Exploring potential inhibitors of acetylcholinesterase, lactate dehydrogenases, and glutathione reductase from Hagenia abyssinica (Bruce) J.F. Gmel. based on multi-target ultrafiltration-liquid chromatography-mass spectrometry and molecular docking.

ETHNOPHARMACOLOGICAL RELEVANCE: Parasitic infections impose a significant burden on public health worldwide. European pharmacopoeia records and ethnopharmacological studies indicate that Hagenia abyssinica (Bruce) J.F. Gmel. has traditionally been used to treat a variety of parasitic infections, while the potential antiparasitic compounds remain ambiguous. AIM OF THE STUDY: Acetylcholinesterase (AChE), lactate dehydrogenases (LDH), and glutathione reductase (GR) are the key target enzymes in the survival of parasites. The aim of our work was to screen antiparasitic compounds targeting AChE, LDH, and GR from H. abyssinica. MATERIALS AND METHODS: Ultrafiltration-liquid chromatography-mass spectrometry (UF-LC-MS) combined with molecular docking was used in this study. Therein, the alamarBlue® and Ellman's methods were employed to reveal the antitrypanosomal effect and AChE inhibitory activity. Meanwhile, the UF-LC-MS was carried out to screen the potential active compounds from H. abyssinica. Subsequently, molecular docking was performed to evaluate the binding mechanisms of these active compounds with AChE, LDH, and GR. Finally, the AChE inhibitory activity of potential inhibitors was detected in vitro. RESULTS: H. abyssinica exhibited significant antitrypanosomal and AChE inhibitory activity. Corilagin, brevifolin carboxylic acid, brevifolin, quercetin, and methyl ellagic acid were recognized as potential AChE inhibitors by UF-LC-MS, while methyl brevifolin carboxylate was identified as AChE, LDH, and GR multi-target inhibitor, with binding degree ranged from 20.96% to 49.81%. Molecular docking showed that these potential inhibitors had a strong affinity with AChE, LDH, and GR, with binding energies ranging from -6.98 to -9.67 kcal/mol. These findings were further supported by the observation that corilagin, quercetin, brevifolin carboxylic acid, and methyl brevifolin carboxylate displayed significant AChE inhibitory activity compared with the positive control (gossypol, 0.42 ± 0.04 mM), with IC50 values of 0.15 ± 0.05, 0.56 ± 0.03, 0.99 ± 0.01, and 1.02 ± 0.03 mM, respectively. CONCLUSIONS: This study confirms the antiparasitic potential of H. abyssinica, supporting the traditional use of H. abyssinica in local ethnopharmacology to treat parasites. At the same time, corilagin, brevifolin carboxylic acid, brevifolin, quercetin, methyl ellagic acid, and methyl brevifolin carboxylate exert their anti-parasitic effects by inhibiting AChE, LDH, and GR, and they are expected to be natural lead compounds for the treatment of parasitic diseases.

Potential hemostatic compounds targeting urokinase plasminogen activator explored from three Euphorbiaceae species: Euphorbia maculata, Euphorbia humifusa, and Acalypha australis, with bio-affinity ultrafiltration UPLC-MS.

INTRODUCTION: Numerous species of the Euphorbiaceae family, including Euphorbia maculata, Euphorbia humifusa, and Acalypha australis, have been used to manage bleeding disorders. However, few investigations have demonstrated their hemostatic potential, and their procoagulant compounds remain elusive. OBJECTIVE: This study aimed to determine the most active procoagulant extracts from the three species' crude extract (CE) and fractions in order to screen out the active compounds and to analyze their possible mechanisms of action. METHODS: An integrative approach, comprising prothrombin time and activated partial thromboplastin time evaluations and urokinase-type plasminogen activator (uPA) inhibitory assessment, followed by bio-affinity ultrafiltration paired with UPLC/QTOF-MS targeting uPA and docking simulations, was used. RESULTS: The extracts with highest procoagulant activity were the CE for both E. maculata (EMCE) and E. humifusa (EHCE) and the n-butanol fraction (NB) for A. australis (AANB). The most promising ligands, namely, isoquercetin, orientin, rutin, and brevifolin carboxylic acid, were selected from these lead extracts. All of these compounds exhibited pronounced specific binding values to the uPA target and showed tight intercalation with the crucial side chains forming the uPA active pocket, which may explain their mode of action. The activity validation substantiated their hemostatic effectivity in inhibiting uPA as they had better inhibition constant (Ki) values than the reference drug tranexamic acid. CONCLUSION: Collectively, the integrative strategy applied to these three species allowed the elucidation of the mechanisms underlying their therapeutic effects on bleeding disorders, resulting in the fast detection of four potential hemostatic compounds and their mode of action.

Screening and identification of potential hypoglycemic and hypolipidemic compounds from aqueous extract of Scutellaria baicalensis Georgi root combing affinity ultrafiltration with multiple drug targets and in silico analysis.

INTRODUCTION: Scutellaria baicalensis Georgi, a traditional Chinese medicine, is widely applied to treat various diseases among people, especially in East Asia. However, the specific active compounds in S. baicalensis aqueous extracts (SBAEs) responsible for the hypoglycemic and hypolipidemic properties as well as their potential mechanisms of action remain unclear. OBJECTIVES: This work aimed to explore the potential hypoglycemic and hypolipidemic compounds from SBAE and their potential mechanisms of action. METHODOLOGY: The in vitro inhibitory tests against lipase and α-glucosidase, and the effects of SBAE on glucose consumption and total triglyceride content in HepG2 cells were first performed to evaluate the hypoglycemic and hypolipidemic effects. Then, affinity ultrafiltration liquid chromatography-mass spectrometry (LC-MS) screening strategy with five drug targets, including α-glucosidase, α-amylase, protein tyrosine phosphatase 1B (PTP1B), lipase and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) was developed to screen out the potential active constituents from SBAE, and some representative active compounds were further validated. RESULTS: SBAE displayed noteworthy hypoglycemic and hypolipidemic properties, and 4, 10, 4, 8, and 8 potential bioactive components against α-amylase, α-glucosidase, PTP1B, HMGCR, and lipase were initially screened out, respectively. The interaction network was thus constructed between the potential bioactive compounds screened out and their corresponding drug targets. Among them, baicalein, wogonin, and wogonoside were revealed to possess remarkable hypoglycemic and hypolipidemic effects. CONCLUSION: The potential hypolipidemic and hypoglycemic bioactive compounds in SBAE and their mode of action were initially explored through ligand-target interactions by combining affinity ultrafiltration LC-MS strategy with five drug targets.

Potential antioxidative and anti-hyperuricemic components in Rodgersia podophylla A. Gray revealed by bio-affinity ultrafiltration with SOD and XOD.

Rodgersia podophylla A. Gray (R. podophylla) is a traditional Chinese medicine with various pharmacological effects. However, its antioxidant and anti-hyperuricemia components and mechanisms of action have not been explored yet. In this study, we first assessed the antioxidant potential of R. podophylla with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing antioxidant power (FRAP) assays. The results suggested that the ethyl acetate (EA) fraction of R. podophylla not only exhibited the strongest DPPH, ABTS radical scavenging and ferric-reducing activities, but also possessed the highest total phenolic and total flavonoid contents among the five fractions. After that, the potential superoxide dismutase (SOD) and xanthine oxidase (XOD) ligands from the EA fraction were quickly screened and identified through the bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS). Accordingly, norbergenin, catechin, procyanidin B2, 4-O-galloylbergenin, 11-O-galloylbergenin, and gallic acid were considered to be potential SOD ligands, while gallic acid, 11-O-galloylbergenin, catechin, bergenin, and procyanidin B2 were recognized as potential XOD ligands, respectively. Moreover, these six ligands effectively interacted with SOD in molecular docking simulation, with binding energies (BEs) ranging from -6.85 to -4.67 kcal/mol, and the inhibition constants (Ki) from 9.51 to 379.44 µM, which were better than the positive controls. Particularly, catechin exhibited a robust binding affinity towards XOD, with a BE value of -8.54 kcal/mol and Ki value of 0.55 µM, which surpassed the positive controls. In conclusion, our study revealed that R. podophylla possessed remarkable antioxidant and anti-hyperuricemia activities and that the UF-LC-MS method is suitable for screening potential ligands for SOD and XOD from medicinal plants.

Advances in microbial analysis: Based on volatile organic compounds of microorganisms in food.

In recent years, microbial volatile organic compounds (mVOCs) produced by microbial metabolism have attracted more and more attention because they can be used to detect food early contamination and flaws. So far, many analytical methods have been reported for the determination of mVOCs in food, but few integrated review articles discussing these methods are published. Consequently, mVOCs as indicators of food microbiological contamination and their generation mechanism including carbohydrate, amino acid, and fatty acid metabolism are introduced. Meanwhile, a detailed summary of the mVOCs sampling methods such as headspace, purge trap, solid phase microextraction, and needle trap is presented, and a systematic and critical review of the analytical methods (ion mobility spectrometry, electronic nose, biosensor, and so on) of mVOCs and their application in the detection of food microbial contamination is highlighted. Finally, the future concepts that can help improve the detection of food mVOCs are prospected.

Modulating Inflammation-Mediated Diseases via Natural Phenolic Compounds Loaded in Nanocarrier Systems.

The global increase and prevalence of inflammatory-mediated diseases have been a great menace to human welfare. Several works have demonstrated the anti-inflammatory potentials of natural polyphenolic compounds, including flavonoid derivatives (EGCG, rutin, apigenin, naringenin) and phenolic acids (GA, CA, etc.), among others (resveratrol, curcumin, etc.). In order to improve the stability and bioavailability of these natural polyphenolic compounds, their recent loading applications in both organic (liposomes, micelles, dendrimers, etc.) and inorganic (mesoporous silica, heavy metals, etc.) nanocarrier technologies are being employed. A great number of studies have highlighted that, apart from improving their stability and bioavailability, nanocarrier systems also enhance their target delivery, while reducing drug toxicity and adverse effects. This review article, therefore, covers the recent advances in the drug delivery of anti-inflammatory agents loaded with natural polyphenolics by the application of both organic and inorganic nanocarriers. Even though nanocarrier technology offers a variety of possible anti-inflammatory advantages to naturally occurring polyphenols, the complexes' inherent properties and mechanisms of action have not yet been fully investigated. Thus, expanding the quest on novel natural polyphenolic-loaded delivery systems, together with the optimization of complexes' activity toward inflammation, will be a new direction of future efforts.

Potential Antioxidative and Anti-Hyperuricemic Components Targeting Superoxide Dismutase and Xanthine Oxidase Explored from Polygonatum Sibiricum Red.

Polygonatum sibiricum Red. (P. sibiricum) has been used as a traditional Chinese medicine with a wide range of pharmacology effects. However, the responsible bioactive compounds and their mechanisms of action concerning its antioxidative and anti-hyperuricemic activities remain unexplored. In this work, the antioxidant capacity of P. sibiricum was firstly evaluated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3ethylbenzthiazoline)-6-sulfonic acid (ABTS) and ferric-reducing antioxidant power (FRAP) assays, from which the ethyl acetate (EA) fraction exhibited the highest DPPH, ABTS radical scavenging, and ferric-reducing capacities. Meanwhile, the EA fraction displayed the highest total phenolic and flavonoid contents among the four fractions. Next, the potential ligands from the EA fraction were screened out by bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS) with superoxide dismutase (SOD) and xanthine oxidase (XOD). As a result, N-trans-p-coumaroyloctopamine, N-trans-feruloyloctopamine, N-trans-feruloyltyramine were identified as potential SOD ligands, while N-cis-p-coumaroyltyramine was determined as potential XOD ligand. Additionally, these four ligands effectively interact with SOD and XOD in the molecular docking analysis, with binding energies (BEs) ranging from -6.83 to -6.51 kcal/mol, and the inhibition constants (Ki) from 9.83 to 16.83 µM, which were better than the positive controls. In conclusion, our results indicated that P. sibiricum has good antioxidative and anti-hyperuricemic activities, and its corresponding active ligands targeting SOD and XOD could be explored by the UF-LC-MS method.

Exploring potential antidiabetic and anti-inflammatory flavonoids from Euphorbia humifusa with an integrated strategy.

E. humifusa Willd, a monoecious annual plant, native to Eastern Asia, has been traditionally attributed to the treatment and prevention of miscellaneous diseases, including diabetes mellitus and its associated complications. Earlier studies have supported this species' pharmacological efficacies including its antibacterial, antidiabetic, and anti-inflammatory properties. Even so, the underlying bioactive components with their mechanisms of action associated with its antidiabetic and anti-inflammatory effects remain elusive. The preamble in vitro assessments of the crude extract and its different fractions revealed that the n-butanol fraction (EHNB) exhibited the best activity, which was subsequently subjected to a rapid screening of candidate ligands through bio-affinity ultrafiltration with the two enzyme targets: α-glucosidase (α-Glu) and cycloxygenase-2 (COX-2) combined with UPLC/QTOF-MS. As a result, 7 compounds were identified from EHNB, among them, vitexin and astragalin were screened out as the most active ligand compounds. Vitexin showed great specific binding (SB) affinity values of 1.26 toward α-Glu and 1.32 toward COX-2, while astragalin showed 1.32 and 1.36, respectively. The docking simulation results exhibited strong interactions of vitexin and astragalin with the key residues of the enzyme targets, suggesting their possible mechanisms of action. The in vitro antidiabetic validation revealed noticeable half-maximal inhibitory effects (IC50) of 36.38 ± 3.06 µM for vitexin and 42.47 ± 4.13 µM for astragalin, much better than that of the positive drug acarbose (109.54 ± 14.23 µM). Similarly, these two compounds showed the inhibitory activity against COX-2 with the half-maximal inhibitory effects (IC50) at 27.91 ± 1.74 µM and 49.05 ± 1.49 µM, respectively. Therefore, these two flavonoid compounds (vitexin and astragalin) were speculated as potential antidiabetic and anti-inflammatory compounds from E. humifusa. Taken together, the integrated strategy applied to E. humifusa led to the fast identification of two potential double-acting flavonoids and enlightened its antidiabetic and anti-inflammatory uses. Besides these findings, the integrated strategy in this study could also be used to facilitate the rapid discovery and development of active candidates from other traditional herbal medicines against multi-drug targets and to aid in revealing their mechanisms of action for their traditional uses.

Potential Antioxidative Components in Azadirachta indica Revealed by Bio-Affinity Ultrafiltration with SOD and XOD.

Azadirachta indica (A. indica) has been widely used due to its diverse pharmacological activities. However, there are currently few studies on its responsible antioxidant ingredients against superoxide dismutase (SOD) and xanthine oxidase (XOD). In this study, the antioxidant activities of A. indica were evaluated by a 2,2'-azinobis-(3-ethyl-benzthiazoline)-6-sulfonic acid) and ferric-ion-reducing antioxidant power method. Meanwhile, total polyphenol and flavonoid content were determined to reveal that they were the highest in ethyl acetate (EA) fraction. Next, compounds with the most antioxidant activity were screened out from EA fraction by bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS) with SOD and XOD. As a result, gallic acid, protocatechuic acid and (-)-epicatechin were identified as potential SOD ligands with relative binding affinity (RBA) values of 2.15, 1.78 and 1.61, respectively. Additionally, these three ligands could effectively interact with SOD in molecular docking with binding energies (BEs) ranging from -3.84 ± 0.37 to -5.04 ± 0.01 kcal/mol. In addition, carnosic acid exhibited a strong binding affinity to XOD with an RBA value of 2.05 and BE value of -8.24 ± 0.71 kcal/mol. In conclusion, these results indicated that A. indica might have good antioxidant activity and antigout potential, and the UF-LC-MS method is suitable and efficient for screening both SOD and XOD ligands from A. indica.

Plukenetia huayllabambana Fruits: Analysis of Bioactive Compounds, Antibacterial Activity and Relative Action Mechanisms.

Plukenetia huayllabambana is an edible plant traditionally used to cure wounds and various infections. The present work assessed, for the first time, the antibacterial efficacy of solvent fractions from P. huayllabambana fruits. The crude methanol extract was obtained applying ultrasound-assisted extraction, followed by partitioning through successive depletion among solvents of increasing polarity to yield fractions (n-hexane, dichloromethane, ethyl acetate, and n-butanol). The minimal inhibitory concentration (MIC) was determined following antibacterial testing, using the broth microdilution technique against a panel of drug-resistant Gram-negative and Gram-positive bacteria. Possible modes of action of the most active fraction were also investigated. Gas chromatography-mass spectrometry (GC-MS) was used to identify phytocompounds that may account for the recorded activities. Methanol, n-hexane (PH-n-Hex), and ethyl acetate extracts inhibited 100% of studied bacteria, with the recorded MIC ranging from 0.125-1 mg/mL. PH-n-Hex appeared as the most active partition, exerting a bacteriostatic effect. PH-n-Hex probably acts by interfering with bacterial biofilm formation, proton pumps, and bacterial cell membrane integrity. The GC-MS analysis of PH-n-Hex led to the identification of 11 potentially bioactive components, including fatty acids, phytosterol, and diterpene alcohol as major ones. P. huayllabambana can be considered as a plant of pharmacological value-a source of potent anti-infective drug entities.

Antioxidant and Anti-Proliferative Properties of Hagenia abyssinica Roots and Their Potentially Active Components.

Hagenia abyssinica (Bruce) J. F. Gmel. is a multipurpose dioecious tree that has been used to treat various ailments, for example, the flowers of H. abyssinica have been widely used as a tea to treat intestinal parasites by local residents and the roots of H. abyssinica could also be used for anticancer purposes. Antioxidant activity could be one of the most important pathways to suppress cancer and there is hardly any information available on the specific chemical components corresponding to the bioactivities of H. abyssinica to date. The present study intended to screen and evaluate the antioxidant and anti-proliferative properties of five different fractions from H. abyssinica along with their corresponding total flavonoid and phenolic contents and then further identify those compounds with the most potent antioxidant and anti-proliferative activities using high performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) and nuclear magnetic resonance (NMR). The total flavonoid and phenolic content assays showed that the ethyl acetate (EA) fraction of H. abyssinica had higher flavonoid and phenolic levels than the other four fractions. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) superoxide radical scavenging abilities, total antioxidant capacity (TAC) assay with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP) were measured to evaluate the antioxidant activities of the five fractions and some pure compounds isolated from the EA fraction, which displayed higher antioxidant properties than that of the other fractions. Caffeic acid from the EA fraction showed even stronger DPPH scavenging ability (IC50 7.858 ± 0.31 µg/mL) than that of Vc (IC50 8.27 ± 0.11 µg/mL) as the positive control. The anti-proliferative properties of four fractions and the ethanol extract were evaluated by the 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay and the EA fraction exhibited higher anti-proliferative activities against three cancer cell lines than that of the other fractions. Additionally, the compounds with good antioxidant activity from the EA fraction of H. abyssinica were screened and identified using LC-MS and NMR and were also found to possess good anti-proliferative activity. In the MTT assay, the quercetin showed the strongest dose-dependent anti-proliferative activities to colon cancer cells (HT-29) and liver cancer cells (HepG2) among all of the compounds isolated. This study provided valuable information on the synergistic antioxidant and anti-proliferative properties of H. abyssinica.

Advances in MS Based Strategies for Probing Ligand-Target Interactions: Focus on Soft Ionization Mass Spectrometric Techniques.

The non-covalent interactions between small drug molecules and disease-related proteins (ligand-target interactions) mediate various pharmacological processes in the treatment of different diseases. The development of the analytical methods to assess those interactions, including binding sites, binding energies, stoichiometry and association-dissociation constants, could assist in clarifying the mechanisms of action, precise treatment of targeted diseases as well as the targeted drug discovery. For the last decades, mass spectrometry (MS) has been recognized as a powerful tool to study the non-covalent interactions of the ligand-target complexes with the characteristics of high sensitivity, high-resolution, and high-throughput. Soft ionization mass spectrometry, especially the electrospray mass spectrometry (ESI-MS) and matrix assisted laser desorption ionization mass spectrometry (MALDI-MS), could achieve the complete transformation of the target analytes into the gas phase, and subsequent detection of the small drug molecules and disease-related protein complexes, and has exerted great advantages for studying the drug ligands-protein targets interactions, even in case of identifying active components as drug ligands from crude extracts of medicinal plants. Despite of other analytical techniques for this purpose, such as the NMR and X-ray crystallography, this review highlights the principles, research hotspots and recent applications of the soft ionization mass spectrometry and its hyphenated techniques, including hydrogen-deuterium exchange mass spectrometry (HDX-MS), chemical cross-linking mass spectrometry (CX-MS), and ion mobility spectrometry mass spectrometry (IMS-MS), in the study of the non-covalent interactions between small drug molecules and disease-related proteins.

Enrichment and analysis of quaternary alkaloids from Zanthoxylum simulans using weak cation exchange solid-phase extraction coupled with LC-MS.

INTRODUCTION: Quaternary alkaloids (QAs) are the major alkaloids in several traditional Chinese medicines, especially in Zanthoxylum simulans. However, few studies on enrichment of QAs from Z. simulans were conducted due to their high polarity and low content. OBJECTIVE: To develop a weak cation exchange (WCX) solid-phase extraction (SPE) coupled with liquid chromatography mass spectrometry (LC-MS) method to enrich and identify QAs from Z. simulans. Meanwhile, the qualitative and quantitative analyses of QAs were carried out based on the optimum conditions of the method. METHODS: Fresh stem bark of Z. simulans was extracted with 70% aqueous methanol and enriched by WCX-SPE. A high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) with an electrospray ionisation (ESI) source was used for the qualitative and quantitative analyses of QAs. RESULTS: Significant improvements were observed in resolution and abundance of the peaks with WCX-SPE. The linearity, limit of detection (LOD) and limit of quantification (LOQ) were determined for this analytical method. The linear relationship (A = 338.85C - 187.72, R2  = 0.99) was explored in the range of 0.5 to 312.5 µg/mL for chelerythrine. The LOD and LOQ for chelerythrine standard solutions were 0.0539 µg/mL and 0.1798 µg/mL, respectively. In addition, 22 peaks were detected successfully with WCX-SPE and nine of them are undetectable without the processing of WCX-SPE. CONCLUSION: A highly selective and efficient method for simultaneous enrichment and identification of QAs from crude extract of Z. simulans was developed for the first time by combining WCX-SPE with LC-MS.

Antioxidant and anti-inflammatory properties of flavonoids from lotus plumule.

The antioxidant and anti-inflammatory mechanisms of action of flavonoids in lotus plumule were systematically analyzed using radical scavenging assays and ELISA kits. By this means, flavonoids displayed significant antioxidant activity by donating electron, H atom as well as capturing DPPH and ABTS+ free radicals, and anti-inflammatory effect by inhibiting the production of the inflammatory mediators (NO radicals, PGE2 and TNF-α) and pro-inflammatory cytokines (IL-1ß and IL-6). Meanwhile, the bioactive components against inflammation targeting COX-2 were also revealed using ultrafiltration coupled to LC-MS (UF-LC/MS). In this way, 12 components showing specific binding to COX-2 were screened out and identified. The structure-activity relationships suggested that flavonoids O-glycosides displayed comparable binding affinities to COX-2 compared with flavonoids C-glycosides and could be considered as the main active components. This study will provide valuable information for the further exploration of lotus plumule as functional foods or in pharmaceutical industries in the near future.

Efficient separation of high-purity compounds from Oxytropis falcata using two-dimensional preparative chromatography.

The separation of high-purity compounds from traditional Tibetan medicines plays an important role in investigating their bioactivity. Nevertheless, it is often quite difficult to isolate compounds with high purity because of the complexity of traditional Tibetan medicines. In this work, an offline two-dimensional reversed-phase preparative method was successfully developed for the separation of high-purity compounds from Oxytropis falcata. Based on the analysis results, an ODS C18 prep column was used for first-dimensional preparation, and 14.8 g of the crude sample was separated into five fractions with a recovery of 74.6%. Then, an XAqua C18 prep column was used to isolate high-purity compounds in the second-dimensional preparation because its separation selectivity is different with the ODS C18 stationary phase. As a result, eight compounds in the crude sample were isolated in more than 98% purity. This is the first report of trans-cinnamic acid (1) and trifolirhizin (2) from Oxytropis falcata. This method has the potential to be an efficient separation method of high-purity compounds from Oxytropis falcata and it shows great promise for the separation of high-purity compounds from complex samples.

Phenolics from Lagotis brevituba Maxim.

A phytochemical investigation on Lagotis brevituba led to the isolation and characterisation of 11 phenolic compounds: p-hydroxy-benzoic acid 1, methyl 3,4-dihydroxybenzoate 2, vanillic acid 3, protocatechuic acid 4, caffeic acid 5, glucose ester of (E)-ferulic acid 6, p-coumaric acid 7, vanillin 8, diosmetin-7-O-ß-d-glucoside 9, chrysoeriol 10 and luteolin 11. Their structures were elucidated using spectroscopic methods and by comparison with data in the literature. Compounds 1-6 were first obtained from the genus Lagotis, and compounds 1-9 were isolated from L. brevituba for the first time. Compound 4 and 11 displayed remarkable antioxidant activities against DPPH radical (IC50 = 5.60 ± 0.09, 27.5 ± 0.06 mg/L, respectively), which were superior to positive control rutin. And compound 11 was also superior to rutin in ABTS assay (IC50 = 2.04 ± 0.13 mg/L).