De-An Guo

Shanghai Institutes for Biological Sciences, Shanghai, Shanghai Shi, China

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Publications (228)499.88 Total impact

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    ABSTRACT: The herb pair of Salvia miltiorrhiza and Panax notoginseng has widely been used for improving coronary and cerebral circulation in China. However, the exact contribution of the major active components of S. miltiorrhiza and P. notoginseng to cardioprotection is far from clear. In the present study, three representative ingredients, salvianolic acid B (SalB) from S. miltiorrhiza and ginsenoside Rg1 (Rg1) and ginsenoside Rb1 (Rb1) from P. notoginseng, were selected to elucidate the mechanism of the herb pair at the ingredient level. The purity of SalB, Rg1, and Rb1 was >99%, as detected by high-performance liquid chromatography. Acute myocardial infarction was introduced by ligation of the left anterior descending coronary artery near the main pulmonary artery. Cardiac contractility was detected through a Mikro-tipped catheter, and cardiac infarct size was determined using triphenyltetrazolium chloride stain. The combination of SalB and Rg1, and not the combination of SalB and Rb1, improved heart contractility in rats with myocardial infarction. The different contributions of Rg1 and Rb1, in combination with SalB, to cardioprotection provides further direction to optimize and modernize the herbal medicines containing S. miltiorrhiza and P. notoginseng. The combination of SalB and Rg1 may provide potential protection against myocardial infarction. Copyright © 2014. Published by Elsevier Taiwan.
    Journal of the Chinese Medical Association : JCMA. 12/2014;
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    ABSTRACT: Cortex Lycii, the root bark of Lycium chinense Mill. or Lycium barbarum L., is a frequently used traditional Chinese medicine. Phytochemical studies have shown that phenolic amides are not only characteristic compounds but also abundant ones in this plant. In the present study, an effective method was developed for structural characterization of phenolic amides from Cortex Lycii by ultra-high performance liquid chromatography coupled with linear ion trap Orbitrap tandem mass spectrometry. The fragmentation of 14 compounds including six cinnamic acid amides, six neolignanamides, and two lignanamides were studied systematically for the first time. It was found that, in the positive ion mode, neutral loss of the tyramide moiety (137 Da) or N-(4-aminobutyl)acetamide moiety (130 Da) were characteristic for these compounds. At least 54 phenolic amides were detected in the extract and 48 of them were characterized, among which 14 known compounds were identified unambiguously by comparing the retention time and mass spectra with those of reference compounds, and 34 components were tentatively identified based on the fragmentation patterns, exact mass, UV spectra, as well as retention time. Fifteen compounds were characterized as potential new ones. Additionally, the developed method was applied to analyze eight batches of samples collected from the northwest of China, and it was found that cinnamic acid amides were the main type of phenolic amides in Cortex Lycii. In conclusion, the identification of these chemicals provided essential data for further phytochemical studies, metabolites identification, and the quality control of Cortex Lycii.
    Analytical and Bioanalytical Chemistry 11/2014; · 3.66 Impact Factor
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    ABSTRACT: Three new ent-kaurane (1-3) and five new ent-pimarane diterpenoids (4-8) and a new oleanane triterpene acid (9), together with 22 known compounds, were isolated from the root bark of the medicinal herb Acanthopanax gracilistylus. The structures of 1-9 were established based on the interpretation of high-resolution MS and 1D- and 2D-NMR data. The absolute configurations of 7 and 11 were determined by single-crystal X-ray diffraction and electronic circular dichroism analysis. Compounds 7 and 8 represent rare naturally occurring structures based on the devinyl ent-pimarane skeleton. Compounds 3, 10, 14, 16, and 17 exhibited potent inhibitory effects on the release of interleukin-1β (IL-1β), interleukin-8 (IL-8), and tumor necrosis factor (TNF-α) in lipopolysaccharide-stimulated peripheral blood mononuclear cells.
    Journal of Natural Products 10/2014; · 3.29 Impact Factor
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    ABSTRACT: Oplopanax elatus (Nakai) Nakai, a member of the ancient angiosperm plant family Araliaceae, is used for the treatment of different disorders in the medicine systems of China, Russia, and Korea, and was designated in Russia as a classical adaptogen. Despite extensive studies of classical adaptogens, there are comparatively few reports concerning the chemical composition and pharmacological effects of O. elatus in English. The plant is a potential source of saponins, flavonoids, anthraquinones, terpenes, and other active compounds. Experimental studies and clinical applications have indicated that O. elatus possesses a number of pharmacological activities, including adaptogenic, anti-convulsant, anti-diabetic, anti-fungal, anti-inflammatory, anti-oxidant, blood pressure modulating, and reproductive function effects. In this review, the chemistry, safety, and therapeutic potential of O. elatus are summarized and highlighted to encourage the further development of this plant. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.
    Chinese Journal of Natural Medicines 10/2014; 12(10):721-9.
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    ABSTRACT: Ten triterpenes in Ganoderma lucidum were quantitatively determined using ultra performance liquid chromatography, with ganoderic acid A serving as the single reference standard. Stable system parameters were established.
    Phytochemistry 09/2014; · 3.35 Impact Factor
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    ABSTRACT: Herbal medicines contain a large number of minor constituents, which could contribute to their therapeutic effects and provide valuable lead compounds for drug discovery. However, to explore minor constituents from complicated herbal extracts is usually laborious and time-consuming. In order to discover minor novel herbal constituents efficiently, we combined heart-cutting and comprehensive two-dimensional liquid chromatography (HC-2DLC) to remove major components from herbal extracts, and then characterized the minor ones by mass spectrometry. This strategy was employed to analyze Pueraria lobata and Pueraria thomsonii, the roots of which are used as the Chinese herbal medicine Ge-Gen. Five major compounds in Ge-Gen extract were removed by on-line heart-cutting, and the minor compounds were separated on an RP×RP 2DLC system (1D, Acquity CSH C18, 2.1×100mm, 1.7μm; 2D, Poroshell Phenyl-Hexyl, 3.0×50mm, 2.7μm). A synchronized gradient elution program was used to improve chromatographic resolution of the second dimension. By using this 2DLC system, a total of 271 and 254 peaks were separated in P. lobata and P. thomsonii within 35min, respectively. The practical and effective peak capacity was 1593 and 677, respectively, and the orthogonality was around 70%. Structures of 12 selected compounds were tentatively characterized by mass spectrometry, and 9 of them were discovered from Ge-Gen for the first time. Contents of these minor compounds in Ge-Gen were preliminarily determined to be 0.01-0.1% (w/w). The HC-2DLC/MS system is a powerful and convenient tool to explore minor novel chemical constituents from complex herbal extracts.
    Journal of Chromatography A 08/2014; · 4.61 Impact Factor
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    ABSTRACT: The preliminary metabolic profile of total diterpene acid (TDA) isolated from Pseudolarix kaempferi was investigated by using in vivo and in vitro tests. Pseudolaric acid C2 (PC2) was identified as the predominant metabolite in plasma, urine, bile and feces after both oral and intravenous administrations to rats using HPLC-UV and HPLC-ESI/MS(n), and demethoxydeacetoxypseudolaric acid B (DDPB), a metabolite proposed to be the glucoside of PC2 (PC2G), as well as pseudolaric acid C (PC), pseudolaric acid A (PA), pseudolaric acid A O-beta-D glucopyranoside (PAG), pseudolaric acid B O-beta-D glucopyranoside (PBG) and deacetylpseudolaric acid A (DPA) originated from TDA could also be detected. It was demonstrated by tests that the metabolism of TDA is independent of intestinal microflora, and neither of pepsin and trypsin is in charge of metabolism of TDA, TDA is also stable in both pH environments of gastric tract and intestinal tract. The metabolites of TDA in whole blood in vitro incubation were found to be PC2, DDPB and PC2G, which demonstrated that the metabolic reaction of TDA in vivo is mainly occurred in blood and contributed to be the hydrolysis of plasma esterase to ester bond, as well as the glucosylation reaction. These results clarified the metabolic pathway of TDA for the first time, which is of great significance to the in vivo active form and acting mechanism research of P. kaempferi.
    08/2014; 49(8):1169-74.
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    ABSTRACT: Microbial transformation of 20(R)-panaxadiol by the fungus Rhizopus chinensis CICC 3043 yielded seven metabolites. Their structures were elucidated on the basis of extensive spectroscopic analyses. R. chinensis could catalyze hydroxylation and further dehydrogenation at C-24 of 20(R)-panaxadiol, as well as hydroxylation at C-7, C-15, C-16, and C-29. Three of these compounds at 10μM could moderately inhibit growth of HepG2 human hepatocellular carcinoma cells with an inhibition rate of about 40%. Three compounds (also at 10μM) showed approximately 30% inhibition on NF-κB transcriptional activity in SW480 human colon carcinoma cells stably transfected with NF-κB luciferase reporter and induced by LPS.
    Phytochemistry 06/2014; · 3.35 Impact Factor
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    ABSTRACT: Ergostanes are major bioactive constituents of the medicinal mushroom Antrodia camphorata. These tetracyclic triterpenoids usually occur as 25R/S epimeric pairs, which renders their chromatographic separation difficult. In this study, we used analytical supercritical-fluid chromatography (SFC) to separate seven pairs of 25R/S-ergostanes from A. camphorata. The (R)- and (S)-forms for each of the seven pairs could be well resolved (Rs>1.3) on a Chiralcel OJ-H column (4.6×250mm, 5μm, chiral), eluted by 10% MeOH in CO2 at 2mL/min with a back pressure of 120bar and a column temperature of 40°C. Particularly, this chiral-SFC method could rapidly and efficiently separate low-polarity epimers like antcin A and antcin B, which were very difficult for RP-HPLC. A 3-min preparative-scale method was established to purify (25S)- and (25R)-antcin A for the first time. However, OJ-H column suffered from peak overlapping of different pairs of ergostanes. We found that Princeton 2-ethylpyridine column (2-EP, 4.6×250mm, 3μm, achiral) could effectively separate different pairs, although the resolutions for 25-R/S forms of each epimeric pair were not as good as OJ-H column. Meanwhile, all the (25S)-forms showed stronger retentions than the corresponding (25R)-epimers on the 2-EP column. These results demonstrated different selectivity of chiral- and achiral-SFC in separating 25R/S-ergostane epimers. Aside from high separation efficiency, SFC also showed advantage over HPLC in short analysis time and low consumption of organic solvents. Finally, both OJ-H and 2-EP columns were used on analytical SFC to separate 25R/S-ergostanes in an extract of A. camphorata.
    Journal of chromatography. A. 06/2014;
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    ABSTRACT: Seven hexahydrobenzophenanthridine-type alkaloids, Ambiguanine A-G, along with eight known alkaloids, were isolated from tubers of Corydalis ambigua var. amurensis. Their structures were elucidated based on extensive spectroscopic analyses, with absolute configurations determined by CD experiments.
    Phytochemistry 06/2014; · 3.35 Impact Factor
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    ABSTRACT: Glycycoumarin is a major bioactive coumarin of licorice (Glycyrrhiza uralensis), one of the most popular herbal medicines worldwide. In this work, the metabolism of glycycoumarin in rats was investigated. After oral administration of 40mg/kg glycycoumarin, 4 and 10 metabolites were respectively detected in rats plasma and urine samples by liquid chromatography coupled with mass spectrometry (LC/MS). These metabolites were tentatively characterized by analyzing their tandem mass spectra and high-resolution mass spectra, and the structures of glucuronides were confirmed by β-glucuronidase hydrolysis. Glycycoumarin mainly undertakes hydroxylation and glucuronidation metabolism, accompanied by hydrogenation and dehydrogenation as minor reactions. Two hydroxylated metabolites, 4''-hydroxyl glycycoumarin and 5''-hydroxyl glycycoumarin, were obtained by microbial transformation of Syncephalastrum racemosum AS 3.264, and their structures were fully identified by 1D and 2D NMR. Both metabolites are new compounds. Furthermore, they were proved to be catalyzed by P450 enzymes by rat liver microsomes incubation experiments. Finally, a metabolic pathway of glycycoumarin in rats was proposed. This is the first systematic study on metabolites identification of glycycoumarin.
    Journal of pharmaceutical and biomedical analysis. 06/2014; 98C:287-295.
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    ABSTRACT: Three new cardenolides (1-3) were isolated from the 90% ethanolic extract of the bark of a wild-type Calotropis gigantea. Their structures were determined by using NMR spectra and LC-MS analysis. Their inhibitory activities were evaluated against non-small cell lung carcinoma (A549) and human cervix epithelial adenocarcinoma (HeLa) cell lines. Compounds 1 and 3 exhibited strong inhibitory effect on two cancer cell lines.
    Natural product research 04/2014; · 1.01 Impact Factor
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    ABSTRACT: Five new oleanane and ursane type triterpenes, namely uncarinic acids F-J (1-5), together with six known triterpenic acids (6-11) were isolated from the stems and hooks of Uncaria rhynchophylla. Structure elucidation of 1-5 was based on the integrated analyses of high-resolution MS data, 1-D ((1)H NMR, (13)C NMR, DEPT) and 2-D (HSQC, HMBC, ROESY) NMR spectra. Compounds 4, 10, and 11 exhibited weak inhibitory effects on LPS-induced NO production in RAW264.7 cells (with IC50 1.48, 7.01, and 1.89μM, respectively) with dexamethasone (IC50 0.04μM) and quercetin (IC50 0.86μM) as the positive controls. 19-OH substituted oleanane triterpenic acids (1, 2, 5, 8) were prone to eliminate CH2O3, whereas those ursane-type encompassing 19-OH (3, 6, 7, 9, 4) were featured by preferred cleavage of H2O while performing the negative collision-induced MS/MS fragmentation on an LTQ/Orbitrap mass spectrometer.
    Fitoterapia 04/2014; · 2.23 Impact Factor
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    ABSTRACT: Over the past 30 years, China has significantly improved the drug development environment by establishing a series of policies for the regulation of new drug approval. The regulatory system for new drug evaluation and registration in China was gradually developed in accordance with international standards. The approval and registration of TCM in China became as strict as those of chemical drugs and biological products. In this review, TCM-based new drug discovery and development are introduced according to the TCM classification of nine categories.
    Chinese Journal of Natural Medicines 04/2014; 12(4):241-50.
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    ABSTRACT: Using activity-guided fractionation, phenolic amides (such as trans-N-caffeoyltyramine) were confirmed as main components from Cortex Lycii responsible for NF-κB inhibition. Fatty acids were identified as the major plant constituent responsible for the PPARγ activation.
    Journal of ethnopharmacology 03/2014; · 2.32 Impact Factor
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    ABSTRACT: Negative ESI-QIT-MS of several subtypes of flavonoid O-glycosides is known to produce deprotonated molecular ions which undergo homolytic fragmentation at the glycosidic bond upon collision-induced dissociation (CID). However, these subtypes have never been simultaneously compared under unified MS conditions. The (-)-ESI-MS(n) fragmentations of 69 flavonoid O-glycosides, involving eight subtypes, were analyzed using a quadrupole ion-trap mass spectrometer with collision energies varying from 18-44%. Factors influencing the homolytic glycosidic bond fragmentation, such as collision energy, hydroxylation of aglycone, and glycosylation pattern, were comprehensively studied. Under the unified CID-QIT-MS(2) conditions, the precursor deprotonated molecular ions [M-H](-) for 3-O-glycosyl, 3,7-di-O-glycosyl and 3,6,7-tri-O-glycosyl flavonols experienced homolytic fragmentation at the glycosidic bond and generated the radical aglycone ion [Y0 -H](-•) . This gas-phase CID fragmentation behavior was not observed for the other subtypes. A general trend was found that hydroxyl substitution at C-6, glycosylation at C-6/C-7, and acetylation of the saccharide moiety remarkably suppressed this fragmentation. In addition, flavonol 3-O-diglycosides (disaccharides) possessing a 1 → 2 glycosidic bond generated more abundant [Y0 -H](-•) product ions than those with a 1 → 3 or 1 → 6 bond. The terminal sugar triggered the homolytic fragmentation in the order Rha > Xyl > Glc. Moreover, new counterexamples were found for previously reported fragmentation rules. The low-energy CID homolytic fragmentation was diagnostic for structural identification of flavonol 3-O-glycosides. We have summarized key factors affecting this fragmentation. The results could be useful for rapid characterization of flavonoid O-glycosides in complicated herbal extracts. Copyright © 2014 John Wiley & Sons, Ltd.
    Rapid Communications in Mass Spectrometry 02/2014; 28(4):385-95. · 2.51 Impact Factor
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    ABSTRACT: The chemical composition of Drynaria fortunei, a traditional Chinese herbal medicine, is very complicated. In order to separate these chemicals to obtain their structural information, an orthogonal sample enrichment procedure was established. The ethyl acetate extract of D. fortunei was pre-separated by Sephadex LH-20 × polyamide columns to yield 15 fractions. These fractions were analyzed successively using a reversed-phase Agilent Zorbax SB-C18 column, coupled with diode array detection and electrospray ionization tandem mass spectrometry. The method reduced co-elution and enriched minor compounds on the basis of their chemical features. A total of 369 compounds were detected by LC/MSn, compared to less than 50 compounds without pre-separation. The pretreatment facilitated the analytical separation of flavonoids, proanthocyanidins, triterpenoids, phenolic acids, and lignans in D. fortunei, and allowed a comprehensive chemical profiling of these constituents. This method could be applied to other multicomponent herbal extracts.
    Planta Medica 02/2014; · 2.35 Impact Factor
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    ABSTRACT: Minor phenolic compounds in licorice (Glycyrrhiza uralensis) have recently been proved for diverse bioactivities and favorable bioavailability, indicating that they may play an important role in the therapeutic effects or herb-drug interactions of licorice. However, so far, their abundance in licorice remains unknown. In this study, a reliable solid-phase extraction coupled with a high-performance liquid chromatography and diode array detection method was established to determine the minor phenolic compounds in licorice. The analytes were enriched by a three-step solid-phase extraction method, and then separated on a YMC ODS-A column by gradient elution. Five coumarins and flavonoids were identified by electrospray ionization tandem mass spectrometry, and then quantified using high-performance liquid chromatography and diode array detection. The amounts of glycycoumarin, dehydroglyasperin C, glycyrol, licoflavonol, and glycyrin in G. uralensis were 0.81 ± 0.28, 1.25 ± 0.59, 0.20 ± 0.08, 0.12 ± 0.04, and 0.17 ± 0.08 mg/g, respectively. Abundances of these compounds in other Glycyrrhiza species (G. glabra, G. inflata, and G. yunnanesis) were remarkably lower than G. uralensis.
    Planta Medica 02/2014; · 2.35 Impact Factor
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    ABSTRACT: Two new cucurbitane triterpenoids, 7β-hydroxycucurbitacin F-25-O-acetate (1) and 2β,3β,20(S),26,27-pentahydroxy-16α,23(S)-epoxycucurbita-5,24-dien-11-one (2) along with eleven known cucurbitane triterpenoids (3-13, resp.) were isolated from the rhizomes of Hemsleya amabilis Diels. The chemical structures of the new isolated compounds were elucidated unambiguously by spectroscopic data analysis. The cytotoxic activities of the isolated cucurbitane triterpenoids were evaluated against the HeLa human cancer cell lines. Hemslein A (5), the main ingredient of Hemsleya amabilis, exhibited the significant cytotoxicity with IC50 value of 0.389 μM.
    Fitoterapia 01/2014; · 2.23 Impact Factor
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    ABSTRACT: Cycloastragenol (CA) is the genuine sapogenin of astragaloside IV (ASI). This study focuses on the preparation of CA from ASI. Five hydrolysis methods were compared including H2SO4 hydrolysis, HCl hydrolysis, two-phase acid hydrolysis, mild acid hydrolysis, and Smith degradation. Seven hydrolysis products were purified, and five of them were identified as new compounds. The results indicated that Smith degradation was the most effective approach to prepare CA. In contrast, mild acid hydrolysis produced CA at a low yield, accompanied with the artificial sapogenin astragenol. The other three acid hydrolysis methods mainly produced astragenol. Furthermore, the reaction conditions for Smith degradation were optimized as follows: ASI was dissolved in 60% MeOH-H2O solution, oxidized with 5 equiv. NaIO4 for 12h, followed by reduction with 3 equiv. NaBH4 for 4h, and finally acidified with 1M H2SO4 at pH2 for 24h. Under the optimal conditions, CA could be prepared from ASI at a yield of 84.4%.
    Fitoterapia 01/2014; · 2.23 Impact Factor

Publication Stats

2k Citations
499.88 Total Impact Points

Institutions

  • 2006–2014
    • Shanghai Institutes for Biological Sciences
      Shanghai, Shanghai Shi, China
  • 2002–2014
    • Peking University
      • • School of Pharmaceutical Sciences
      • • Modern Research Center for Traditional Chinese Medicine
      Peping, Beijing, China
  • 2008–2013
    • China Pharmaceutical University
      Nan-ching-hsü, Jiangxi Sheng, China
    • Chinese Academy of Sciences
      • Research Center for Modernization of Traditional Chinese Medicine
      Peping, Beijing, China
    • Shanghai University of Traditional Chinese Medicine
      • Department of Chinese Materia Medica
      Shanghai, Shanghai Shi, China
    • Shenyang Pharmaceutical University
      • School of Traditional Chinese Materia Medica
      Feng-t’ien, Liaoning, China
    • Dalian Medical University
      Lü-ta-shih, Liaoning, China
  • 2006–2013
    • Northeast Institute of Geography and Agroecology
      • Research Center for Modernization of Traditional Chinese Medicine
      Beijing, Beijing Shi, China
  • 2012
    • China Academy of Traditional Chinese Medicine
      Peping, Beijing, China
  • 2007–2012
    • Peking University Health Science Center
      Peping, Beijing, China
    • National Institute for the Control of Pharmaceutical and Biological Products
      Peping, Beijing, China
  • 2004–2005
    • Tianjin University
      T’ien-ching-shih, Tianjin Shi, China