NMR and multivariate methods: Identification of chemical markers in extracts of pedra-ume-caá and their antiglycation, antioxidant, and enzymatic inhibition activities.

INTRODUCTION: In Brazil, the plant group popularly known as "pedra-ume-caá" is used in folk medicine for the treatment of diabetes, and its raw material is commonly sold. OBJECTIVE: The aim of the study was to apply a method for chemical identification of extracts of dry pedra-ume-caá leaves using HPLC-high-resolution mass spectrometry (HRMS) and NMR and develop a multivariate model with NMR data to authenticate commercial samples. In addition, to evaluate the biological activities of the extracts. MATERIALS AND METHODS: Dry extracts of Myrcia multiflora, Myrcia amazonica, Myrcia guianensis, Myrcia sylvatica, Eugenia punicifolia leaves, and 15 commercial samples (sold in Manaus and Belém, Brazil) were prepared by infusion. All the extracts were analysed using HPLC-high-resolution mass spectrometry (HRMS), NMR, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The antidiabetic effect of extracts was evaluated according to enzymatic inhibition. Their content of total phenols, cell viability, and antioxidant and antiglycation activities were also determined. RESULTS: HPLC-HRMS and NMR analysis of these extracts permitted the identification of 17 compounds. 1H NMR data combined with multivariate analyses allowed us to conclude that catechin, myricitrin, quercitrin, and gallic and quinic acids are the main chemical markers of pedra-ume-caá species. These markers were identified in 15 commercial samples of pedra-ume-caá. Additionally, only the extracts of M. multiflora and E. punicifolia inhibited α-glucosidase. All the extracts inhibited the formation of advanced glycation end products (AGEs) and showed free-radical-scavenging activity. These extracts did not present cytotoxicity. CONCLUSION: This study revealed the chemical markers of matrices, and it was possible to differentiate the materials marketed as pedra-ume-caá. Moreover, this study corroborates the potential of these species for treating diabetes.

Characterisation and critical processes identification for production of herbal preparations using 1H-NMR and chemometrics: A case study of Trichosanthis Pericarpium injection.

INTRODUCTION: Herbal preparations are extensively utilised for the treatment of diseases in Asian countries. However, the variations in origin, climate, and production processes can lead to inconsistencies in the quality of herbal preparations. Existing quality control methods only target a few components in the finished product but ignore the control in the pharmaceutical process. Therefore, this study intends to develop a comprehensive component analysis method for intermediates in the pharmaceutical process to reveal the change patterns of substances and deepen the process understanding. OBJECTIVE: This study aims to develop a rapid and comprehensive process characterisation and critical process identification method for herbal preparations. METHODS: Six batches of Trichosanthis Pericarpium injection (TPI) intermediates were collected from the production process. Proton nuclear magnetic resonance (1H-NMR) spectra were acquired for qualitative and quantitative analysis of the se intermediates. Subsequently, chemometrics were used to identify critical processes and potential chemical markers. RESULTS: A total of 39 components in intermediates were identified, and the transfer of 25 components during the production process was investigated. Column chromatography was determined as the critical process. Nine components were identified as chemical markers. CONCLUSION: The application of 1H-NMR facilitated a comprehensive reflection of the chemical composition information of process intermediates, enabling investigations into the transfer of multi-component substances and accurate identification of critical processes and chemical markers.

Study on the quality difference of Cyperus rotundus before and after vinegar processing based on ultra-high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry and molecular network combined with color parameters.

Cyperus rotundus is the dry rhizome of the Cyperaceae plant Cyperus. Although there are two types of processed products in clinics, their quality differences are not clear, and the identification methods are more complex. In this study, the chemical composition of different processed products of Cyperus rotundus was characterized using ultra-high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry and molecular network analysis, to identify the potential chemical markers and to establish a quick and simple color-based discrimination method. Among the 65 compounds analyzed, 12 showed significant differences. Observing the color, the surface brightness (L*) of Cyperus rotundus decreased after vinegar processing, while red (a*) and yellow (b*) values increased. These color values correlated significantly with chemical compositions. Finally, a color discriminant function was established and verified for raw Cyperus rotundus and vinegar-processing Cyperus rotundus. Based on this study, Cyperus rotundus' quality can be effectively controlled and provides a method for the comprehensive characterization of chemical components and chemical markers of other traditional Chinese medicine and processed products, as well as new ideas and methods in identification and quality evaluation.

Dissecting chemical markers for controlling "Paozhi" method of traditional Chinese medicine with untargeted metabolomics: Vinegar-baked Euphorbia kansui as a case study.

The processing of Traditional Chinese Medicine requires the appropriate parameters, while the specific chemical markers are still absent to obtain the optimized processing. In this study, we used vinegar-baked Euphorbia kansui as a case to dissect the chemical markers for the baking process using untargeted metabolomics. The robust chemical markers were selected based on the three rules, correlation, significant difference, and controllability. All the differential features were categorized based on their mass defects. After the differential analysis, 310 differential compounds were screened out and could be mainly divided into six categories: diacylglycerols and triacylglycerols demonstrated increasing trends with the baking time in the discriminant model, while ingenane-type diterpenes, jatrophane-type diterpenes, fatty acid esters, and fatty acids had decreasing trends. It was unexpected to find that the diterpenes did not correlate with the baking time. Only very few compounds meet the three rules. They were validated with a high-performance liquid chromatography method. Finally, only 13-Hydroxy-9,11-octadecadienoic acid and its isomer 9-Hydroxy-10,12-octadecadienoic acid could be used further to differentiate the commercial vinegar-baked Euphorbia kansui. It would be of interest to evaluate whether these two compounds could be utilized as markers to control more processing methods in future studies.

Two Olean-27-carboxylic Acid-Type Triterpenoids as Chemical Markers Isolated from Saxifraga umbellulata.

Two olean-27-carboxylic acid-type triterpenoids (1 and 2) were isolated from Saxifraga umbellulata (Saxifragaceae), representing the first case in the chemical discoveries of genus Saxifraga. Compound 1 was determined to be a new compound named 'Saxifragic acid' based on the comprehensive spectroscopic and X-ray crystallographic analyses. Compound 2 (deacetylated saxifragic acid) is a known compound reported before, but its absolute configuration through X-ray crystallographic analyses was first described here. In addition, their cytotoxicity against five digestive human cancer cell lines (BGC-823, GBC-SD, CCC-9810, HT-29, and HepG2) and hepatoprotective activity against CCl4 -induced L-o2 cell injury in vitro were evaluated. Interestingly, UPLC-QTOFMS analysis showed that these two compounds could be used as chemical markers to discriminate between S. umbellulata and S. tangutica, both of which are used for the treatment of hepatobiliary diseases in traditional Tibetan medicine.

Based on UPLC/MS/MS and Bioinformatics Analysis to Explore the Difference Substances and Mechanism of Curcumae Radix (Curcuma wenyujin) in Dysmenorrhea.

BACKGROUND: Curcumae Radix (CW) is traditionally used to treat dysmenorrhea caused by uterine spasm. However, the changes of its composition and anti-uterine spasms during vinegar processing and the mechanism in treating dysmenorrhea are not clear. OBJECTIVE: To elucidate the changes of anti-uterine spasm and its substance basis, and the mechanism of treating dysmenorrhea before and after vinegar processing. METHODS: The uterine spasm contraction model was established, and the uterine activity and its inhibition rate were calculated to evaluate the differences. The main chemical constituents of CW were quickly analyzed by UPLC-Q-TOF-MS/MS technology, and the differences between them were explored by multivariate statistical analysis. Then, the regulatory network of "active ingredients-core targets-signal pathways" related to dysmenorrhea was constructed by using network pharmacology, and the combination between differential active components and targets was verified by molecular docking. RESULTS: CW extract relaxed the isolated uterine by reducing the contractile tension, amplitude, and frequency. Compared with CW, the inhibitory effect of vinegar products was stronger, and the inhibition rate was 70.08 %. 39 compounds were identified from CW and 13 differential components were screened out (p<0.05). Network pharmacology screened 11 active components and 32 potential targets, involving 10 key pathways related to dysmenorrhea. The results of molecular docking showed that these differentially active components had good binding activity to target. CONCLUSION: It was preliminarily revealed that CW could treat dysmenorrhea mainly through the regulation of inflammatory reaction, relaxing smooth muscle and endocrine by curcumenone, 13-hydroxygermacrone, (+)-cuparene, caryophyllene oxide, zederone, and isocurcumenol.

Effect of Different Processing Methods on the Chemical Constituents of Scrophulariae Radix as Revealed by 2D NMR-Based Metabolomics.

Scrophulariae Radix (SR) is one of the oldest and most frequently used Chinese herbs for oriental medicine in China. Before clinical use, the SR should be processed using different methods after harvest, such as steaming, "sweating", and traditional fire-drying. In order to investigate the difference in chemical constituents using different processing methods, the two-dimensional (2D) 1H-13C heteronuclear single quantum correlation (1H-13C HSQC)-based metabolomics approach was applied to extensively characterize the difference in the chemical components in the extracts of SR processed using different processing methods. In total, 20 compounds were identified as potential chemical markers that changed significantly with different steaming durations. Seven compounds can be used as potential chemical markers to differentiate processing by sweating, hot-air drying, and steaming for 4 h. These findings could elucidate the change of chemical constituents of the processed SR and provide a guide for the processing. In addition, our protocol may represent a general approach to characterizing chemical compounds of traditional Chinese medicine (TCM) and therefore might be considered as a promising approach to exploring the scientific basis of traditional processing of TCM.

UHPLC-Q-Orbitrap-MS-Based Metabolomics Reveals Chemical Variations of Two Types of Rhizomes of Polygonatum sibiricum.

The rhizomes of Polygonatum sibiricum are commonly consumed as food and also used as medicine. However, the metabolic profile of P. sibiricum has not been fully revealed yet. Recently, we developed a novel evergreen species of P. sibiricum. The objectives of this study were to compare the metabolic profiles of two types of P. sibiricum, i.e., the newly developed evergreen type (Gtype) and a wide-type (Wtype), by using UHPLC-Q-Orbitrap-MS-based untargeted metabolomics approach. A total of 263 and 258 compounds in the positive and negative modes of the mass spectra were tentatively identified. Distinctively different metabolomic profiles of these two types of P. sibiricum were also revealed by principal component analysis (PCA) and principal coordinates analysis (PCoA). Furthermore, by using partial least squares discriminant analysis (PLS-DA) modeling, it was found that, as compared with Wtype, Gtype samples had significantly higher content of oxyberberine, proliferin, alpinetin, and grandisin. On the other hand, 15 compounds, including herniarin, kaempferol 7-neohesperidoside, benzyl beta-primeveroside, vanillic acid, biochanin A, neoschaftoside, benzyl gentiobioside, cornuside, hydroxytyrosol-glucuronide, apigenin-pentosyl-glucoside, obacunone, 13-alpha-(21)-epoxyeurycomanone, vulgarin, digitonin, and 3-formylindole, were discovered to have higher abundance in Wtype samples. These distinguishing metabolites suggest the different beneficial health potentials and flavor attributes of the two types of P. sibiricum rhizomes.

Chemical Characterization and Nutritional Markers of South African Moringa oleifera Seed Oils.

Moringa oleifera Lam (syn. M. ptreygosperma Gaertn.) leaves are globally acclaimed for their nutritional content and mitigation of malnutrition. In most impoverished rural communities including Limpopo, Mpumalanga and KwaZulu Natal of South Africa, powdered leaves of Moringa oleifera are applied as a nutritional supplement for readily available food such as porridge for malnourished children and even breast-feeding mothers. Widely practiced and admired is also the use of the plant seed in the do-it-yourself purification of water by rural South Africans. This study aimed at identifying the chemical and nutritional marker compounds present in South African Moringa oleifera seed oils using high resolution 1-2-dimension gas chromatography in order to give scientific validation to its uses in cosmetics and particularly in culinary practices. Results obtained from two-dimension tandem mass spectrometry chemical signature revealed over 250 compounds, five times more than those reported from one-dimension gas chromatography. Whereas previous reports from gas chromatography-mass spectrometry analysis reported oleic acid (70-78%) as the major compound from oil samples from other countries, M. oleifera seed oil from South Africa is marked by cis-13-octadeaconic acid with 78.62% and 41.9% as the predominant monounsaturated fatty acid in the hexane and dichloromethane extracts respectively. This was followed by cis-vaccenic acid, an isomer of oleic acid at 51% in the acetone extract, 9-octadecanoic acid-(z)-methyl ester at 39.18%, 21.34% and 10.06% in dichloromethane, hexane and acetone extracts respectively. However, a principal component analysis with R2 = 0.98 of the two-dimension tandem mass spectrometry cum chemometric analysis indicated n-hexadecanoic acid, oleic acid, 9-octadecanoic acid-(z)-methyl ester and cis-vaccenic acid with a probability of 0.96, 0.88, 0.80 and 0.79 respectively as the marker compounds that should be used for the quality control of moringa seed oils from South Africa. This study demonstrates that South African Moringa oleifera oils contain C-18 monounsaturated fatty acids similar to oils from Egypt (76.2%), Thailand (71.6%) and Pakistan (78.5%) just to mention but a few. These fatty acids are sunflower and olive oil type-compounds and therefore place moringa seed oil for consideration as a cooking oil amongst its other uses.

Exploration of Habitat-Related Chemical Markers for Stephania tetrandra Applying Multiple Chromatographic and Chemometric Analysis.

Geo-authentic herbs refer to medicinal materials produced in a specific region with superior quality. Stephania tetrandra S. Moore (S. tetrandra) is cultivated in many provinces of China, including Anhui, Zhejiang, Fujian, Jiangxi, Hunan, Guangxi, Guangdong, Hainan, and Taiwan, among which Jiangxi is the geo-authentic origin. To explore habitat-related chemical markers of herbal medicine, an integrated chromatographic technique including gas chromatography-mass spectrometry (GC-MS), ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) combined with chemometric analysis was established. The established methods manifested that they were clearly divided into two groups according to non-authentic origins and geo-authentic origins, suggesting that the metabolites were closely related to their producing areas. A total of 70 volatile compounds and 50 non-volatile compounds were identified in S. tetrandra. Meanwhile, tetrandrine, fangchinoline, isocorydine, magnocurarine, magnoflorine, boldine, and higenamine as chemical markers were accurately quantified and suggested importance in grouping non-authentic origins and geo-authentic origins samples. The discriminatory analysis also indicated well prediction performance with an accuracy of 80%. The results showed that the multiple chromatographic and chemometric analysis technique could be used as an effective approach for discovering the chemical markers of herbal medicine to fulfill the evaluation of overall chemical consistency among samples from different producing areas.

The super-food Manuka honey, a comprehensive review of its analysis and authenticity approaches.

Manuka honey (MH) stands out from other honey types as a unique super-food with clinically proven antimicrobial and wound healing activities. Its unique traits and the broad range of applications (i.e. food, cosmetics, nutraceuticals /natural health products) have marked up its price 6 to 25 times than other honey types. Concurrent to the increased market demand, more fraudulence of MH emerged. This urged for the employment of analytical tools for the authenticity and quality assessment of MH and has been the focus of many researchers during the last decades. Our main focus was to review the literature dealing with MH authenticity during the period from 2010 to mid-2021 comprehensively via the Scifinder (https://sinfinder.cas.org) and Web of Science (https://webofknowledge.com) research engines. We used "manuka honey analysis", "manuka honey quality control", and "manuka honey authenticity" as a search terms, applied Boolean operators 'AND/OR' combination, performing in Jan 2017 from the following electronic databases. The state-of-the-art analytical approaches and respective chemical markers of MH are highlighted. The present study capitalizes on the most updated methodologies employed for the quality control and analysis of MH to ensure its authenticity and adulteration detection. The unique constituents of MH allowed for its successful discrimination through various analytical platforms, including mass spectrometry coupled to suitable chromatographic separation (i.e. GC-MS and LC-MS), nuclear magnetic resonance (NMR), and fluorescence analysis. Moreover, chemometric tools present potential for MH discrimination and has yet to be capitalized more upon for MH quality control analysis.

An integrative method based on UHPLC-Q-TOF-MS/MS combined with metabolomics to authenticate Isodon rubescens.

Genuine regional drugs have played a vital role in clinical use for a long time. There are differences in traditional Chinese medicines (TCM) from different regions based on their chemical composition. Differences in chemical composition may lead to deviations in therapeutic effects. To our knowledge, to date, there are no effective methods for distinguishing genuine regional drugs based on the differences in their chemical composition. Therefore, establishing an analytical platform for distinguishing the compounds used in TCM from various geographical locations is essential. In this work, an integrated platform based on UPLC-Q-TOF-MS/MS combined with plant metabolomics approach was established for comprehensively distinguishing genuine regional drugs. Isodon rubescens (Hemsl.) Hara, a widely used herbal medicine of China, was chosen for this study and 24 samples from four geographical locations in China were collected. A total of 60 ent-kaurane diterpenoids were tentatively identified, and then the samples from four geographical origins were distinguished using PCA (principal component analysis) and PLS-DA (partial least squares discrimination analysis). Different compounds were identified among the samples collected from the four geographical locations, and 12 of them were regarded as marker compounds responsible for the distinction. Our study highlights the essence and predictive ability of metabolomics in detecting minute differences in the same varieties of TCM samples based on the levels and compositions of their metabolites. These results showed that the analysis using UHPLC-Q-TOF-MS/MS combined with metabolomics could be applied to distinguish the geographical origins and varieties of TCM.

Authentication of three main commercial Pheretima based on amino acids analysis.

Pheretima has been used as an animal-derived traditional Chinese medicine for thousands of years in Asian countries due to its multi-activities. However, more than half of the commercial Pheretima are adulterants according to the previous research. Besides, the standards of Pheretima are still inadequate in the identification of Pheretima species. In this study, an amino acids (AAs) analytical method established based on the ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QqQ-MS) in multiple reaction monitoring (MRM) mode through derivatization with 9-fluorenylmethoxycarbonyl chloride (Fmoc-Cl) was used for qualitative and quantitative analysis of the total AAs of three main commercial Pheretima (two major Pheretima species, Amynthas aspergillum, Metaphire vulgaris, and one main counterfeit, M. magna). As a result, 16 AAs were detected and quantitated in their hydrolyzed samples. Then, multivariate statistical analysis was applied to distinguish the three commercial Pheretima based on their AAs level. Finally, four AAs (Thr, Glu, Asp, and Arg) were screened as species-differential AAs, which may be used as chemical markers to distinguish the three commercial Pheretima. This study deeply described the outline of AAs in Pheretima and offered a good reference for its species authentication.

Comprehensive profiling of the chemical components and potential markers in raw and processed Cistanche tubulosa by combining ultra-high-performance liquid chromatography coupled with tandem mass spectrometry and MS/MS-based molecular networking.

Chinese materia medica processing is a distinguished and unique pharmaceutical technique in traditional Chinese medicine (TCM), which has played an important role in reducing side effects, increasing medical potencies, altering the properties and even changing the curative effects of raw herbs. The efficacy improvement in medicinal plants is mainly caused by changes in the key substances through an optimized processing procedure. Thus, the use of a rapid method for determining suitable chemical markers between raw and processed TCM is critical in order to elucidate how the bioactive compounds influence the clinical effects. In this study, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry combined with MS/MS-based molecular networking (MN) and a multivariate statistical analysis method is proposed for the first time. This combination was used to identify the complex chemical composition and clarify the changed constituents between raw and processed Cistanche tubulosa (C. tubulosa). The chemical analysis results demonstrated that a total of 85 compounds were identified in the crude and processed C. tubulosa. Moreover, 34 compounds were detected as chemical markers. This systematic research into chemical constituents and chemical markers of crude and processed C. tubulosa lays a solid foundation for further study of the quality control of C. tubulosa. Moreover, the study provides a new and valuable technical strategy for analyzing chemical components and identifying potential chemical markers for the processing of herbal medicines.Graphical abstract.

A strategy for practical authentication of medicinal plants in traditional Chinese medicine prescription, paeony root in ShaoYao-GanCao decoction as a case study.

Authentication of Chinese medicine materials in prescriptions is extremely difficult due to the complicated chemical matrix. A strategy integrating in-depth profiling, chemical marker selection, and selected detection was established and exemplarily applied to authenticate paeony root in ShaoYao-GanCao decoction. First, an ultra-performance liquid chromatography/linear trap quadrupole-Orbitrap method was developed to probe the chemical compositions of the decoction. Second, 20 batches of decoctions prepared from white paeony root and red paeony root were compared by a metabolomics method, and multistep chemometrics analysis distinguished the chemical markers. Third, an ultra-performance liquid chromatography/QDa-selected ion monitoring method was developed to authenticate the paeony root in decoctions. As a result, 161 compounds were characterized, including 84 triterpene saponins, 42 flavonoids, and 10 monoterpenes. Four chemical markers and paeoniflorin were successfully screened out as chemical markers for white paeony root. The selected ion monitoring method easily differentiated authentic decoction (prepared from white paeony root) from fraud decoction (prepared from red paeony root) by monitoring the above five chemical markers. In conclusion, the strategy was proved effective in authentication of paeony root in ShaoYao-GanCao decoction, and it can also be applied to authenticate other Chinese medicine materials in prescriptions, which will greatly avail the quality enhancement of prescriptions.

Application of the Dehydration Homogeneous Liquid-Liquid Extraction (DHLLE) Sample Preparation Method for Fingerprinting of Honey Volatiles.

Recently, we proposed a new sample preparation method involving reduced solvent and sample usage, based on dehydration homogeneous liquid-liquid extraction (DHLLE) for the screening of volatiles and semi-volatiles from honey. In the present research, the method was applied to a wide range of honeys (21 different representative unifloral samples) to determine its suitability for detecting characteristic honey compounds from different chemical classes. GC-FID/MS disclosed 130 compounds from different structural and chemical groups. The DHLLE method allowed the extraction and identification of a wide range of previously reported specific and nonspecific marker compounds belonging to different chemical groups (including monoterpenes, norisoprenoids, benzene derivatives, or nitrogen compounds). For example, DHLLE allowed the detection of cornflower honey chemical markers: 3-oxo-retro-α-ionols, 3,4-dihydro-3-oxoedulan, phenyllactic acid; coffee honey markers: theobromine and caffeine; linden honey markers: 4-isopropenylcyclohexa-1,3-diene-1-carboxylic acid and 4-(2-hydroxy-2-propanyl)cyclohexa-1,3-diene-1-carboxylic acid, as well as furan derivatives from buckwheat honey. The obtained results were comparable with the previously reported data on markers of various honey varieties. Considering the application of much lower volumes of very common reagents, DHLLE may provide economical and ecological advantages as an alternative sample preparation method for routine purposes.

Chemical Fingerprinting of Cryptic Species and Genetic Lineages of Aneura pinguis (L.) Dumort. (Marchantiophyta, Metzgeriidae).

Aneura pinguis (L.) Dumort. is a representative of the simple thalloid liverworts, one of the three main types of liverwort gametophytes. According to classical taxonomy, A. pinguis represents one morphologically variable species; however, genetic data reveal that this species is a complex consisting of 10 cryptic species (named by letters from A to J), of which four are further subdivided into two or three evolutionary lineages. The objective of this work was to develop an efficient method for the characterisation of plant material using marker compounds. The volatile chemical constituents of cryptic species within the liverwort A. pinguis were analysed by GC-MS. The compounds were isolated from plant material using the HS-SPME technique. Of the 66 compounds examined, 40 were identified. Of these 40 compounds, nine were selected for use as marker compounds of individual cryptic species of A. pinguis. A guide was then developed that clarified how these markers could be used for the rapid identification of the genetic lineages of A. pinguis. Multivariate statistical analyses (principal component and cluster analysis) revealed that the chemical compounds in A. pinguis made it possible to distinguish individual cryptic species (including genetic lineages), with the exception of cryptic species G and H. The classification of samples based on the volatile compounds by cluster analysis reflected phylogenetic relationships between cryptic species and genetic lineages of A. pinguis revealed based on molecular data.

Application of enantiomeric fractions in environmental forensics: Uncertainties and inconsistencies.

The assumption that only biological processes are enantioselective introduces challenges in the reliability of enantioselective analysis as a tool for discriminating biotic and abiotic processes in the environmental fate of chiral pollutants. Enantioselectivity does not depend on the nature of the fate process a chiral contaminant undergoes but on the interaction of the chiral contaminant with homochirality inducing external agents (e.g. chiral molecules, macromolecules or surfaces such as enzymes, blood plasma, proteins, chiral co-pollutants, humic acid and soil organominerals). The environmental behavior of a chiral contaminant is difficult to anticipate because the interactions between the chiral contaminants and the homochirality inducing external agents is often complex and strongly influenced by local environment conditions such as pH, redox conditions, organic carbon, organic nitrogen, humic acid, and redox conditions. Furthermore, the use of enantioselective analysis in environmental forensics depend on the adequate separation and accurate identification and quantification of the enantiomers of the chiral contaminant. Matrix effects, instrument effects, inadequate enantioselective separation, and poor quantification techniques introduce uncertainties in the determination of enantiomeric composition. Here we present the weaknesses of this assumption and recommend using enantiomeric fractions as chemical markers of biotransformation with caution. We recommend using stable isotopes, including abiotic controls to determine if enantioselective sorption occurs, and determining stability of enantiomers in solvent or at elevated temperatures to account for confounding factors arising from matrix effects, enantioselective abiotic processes, and enantiomerization due solvent and thermal lability of the chiral analyte, respectively to maintain the integrity of the utility of enantiomeric composition changes as an environmental forensics tool.

Study on steroidal saponins in crude and stir-fried Fructus Tribuli by ultra-high-performance liquid chromatography-mass spectrometry coupled with multivariate statistical analysis.

Fructus Tribuli is a traditional Chinese medicine used clinically for many years. Crude Fructus Tribuli and stir-fried Fructus Tribuli are recorded in the Pharmacopoeia of the People's Republic of China. However, the differences between steroidal saponins in crude Fructus Tribuli and stir-fried Fructus Tribuli have not been compared. In this study, ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry along with multivariate statistical analysis was developed to discriminate the chemical profiles and identify the steroidal saponins of crude Fructus Tribuli and stir-fried Fructus Tribuli. Additionally, an ultra-high-performance liquid chromatography triple-quadrupole mass spectrometer was used for the simultaneous quantification of nine major steroidal saponins to analyze the variations between crude Fructus Tribuli and stir-fried Fructus Tribuli. Finally, a total of 30 steroidal saponins whose structures or contents changed significantly after processing were found and identified. The mechanism of structural transformations deduced indicated that during the stir-frying of Fructus Tribuli, C-22 hydroxy furostanol saponins were converted to the corresponding furostanol saponins containing C-20-C-22 double bonds by dehydroxylation and deglycosylation reactions that occurred in the spirostanol saponins causing the generation of steroidal sapogenins. This study was successfully applied to the global analysis of crude Fructus Tribuli and stir-fried Fructus Tribuli. The results of this research will be beneficial to explore the processing mechanism of Fructus Tribuli.

Mass Spectrometry-Based Metabolomics Combined with Quantitative Analysis of the Microalgal Diatom (Chaetoceros calcitrans).

Although many metabolomics studies of higher land plant species have been conducted, similar studies of lower nonland plant species, which include microalgae, are still developing. The present study represents an attempt to characterize the metabolic profile of a microalgal diatom Chaetoceros calcitrans, by applying high-resolution mass spectrometry detection, via Q-ExactiveTM Plus Orbitrap mass spectrometry. The results showed that 54 metabolites of various classes were tentatively identified. Experimentally, the chloroform and acetone extracts were clearly distinguished from other solvent extracts in chemometric regression analysis using PLS, showing the differences in the C. calcitrans metabolome between the groups. In addition, specific metabolites were evaluated, which supported the finding of antioxidant and anti-inflammatory activities. This study also provides data on the quantitative analysis of four carotenoids based on the identification results. Therefore, these findings could serve as a reliable tool for identifying and quantifying the metabolome that could reflect the metabolic activities of C. calcitrans.