Exploration of material basis: Chemical composition profile and metabolic profile in Xiao Jianzhong Granules.

Chemical composition, antimicrobial activity, and antioxidant capacity of Micromeria flagellaris Baker and M. madagascariensis Baker: Two endemic species from Madagascar as sources of essential oils

The ability to determine combustion and thermal decomposition (pyrolysis) products at trace concentrations can lead to important information on catalytic pathways, the degradation process itself, and structural (fingerprint) information on the parent molecule(s), among others. Gas chromatography coupled with mass spectrometry (GC/MS) is well suited to separate and identify the volatile molecules and molecular fragments generated by combustion and pyrolysis processes. Whereas, pyrolysis (conducted in an inert atmosphere) is often used as a sample introduction device directly coupled to GC/MS, combustion is generally carried out offline and its products are collected and analyzed with GC/MS, or even pyrolysis‐GC/MS. In the past few years, this powerful technique has been used to examine a variety of sample types for quite diverse applications. This chapter describes the state of the art and the progress of GC/MS for the measurement of combustion and pyrolysis products. An introduction to the technique, including the principles of GC/MS, is first provided, followed by a demonstration of the instrument's capabilities for combustion and pyrolysis research. All reports discussed herein were selected in part to demonstrate the diversity of current combustion and pyrolysis research using GC/MS. The present authors' studies with temperature‐programmed desorption in conjunction with GC/MS to characterize oxygen shuttling on the chars derived from different gaseous environment, are highlighted. Finally, the use of GC/MS in combination with isotope‐labeling techniques to reveal complex reaction pathways and mechanisms is discussed.

Exploration of material basis: Chemical composition profile, metabolic profile and pharmacokinetic characteristics in Xingbei Zhike granule

To obtain a detailed picture of sulfur deprivation-induced H(2) production in microalgae, metabolome analyses were performed during key time points of the anaerobic H(2) production process of Chlamydomonas reinhardtii. Analyses were performed using gas chromatography coupled to mass spectrometry (GC/MS), two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC-TOFMS), lipid and starch analysis, and enzymatic determination of fermentative products. The studies were designed to provide a detailed metabolite profile of the solar Bio-H(2) production process. This work reports on the differential analysis of metabolic profiles of the high H(2)-producing strain Stm6Glc4 and the wild-type cc406 (WT) before and during the H(2) production phase. Using GCxGC-TOFMS analysis the number of detected peaks increased from 128 peaks, previously detected by GC/MS techniques, to ∼1168. More detailed analysis of the anaerobic H(2) production phase revealed remarkable differences between wild-type and mutant cells in a number of metabolic pathways. Under these physiological conditions the WT produced up to 2.6 times more fatty acids, 2.2 times more neutral lipids, and up to 4 times more fermentation products compared with Stm6Glc4. Based on these results, specific metabolic pathways involving the synthesis of fatty acids, neutral lipids, and fermentation products during anaerobiosis in C. reinhardtii have been identified as potential targets for metabolic engineering to further enhance substrate supply for the hydrogenase(s) in the chloroplast.

Chemical composition and larvicidal activity of edible plant-derived essential oils against the pyrethroid-susceptible and -resistant strains of Aedes aegypti (Diptera: Culicidae)

New varieties and rootstocks adapted to tropical climates remain a challenge for improving wine production and quality, emphasising the need to optimise sensory characteristics and typicity. This study aimed to characterise the oenological potential of wines from the ‘Arinto’ and ‘Fernão Pires’ cultivars, grafted onto IAC 572 and 1103 Paulsen rootstocks, in a semiarid tropical region over four consecutive vintages (considering the first and second semesters). The impact of harvest season, rootstock, and cultivar on the chemical and volatile composition was evaluated to provide new insights into tropical wine typicity. Gas chromatography coupled with mass spectrometry (GC-MS) was used to quantify volatile compounds. The season of harvest was the most influential factor, followed by cultivar and rootstock. Wines produced from grapes harvested in the second semester of the year exhibited greater oenological potential, with higher concentrations of key volatile compounds, including ethyl esters, higher alcohol acetates, and terpenes. Principal Component Analysis (PCA) identified phenylethyl acetate, isoamyl acetate, linalool, ethyl propanoate, ethyl hexanoate, and ethyl octanoate as markers of wines from the second semester. Additionally, methyl geranate was detected for the first time, suggesting its potential as a typicity marker for these varieties. These findings reinforce the viability of ‘Arinto’ and ‘Fernão Pires’ for tropical wine production, providing valuable knowledge for viticultural strategies in emerging tropical winegrowing regions.

Each wine has a unique chemical composition that is influenced by the grape variety, the geology and climate of the vine's growth (terroir), and the winemaking process. Despite the fact that several scientific reports have been published about the characteristic of wines from The Old and The New World Countries, data on the specific characteristics of wines from the cool climate regions is still lacking. The objective of this study was to develop analytical methods for evaluating the quality of domestically produced wines in terms of the concentration of specific bioactive compounds, such as: • organic acids and polyphenols determined in one course of analytical procedure, using solvent extraction of liquid samples through an ultrasound-assisted porous membrane (UASE-PMLS) in conjunction with gas chromatography coupled with mass spectrometry (GC-MS) at the stage of final determinations; • biogenic amines using two analytical procedures (a) capillary electrophoresis coupled with mass spectrometry (CE-MS) and (b) salting-out liquid-liquid microextraction technique coupled with GC- MS (SALLME-GC-MS). Furthermore, micro- and macroelements were determined. All the data gathered were used to ascertain the correlations between wines' various physicochemical properties by multivariate statistical analysis. The research work was conducted in accordance with the principles of Green Analytical Chemistry, and the developed methods were assessed for their green nature using the Analytical EcoScale and the GAPI Index.

HPLC and GC/MS determination of 4-aminobiphenyl haemoglobin adducts in fetuses exposed to the tobacco smoke carcinogen in utero

Metabolomics technology has enabled an important method for the identification and quality control of Traditional Chinese Medical materials. In this study, we isolated metabolites from cultivated Dendrobium officinale and Dendrobium huoshanense stems of different growth years in the methanol/water phase and identified them using gas chromatography coupled with mass spectrometry (GC-MS). First, a metabolomics technology platform for Dendrobium was constructed. The metabolites in the Dendrobium methanol/water phase were mainly sugars and glycosides, amino acids, organic acids, alcohols. D. officinale and D. huoshanense and their growth years were distinguished by cluster analysis in combination with multivariate statistical analysis, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Eleven metabolites that contributed significantly to this differentiation were subjected to t-tests (P<0.05) to identify biomarkers that discriminate between D. officinale and D. huoshanense, including sucrose, glucose, galactose, succinate, fructose, hexadecanoate, oleanitrile, myo-inositol, and glycerol. Metabolic profiling of the chemical compositions of Dendrobium species revealed that the polysaccharide content of D. huoshanense was higher than that of D. officinale, indicating that the D. huoshanense was of higher quality. Based on the accumulation of Dendrobium metabolites, the optimal harvest time for Dendrobium was in the third year. This initial metabolic profiling platform for Dendrobium provides an important foundation for the further study of secondary metabolites (pharmaceutical active ingredients) and metabolic pathways.

The complex chemical composition of crude oils presents many challenges for rapid chemical characterization in the case of a spill. A number of approaches are currently used to "fingerprint" petroleum-derived samples. Gas chromatography coupled with mass spectrometry (GC-MS) is the most common, albeit not very rapid, technique; however, with GC-MS alone, it is difficult to resolve the complex substances in crude oils. The present study examined the potential application of ion mobility spectrometry-mass spectrometry (IMS-MS) coupled with chem-informatic analyses as an alternative high-throughput method for the chemical characterization of crude oils. We analyzed 19 crude oil samples from on- and offshore locations in the Gulf of Mexico region in the United States using both GC-MS (biomarkers, gasoline range hydrocarbons, and n-alkanes) and IMS-MS (untargeted analysis). Hierarchical clustering, principal component analysis, and nearest neighbor-based classification were used to examine sample similarity and geographical groupings. We found that direct-injection IMS-MS performed either equally or better than GC-MS in the classification of the origins of crude oils. In addition, IMS-MS greatly increased the sample analysis throughput (minutes vs hours per sample). Finally, a tabletop science-to-practice exercise, utilizing both the GC-MS and IMS-MS data, was conducted with emergency response experts from regulatory agencies and the oil industry. This activity showed that the stakeholders found the IMS-MS data to be highly informative for rapid chemical fingerprinting of complex substances in general and specifically advantageous for accurate and confident source-grouping of crude oils. Collectively, the present study shows the utility of IMS-MS as a technique for rapid fingerprinting of complex samples and demonstrates its advantages over traditional GC-MS-based analyses when used for decision-making in emergency situations. Environ Toxicol Chem 2021;40:1034-1049. © 2020 SETAC.

Identification of Vitamin D3 Oxidation Products Using High-Resolution and Tandem Mass Spectrometry.

Simple SummaryThe waxy layer covering the surface of most terrestrial insects is mainly composed of non-polar lipids termed cuticular hydrocarbons (CHCs). These have a long research history as important dual traits for both desiccation prevention and chemical communication. We analyzed CHC profiles of seven species of the insect order Blattodea (termites and cockroaches) with the most commonly applied chromatographic method, gas-chromatography coupled with mass spectrometry (GC-MS), and the more novel approach of silver-assisted laser desorption/ionization mass spectrometry (Ag-LDI-MS). Comparing these two analytical methods, we demonstrated that the conventional GC-MS approach does not provide enough information on the entire CHC profile range in the tested species. Ag-LDI-MS was able to detect very long-chain CHCs ranging up to C58, which remained undetected when solely relying on standard GC-MS analysis. Additionally, we measured the body surface areas of each tested species applying 3D scanning technology to assess their respective CHC amounts per mm2. When adjusting for body surface areas, proportional CHC quantity distributions shifted considerably between our studied species, suggesting the importance of including this factor when conducting quantitative CHC comparisons, particularly in insects that vary substantially in body size.Most of our knowledge on insect cuticular hydrocarbons (CHCs) stems from analytical techniques based on gas-chromatography coupled with mass spectrometry (GC-MS). However, this method has its limits under standard conditions, particularly in detecting compounds beyond a chain length of around C40. Here, we compare the CHC chain length range detectable by GC-MS with the range assessed by silver-assisted laser desorption/ionization mass spectrometry (Ag-LDI-MS), a novel and rarely applied technique on insect CHCs, in seven species of the order Blattodea. For all tested species, we unveiled a considerable range of very long-chain CHCs up to C58, which are not detectable by standard GC-MS technology. This indicates that general studies on insect CHCs may frequently miss compounds in this range, and we encourage future studies to implement analytical techniques extending the conventionally accessed chain length range. Furthermore, we incorporate 3D scanned insect body surface areas as an additional factor for the comparative quantification of extracted CHC amounts between our study species. CHC quantity distributions differed considerably when adjusted for body surface areas as opposed to directly assessing extracted CHC amounts, suggesting that a more accurate evaluation of relative CHC quantities can be achieved by taking body surface areas into account.

Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne disease in cattle and other ruminants, is proposed to be at least one of the causes of Crohn disease in humans. MAP and Mycobacterium avium subspecies avium, a closely related opportunistic environmental bacterium, share 95% of their genes and exhibit homologies of more than 99% between these genes. The identification of molecules specific for MAP is essential for understanding its pathogenicity and for development of useful diagnostic tools. The application of gas chromatography, mass spectrometry, and nuclear magnetic resonance led to the structural identification of a major cell wall lipopeptide of MAP, termed Para-LP-01, defined as C20 fatty acyl-D-Phe-N-Me-L-Val-L-Ile-L-Phe-L-Ala methyl ester. Variations of this lipopeptide with different fatty acyl moieties (C16 fatty acyl through C17, C18, C19, C21 to C22) were also identified. Besides the specificity of this lipopeptide for MAP, the presence of an N-Me-L-valine represents the first reported N-methylated amino acid within an immunogenic lipopeptide of mycobacteria. Sera from animals with Johne disease, but not sera from uninfected cattle, reacted with this lipopeptide, indicating potential biological importance.

BackgroundYi Guan Jian Decoction (YGJD), a famous Chinese prescription, has long been employed clinically to treat liver fibrosis. However, as of date, there is no report on the effects of YGJD from a metabonomic approach. In this study, a urine metabonomic method based on gas chromatography coupled with mass spectrometry (GC/MS) was employed to study the protective efficacy and metabolic profile changes caused by YGJD in carbon tetrachloride (CCl4)-induced liver fibrosis.MethodsUrine samples from Wistar rats of three randomly divided groups (control, model, and YGJD treated) were collected at various time-points, and the metabolic profile changes were analyzed by GC/MS with principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA). Furthermore, histopathology and biochemical examination were also carried out to ensure the success of CCl4-induced liver fibrosis model.ResultsUrine metabolic profile studies suggested distinct clustering of the three groups, and YGJD group was much closer to the control group by showing a tendency of recovering towards the control group. Fourteen significantly changed metabolites were found, and YGJD treatment could reverse the levels of these metabolites to normal levels or close to normal levels.ConclusionsThe current study indicates that the YGJD has significant anti-fibrotic effects on CCl4-induced liver fibrosis in rats, which might be by regulating the dysfunction of energy metabolism, amino acid metabolism, tryptophan metabolism, cytochrome P450 metabolism, and gut microflora metabolism. The metabonomic approach can be recommended to study the pharmacological effect and mechanism of complex Chinese medicines.

A new laboratory method, based on chemical and geochemical analysis of the residual hydrocarbons extracted by washing the core plugs and/or the drilling cuttings with solvents (toluene or chloroform) before undergoing routine petrophysical analyses, has been developed for evaluating the characteristics of crude oils and gas condensates which saturate a formation. The results of the analyses are expressed in profiles which enable variations in composition and molecular heterogeneity of the hydrocarbons in a reservoir to be clearly detected. The techniques used are Rock-Eval pyrolysis, which gives indications on the quantity and quality of the residual hydrocarbons present in the rock, gas chromatography coupled with mass spectroscopy (GC-MS) for molecular analysis, and thin layer chromatography with a flame ionization detector (TLC-FID) for subdividing the residual hydrocarbons into different groups (paraffins, aromatics, resins and asphaltenes). The paper shows the results obtained on analyzing the residual hydrocarbons of cores and cuttings of different wells, including horizontal wells. Introduction In the oil industry the study of reservoir rock usually consists of its petrographic, petrophysical and sedimentological characterizations, which are obtained using laboratory methods, well log recordings and from well production tests. It is in this direction that all efforts, aimed at improving knowledge of a reservoir, are being placed. The past few years have witnessed, for example, improvements in the traditional techniques of well logging, and the emergence of others, such as image logs; while many core analysis laboratories have acquired new and more sophisticated equipment, such as tomographers, which enable a more thorough examination of the internal structure of the porous medium and evaluation of the influence which a rock's heterogeneity has on its transport properties. On the other hand, the only information on the fluids present in a formation has remained that derived from samples taken from well bottom hole or from surface separators. To extend our knowledge on reservoir hydrocarbons and their distribution in a formation, an integrated series of methods has been developed. These laboratory methods are based on the analysis of the hydrocarbons remaining in core plugs or drilling cuttings, and are quickly able to provide important information concerning the chemical composition and molecular characteristics of the oils or gas condensates present in a reservoir. Despite it being well known that the invasion of drilling mud filtrate can have a negative influence on the quality of these findings, as indeed it can on all other measurements, the small amounts of residual hydrocarbons recoverable are sufficient for the methods which will be described, together several applicative examples, in this paper. Due to the different nature of the information obtainable and its difficulty of use, this set of methods is based on three different techniques, namely Rock-Eval pyrolysis (RE), gas chromatography coupled with mass spectroscopy (GC-MS) and thin layer chromatography with a flame ionization detector (TLC-FID) (Fig.1). As a result of these point analyses, it is possible to distinguish between indigenous and migrated hydrocarbons, to investigate their origins and maturity, to establish with precision the existence of any possible gas/oil or water/oil contacts, to draw up molecular composition profiles of hydrocarbons and obtain information concerning their chemical composition, to identify zones in which heavy hydrocarbons (resins and asphaltenes) are present, to establish the real presence of compositional gradients and to obtain indications regarding the productive potential of a formation. The only real limitation of these methods concerns the use of oil-based mud to drill a well. In fact, the oil used to prepare the drilling mud mixes with the original hydrocarbons, modifying irreversibly the composition of the residual hydrocarbons to be analysed. P. 103