Mingsong Fan

Metabolism and Pharmacokinetics of Mangiferin in Conventional Rats, Pseudo-Germ-Free Rats, and Streptozotocin-Induced Diabetic Rats

To clarify the role of the intestinal flora in the absorption and metabolism of mangiferin and to elucidate its metabolic fate and pharmacokinetic profile in diabetic rats, a systematic and comparative investigation of the metabolism and pharmacokinetics of mangiferin in conventional rats, pseudo-germ-free rats, and streptozotocin (STZ)-induced diabetic rats was conducted. Forty-eight metabolites of mangiferin were detected and identified in the urine, plasma, and feces after oral administration (400 mg/kg). Mangiferin underwent extensive metabolism in conventional rats and diabetic rats, but the diabetic rats exhibited a greater number of metabolites compared with that of conventional rats. When the intestinal flora were inhibited, deglycosylation of mangiferin and sequential biotransformations would not occur. Pharmacokinetic studies indicated a 2.79- and 2.35-fold increase in the plasma maximum concentration and the area under the concentration-time curve from 0 to 24 h of mangiferin in diabetic rats compared with those for conventional rats, whereas no significant differences were observed between conventional rats and pseudo-germ-free rats. Further real-time quantitative reverse transcription-polymerase chain reaction results indicated that the multidrug resistance (mdr) 1a level in the ileum increased, whereas its level in the duodenum and the mdr1b mRNA levels in the duodenum, jejunum, and ileum decreased in diabetic rats compared with those in conventional rats. With regard to the pseudo-germ-free rats, up-regulated mdr1a mRNA levels and down-regulated mdr1b mRNA levels in the small intestines were observed. The diabetic status induced increased UDP-glucuronosyltransferase (UGT) 1A3, UGT1A8, UGT2B8, and sulfotransferase (SULT) 1A1 mRNA levels and decreased catechol-O-methyltransferase (COMT), UGT2B6, UGT2B12, and SULT1C1 mRNA levels. These results might partially explain the different pharmacokinetic and metabolic disposition of mangiferin among conventional and model rats.

Analysis and detection of the chemical constituents of Radix Polygalae and their metabolites in rats after oral administration by ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Radix Polygalae (RP), the dried root of Polygala tenuifolia Willd., is a well-known traditional Chinese medicine to mediate sedative, antipsychotic, cognitive improving, neuroprotective, and anti-inflammatory therapeutic effects on the central nervous system. In this work, ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS/MS) was established for the separation and characterization of the chemical constituents in Radix Polygalae and their metabolites in rat plasma and urine after oral administration. Samples were separated on an Agilent Zorbax Eclipse Plus-C18 column (100mm×2.1mm, 1.8μm) with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Overall, 50 compounds were characterized from the RP, 9 of which are to our knowledge reported for the first time. In vivo, 10 components and 2 metabolites were observed in rat plasma, and 27 components and 7 metabolites were detected in rat urine. The results from this work improve our understanding on the chemical constituents of RP and their metabolic profiling.

Identification of major xanthones and steroidal saponins in rat urine by liquid chromatography–atmospheric pressure chemical ionization mass spectrometry technology following oral administration of Rhizoma Anemarrhenae decoction

Rhizoma Anemarrhenae (Zhimu in Chinese), the dried rhizome of Anemarrhena asphodeloides Bge. (Fam. Liliaceae), is a well-known traditional Chinese medicinal herb and has been used clinically in China for centuries to cure various diseases. However, like other traditional Chinese medicines, the effective constituents of this medicine, especially the assimilation and metabolites in vivo, which are very important to show their effects, have not been systematically studied. In this paper, solid-phase extraction and liquid chromatography-atmospheric pressure chemical ionization mass spectrometry technologies were used to study the constituents absorbed into rat urine and their metabolites after oral administration of Rhizoma Anemarrhenae decoction. A total of 11 compounds, including two xanthones, three of their metabolites and six steroidal saponins, were identified in rat urine sample. They were neomangiferin (1), glucuronide and monomethyl conjugate of mangiferin (2), mangiferin (3), monomethyl conjugate of mangiferin (4), dimethyl conjugate of mangiferin (5), timosaponin N or timosaponin E1 (6), timosaponin BII (7), timosaponin BIII (8), anemarrhenasaponin I or anemarrhenasaponin II (9), timosaponin AII (10) and timosaponin AIII (11). The results would efficaciously narrow the potentially active compounds range in Rhizoma Anemarrhenae decoction, and pave a helpful way for follow-up mechanism of action research.

Identification of major alkaloids and steroidal saponins in rat serum by HPLC-diode array detection-MS/MS following oral administration of Huangbai-Zhimu herb-pair Extract

Huangbai-Zhimu herb-pair (HBZMHP) is a widely used Chinese traditional medicine formula in treating various diseases; however, its active components have remained unknown. In this paper, serum chemistry and combined high-performance liquid chromatography (HPLC), diode-array detection and mass-spectrometry (MS) techniques were used to study the constituents of HBZMHP extract absorbed into rat serum after oral administration. A total of nine characteristic HPLC peaks in the TIC chromatograms were identified as magnoflorine (1), menisperine (2), palmatine (3), berberine (4), timosaponin N or timosaponin E1 (5), timosaponin D (6), timosaponin BIII, anemarsaponin C or xilingsaponin B (7) timosaponin BII (8) and timosaponin AIII (9). All of the identified peaks were constituents of HBZMHP extract. The results narrow the range of active compounds to be found in HBZMHP extract, and pave the way for the follow-up action mechanism research.

Ellagic acid derivatives from the stem bark of Dipentodon sinicus

Ellagic acid derivatives were isolated from Dipentodon sinicus and their structures were identified as 3,3′,4′-tri-O-methylellagic acid (1), 3,3′-di-O-methylellagic acid (2), 4,4′-di-O-methylellagic acid (3), 3,3′-di-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (4), 3,3′,4′-tri-O-methylellagic acid-4′-O-β-D-glucopyranoside (5), 3,3′-di-O-methylellagic acid-4′-O-β-D-glucopyranoside (6), and ellagic acid (7). All the compounds were isolated for the first time from the title plant.

Complete NMR spectral assignments of two new iridoid diastereoisomers from the flowers of Plumeria rubra L. cv. acutifolia

Two new iridoid diastereoisomers (1, 2), together with five known compounds, were isolated from the flowers of Plumerian rubra L. cv. acutifolia. Their structures were elucidated by the means of in‐depth spectroscopic and mass‐spectrometric analyses, particularly 1D and 2D NMR spectroscopy. Copyright

Cytotoxic triterpenoid saponins from Vaccaria segetalis

By the guidance of bioassay, one new cytotoxic triterpenoid saponin, 3-O-[β-d-galactopyranosyl-(1 → 2)-β-d-glucuronopyranosyl] quillaic acid 28-O-β-d-glucopyranosyl-(1 → 3)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[β-d-fucopyranosyl-(1 → 4)]-β-d-fucopyranoside (1), and five known cytotoxic triterpenoid saponins, vaccaroside E (2), vaccaroside G (3), vaccaroside B (4), segetoside H (5) and segetoside I (6), were isolated from Vaccaria segetalis. Their structures were established on the basis of ESI-MS, IR, extensive NMR (1H NMR, 13C NMR, TOCSY, 1H–1H COSY, DEPT, HMQC, HMBC and ROESY) analyses, chemical degradation, and by comparing with previously reported data. Compounds 1–6 showed moderate cytotoxic activities against LNcap, P-388 and A-549 cell lines with IC50 values in the range 0.1–12.9 μM.

Analysis of Multiple Constituents in Cong‐Ming‐Tang, a Chinese Herbal Formula for the Treatment of Amnesia, by High‐performance Liquid Chromatography with Quadrupole Time‐of‐flight Mass Spectrometry

INTRODUCTION Cong-Ming-Tang (CMT), named smart-soup in English, is a well-known traditional Chinese medicine formula for the treatment of amnesia in China. However, the isolation, purification and identification procedures of the major bioactive constituents in CMT are difficult and time consuming. OBJECTIVE To establish a rapid and sensitive high-performance liquid chromatography/electrospray ionisation with quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF/MS/MS) method that could be applied to rapidly separate and identify the major bioactive constituents in CMT. METHODS Methanolic extract of CMT was used for HPLC-QTOF/MS/MS analysis. Separation was performed on an Agilent Poroshell 120 EC- C18 column (2.7 ×100 mm .i.d., 2.7 µm) with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Both positive and negative ion modes were employed. RESULTS This analytical tool allowed the identification of 55 compounds from CMT formulae by comparing their retention times and MS spectra with those of authentic compounds or literature data in both positive and negative ion modes, including 4 xanthone C-glycosides, 4 sucrose esters, 11 oligosaccharide multi-esters,15 triterpene saponins, 15 triterpene acids, 2 lignans and 4 phenylpropanoids. Onjisaponin MF was tentatively elucidated as a new triterpene saponin based on the summarised fragmentation rules. CONCLUSION HPLC-QTOF/MS/MS provides a new powerful approach to identify the major chemical constituents in CMT rapidly and accurately. This study proposed a series of potential bioactive components without preparative isolation from the crude extract of CMT and indicated that the HPLC-QTOF/MS/MS method also can be a promising tool for the analysis of other traditional Chinese medicines.

Bioactivity-guided Fractionation and Analysis of Compounds with Anti-influenza Virus Activity from Gardenia jasminoides Ellis

Bioassay-guided fractionation of extracts from Fructus Gardeniae led to analysis of its bioactive natural products. After infection by influenza virus strain A/FM/1/47-MA in vivo, antiviral activity of the extracts were investigated. The target fraction was orally administered to rats and blood was collected. High-performance liquid chromatography coupled with photo diode array detector and electrospray ion trap multiple-stage tandem mass spectrometry was applied to screen the compounds absorbed into the blood. A structural characterization based on the retention time, ultraviolet spectra, parent ions and fragmentation ions was performed. Thirteen compounds were confirmed or tentatively identified. This provides an accurate profile of the composition of bioactive compounds responsible for the anti-influenza properties.

Ellagic acid glycosides from the stem bark of Aphananthe aspera

Five ellagic acid glycosides were isolated from Aphananthe aspera and their structures were identified as 3-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (1), 3-O-methylellagic acid-4′-O-β-D-xylopyranoside (2), 3,3′-di-O-methylellagic acid-4′-O-β-D-xylopyranoside (3), 3,3′, 4-tri-O-methylellagic acid-4′-O-β-D-glucopyranoside (4), and 3,3′-di-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (5) on the basis of spectroscopic analysis. Compound 1 is new, and all the compounds were isolated for the first time from the title plant.