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The synthesis of 2,3,4,5,10,11-hexahydro-1H-diben- zo[b,e][1,4]diazepin-1-ones was revisited and a catalyst-free method was established, by exploring the reactivity of 3-[(2-aminoaryl)amino]dimedones towards carbonylated electrophiles. 2D NMR and single-crystal X-ray diffraction studies were used to characterize the structures unequivocally and to review the mechanism leading to the formation of supposed positional isomers. The action of 3-[(2-aminoaryl)amino]di- medones on chromene-3-carboxylic acid, fumaryl, and oxalyl chloride has led to dibenzo[b,e][1,4]diazepin-1-one ring opening to produce novel Z-configured enaminone and linear diamides. [ABSTRACT FROM AUTHOR]

Rhodiola rosea L. extracts have shown neuroprotective, anti-fatigue, anti-inflammatory and anti-tumor properties. However, the studies on their effect on T cell function are rather scarce. We examined the potential of R. rosea extract and its major constituents – salidroside, rosarin, rosavin and rosin to alter cell growth of human Jurkat T cells, apoptosis of splenic mouse CD3 T cells and expression of the surface markers and phosphorylation of extracellular signal-regulated kinase (ERK). The initial screening for cell viability in Jurkat T cells and for apoptosis of mouse T cells showed the strongest activity for rosavin and rosarin. Rosarin and rosavin did not alter significantly the dynamic of CD69 expression upon stimulation, but altered TNF-related apoptosis-inducing ligand (TRAIL) expression. Rosavin inhibited TRAIL up-regulation, while rosarin showed an opposite effect. Indeed, rosarin increased the frequencies of CD3 + TRAIL + T cells and the fold inhibition of ERK phosphorylation. Our data showed that different effects of rosarin and rosavin on TRAIL expression can involve distinct action on ERK signaling and hence highlighted their potential to manipulate TRAIL as a tool to rescue the resistance to apoptosis in autoimmune diseases and cancer. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) is one of the most widely used analytical techniques in numerous domains where molecules are objects of investigation. However, major limitations of multidimensional NMR experiments come from their low sensitivity and from the long times needed for their acquisition. In order to overcome such limitations, fast repetition NMR techniques allowed for the reduction of 2D experimental time and for the conversion of the gained time into a higher number of scans leading to a better sensitivity. Thus, fast repetition 2D heteronuclear NMR techniques have allowed new advances in NMR, especially to access infomation on low abundant nuclei, to enhance the detection of low concentrated compounds and to probe weak interactions like hydrogen bonds at natural abundance. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bioassay guided fractionation of the cytotoxic extract of the plant Cuscuta reflexa, employing cytotoxic assay against a panel of 60 cell lines, led to the isolation of 13 compounds identified as odoroside H ( 1), 21-hydroxyodoroside H ( 2), neritaloside ( 3), strospeside ( 4), 16- β-hydroxydigitoxin ( 5), N-trans and cis feruloyl tyramines ( 6 and 7), ethyl caffeate ( 8), coumarins ( 9 and 10), ursolic acid ( 11), β-sitosterol glucoside ( 12), and 4-O-p-coumaroyl- β-D-glucoside ( 13). Compound 2 was found to be a new natural product while 1, 3, 4, 5, 6, 7, 10, and 11 are known compounds isolated from this source for the first time. Compounds 1, 3, and 4 possessed very good cytotoxic activity against renal and prostate cancer cell lines. Of these compounds, 1 showed a positive hollow fiber test and was selected for in vivo xenograft testing. The structures of compounds 1-5 have been established through chemical and spectral studies including UV, IR, mass, NMR (H and C), and 2D NMR (COSY-45°, NOESY, HMQC, HMBC, and J-resolved) experiments. [ABSTRACT FROM AUTHOR]

Bio-refinery processes require use of the most suitable lignocellulosic biomass for enzymatic saccharification and microbial fermentation. Glucose yield from biomass solid fractions obtained after dilute sulfuric acid (1%) pretreatment (at 180 °C) was investigated using 14, 8, and 16 varieties of rice, wheat, and sorghum, respectively. Biomass solid fractions of each crop showed similar cellulose content. However, glucose yield after enzymatic hydrolysis (cellulase loading at 6.6 filter paper unit/g-biomass) was different among the varieties of each crop, indicating genotypic differences for rice, wheat, and sorghum. Nuclear magnetic resonance method revealed that the high residual level of lignin aromatic regions decreased glucose yield from solid fraction of sorghum. [ABSTRACT FROM PUBLISHER]

The present state of the routine 2D COSY- and HSQC-NMR spectroscopy is reported. After a short introduction into the basic theory of 2D NMR the pulse sequences of COSY and HSQC are explained. Using an example from natural product chemistry the procedures during the analysis of these 2D NMR spectra are demonstrated. [ABSTRACT FROM AUTHOR]

A primary goal of metabolomics is the characterization of a potentially very large number of metabolites that are part of complex mixtures. Application to biofluids and tissue samples offers insights into biochemical metabolic pathways and their role in health and disease. 1D 1H and 2D 13C-1H HSQC NMR spectra are most commonly used for this purpose. They yield quantitative information about each proton of the mixture, but do not tell which protons belong to the same molecule. Interpretation requires the use of NMR spectral databases, which naturally limits these investigations to known metabolites. Here, a new method is presented that uses complementary ion exchange resin beads to differentially attenuate 2D NMR cross-peaks that belong to different metabolites. Based on their characteristic attenuation patterns, cross-peaks could be clustered and assigned to individual molecules, including unknown metabolites with multiple spin systems, as demonstrated for a metabolite model mixture and E. coli cell lysate. [ABSTRACT FROM AUTHOR]

Phytochemical investigations of the roots of Spergularia marginata had led to the isolation of four previously undescribed triterpenoid saponins, a known one and one spinasterol glycoside. Their structures were established by extensive NMR and mass spectroscopic techniques as 3- O -β-D-glucuronopyranosyl echinocystic acid 28- O -α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L- arabinopyranosyl ester, 3- O -β-D-glucopyranosyl-(1 → 3)-β-D-glucuronopyranosyl echinocystic acid 28- O -α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)- α-L-arabinopyranosyl ester, 3- O -β-D-glucopyranosyl-(1 → 4)-3- O -sulfate-β-D-glucuronopyranosyl echinocystic acid 28- O -α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl ester, and 3- O -β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl 21- O -acetyl acacic acid. Their cytotoxicity was evaluated against two human cancer cell lines SW480 and MCF-7. The most active compound showed a cytotoxicity with IC 50 14.2 ± 0.8 μ M (SW480), and 18.7 ± 0.8 μ M (MCF-7), respectively. [ABSTRACT FROM AUTHOR]

Exploration of new and promising anticancer compounds continues to be one of the main tasks of cancer research because of the drug resistance, high cytotoxicity and limitations of tumor selectivity. Natural products represent a better choice for cancer treatment in comparison with synthetic compounds because of their pharmacokinetic properties and lower side effects. In the current study, we isolated a steroidal saponin, named Cepa2, from the dry roots of shallot ( Allium cepa L. Aggregatum group), and determined its structure by using two-dimensional nuclear manganic resonance (2D NMR). The 1 H NMR and 13 C NMR data revealed that the newly isolated Cepa2 compound is identical to alliospiroside A (C 38 H 60 O 12 ) [(25S)-3 β -hydroxyspirost-5-en-1 β -yl-2-O-(6-deoxy- α -L-mannopyranosyl)- α -L-arabinopyranoside], whose anticancer activity remains elusive. Our in vitro examination of the cytotoxic activity of the identified Cepa2 against P3U1 myeloma cancer cell line showed its high efficiency as an anticancer with 91.13% reduction in P3U1 cell viability 12 h post-treatment. The reduction of cell viability was correlated with the increase in reactive oxygen species levels in Cepa2-treated P3U1 cells, as compared with untreated cells. Moreover, scanning electron microscope results demonstrated apoptosis of the Cepa2-treated P3U1 cells in a time course-dependent manner. The results of our study provide evidence for the anticancer properties of the natural Cepa2/alliospiroside A extracted from shallot plants, and a strong foundation for in-depth investigations to build theoretical bases for cell apoptosis and development of novel anticancer drugs. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to identify molecular alterations in the human blood serum related to bipolar disorder, using nuclear magnetic resonance (NMR) spectroscopy and chemometrics. Methods: Metabolomic profiling, employing H-NMR, H-NMR T-edited, and 2D-NMR spectroscopy and chemometrics of human blood serum samples from patients with bipolar disorder ( n = 26) compared with healthy volunteers ( n = 50) was performed. Results: The investigated groups presented distinct metabolic profiles, in which the main differential metabolites found in the serum sample of bipolar disorder patients compared with those from controls were lipids, lipid metabolism-related molecules (choline, myo-inositol), and some amino acids ( N-acetyl- l-phenyl alanine, N-acetyl- l-aspartyl- l-glutamic acid, l-glutamine). In addition, amygdalin, α-ketoglutaric acid, and lipoamide, among other compounds, were also present or were significantly altered in the serum of bipolar disorder patients. The data presented herein suggest that some of these metabolites differentially distributed between the groups studied may be directly related to the bipolar disorder pathophysiology. Conclusions: The strategy employed here showed significant potential for exploring pathophysiological features and molecular pathways involved in bipolar disorder. Thus, our findings may contribute to pave the way for future studies aiming at identifying important potential biomarkers for bipolar disorder diagnosis or progression follow-up. [ABSTRACT FROM AUTHOR]

Hesperidin is flavonoid molecule found in citrus fruits ( Citrus reticulata), especially difficult to extract, classify and characterize. Present work is to study the unresolved relative configuration of Hesperidin through the dihedral angle, coupling constant and different NMR techniques. The Karplus equation and its modifications have been originated from the valence bond theory and associated with dihedral angle and coupling constant. The result data set of calculated dihedral angle can probe significant method to assign the virtual configuration of natural products and also resolved stereochemistry of Hesperidin at C-2 position in. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We propose a 13 C detected experiment, the (H)CNMQC pulse sequence for measuring one-bond and long-range 15 N 13 C scalar coupling constants in small organic molecules at the natural isotopic abundance. The previously proposed 1 H detected H(C)NMBC experiment performs poorly in situations where the carbon atom of interest has no attached protons, in the presence of splittings due to the homonuclear H H couplings, unwanted coherence leaks and considerable t 1 -noise. These problems are largely avoided in the (H)CNMQC experiment based on direct 13 C detection. In many cases the new experiment improves the measurement sensitivity and accuracy, not least because the 15 N 13 C couplings are measured in the directly detected dimension enabling one-dimensional measurements. [ABSTRACT FROM AUTHOR]

We present here the application of one-dimensional and two-dimensional NMR techniques to characterize the structure of methoxyl end-functionalized polystyrenes (PS). The peaks in H-NMR spectra corresponding to main-chain, side-chain and chain-end groups are assigned by H-H gCOSY, H-C gHSQC and gHMBC spectra. For the first time, the spin-lattice relaxation time ( T ) of protons of the chain-ends is revealed to be affected more by polymer molecular weight (MW) than by the protons of the main-chains and the side-chains (almost independent from MW). As a result, a much higher delay time ( d1) for chain-ends ( d1 > 20 T ) is needed for quantitative NMR measurement when using end-group estimation method to obtain the MW of PS, which is in accordance with the value estimated by GPC. An improved method for the polymer MW determination is established, by combination of different NMR techniques to distinguish the peaks, and a large d1 setting to achieve quantitative NMR analysis. [ABSTRACT FROM AUTHOR]

The structure of a novel compound from Adansonia digitata has been elucidated, and its 1H and 13C NMR spectra have been assigned employing a variety of one-dimensional and two-dimensional NMR techniques without degradative chemistry. The Advanced Chemistry Development ACD/Structure Elucidator software was important for determining part of this structure that contained a fused bicyclic system with very few hydrogen atoms, which in turn, exhibited essentially no discriminating HMBC connectivities throughout that portion of the molecule. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Some novel chemically modified frameworks of ursolic acid have been designed and synthesized. The key step was the cycloaddition of azidopropyl-3β-hydroxy-urs-12-en-28-oate with the appropriate C28 propargyl esters of ursolic, corosolic, asiatic, oleanolic, and betulinic acid under Click reaction conditions, and the products were obtained in 74–84% yields. In view of their intriguing structural diversity, they have been subjected to detailed 1D and 2D NMR studies and their structures are thoroughly assigned. The synthesized compounds were screened for their anticancer potential against two human breast cancer cell lines (MCF-7 & MDA-MB-231) using sulforhodamine B cell proliferation assay. The GI50data revealed that the synthesized compounds exhibit highly potent activities against the two tested cell lines. Interestingly, the synthesized compounds showed selectivity and higher activity against MDA-MB-231 cell line than MCF-7. Among the tested compounds, compound17is the most potent one with GI50value of 1.4 ± 0.1 μM and showed 2.9 times more activity than the standard doxorubicin against MDA-MB-231. In addition,17arrests cells in mitotic phase of cell cycle, resulting in a change in cell phenotype. In view of the selective and highly promising activity against breast cancer cell lines, these compounds can serve as promising leads for further development. [ABSTRACT FROM PUBLISHER]

We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track ( TinT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered. TinT was applied successfully to several protein systems during a temperature ramp in isotope exchange experiments. A comparison with a state-of-the-art algorithm showed promising results for great numbers of spectra and low signal to noise ratios, when the graduality of the perturbation is appropriate. TinT can be applied to different kinds of high throughput chemical shift mapping experiments, with quasi-continuous variations, in which a quantitative automated recognition is crucial. [ABSTRACT FROM AUTHOR]

• Accurate characterization of pore structure of different coal ranks using 2D NMR. • Characterize the pore throat characteristics of different coal ranks. • Analyze T 1 -T 2 spectra and 3D peak map to obtain the development of coal pores. In order to accurately characterize the porosity and pore throat structure of different coal grades under liquid nitrogen fracturing cycles, this paper tests the T 2 and T 1 -T 2 sequences of different grades of coal samples (lignite, bituminous coal and anthracite) before and after the fracturing cycles. The results show that the total pore space of A, L and B is arranged in descending order according to the initial state. The internal porous throat distribution of lignite and anthracite coal samples is wider. With the increase of the number of fracturing cycles, the internal pore space of the three coal grade coal samples has been improved, of which lignite has the largest lifting rate; The internal porous throat distribution of L coal samples was reduced by 0.97%. The internal pore space of B and A coal samples increased by 34.62% and 6.33%, respectively, the pore-throat distribution increased by 28.96% and 16.98%, respectively. [ABSTRACT FROM AUTHOR]

• Steroidal-chromium carbonyl complexes have been shown to keep a significant affinity for the estradiol receptor. • Use of techniques newly available in the early 1980s, such as 2D NMR and Fourier transform IR, to characterize bioorganometallic molecules and to use them as non-radioactive tracers for detection of estradiol receptors in breast cancer cells. • Carbonyl Metallo-Immuno Assay (CMIA) is a non-isotopic immunoassay that allows the simultaneous multi-assay of three antiepileptic drugs (carbamazepin, phenobarbital and diphenylhydantoin). Bioorganometallic chemistry is now a maturing field attracting researchers around the world, and also across the Periodic Table. It has found applications in a broad range of areas such as drug discovery, biocatalysis and imaging. We review here the first experiments carried out in the early 1980′s at the Ecole Nationale Supérieure de Chimie de Paris under the leadership of Gérard Jaouen, a key figure and visionary in the development of this theme. However, they also required important contributions from Canadian collaborators with expertise in NMR and IR spectroscopy, together with the availability of more powerful and versatile instrumentation. This collaboration found its fulfillment in the demonstration of the use of metal carbonyl complexes (exemplified by an estradiol derivative labeled by a Cr(CO) 3 unit) as non-isotopic tracers allowing the detection of estradiol receptors, an essential marker for setting up a targeted therapy for breast cancer. This approach was based on the premise that the intense metal carbonyl stretching vibrations are found in a window (2100–1850 cm−1) where the protein itself does not absorb. The field was extended to the arena of non-isotopic immunoassays, including the simultaneous detection of multiple antiepileptic drugs bearing metal carbonyl labels. More recently, taking advantage of the new technique of atomic force microscopy-infrared spectroscopy (AFM-IR) it has been possible to accomplish direct tracing of these complexes in cells. The contributions of the original group of workers in the field are highlighted, and placed in the perspective of today's subsequent emphasis on the management of previously untreatable cancers. [Display omitted] [ABSTRACT FROM AUTHOR]

New isolates of Streptomyces champavatii were isolated from marine sediments of the Gotland Deep (Baltic Sea), from the Urania Basin (Eastern Mediterranean), and from the Kiel Bight (Baltic Sea). The isolates produced several oligopeptidic secondary metabolites, including the new octapeptide champacyclin (1a) present in all three strains. Herein, we report on the isolation, structure elucidation and determination of the absolute stereochemistry of this isoleucine/leucine (Ile/Leu = Xle) rich cyclic octapeptide champacyclin (1a). As 2D nuclear magnetic resonance (NMR) spectroscopy could not fully resolve the structure of (1a), additional information on sequence and configuration of stereocenters were obtained by a combination of multi stage mass spectrometry (MSn) studies, amino acid analysis, partial hydrolysis and subsequent enantiomer analytics with gas chromatography positive chmical ionization/electron impact mass spectrometry (GC-PCI/EI-MS) supported by comparison to reference dipeptides. Proof of the head-to-tail cyclization of (1a) was accomplished by solid phase peptide synthesis (SPPS) compared to an alternatively side chain cyclized derivative (2). Champacyclin (1a) is likely synthesized by a non-ribosomal peptide synthetase (NRPS), because of its high content of (d)-amino acids. The compound (1a) showed antimicrobial activity against the phytopathogen Erwinia amylovora causing the fire blight disease of certain plants.

Chemical analysis of the organic extract of Theonella swinhoei yielded two new tridecadepsipeptides of the theonellapeptolide family, namely sulfinyltheonellapeptolide, characterized by a methylsulfinylacetyl group at the N-terminus, and theonellapeptolide If, the first member of this class of compounds to show four valine residues. The structures of the compounds, isolated along with the known theonellapeptolide Id, were determined by extensive 2D NMR and MS/MS analyses followed by application of Marfey’s method. The isolated peptides exhibited moderate antiproliferative activity against HepG2 cells, a hepatic carcinoma cell line.

A structural study of epoxidized natural rubber (ENR-50) and its cyclic dithiocarbonate derivative was carried out using NMR spectroscopy techniques. The overlapping 1H-NMR signals of ENR-50 at δ 1.56, 1.68–1.70, 2.06, 2.15–2.17 ppm were successfully assigned. In this work, the 13C-NMR chemical shift assignments of ENR-50 were consistent to the previously reported work. A cyclic dithiocarbonate derivative of ENR-50 was synthesized from the reaction of purified ENR-50 with carbon disulfide (CS2), in the presence of 4-dimethylaminopyridine (DMAP) as catalyst at reflux temperature. The cyclic dithiocarbonate formation involved the epoxide ring opening of the ENR-50. This was followed by insertion of the C–S moiety of CS2 at the oxygen attached to the quaternary carbon and methine carbon of epoxidized isoprene unit, respectively. The bands due to the C=S and C–O were clearly observed in the FTIR spectrum while the 1H-NMR spectrum of the derivative revealed the peak attributed to the methylene protons had split. The 13C-NMR spectrum of the derivative further indicates two new carbon peaks arising from the >C=S and quaternary carbon of cyclic dithiocarbonate. All other 1H- and 13C-NMR chemical shifts of the derivative remain unchanged with respect to the ENR-50.

The 7-C60-adduct of N,N-(tetrachlorophthaloyl)dehydroabietylamine was synthesized for the first time and characterized by IR, UV-vis, mass and NMR spectral studies. The 1H-NMR and 13C-NMR resonance signals of the new compound are unambiguously assigned by using homo- and heteronuclear 2D NMR spectroscopic techniques such as COSY, ROESY, HSQC and HMBC. The C1 symmetric structure with 6,6-junction of compound was determined.

Galanthamine, an acetylcholinesterase inhibitor marketed as a hydrobromide salt (Razadyne®, Reminyl®) for the treatment of Alzheimer’s disease (AD), is obtained from Amaryllidaceae plants, especially those belonging to the genera Leucojum, Narcissus, Lycoris and Ungernia. The growing demand for galanthamine has prompted searches for new sources of this compound, as well as other bioactive alkaloids for the treatment of AD. In this paper we report the isolation of the new alkaloid 11β-hydroxygalanthamine, an epimer of the previously isolated alkaloid habranthine, which was identified using NMR techniques. It has been shown that 11β-hydroxygalanthamine has an important in vitro acetylcholinesterase inhibitory activity. Additionally, Hippeastrum papilio yielded substantial quantities of galanthamine.

From the seeds of white currant (Ribes rubrum, cv. White Champagne), a new sesquiterpenoid glucoside (1) was isolated, along with two known compounds: dihydrophaseic acid 3’-O-β-Dglucopyranoside (2), and 3-carboxymethyl-indole-1-N-β-Dglucopyranoside (3). The structure of the new compound was identified as dihydrophaseic acid 3’-O-β-D-glucopyranosyl-1,6-β-D-glucopyranoside, based on extensive NMR and MS spectral studies.

Twenty compounds were isolated from the aerial parts of Salvia willeana (Holmboe) Hedge, growing wild in Cyprus. These compounds comprise one new and one known acetophenone, one megastigmane glucoside, five phenolic derivatives, two caffeic acid oligomers, three flavonoids, two lignans, two triterpene acids, one monoterpene glucoside, and two fatty acids. The structures of the isolated compounds were established by means of NMR [(Rotating-frame OverhauserEffect SpectroscopY) (1H-1H-COSY (COrrelation SpectroscopΥ), 1H-13C-HSQC (Heteronuclear Single Quantum Correlation), HMBC (Heteronuclear Multiple Bond Correlation), NOESY (Nuclear Overhauser Effect SpectroscopY), ROESY (Rotating-frame Overhauser Effect SpectroscopY)] and MS spectral analyses. This is the first report of the natural occurrence of 4-hydroxy-acetophenone 4-O-(3,5-dimethoxy-4-hydroxybenzoyl)-β-d-glucopyranoside. A chemical review on the non-volatile secondary metabolites has been carried out. Based on the literature data, the analysis revealed that the chemical profile of S. willeana is close to that of S. officinalis L.

• A new joint experiment is designed for petrophysical evaluation in shale. • Dissolved methanol can be used to identify hydrogen components in shale. • 1D/2D translational diffusion model is introduced for theoretical analysis of shale NMR mechanism. • A comprehensive interpretation scheme of shale is established based on T 1 / T 2 - T 2 map. • Wettability and mobility characteristics of shale are provided through interpretation scheme. Shale oil is one of the important unconventional fossil fuels resources. Understanding the petrophysical properties of shale contributes to the exploration and clean production of shale oil resources. 1H nuclear magnetic resonance (NMR) is a potential technique that can provide for shale petrophysical properties. However, current NMR-based technique for shale petrophysical characterization, due to the complexity of shale, usually requires some auxiliary geochemical experiments. Since a multi-step solvent extraction (MSSE) experiment has a merit in separating hydrocarbons and water in shale, in this work, two-dimensional (2D) NMR measurements combined with MSSE experiments were proposed for the first time to study the petrophysical properties of shale. A mixture of dichloromethane and methanol in a ration of 9:1 was prepared as a solvent for the extraction. Sufficient natural air-drying time allows for the removal of dichloromethane while retaining methanol. The comprehensive experiments show that the signal change induced by residual methanol from T 1 / T 2 - T 2 map, before and after extraction and natural air-drying, can be used to identify pore-fluid and evaluate the mobility of hydrocarbon. For insight into the essence of experimental phenomena, quasi-1D/2D translational diffusion model were employed to analyze the T 1 / T 2 and T 2 responses of pore fluids. Wettability characteristics and detailed hydrocarbon mobility of shale were obtained from the theoretical analyses based on the translational diffusion models and T 1 / T 2 - T 2 map. Combined the experimental results with the theoretical analysis, a comprehensive interpretation scheme was established for shale based on the T 1 / T 2 - T 2 map, including fluid identification, wettability evaluation, and hydrocarbon mobility characterization. [ABSTRACT FROM AUTHOR]

Wild marigold (Tagetes minuta), a flowering plant of the family Asteraceae contains compounds of pharmaceutical and nutritional importance especially essential oils and flavonols. Identification, characterization of flavonols and determination of their antibacterial activity were major objectives of the current study. The isolation and purification of flavonols was accomplished using chromatographic techniques while structural elucidation was completed by LC-MS and NMR spectroscopy. The extracts and purified compounds were tested against various bacterial strains for antibacterial activity. A total of nineteen flavonols were isolated from this species. Of these, seventeen were of butanol and two of ethyl acetate extracts. Based on the concentration and purity, eight potential flavonols were selected and structurally elucidated. Four flavonols, 6-hydroxyquercetin 7-O-β-(6''-galloylglucopyranoside) (2), 6-hydroxykaempferol 7-O-β-glucopyranoside (5), 6-hydroxykaempferol 7-O-β-(6''-galloylglucopyranoside) (7), 6-hydroxyquercetin 7-O-β-(6''-caffeoylglucopyranoside) (9), were identified for the first time from T. minuta. Butanol and ethyl acetate extracts of flowers and seeds showed significant antibacterial activity against Micrococcus leteus, Staphylococcus aureus, Bacillus subtilis and Pseudomonas piket. Among the isolated flavonols only 1, 2 and 18 were found to possess significant antibacterial activity against M. luteus. The extracts and purified flavonols from T. minuta can be potential candidates for antibacterial drug discovery and support to ethnopharmacological use.

The article discusses a study related to structure elucidation of cycloartane triterpene glycoside from Souliea vaginata by using the nuclear magnetic resonance (NMR) technology. It mentions role of Souliea vaginata as Chinese folk medicine that is used for treatment of conjunctivitis, pharyngitis and enteritis. It also mentions that the isolated compound gave positive Liebermann–Burchard reaction.

NMR spectroscopy with compact instruments opens new perspectives for the use of NMR. While the field strength of compact instruments is low, they potentially match today's high-field instruments in methodical diversity, although by default they are operated in non-expert mode with a mouse click. Because size and price are low, they open new opportunities for the use of NMR spectroscopy. One is product and quality control and another is real-time reaction monitoring in the academic and industrial research laboratory on the workbench by observing nuclei such as 1 H, 13 C, 31 P, 19 F, 7 Li and 11 B. With compact NMR spectrometers, not only standard one-dimensional experiments can be executed to retrieve chemical information but also the two-dimensional experiments such as HSQC, HMBC, HETCOR and COSY. The state of the art and progress in compact NMR spectroscopy is reviewed concerning 1D and 2D spectroscopy along with their use in product control and reaction monitoring. [ABSTRACT FROM AUTHOR]

Agricultural by-products such as wheat straw are attractive feedstocks for the production of second-generation bioethanol due to their high abundance. However, the presence of lignin in these lignocellulosic materials hinders the enzymatic hydrolysis of cellulose. The purposes of this work are to study the ability of a laccase-mediator system to remove lignin improving saccharification, as a pretreatment of wheat straw, and to analyze the chemical modifications produced in the remaining lignin moiety. Up to 48 % lignin removal from ground wheat straw was attained by pretreatment with Pycnoporus cinnabarinus laccase and 1-hydroxybenzotriazole (HBT) as mediator, followed by alkaline peroxide extraction. The lignin removal directly correlated with increases (∼60 %) in glucose yields after enzymatic saccharification. The pretreatment using laccase alone (without mediator) removed up to 18 % of lignin from wheat straw. Substantial lignin removal (37 %) was also produced when the enzyme-mediator pretreatment was not combined with the alkaline peroxide extraction. Two-dimensional nuclear magnetic resonance (2D NMR) analysis of the whole pretreated wheat straw material swollen in dimethylsulfoxide- d revealed modifications of the lignin polymer, including the lower number of aliphatic side chains involved in main β- O-4′ and β-5′ inter-unit linkages per aromatic lignin unit. Simultaneously, the removal of p-hydroxyphenyl, guaiacyl, and syringyl lignin units and of p-coumaric and ferulic acids, as well as a moderate decrease of tricin units, was observed without a substantial change in the wood polysaccharide signals. Especially noteworthy was the formation of Cα-oxidized lignin units during the enzymatic treatment. [ABSTRACT FROM AUTHOR]

Pearl millet ( Pennisetum glaucum ) stands sixth among the most important cereal crops grown in the semi-arid and arid regions of the world. The downy mildew disease caused by Sclerospora graminicola , an oomycete pathogen, has been recognized as a major biotic constraint in pearl millet production. On the other hand, basidiomycetes are known to produce a large number of antimicrobial metabolites, providing a good source of anti-oomycete agrochemicals. Here, we report the discovery and efficacy of a compound, named G_app7, purified from Ganoderma applanatum on inhibition of growth and development of S. graminicola , as well as the effects of seed treatment with G_app7 on protection of pearl millet from downy mildew. G_app7 consistently demonstrated remarkable effects against S. graminicola by recording significant inhibition of sporangium formation (41.4%), zoospore release (77.5%) and zoospore motility (91%). Analyses of G_app7 compound using two-dimensional nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry revealed its close resemblance to metominostrobin, a derivative of strobilurin group of fungicides. Furthermore, the G_app7 was shown to stably maintain the inhibitory effects at different temperatures between 25 and 80 °C. In addition, the anti-oomycete activity of G_app7 was fairly stable for a period of at least 12 months at 4 °C and was only completely lost after being autoclaved. Seed treatment with G_app7 resulted in a significant increase in disease protection (63%) under greenhouse conditions compared with water control. The identification and isolation of this novel and functional anti-oomycete compound from G. applanatum provide a considerable agrochemical importance for plant protection against downy mildew in an environmentally safe and economical manner. [ABSTRACT FROM AUTHOR]

Background: The requirement for efficient and green conversion technologies has prompted hydrothermal processing as a promising treatment option for sustainable biorefinery industry. The treatment has been applied to process plenty of lignocellulose materials, yielding abundant high value-degraded products, especially the products in the liquid fraction. Therefore, it is essential to systematically evaluate the degraded products in aqueous fraction by comprehensive analysis and structural characterization during the treatment. Results: Rapeseed straw was hydrothermally treated at temperature ranging from 145 to 205 °C for various retention time (15, 30, 60 and 120 min), and the degraded polysaccharides and lignin products in aqueous phase were systematically evaluated by comprehensive analysis and structural characterization. Results showed that with an increase of severity, the polymers were gradually depolymerized resulting in a decrease of the molecular weight from 8430 (log R0 3.26) to 2130 g/mol (log R0 5.08), an increase of oligosaccharides from 19.44 (log R0 2.88) to 99.94 g/kg (log R0 4.32) and an increase of monosaccharides from 0.91 (log R0 2.88) to 30.43 g/kg (log R0 4.37). With the increase of monosaccharide degradation components (8.26 to 125.68 g/kg), the saccharides gradually decreased after its maximum value. The maximum yield of oligosaccharides (99.94 g/kg) accompanying a relatively low level of monosaccharides (17.77 g/kg) was obtained at a high temperature (190 °C) for a short reaction time (15 min). The degraded polysaccharides had a linear backbone of (1 → 4)-linked β-d-xylopyranosyl xylan decorated with branches based on 2D NMR spectra analysis. Lignin was strongly condensed with a decrease of S/G ratio as the severity increased. The yields of the degraded constitutions have a incomplete linear correlation with the treatment severity. Conclusions: The liquid fractions obtained from hydrothermal treatment were subjected to comprehensive analysis and structural characterization. Results indicated that hydrothermal treatment had a significant influence on the composition and structure of the polysaccharides and lignin in the aqueous phase. The treatment could be adopted to obtain XOS-rich fraction with limited formation of by-products. In addition, the result was expected to further reveal the mechanisms of hydrothermal treatment on rapeseed straw and to facilitate the value-added applications of agricultural residues in the biorefinery industry. [ABSTRACT FROM AUTHOR]

A new flavonoid, 2-(3,5-dihydroxy-4-methoxy-phenyl)-3,5-dihydroxy-8,8-dimethyl-2,3-dihydro-8H-pyrano[3,2]chromen-4-one, together with previously reported epicatechin was isolated from the ethyl acetate soluble fraction of the methanol extract of the stem bark ofCommiphora pedunculata. The structures of these compounds were elucidated based on extensive analysis of their spectral data, including 1 and 2D NMR. The compounds were active against 9 out of 12 tested microorganisms including a resistant strain; vancomycin-resistantentrococci(VRE),Escherichia coli, Staphylococcus aureusandCandida albicans. The zones of inhibition ranged between 22 and 34 mm against the microorganisms. The minimum inhibitory concentration was as low as 6.25 μg/mL againstShigella dysentriae, Bacillus cereusandS. aureuswhile the minimum bactericidal concentration was as low as 50 μg/mL againstPseudomonas aeruginosa,VRE andC. albicans. This is the first report of the isolation of the compound. [ABSTRACT FROM PUBLISHER]

Conformational analysis of eight-membered P,N-heterocycles (PR') in the solution has been performed by means of NMR spectroscopy and quantum chemical calculations. The equilibrium of the С-symmetrical (crown, major) and С-symmetrical ( chair-boat, minor) forms of the compounds has been revealed, the transition barriers being of about 12 kcal/mol. The presence of an aromatic substituent at the nitrogen atom significantly shifts the equilibrium towards the dominating form. [ABSTRACT FROM AUTHOR]

Physicochemical characteristics of corn stover pretreated by soaking in aqueous ammonia (SAA) and low-moisture anhydrous ammonia (LMAA) were compared and investigated. The glucan digestibility of the treated biomass reached 90 % (SAA) and 84 % (LMAA). The LMAA pretreatment enhanced the digestibility by cleaving cross-linkages between cell wall components, whereas the SAA pretreatment additionally improved the digestibility by efficiently removing a major portion of the lignin under mild reaction conditions without significant loss of carbohydrates. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) revealed the structural and chemical transformations of lignin during the pretreatments. Both pretreatments effectively cleaved ferulate cell wall cross-linking that is associated with the recalcitrance of grass lignocellulosics toward enzymatic saccharification. Extracted lignin from SAA pretreatment was extensively depolymerized but retained 'native' character, as evidenced by the retention of β-ether linkages. [ABSTRACT FROM AUTHOR]

Background: Pleurotus ostreatus is the second edible mushroom worldwide, and a model fungus for delignification applications, with the advantage of growing on woody and nonwoody feedstocks. Its sequenced genome is available, and this gave us the opportunity to perform proteomic studies to identify the enzymes overproduced in lignocellulose cultures. Results: Monokaryotic P. ostreatus (PC9) was grown with poplar wood or wheat straw as the sole C/N source and the extracellular proteins were analyzed, together with those from glucose medium. Using nano-liquid chromatography coupled to tandem mass spectrometry of whole-protein hydrolyzate, over five-hundred proteins were identified. Thirty-four percent were unique of the straw cultures, while only 15 and 6 % were unique of the glucose and poplar cultures, respectively (20 % were produced under the three conditions, and additional 19 % were shared by the two lignocellulose cultures). Semi-quantitative analysis showed oxidoreductases as the main protein type both in the poplar (39 % total abundance) and straw (31 %) secretomes, while carbohydrate-active enzymes (CAZys) were only slightly overproduced (14-16 %). Laccase 10 (LACC10) was the main protein in the two lignocellulose secretomes (10-14 %) and, together with LACC2, LACC9, LACC6, versatile peroxidase 1 (VP1), and manganese peroxidase 3 (MnP3), were strongly overproduced in the lignocellulose cultures. Seven CAZys were also among the top-50 proteins, but only CE16 acetylesterase was overproduced on lignocellulose. When the woody and nonwoody secretomes were compared, GH1 and GH3 β-glycosidases were more abundant on poplar and straw, respectively and, among less abundant proteins, VP2 was overproduced on straw, while VP3 was only found on poplar. The treated lignocellulosic substrates were analyzed by two-dimensional nuclear magnetic resonance (2D NMR), and a decrease of lignin relative to carbohydrate signals was observed, together with the disappearance of some minor lignin substructures, and an increase of sugar reducing ends. Conclusions: Oxidoreductases are strongly induced when P. ostreatus grows on woody and nonwoody lignocellulosic substrates. One laccase occupied the first position in both secretomes, and three more were overproduced together with one VP and one MnP, suggesting an important role in lignocellulose degradation. Preferential removal of lignin vs carbohydrates was shown by 2D NMR, in agreement with the above secretomic results. [ABSTRACT FROM AUTHOR]

4- N , N -dimethylamino-4′- N ′-methyl-stilbazolium tosylate (DAST) crystal has excellent properties of nonlinear optics and electro-optical effect, and it can be used in the fields of radiation and detection through wave bands from infrared to terahertz. Besides, DAST thin films have exhibited their excellent properties and have expanded application fields of DAST material. CD 3 OD was chosen as the solvent to conduct 1 H NMR, 13 C NMR, 1 H– 1 H COSY, 1 H– 13 C HSQC and 1 H– 13 C HMBC characterization of DAST respectively. All peaks in 1 H and 13 C NMR spectra of DAST were assigned with assistance of 2D NMR correlation peaks. [ABSTRACT FROM AUTHOR]

The transformations of (E)-3-[3-(2-hydroxyaryl)-3-oxoprop-1 -en-1 -yl]chromones in the presence of methylhydrazine and aromatic bisnucleophiles are described. The reactions generally lead to chro-mone ring transformation via pyrone ring-opening and heterocycliza-tion to give novel diazoles and (Z)-3-aminomethylenechromanones, respectively. Piperazine catalyzes chromanone ring closure of the starting substrate to afford chromone-chromanone dyads. [ABSTRACT FROM AUTHOR]

Type III collagen belongs to one of the twenty-eight known collagen types. It is found throughout the body, including being a major component of blood vessels, internal organs, and skin. A collagen molecule comprises of over a thousand amino acids, which are all arranged in three left-handed peptide chains folded together into a characteristic right-handed triple helix. Type III collagen is known to play a role in wound healing and tissue repair, and is the cause for hereditary Ehlers-Danlos syndrome (EDS) type IV which often leads to ruptures of large arteries and internal organs and, in severe cases, death. However, due to the large size of its molecule, not much is known about how type III collagen's structure influences the functions it has in the body. Two-dimensional nuclear magnetic resonance (2D NMR) is a relatively new analytical technique that has become increasingly more utilized in the study of biological molecules, since it has the ability to detect relationships of atoms both through their bonds and through space. Still, because of the length and repetitive nature of its sequence, the best way to study the collagen molecule by NMR is with model peptide sequences that mimic a particular collagen segment of interest. This review summarizes the research conducted up to this point on collagens using nuclear magnetic resonance. [ABSTRACT FROM AUTHOR]