the difference in the physico-chemical properties of diastereomers and based on the literature data, we developed a qualitative HPLC method. The chromatograms were recorded using a diode array detector at 290 nm and a mass spectrometer operated in negative ionization mode. Our data suggest that a biphenyl column and gradient elution using 0.1% formic acid in water and 0.2% formic acid in methanol, with the organic phase gradient from 7% to 21% and a flow rate of 0.65 mL/min for 15 min at 60 °C, provides the best conditions for the separation of taxifolin diastereomers. This method was validated for quantitative analysis. We discovered that the cis-isomer was present in all the analyzed samples, with its quantity ranging from 0.8% to 9.5%. TAXs can be considered a sample enriched with diastereomers. [ABSTRACT FROM AUTHOR]

Bopyeo-tang (BPT) is composed of six medicinal herbs (Morus alba L., Rehmannia glutinosa (Gaertn.) DC., Panax ginseng C.A.Mey., Aster tataricus L.f., Astragalus propinquus Schischkin, and Schisandra chinensis (Turcz.) Baill.) and has been used for the treatment of lung diseases. This study focused on establishing an analytical method that can simultaneously quantify nine target compounds (i.e., hydroxymethylfurfural, mulberroside A, chlorogenic acid, calycosin-7-O-glucoside, 3,5-dicaffeoylquinic acid, quercetin, kaempferol, schizandrin, and gomisin A) from a BPT sample using high-performance liquid chromatography with a photodiode array detector (HPLC–PDA) and ultra-performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS). The separation of compounds in both analyses was performed on a C18 reversed-phase column using the gradient elution of water–acetonitrile as the mobile phase. In particular, the multiple reaction monitoring mode was applied for quick and accurate detection in UPLC–MS/MS analysis. As a result of analyzing the two methods, HPLC–PDA and UPLC–MS/MS, the coefficient of determination of the regression equation for each compound was ≥0.9952, and recovery was 85.99−106.40% (relative standard deviation (RSD) < 9.58%). Precision testing of the nine compounds was verified (RSD < 10.0%). The application of these analytical assays under optimized conditions for quantitative analysis of the BPT sample gave 0.01–4.70 mg/g. Therefore, these two assays could be used successfully to gather basic data for clinical research and the quality control of BPT. [ABSTRACT FROM AUTHOR]

Tofacitinib citrate (RR-isomer) is a janus kinase (JAK) inhibitor approved for the treatment of rheumatoid arthritis (RA) in adults who have had an inadequate response or intolerance to methotrexate. The presence of the enantiomer of tofacitinib citrate (SS-isomer) is monitored for quality control as a possible impurity in the final product. In this study, a reversed-phase high-performance liquid chromatography (RP-HPLC) method based on a chiral recognition mechanism for the separation of tofacitinib citrate and its enantiomer was established based on the principles of green analytical chemistry. A CHIRALPAK IH column was used with a mobile phase of ammonium acetate buffer (pH 8.0) and acetonitrile in a gradient elution at a detection wavelength of 285 nm. The calibration curve exhibited excellent linearity over the range of 0.1002–20.04 μg/mL (r = 0.9999). The average recovery of the enantiomer was 98.6% with a relative standard deviation (RSD) of 0.7%. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.04 and 0.1 μg/mL, respectively. This RP-HPLC method was suitable for detecting the enantiomers of tofacitinib citrate in tablets. Furthermore, the method proved to be environmentally friendly based on the evaluation by Analytical Eco-Scale, Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI). [ABSTRACT FROM AUTHOR]

Background The consumption of foods containing amphenicols, a type of antibiotic, is a major concern for human health. A stable and accurate detection method can provide technical support for food-safety monitoring. Objective An effective and efficient method was established for determining amphenicols in animal-derived foods through the simultaneous use of solid-phase extraction (SPE) cleanup and ultrahigh-performance liquid chromatography/mass spectrometry (UPLC-MS/MS). Method Samples were extracted using 1.0% ammoniated ethyl acetate solution, degreased with n -hexane, and then concentrated and cleaned using a C18 SPE column. Next, gradient elution was performed using methanol and 0.05% aqueous ammonia as the mobile phase, followed by separation using a C18 column. The target compound was detected using electrospray ionization, both in positive and negative modes, through multiple reaction monitoring, and quantified using an internal-standard method. Results The content of chloramphenicol (CAP), florfenicol (FF), and florfenicol amine (FFA) (content range: 0.2–8.0 µg/kg) as well as that of thiamphenicol (TAP; content range: 1.0–40.0 µg/kg) show a good linear relationship, with a correlation coefficient of r  >   0.999. Furthermore, recoveries of 86.7–111.9% and relative standard deviations of <9.0% were achieved. The limits of detection and quantification are obtained as 0.03–0.33 and 0.1–1.0 μg/kg, respectively. Conclusions The proposed method has excellent stability and accuracy, and can be successfully used for the qualitative and quantitative determination of amphenicols, i.e. CAP, TAP, FF, and FFA residues in 210 animal-derived food samples, of which FF and FFA were detected in four samples. Highlights A stable and accurate method was successfully established for the simultaneous determination of CAP, TAP, FF, and FFA in animal-derived foods using UPLC-MS/MS. Effective sample pretreatment was established, lipids were removed using n -hexane, concentration and cleanup were achieved with the C18 SPE column, and matrix effects were effectively reduced, thus improving the method's accuracy and stability. The method was validated for eight common animal-source foods, including beef, lamb, pork, chicken, egg, milk, fish, and honey. This method has good applicability for CAP, TAP, FF, and FFA in animal-derived foods. [ABSTRACT FROM AUTHOR]

Background There is an increasing interest in the use of a combination of trans -resveratrol and vitamin E in dietary supplements. Determination of the content of both components is essential for confirmation of the quality of the product. Objective To establish the applicability and ensure the greenness of the previously developed high-throughput HPLC/UV method for the simultaneous determination of trans -resveratrol and alpha-tocopherol acetate (vitamin E) in dietary supplements. Method Separation was performed on RP C8 Select B chromatographic column, using acetonitrile and water in the mobile phase, with gradient elution. Full method validation was performed in accordance with ICH Q2(R1). The greenness of the method was assessed using the analytical eco-scale (AES) methodology and the analytical greenness metric (AGREE). Results The method is selective, linear, precise, and accurate over defined concentration ranges (185–369 µg/mL of trans -resveratrol and 37–75 µg/mL of alpha-tocopherol acetate), and it has a suitable sensitivity (limits of detection and quantification are 7.7 and 23.3 µg/mL for resveratrol and 2.6 and 7.8 µg/mL for tocopherol acetate, respectively). The obtained analytical eco-scale score of 77 and the pale green AGREE pictogram with an overall score of 0.61 confirm the method's greenness. Conclusions The sensitivity and selectivity of the method, its short analysis time (7 min), the low negative environmental impact, and the simple sample preparation make the method readily applicable to inline quality control procedures. Highlights A method for simultaneously analyzing vitamin E and resveratrol in dietary supplements is presented. The method is rapid, includes a simple sample preparation procedure, and has a low environmental impact. [ABSTRACT FROM AUTHOR]

Antibiotics treat bacterial infections, whereas antiviral drugs treat viral illnesses. Antivirals are used to treat a variety of infectious diseases, including COVID-19 and influenza. The technique of reversed-phase high-performance liquid chromatography (RP-HPLC) provides more sensitivity and precision than other approaches, particularly spectrophotometric. This research seeks to develop a simple method for simultaneously quantifying acyclovir, amantadine, and oseltamivir in creams and capsules. The RP-HPLC method optimization and development for verifying the separation and quantification of three antiviral drugs included the investigation of the optimal buffer concentration, pH value, and acetonitrile content. On a C8 HyperClone BDS column, the RP-HPLC system with UV detection achieved separation (250 x 4.60 mm, 130A, and 5). The mixture of acetonitrile and acetate buffer as mobile phase gradient elution at a detection wavelength of 254 nm and 1 mL/min flow rate. The proposed method provided a linear range of 0.08-10.5, 0.06-4.5 and 0.02-14 μg/mL, as well as excellent validated values for LOD (0.0205, 0.0107, and 0.0083 μg/mL) and LOQ (0.0621, 0.0324 and 0.0251 μg/mL) with a coefficient of determination (r2) of the regression line of 0.9998, 0.9988, and 0.9994 for acyclovir, amantadine, and oseltamivir, respectively. [ABSTRACT FROM AUTHOR]

Sanguisorba officinalis L. possesses detoxifying, analgesic, and hemostatic properties. After charred processing, S. officinalis exhibits significantly enhanced medicinal effects. Currently, most pharmacokinetic studies focus on the chemical constituents of unprocessed S. officinalis. There is limited research on the comparison of chemical constituents before and after processing. This study established a pharmacokinetic method using ultra‐high‐performance liquid chromatography‐tandem mass spectroscopy (UHPLC‐MS/MS) to simultaneously determine the levels of four tannin compounds in rat plasma. In negative ion mode, MS/MS detection was performed using an electrospray ionization source. Chromatographic separation was performed using WATERS ACQUITY HSS T3 column (2.1 × 100 mm, 1.8 µm) with a gradient elution of water and acetonitrile as the mobile phase. The pharmacokinetic results indicate that all four compounds reached peak concentrations within 2 h, demonstrating rapid absorption into the bloodstream within the gastrointestinal tract. Notably, the absorption was generally faster in the charred compound of S. officinalis after processing. These four compounds exhibited slower elimination in rat plasma, while in S. officinalis charcoal, the compounds were eliminated more rapidly. The pharmacokinetic results have revealed the pharmacokinetic characteristics of the four analytes in rat plasma which provides valuable reference information for further investigating the in vivo absorption process of S. officinalis after processing. [ABSTRACT FROM AUTHOR]

Objectives] This study was conducted to explore the occurrence levels of endocrine disruptors ( EDCs) in rural areas around a county landfill in Tongren City. [Methods] The water around the landfill was sampled and analyzed. A solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry ( SPE-UPLC-MS/MS) method was established for the determination of 27 ED Cs. After the HLB solid-phase extraction column was activated, a water sample, which was adjusted with phosphoric acid to a pH of 2 ( ± 0. 5) and added with 500 mg of disodium EDTA, was loaded, and 5 ml of water and 20% methanol water was added for washing. Next, 10 ml of elution solution was added for elution, and the collected eluate was evaporated under reduced pressure at 40 oC to near dryness, and 10 ml of reconstitution solution was added to a constant volume. An ACQUITY UPLC BEH C18 (100 x2.1 mm, 2.6μm) chromatographic column was adopted for LC separation by gradient elution with pure water solution-acetonitrile as the mobile phase. For MS detection, the MRM mode was adopted for collection, and the positive and negative ion modes were switched for simultaneous determination, and the internal standard method was used for quantification. [Results] The correlation coefficient R2 was greater than 0. 99 in the linear range of each target substance. The limits of quantitation in the method were between 0.05 and 2.00 ng/L, and the recoveries ranged from 75.3% to 105. 7%. [Conclusions] The method has high sensitivity, good accuracy and strong practical value. [ABSTRACT FROM AUTHOR]

Oxidative stress degrades skin collagen and elastin and causes inflammatory reactions that affect mitochondrial DNA leading to aging. In the present study, a potential cosmetic nano-emulsion (o/w) of seven substances (chlorogenic acid, caffeine, rutin, hesperidin, quercetin, α-tocopherol and retinol) with antioxidant and anti-aging properties was prepared and analyzed. The lipophilic components were entrapped in the dispersed nanoparticles (jojoba) of the emulsion while the hydrophilic ones dissolved in the aqueous phase (glycerol/water). Suitable excipients were selected using an experimental design methodology with two mixtures and two responses (particle size and zeta potential). The quantitative extraction of chlorogenic acid and caffeine from Crithmum maritimum L. plant and coffee beans (Coffea arabica L.) and their stability were also studied. The analysis of the substances was carried out on an HPLC-DAD, with a phenyl column and gradient elution system (solvent A: water with 0.2% formic acid and B: acetonitrile with 0.2% formic acid). Validation of the method was performed in terms of linearity (r2 > 0.998), precision and repeatability (%RSD < 2) while the limits of detection (LLODs) and quantification (LLOQs) were also determined. The antioxidants were quantified after being extracted from the substrate (%recovery 96.7–102.5, %RSD < 2). [ABSTRACT FROM AUTHOR]

A new stability-indicating liquid chromatography method was developed for the quantification of empagliflozin and two synthetic impurities. The chromatographic conditions included Spherisorb® RP-18 column (150 × 4.6 mm, 5 μm) with a PDA detector, using acetonitrile and formic acid (pH 4.0) as mobile phase in gradient elution and flow-rate of 1.2 mL·min−1. The gradient increasing from 51 to 100% acetonitrile until 11.00 min, followed by decreasing the solvent from 100% to the initial ratio from 11.01 to 15.00 min. The method was validated according to International Council of Harmonization guidelines. The LOD and LOQ values for impurities A and B were 35 and 15 ng·mL−1, respectively, (for LOD) and 115 and 35 ng.mL−1, respectively (for LOQ). The method was linear in the range of 80–140, 115–1150 and 35–350 ng·mL−1 for EMPA, impurities A and B, respectively, and the correlation coefficient were > 0.999 in all situations, indicating the method good linearity. The developed method showed a good recovery for empagliflozin and added impurities. The method has proven to be precise, demonstrated values less than 2.0% to empagliflozin and 5.0% to synthetic impurities, robust and selective with no interference from other products in the determination of analytes. The in silico toxicity prediction suggested that the impurities do not present any toxicity risk for the parameters evaluated. [ABSTRACT FROM AUTHOR]

Metabolomics is a relatively novel omics tool to provide potential biomarkers for early diagnosis of the diseases and to insight the pathophysiology not having discussed ever before. In the present study, an ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was employed to the plasma samples of Group T1: Patients with ectopic pregnancy diagnosed using ultrasound, and followed-up with beta-hCG level (n = 40), Group T2: Patients with ectopic pregnancy diagnosed using ultrasound, underwent surgical treatment and confirmed using histopathology (n = 40), Group P: Healthy pregnant women (n = 40) in the first prenatal visit of pregnancy, Group C: Healthy volunteers (n = 40) scheduling a routine gynecological examination. Metabolite extraction was performed using 3 kDa pores - Amicon® Ultra 0.5 mL Centrifugal Filters. A gradient elution program (mobile phase composition was water and acetonitrile consisting of 0.1% formic acid) was applied using a C18 column (Agilent Zorbax 1.8 μM, 100 x 2.1 mm). Total analysis time was 25 min when the flow rate was 0.2 mL/min. The raw data was processed through XCMS – R program language edition where the optimum parameters detected using Isotopologue Parameter Optimization (IPO). The potential metabolites were identified using MetaboAnalyst 5.0 and finally 27 metabolites were evaluated to be proposed as potential biomarkers to be used for the diagnosis of ectopic pregnancy. [ABSTRACT FROM AUTHOR]

Fatty acid analysis is an essential step in evaluating the potential of macroalgae for biodiesel production. An extraction method was developed to simultaneously analyze up to five types of biodiesel-fuel-related fatty acids (myristic acid, palmitic acid, cis-palmitvaccenic acid, stearic acid, and oleic acid) in macroalgae using liquid chromatography and tandem mass spectrometry (LC–MS/MS). Lypophilization and solid-phase extraction (SPE) techniques were applied to improve the extraction efficiency and effectively purify samples. The optimal conditions for SPE were set by comparing the recoveries according to the various solvent conditions for each step (loading, washing, and elution). In addition, the introduction of trimethylaminoethyl (TMAE) derivatives to the hydroxyl group of the target analyte increased the ionization efficiency and sensitivity. The derivatized samples were analyzed using the LC–MS/MS method with electrospray ionization in the positive and multiple-reaction monitoring modes. The target analytes were separated and detected within 13.5 min using a CAPCELL PAK C18 MGII S3 column. Gradient elution was performed using distilled water and acetonitrile containing 5 mM ammonium acetate. This method offers a reliable and sensitive tool for the analysis of macroalgae samples for their potential use in biodiesel production. To the best of our knowledge, this is the first report on the simultaneous determination of fatty acids in macroalgae using LC–MS/MS with TMAE derivatization. [ABSTRACT FROM AUTHOR]

Objective: To establish a high-performance liquid chromatography–tandem mass spectrometry method (HPLC–MS/MS) to simultaneously determine colistin sulfate and tigecycline in human plasma. Methods: Polymyxin B1 internal standard (20 µL) was added into 200 µL of plasma sample. The samples were treated with methanol-5% trichloroacetic acid (50:50, V/V) solution, and the protein precipitation method was adopted for post-injection analysis. The chromatographic column was a Dikma C18 (4.6 mm × 150 mm, 5 μm). For the mobile phase, 0.1% formic acid in aqueous solution was used for phase A, 0.1% formic acid in acetonitrile solution for phase B, and gradient elution was also applied. The flow rate was 0.8 mL/min, the column temperature was 40 °C, and the injection volume was 10 µL; Electrospray ionization and multiple reaction ion monitoring were adopted and scanned by the HPLC–MS/MS positive ion mode. Results: The endogenous impurities in the plasma had no interference in the determination of the analytes. There existed a good linear relationship of colistin sulfate within the range of 0.1–10 µg/mL (R2 = 0.9986), with the lower limit of quantification (LLOQ) of 0.1 µg/mL. There existed a good linear relationship of tigecycline within the range of 0.05–5 µg/ mL (R2 = 0.9987), with the LLOQ of 0.05 µg/mL. The intra- and inter-day relative standard deviations of colistin sulfate and tigecycline were both less than 15%, and the accuracy was between 88.21% and 108.24%. The extraction had good stability, the extraction recovery rate was 87.75–91.22%, and the matrix effect was 99.40–105.26%. Conclusion: This study successfully established a method for simultaneously detecting colistin sulfate and tigecycline plasma concentrations. The method was simple, rapid, and highly sensitive and could be applied for therapeutic medication monitoring. [ABSTRACT FROM AUTHOR]

A green, efficient, sensitive and accurate detection method by HPLC–DAD and LC–MS/MS was developed and validated for the quantification of morphine, hydromorphone, oxycodone, ketamine tramadol, dezocine, ropivacaine, remifentanil, butorphanol, bupivacaine, droperidol, fentanyl, lornoxicam and sufentanil. The 14 mixtures were chromatographed via HPLC–DAD method which employed 0.05 mol/L potassium dihydrogen phosphate solution-acetonitrile as the mobile phase, the analytes were gradient elution on a SinoChrom ODS-BP C18 column with a total separation time of 35 min, and 14 mixtures showed a good linear relationship in the linear range. The Limit of Quantitation (LOQ) ranged from 0.10 to 20.0 µg/mL, the inter-day and intra-day precision of each analyte is within 1.1–2.0% and 0.4–1.3%, and the average absolute recovery of all compounds was above 98%. The LC–MS/MS method was used to successfully separate the 14 mixtures within 10 min which employed 0.1% formic acid-acetonitrile as the mobile phase, the analytes were gradient elution on a ACQUITY UPLC-BEH C18 column with a total separation time of 13 min, and 14 mixtures showed a good linear relationship in the linear range. The LOQ ranged from 0.005 to 0.2 ng/mL, the inter-day and intra-day precision of each analyte is within 1.2–4.1% and 0.6–3.3%, and the average absolute recovery of all compounds was above 93%. The proposed method has been successfully applied in the clinic and provides a strong technical basis for the quantitative detection of these 14 mixtures for detecting drug abuse, and for studying the stability and compatibility of analgesic solutions. The proposed methods were validated against ICH guidelines. [ABSTRACT FROM AUTHOR]

Isoflavone exhibits estrogen-like structure and activity and has various physiological and pharmacological functions, such as anticancer, antioxidant, and anti-inflammatory. In this study, several deep eutectic solvents (DESs) were synthesized and used as mobile phase additives to optimize the analytical conditions of five isoflavones. The DES composed of choline chloride:citric acid (molar ratio 1:1) was the most effective mobile phase additive with reduced peak tailing, improved peak shape, and increased number of theoretical plates. The effectiveness of the DES highlights its potential as a mobile phase additive. The optimal high-performance liquid chromatography (HPLC) conditions for the isoflavones were determined by the Intelligent HPLC simulator. The optimal conditions for gradient elution were water (A): acetonitrile (B) for 0 min, 25% B; 15 min, 25% B; 17 min, 35% B; and 50 min, 35% B. This approach provided excellent linearity (0.5 to 500 μg/mL, R2 ≥ 0.9991), limits of detection (0.024 to 0.109 μg/mL), limits of quantification (0.079 to 0.363 μg/mL), and precision (1.74 to 4.80%). [ABSTRACT FROM AUTHOR]

Firocoxib is a nonsteroidal anti-inflammatory drug. It provides control of postoperative pain and inflammation associated with soft tissue and orthopedic surgery in dogs, and control of pain and inflammation associated with osteoarthritis in horses. A high-speed stability-indicating reversed-phase high-performance liquid chromatography method was developed to determine firocoxib and its related substances in bulk batches of firocoxib drug substance. Firocoxib was dissolved in neat acetonitrile (ACN) and analyzed on a short HALO (fused-core) biphenyl column (30 × 4.6 mm i.d. 2.7-μm particle size) at flow rate of 2.5 mL/min. Column temperature was maintained at 50°C. Mobile phase A is composed of 0.1% of H3PO4 in water and mobile phase B is composed of ACN. Analytes were detected with UV detection at 240 nm and quantitated against an external reference standard. Firocoxib and its related compounds were adequately separated within 4 min by a gradient elution. The method was validated for specificity, linearity, accuracy, precision and robustness according to method validation guidelines described in The International Conference on Harmonization. The validation data demonstrated that this method is sensitive, accurate, robust, specific and stability-indicating. [ABSTRACT FROM AUTHOR]

This study presents an efficient method for the sequential separation of lanthanides and uranium using a high-performance ion exchange chromatographic column. The used SCX column provides both electrostatic and hydrophobic interactions for the retention and separation of lanthanides and uranyl. Dual gradient elution (pH and α-hydroxyisobutyric acid concentration) enables continuous elution of uranyl before and after the elution of all the lanthanides. The proposed single-column separation protocol was validated by the effective separation of simulated spent nuclear fuel, which can be used to measure burn-up rates. [ABSTRACT FROM AUTHOR]

This article, published in Chemistry of Natural Compounds, explores the chemical constituents of Aralia echinocaulis, a plant commonly used in traditional Chinese medicine. The study identifies 14 compounds, 12 of which are reported for the first time from this plant. The structures of these compounds are determined through extensive 1D NMR analysis and comparison with references. The article provides detailed information about the chemical composition of Aralia echinocaulis and its potential applications in medicine. The document can be valuable for researchers studying these compounds and their potential uses. The authors acknowledge the support of the National Natural Science Foundation of China. [Extracted from the article]

This study introduces an advanced analytical method for quality control of botanical drugs, focusing on Hwang-ryeon-hae-dok-tang (HRHDT), a traditional herbal prescription utilized for inflammation, gastritis, fever, and hypertension. Botanical drugs pose a challenge due to their complex composition, requiring reliable and robust analytical techniques. Our step-by-step procedure included defining the analytical target profile, risk assessment, screening and optimizing design of experiment, measuring the design space, and Monte Carlo simulation. The established HPLC-PDA method enables the simultaneous analysis of four major compounds (geniposide, baicalin, palmatine, and berberine) present in HRHDT. The optimized conditions involve a gradient elution with acetonitrile and water, both containing 0.1% trifluoroacetic acid, a 32 °C column temperature, 254 nm detection wavelength, and 1.0 mL/min flow rate. A successful validation demonstrated excellent linearity (R°: 0.9984-0.9989) and accuracy (recovery: 100.61%-102.44%), with precise repeatability and intermediate precision (%RSD: 0.39%-0.83%). These results further confirm the reliability and accuracy of the analytical method. Overall, our design-based approach not only facilitated the development of robust analytical methods but also allowed for flexible operation ranges. Therefore, this methodology holds significant potential for ensuring the quality of botanical drug products within the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

A novel leucine carbamate prodrug (3-L) has been synthesized to improve the low oral bioavailability of cycloicaritin. To assess the pharmacokinetic properties of the prodrug, a selective, sensitive and reliable liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for the simultaneous determination of cycloicaritin and its carbamate prodrug 3-L in rat plasma with daidzein as internal standard was developed and validated. Ethanoic acid was added to plasma samples to maintain the stability of the prodrug. The samples were prepared employing a liquid–liquid extraction (LLE) method using tert-butyl methyl ether in a low plasma sample volume of 25 μL, and then separated on an ACE Excel 2 C18-Amide column (50 mm × 2.1 mm, 2 μm) by gradient elution at a flow rate of 0.4 mL min−1. A triple quadrupole tandem mass spectrometer system with a positive ESI interface was used for quantification in multiple reaction monitoring (MRM) mode. Cycloicaritin and 3-L both showed excellent linearity over the concentration range of 1–2000 ng mL−1 (r ≥ 0.995), with a lower limit of quantification of 1 ng mL−1. The accuracy varied from −5.2% to 14% for all analytes, and the intra- and inter-day precision was less than 14% across quality control levels. The method described herein was successfully applied to the pharmacokinetic study of orally administered 3-L in rats. [ABSTRACT FROM AUTHOR]

An approach to the determination of five sesquimustard markers, namely, bis(2-hydroxyethylthio)methane (BHETM), 1,2-bis(2-hydroxyethylthio)ethane (BHETE), 1,3-bis(2-hydroxyethylthio)-n-propane (BHETPr), 1,4-bis(2-hydroxyethylthio)-n-butane (BHETB), and 1,5-bis(2-hydroxyethylthio)-n-pentane (BHETPe) in environmental water using high-performance liquid chromatography with high-resolution mass spectrometry was developed for the first time. These substances are produced in aqueous media during hydrolysis of sulfur sesquimustards (bis(2-chloroethylthio)alkanes, n = 1–5). In this study, the conditions of mass spectrometric detection (optimal transitions for multiple reaction monitoring) and the gradient elution program for the HPLC separation of the analytes were optimized. The proposed technique was tested with water samples, and it showed good accuracy, precision, and selectivity. Accuracy was estimated by comparing the calculated concentration and the actual concentration entered into the sample. The absence of interfering influence of water sample components was also indicated. Limits of detection of BHETM, BHETE, BHETPr, BHETB, and BHETPe by using the proposed HPLC–MS/MS approach were 50, 5, 2, 2, and 0.5 ng/mL, respectively. [ABSTRACT FROM AUTHOR]

We characterized thermally polymerized organo‐silica hybrid monolithic capillaries to test their applicability in the gradient elution of peptides. We have used a single‐pot approach utilizing 3‐(methacryloyloxy)propyltrimethoxysilane (MPTMS), ethylene dimethacrylate (EDMA), and n‐octadecyl methacrylate (ODM) as functional monomers. The organo‐silica monolith containing MPTMS and EDMA was compared with the stationary phase prepared by adding ODM to the original polymerization mixture. Column prepared using a three‐monomer system provided a lower accessible volume of flow‐through pores, a higher proportion of mesopores, and higher efficiency. We utilized isocratic and gradient elution data to predict peak widths in gradient elution. Both protocols provided comparable results and can be used for peptide peak width prediction. However, applying gradient elution data for peak width prediction seems simpler. Finally, we tested the effect of gradient time on achievable peak capacity in the gradient elution of peptides with a column prepared with a three‐monomer system providing a higher peak capacity. However, the performance of hybrid organo‐silica monolithic stationary phases in gradient elution of peptides must be improved compared to other monolithic stationary phases. The limiting factor is column efficiency in highly aqueous mobile phases, which needs to be focused on. [ABSTRACT FROM AUTHOR]