Li Yang

China Pharmaceutical University, Nan-ching-hsü, Jiangxi Sheng, China

Are you Li Yang?

Claim your profile

Publications (102)186.86 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Sweroside, a major active iridoid in Swertia pseudochinensis Hara, is recognized as an effective agent in the treatment of liver injury. Based on previous reports, the relatively short half-life (64 min) and poor bioavailability (approximately 0.31%) in rats suggested that not only sweroside itself but also its metabolites could be responsible for the observed hepato-protective effect. However, few studies have been carried out on the metabolism of sweroside. Therefore, the present study aimed at identifying the metabolites of sweroside in rat urine after a single oral dose (100 mg/kg). With ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF-MS), the metabolic profile revealed 11 metabolites in rat urine, including phase I, phase II and aglycone-related products. The chemical structures of metabolites were proposed based on accurate mass measurements of protonated or deprotonated molecules and their fragmentation patterns. Our findings showed that the aglycone of sweroside (M05) and its glucuronide conjugate (M06) were principal circulating metabolites in rats. While several other metabolic transformations, occurring via reduction, N-heterocyclization and N-acetylation after deglycosylation, were also observed. Two metabolites (M05 and M06) were isolated from the rat urine for structural elucidation and identifcation of reaction sites. Both M05 and M06 were characterized by 1H, 13C and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. UHPLC/Q-TOF-MS analysis has provided an important analytical platform to gather metabolic profile of sweroside. Copyright © 2014 John Wiley & Sons, Ltd.
    Biological Mass Spectrometry 11/2014; 49(11). · 3.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel comprehensive method with supercritical sluid chromatography-photodiode array detector-mass spectrometry (SFC-PDA-MS) was developed for the qualitative and quantitative analyses of chiral isomer pair in Ban Lan Gen (dried root of Isatis indigotica) and processed product. A standard goitrin/epigoitrin racemic mixture was used for method development. A total of six chiral stationary phases (CSPs) were screened and the (S, S)-Whelk-O 1 (4.6 ´ 250 mm, 10 μm) column was chosen as it offers the baseline resolution for the enantiomeric pair with separation accomplished in 6 minutes. A single quadrupole MS and a PDA detector were used in line for the detection. The validated method was applied successfully in the analysis of different samples. Results indicated that the developed assay was fast, sensitive and reproducible. SFC should be an integral part of the overall analytical platform for TCM and natural product research, especially in the area of chiral analysis.
    RSC Advances 09/2014; · 3.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The toxicity assessment of herbal medicines is important for human health and appropriate utilization of these medicines. However, challenges have to be overcome because of the complexity of coexisting multiple components in herbal medicines and the highly interconnected organismal system. In this study, a target profiling approach was established by combining the characteristic fingerprint analysis of herbal chemicals with potential toxicity through a precursor ion scan-based mass spectroscopy and the target profiling analysis of biomarkers responsible for the toxicity. Through this newly developed approach, the comparative hepatotoxicity assessment of two herbal medicines from the same genus, Senecio vulgaris L. and Senecio scandens Buch.-Ham, was performed. Significant differences were found between the two species in their chemical markers (i.e., pyrrolizidine alkaloids) and biomarkers (i.e., bile acids) responsible for their toxicities. This result was consistent with the conventional toxicity assessment conducted by histopathological examination and clinical serum index assay on experimental animal models. In conclusion, this study provided a new approach for the hepatotoxicity assessment of herbal medicines containing pyrrolizidine alkaloids, which are widely distributed in various herbal medicines. The target profiling approach may shed light on the toxicity assessment of other herbal medicines with potential toxicity.
    Analytical and Bioanalytical Chemistry 09/2014; · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sterol regulatory element-binding proteins (SREBPs) are major transcription factors regulating the expression of genes involved in biosynthesis of cholesterol, fatty acid and triglyceride. We investigated the effect of the specific SREBP suppressor andrographolide, a natural compound isolated from Andrographis paniculata, on the regulation of SREBP signaling by western blot, reporter gene assay and Q-PCR analysis. In addition, the anti-obesity effects of andrographolide were evaluated in C57BL/6 mice with high-fat diet (HFD)-induced obesity. Our results showed that andrographolide downregulated the expressions of SREBPs target genes and decreases cellular lipid accumulation in vitro. Further, andrographolide (100 mg/kg/day) attenuated HFD-induced body weight gain and fat accumulation in liver or adipose tissues, and improved serum lipid levels and insulin or glucose sensitivity in HFD-induced obese mice. Meanwhile, andrographolide effectively suppressed the respiratory quotient (RQ), energy expenditure (EE) and their oxygen consumption, which might contribute to the decreased body-weight gain of the obese mice fed with a HFD. Consistently, andrographolide regulates SREBPs target genes and metabolism associated genes in liver or brown adipose tissue (BAT), which may directly contribute to the lower lipid level and enhanced insulin sensitivity. Take together, andrographolide ameliorates lipid metabolism and improved glucose utilization in the HFD-induced obesity mice. Therefore, andrographolide could be a potential leading compound used for the prevention or treatment of obesity and insulin resistance.
    Journal of Pharmacology and Experimental Therapeutics 09/2014; · 3.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Retinoic acid (RA) and bile acids share common roles in regulating lipid homeostasis and insulin sensitivity. In addition, the receptor for RA (retinoid x receptor) is a permissive partner of the receptor for bile acids, farnesoid x receptor (FXR/NR1H4). Thus, RA can activate the FXR-mediated pathway as well. The current study was designed to understand the effect of all-trans RA on bile acid homeostasis. Mice were fed an all-trans RA-supplemented diet and the expression of 46 genes that participate in regulating bile acid homeostasis was studied. The data showed that all-trans RA has a profound effect in regulating genes involved in synthesis and transport of bile acids. All-trans RA treatment reduced the gene expression levels of Cyp7a1, Cyp8b1, and Akr1d1, which are involved in bile acid synthesis. All-trans RA also decreased the hepatic mRNA levels of Lrh-1 (Nr5a2) and Hnf4α (Nr2a1), which positively regulate the gene expression of Cyp7a1 and Cyp8b1. Moreover, all-trans RA induced the gene expression levels of negative regulators of bile acid synthesis including hepatic Fgfr4, Fxr, and Shp (Nr0b2) as well as ileal Fgf15. All-trans RA also decreased the expression of Abcb11 and Slc51b, which have a role in bile acid transport. Consistently, all-trans RA reduced hepatic bile acid levels and the ratio of CA/CDCA, as demonstrated by liquid chromatography-mass spectrometry. The data suggest that all-trans RA-induced SHP may contribute to the inhibition of CYP7A1 and CYP8B1, which in turn reduces bile acid synthesis and affects lipid absorption in the gastrointestinal tract.
    Biochemical pharmacology. 08/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Danning tablets (DNts) is commonly prescribed in China as a cholagogic formula. Our previous studies showed that DNts exerted the protective effect on alpha-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis in a dose-dependent mannar. However, the detailed molecular mechanisms of DNts against ANIT-induced cholestasis are still not fully explored.
    BMC Complementary and Alternative Medicine 07/2014; 14(1):249. · 2.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Six new diterpenoids, 4-epi-7α-O-acetylscoparic acid A (1), 7α-hydroxyscopadiol (2), 7α-O-acetyl-8,17β-epoxyscoparic acid A (3), neo-dulcinol (4), dulcinodal-13-one (5), and 4-epi-7α-hydroxydulcinodal-13-one (6), and a new flavonoid, dillenetin 3-O-(6″-O-p-coumaroyl)-β-d-glucopyranoside (10), along with 12 known compounds, were isolated from the aerial parts of Scoparia dulcis. The 7S absolute configuration of the new diterpenoids 1-4 and 6 was deduced by comparing their NOESY spectra with that of a known compound, (7S)-4-epi-7-hydroxyscoparic acid A (7), which was determined by the modified Mosher's method. The flavonoids scutellarein (11), hispidulin (12), apigenin (15), and luteolin (16) and the terpenoids 4-epi-scopadulcic acid B (9) and betulinic acid (19) showed more potent α-glucosidase inhibitory effects (with IC50 values in the range 13.7-132.5 μM) than the positive control, acarbose. In addition, compounds 1, 11, 12, 15, 16, and acerosin (17) exhibited peroxisome proliferator-activated receptor gamma (PPAR-γ) agonistic activity, with EC50 values ranging from 0.9 to 24.9 μM.
    Journal of natural products. 06/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gigantol is a typical bibenzyl compound isolated from Dendrobii Caulis that has been widely used as a medicinal herb in China for the treatment of diabetic cataract, cancer and arteriosclerosis obliterans and as a tonic for stomach nourishment, saliva secretion promotion and fever reduction. However, few studies have been carried out on its in vivo metabolism. In the present study, a rapid and sensitive method based on ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) in positive ion mode was developed and applied to identify the metabolites of gigantol in rat urine after a single oral dose (100 mg/kg). Chromatographic separation was performed on an Acquity UPLC HSS T3 column (100 × 2.1 mm i. d., 1.8 µm) using acetonitrile and 0.1% aqueous formic acid as mobile phases. A total of 11 metabolites were detected and identified as all phase II metabolites. The structures of the metabolites were identified based on the characteristics of their MS, MS(2) data and chromatographic retention times. The results showed that glucuronidation is the principal metabolic pathway of gigantol in rats. The newly identified metabolites are useful to understand the mechanism of elimination of gigantol and, in turn, its effectiveness and toxicity. As far as we know, this is the first attempt to investigate the metabolic fate of gigantol in vivo. Copyright © 2014 John Wiley & Sons, Ltd.
    Biomedical Chromatography 06/2014; · 1.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass-directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)-seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid-induced toxicity. This article is protected by copyright. All rights reserved.
    Journal of Separation Science 05/2014; · 2.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: There is no method available to simultaneously detect GABA, Glu, Epi, NE, DA, 5-HT and 5-HIAA in mouse hippocampus. A rapid and sensitive LC-MS/MS method has been developed for simultaneously measuring seven neurotransmitters in mouse hippocampus. The analytes were detected in positive mode with multiple reaction monitoring (MRM) and the procedure was completed in less than 9min. This method exhibited excellent linearity for all of the analytes with regression coefficients higher than 0.99, and showed good intra- and inter-day precisions (RSD<15%) with good accuracy (80-120%). Moreover, the method was successfully applied for the quantitative determination of neurotransmitters in a mouse depression model induced by successive methylprednisolone injections. The results indicated that this depression model was closely associated with the decreased level of Epi (p=0.002) and elevated ratio of 5-HIAA/5-HT (p=0.01), which has never been reported elsewhere. Compared with previous methods, current approach is more convenient without any pre-column derivatization of the analytes but enhances detectability with incremental neurotransmitter profile and shortens detection time. This work represents the first accurate simultaneous determination of seven neurotransmitters in the mouse depression model induced by methylprednisolone. The reliable method will benefit the research of neurological diseases with the altered neurotransmitter profile in brain.
    Journal of neuroscience methods 04/2014; · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 20(S)-Protopanaxadiol (PPD), a dammarane-type triterpenoid sapogenin, acts as the pharmacophore of ginsenosides which are considered as the principal bioactive components in Chinese ginseng. To fully understand the mechanism of action of PPD, it is important to study its metabolic profiles in vivo. Plasma, urine, fece and bile were collected after administration of PPD formulated in 0.5% aqueous Tween-80 to rats (150 mg/kg). Samples were analyzed by using a sensitive and reliable method based on ultra-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS/MS) in both positive and negative ion mode. The chemical structures of metabolites were elucidated by comparing the retention time, accurate molecular mass, and fragmentation patterns of analytes with those of PPD. In total 29 metabolites, including 10 new metabolites (M20-M29), were tentatively identified and characterized. Among them, two metabolites (M3 and M4) were unambiguously identified by matching their retention times and fragmentation patterns with their standards. Principal metabolites, namely, 20, 24-oxide metabolites (M3 and M4), 26/27-carboxylic acid derivatives (M22 and M23) and a glucuronidated product (M28), were found in the rat plasma. The results showed that phase I metabolites are monooxygenation, dioxygenation and oxidative dehydrogenation metabolites, and phase II metabolic pathways were demonstrated to be cysteine conjugation and glucuronidation. The newly identified metabolites are useful to understand the mechanism of elimination of PPD and, in turn, its effectiveness and toxicity. Copyright © 2014 John Wiley & Sons, Ltd.
    Rapid Communications in Mass Spectrometry 03/2014; 28(6):595-604. · 2.51 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pyrrolizidine alkaloids (PAs) are among the most hepatotoxic natural products that produce irreversible injury to humans via consumption of herbal medicine, tea preparation, and honey. Toxicity and death caused by PA exposure have been reported worldwide. Metabolomics and genomics provide scientific and systematic views of living organism, and have become powerful techniques for toxicology research. In this study, senecionine hepatotoxicity on rats was determined via a combination of metabolomic and genomic analyses. From the global analysis generated from two omics data, the compromised bile acid homeostasis in vivo was innovatively demonstrated and confirmed. Serum profiling of bile acids was altered with significantly elevated conjugated bile acids after senecionine exposure, which was in accordance with toxicity. Similarly, the hepatic mRNA levels of several key genes associated with bile acid metabolism were significantly changed. This process included cholesterol 7- hydroxylase, bile acid CoA-amino acid N-acetyltransferase, sodium taurocholate co-transporting polypeptide, organic anion-transporting polypeptides, and multi-drug-resistance-associated protein 3. In conclusion, cross-omics study provides a comprehensive analysis method for studying the toxicity caused by senecionine, which is a hepatotoxic PA. Moreover, the change in bile acid metabolism and the respective transporters may provide a new PA toxicity mechanism.
    Chemical Research in Toxicology 03/2014; · 3.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are legitimate therapeutic targets for Alzheimer's disease. The classical approach for screening potential AChE/BChE inhibitors was developed by Ellman. However, the background color of compounds or plant extracts remained uncertain and frequently interfered with the detection of the secondary reaction, thereby easily yielding false positive or false negative results. Rapid, selective, and sensitive ultra-performance liquid chromatography combined with electrospray ionization tandem mass spectrometry method was developed and used for the detection of AChE and BChE inhibition by directly determining the common product, choline (Ch). Proper separation was achieved for choline and chlormequat (internal standard) within 1.2min via isocratic elution (0.1% fromic acid:methanol=98:2) on an HSS T3 column following a simple precipitation of proteins for sample treatment. The relative standard deviations of the intra- and inter-day precisions were below 7.34 and 9.09%, respectively, whereas the mean accuracy for the quality control samples was 100.31±10.93%. The method exhibited the advantages of small total reaction volume (100μL), short analysis time (1.2min), high sensitivity (LOQ of 0.036μM for Ch), and low cost (little consumption enzymes of 0.0035 and 0.008unitmL(-1) for AChE and BChE, and substrates of 5.505 and 7.152μM for ACh and BCh in individual inhibition, respectively), and without matrix effect (90.00-105.03%). The developed method was successfully applied for detecting the AChE and BChE inhibitive activities for model drugs, including galanthamine, tacrine, neostigmine methylsulfate, eserine, as well as β-carboline and quinazoline alkaloids from Peganum harmala.
    Journal of pharmaceutical and biomedical analysis 02/2014; 94C:215-220. · 2.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The metabolic investigation of natural products is a great challenge because of unpredictable metabolic pathways, little knowledge on metabolic effects, and lack of recommended analytical methodology. Herein, a combined strategy based on ultrahigh-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF-MS), nuclear magnetic resonance (NMR) spectroscopy, and electronic circular dichroism (ECD) calculation was developed and employed for the human metabolism study of gentiopicroside (GPS), a naturally hepato-protective iridoid glycoside. The whole metabolic study consisted of three major procedures. First, an improved UHPLC/Q-TOF-MS method was used to separate and detect a total of 15 GPS metabolites that were obtained from urine samples (0 to 72 h) of 12 healthy male participants after a single 50-mg oral dose of GPS. Second, a developed "MS-NMR-MS" method was applied to accurately identify molecular structures of the observed metabolites. Finally, given that the associated stereochemistry may be a crucial factor of the metabolic activation, the absolute configuration of the reactive metabolites was revealed through chemical calculations. Based on the combined use, a pair of diastereoisomers (G05 and G06) were experimentally addressed as the bioreactive metabolites of GPS, and the stereochemical determination was completed. Whereas several novel metabolic transformations, occurring via oxidation, N-heterocyclization and glucuronidation after deglycosylation, were also observed. The results indicated that GPS has to undergo in vivo metabolism-based activation to generate reactive molecules capable of processing its hepato-protective activity.
    Analytical and Bioanalytical Chemistry 01/2014; · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Dencichine, one of the non-protein amino acids present in the roots of Panax notoginseng has been found to shorten bleeding time of mice and increase the number of platelets. However, the exact underlying mechanisms have not been elucidated yet. This study was aimed to identify the hemostatic effect of dencichine and uncover its mechanisms. Materials and methods Hemostatic effect was assessed by measuring tail bleeding time and coagulation indices of rats. PT, APTT, TT and FIB concentration were measured using a Sysmex CA-1500 plasma coagulation analyzer. Platelet aggregation rate was determined by using a platelet aggregometer. Concentration of cyotosolic calcium was evaluated by Fluo-3 and levels of cyclic adenosine monophosphate (cAMP) and thromboxane A2 (TXA2) were measured by ELISA method. Results and conclusion Dencichine administered orally shortened tail bleeding time, reduced APTT and TT but increased the concentration of FIB in plasma in a dose-dependent manner. When induced with trap, dencichine could elevate the cytoplasmic concentration of calcium, and secretion of TXA2 as well as the ratio of TXA2 to PGI2 from platelets. Meanwhile, it decreased the level of intracellular cAMP. However, CNQX could block the enhanced hemostatic effect of dencichine. These results suggested that dencichine exerted hemostatic function via AMPA receptors on platelets, therefore, facilitated coagulation cascade in a paracrine fashion by control of platelet cytosolic calcium influx, cAMP production and TXA2 release. Current study may contribute to its clinical use in therapy of hemorrhage.
    Thrombosis Research 01/2014; · 3.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Diabetic retinopathy (DR) is the most common and serious complication of diabetes mellitus (DM). The present study investigates the amelioration of ethanol extract of Dendrobium chrysotoxum Lindl (DC) on streptozotocin (STZ)-induced DR and its engaged mechanism. Retinal immunofluorescence staining with cluster of differentiation 31 (CD31) demonstrated that DC (30-300mg/kg) decreased the increased retinal vessels in STZ-induced diabetic rats. Retinal histopathological observation also showed that retinal vessels were decreased in DC-treated diabetic rats. DC decreased the increased retinal mRNA expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) in diabetic rats, and DC also decreased the elevated serum VEGF level. Immunohistochemical staining further evidenced that DC decreased VEGF and VEGFR2 expression in retinas. Retinal mRNA expression of matrix metalloproteinase (MMP) 2 /9 was decreased in DC (300mg/kg)-treated diabetic rats. Serum levels of MMP 2/9, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) A/B, insulin-like growth factor 1 (IGF-1), interleukin 1β (IL-1β), and IL-6 were all decreased in DC-treated diabetic rats. In addition, DC decreased the increased phosphorylation of p65 and the increased expression of intercellular adhesion molecule-1 (ICAM-1). In conclusion, DC can alleviate retinal angiogenesis during the process of DR via inhibiting the expression of VEGF/VEGFR2, and some other pro-angiogenic factors such as MMP 2/9, PDGF A/B, bFGF, IGF-1. In addition, DC can also ameliorate retinal inflammation via inhibiting NFκB signaling pathway.
    Vascular Pharmacology. 01/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: To establish the local quality standard for Dendrobii devoniani caulis from Longling, Yunnan, the pharmacognostic characteristics microscopic characteristics and TLC identification were developed. Sulfuric acid-phenol method was used to determine the content of polysaccharide. An HPLC method was adopted to determine the content of mannose, and extractives were determined according to the procedures recorded in the Appendix of Chinese Pharmacopoeia(2010). The results showed a strong characteristics microscopic of Dendrobii devoniani caulis, and its TLC identification had a good resolution with clear spots; the content of polysaccharide is 35.7% -52.1% (average 42.7%), mannose 27.8%-46.1% (average 35.8%), and extract 4.5%-10.6% (average 7.38%). The method is simple, accurate and reliable, with good reproducibility. The established standard is acceptable for quality evaluation of Dendrobii devoniani caulis from Longling, Yunnan.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 12/2013; 38(23):4113-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Endophytic fungi are symbiotic with plants and possess multi-enzyme systems showing promising metabolite potency with region- and stereo-selectivities. The aim of this study was to utilize these special microorganisms as an in vitro model to mimic the potential mammalian metabolites of a natural iridoid gentiopicroside (GPS, 1). The fungi isolated from a medicinal plant Dendrobium candidum Lindl were screened for their biotransformation abilities using GPS as the substrate and one strain with high converting potency was identified as Penicillium crustosum 2T01Y01 based on the sequence of the internal transcribed spacer of ribosomal DNA (rDNA-ITS) region. On an optimized incubation of P. crustosum 2T01Y01 with the substrate, seven deglycosylated metabolites were detected using an ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS). A preparative-scaled biotransformation with whole-cells of the endophytic fungus resulted in the production of five metabolites including three novel ones as 5α-(hydroxymethyl)-6β-methyl-3,4,5,6-tetrahydropyrano[3,4-c]pyran-1(8H)-one (2), (Z)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (3) and (E)-4- (1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (4), along with two known ones, 5α-(hydroxymethyl)- 6β-methyl-1H,3H-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (5) and 5α-(hydroxymethyl)-6α-methyl-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (6), aided by the nuclear magnetic resonance and high-resolution mass spectral analyses. The other two metabolites were tentatively identified by on-line UPLC/Q-TOF-MS as 5-hydroxymethyl-5,6-dihydroisochromen-1-one (7) and 5-hydroxymethyl-3,4,5,6- tetrahydroisochromen-1-one (8), among them 8 is a new metabolite. To test the metabolic mechanism, the β-glucosidase activity of the fungus P. crustosum 2T01Y01 was assayed using ρ-nitrophenyl-β-D-glucopyranoside (ρNPG) as a probe substrate and the biotransformation pathways for GPS by the strain 2T01Y01 was proposed. In addition, the hepatoprotective activities of GPS and the metabolites 2, 5 and 6 against human hepatocyte cells line HL-7702 injury induced by hydrogen peroxide (H2O2) were evaluated.
    Applied and Environmental Microbiology 10/2013; · 3.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 20(S)-Protopanaxatriol (PPT), one of the aglycones of ginsenosides, has been shown to exert cardioprotective effects against myocardial ischemic injury. However, studies on PPT metabolism have rarely been reported. This study is the first to investigate the in vivo metabolism of PPT following oral administration by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) and nuclear magnetic resonance (NMR) spectroscopy. The structures of the metabolites were identified based on the characteristics of their MS data, MS(2) data, and chromatographic retention times. A total of 22 metabolites, including 17 phase I and 5 phase II metabolites, were found and tentatively identified by comparing their mass spectrometry profiles with those of PPT. Two new monooxygenation metabolites, (20S,24S)-epoxy-dammarane-3,6,12,25-tetraol and (20S,24R)-epoxy-dammarane-3,6,12,25-tetraol, were chemicallly synthesized and unambiguously characterized according to the NMR spectroscopic data. The metabolic pathways of PPT were proposed accordingly for the first time. Results revealed that oxidation of (1) double bonds at Δ((24,25)) to form 24,25-epoxides, followed by rearrangement to yield 20,24-oxide forms; and (2) vinyl-methyl at C-26/27 to form corresponding carboxylic acid were the predominant metabolic pathways. Phase II metabolic pathways were proven for the first time to consist of glucuronidation and cysteine conjugation. This study provides valuable and new information on the metabolism of PPT, which is indispensable for understanding the safety and efficacy of PPT, as well as its corresponding ginsenosides.
    Journal of pharmaceutical and biomedical analysis 10/2013; 88C:497-508. · 2.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, metabolites in the urine samples of rats orally administered with acteoside, a phenylethanoid glycoside compound, were detected and identified using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC/ESI-QTOF-MS) combined with an automated MS(E) technique. Up to 35 metabolites (19 metabolites of the parent drug and 16 metabolites of the degradation products) were observed, including processes of oxidization, glucuronidation, sulfation, and methyl conjugation. According to the metabolic pathways, acteoside mainly functioned as a prodrug and underwent hydrolysis before being absorbed into the blood. The degradation products, especially caffeic acid and hydroxytyrosol, were involved in further metabolism which was responsible for the low oral bioavailability but obvious pharmacological activities of acteoside. In summary, this work provided valuable information on acteoside metabolism through the rapid and reliable UPLC/ESI-QTOF-MS technique, which could be widely used for the investigation of natural product metabolites.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 09/2013; 940C:77-85. · 2.78 Impact Factor

Publication Stats

346 Citations
186.86 Total Impact Points


  • 2006–2013
    • China Pharmaceutical University
      • Department of Pharmacognosy
      Nan-ching-hsü, Jiangxi Sheng, China
    • Shanghai University of Traditional Chinese Medicine
      • • Institute of Chinese Materia Medica
      • • Key Laboratory of Standardization of Chinese Medicines of Ministry of Education
      Shanghai, Shanghai Shi, China
  • 2008–2012
    • Northeast Institute of Geography and Agroecology
      • • Laboratory of Analytical Chemistry for Life Science
      • • Dalian Institute of Chemical Physics
      Beijing, Beijing Shi, China