Minor triterpenoid acids from an aqueous extract of Uncaria rhynchophylla / 药学学报

Seventeen minor triterpenoid acids (1-17) were isolated from an aqueous decoction of Uncaria rhynchophylla by a combinatory application of column chromatography using multiple stationary phases, including macroporous adsorbent resin, MCI resin, Sephadex LH-20, Toyopearl HW-40C, silica gel, and C18 reversed phase silica gel, combined with separation techniques of flash chromatography (FC) and high performance liquid chromatography (HPLC). Their structures were determined by analysis of HR-ESI-MS, UV, CD, and IR as well as 1D and 2D NMR spectroscopic data, of which eight new compounds (1-8) are named successively uncarinic acids Q-X, while the structures of 2 and 7 were confirmed by single crystal X-ray diffraction. In the in vitro assays, 27-hydroxyolean-12-en-28-oic acid (17) inhibited TGF-β-induced HSC-T6 cell activation at the concentration of 5 μmol·L-1.

Megastigmanes from an aqueous extract of Uncaria rhynchophylla / 药学学报

Five new megastigmanes (1-5) were isolated from a decoction of Uncaria rhynchophylla by separation techniques of column chromatography using a combination of multiple stationary phases, including macroporous adsorbent resin, MCI resin, silica gel, Sephadex LH-20, and Toyopearl HW-40F, and reversed phase HPLC. Their structures were characterized by spectroscopic data analysis of HR-ESI-MS, NMR, and CD, in combination with Mosher's mothed as well as ECD and NMR calculations. The new compounds were named uncarphyllonone A (1), uncarphyllonols A (2) and B (3), and uncarphabscisic acids A (4) and B (5). Although the structures of 3 and 4 were previously reported, the reported NMR spectroscopic data were incorrect or do not support the assigned structures in literatures. This is also the first report of discovery of new megastigmane natural products from the Uncaria genus.

New triterpenoid saponins from the leaves of Ilex chinensis and their hepatoprotective activity / 中国天然药物

Seven new triterpenoid saponins, including five ursane-type saponins, ilexchinenosides R-V (1-5), and two oleanane-type saponins, ilexchinenosides W-X (6-7), with four known triterpenoid saponins (8-11) were isolated from the leaves of Ilex chinensis. Their structures were elucidated by comprehensive spectroscopic 1D and 2D NMR and HR-ESI-MS data. Their sugar moieties were determined by HPLC analysis compared with standards after hydrolysis and derivatization. Compounds 1, 2, 4, 9 and 10 exhibited potential hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell injury in vitro.

Two folate-derived analogues from an aqueous decoction of Uncaria rhynchophylla / 中国天然药物

Two new folate-derived analogues, named uncarophyllofolic acids A (1) and B (2), respectively, were isolated from the Uncaria rhynchophylla hook bearing stem (Gouteng in Chinese). The distinct stereochemical structures of 1 and 2 were determined by spectroscopic data analysis in combination with acidic hydrolysis and Marfey's derivatization, along with comparison of their specific rotation and Cotton effect (CE) data with those of the biogenetically related known derivatives as well as theoretical calculations of electronic circular dichroism (ECD) spectra. A plausible biosynthetic pathway of 1 and 2, associating to folate metabolism and the previously reported orychophragines A-C from Orychophragmus violaceus, is discussed.

Alkaloids from an aqueous extract of Uncaria rhynchophylla / 药学学报

Five alkaloids were isolated from a decoction of Uncaria rhynchophylla by a combination of various chromatographic techniques, including macroporous adsorbent resin, MCI resin, silica gel, Sephadex LH-20, and reversed phase HPLC. Their structures were characterized by comprehensive analyses of spectroscopic data as monoterpene indole alkaloids (+)-(7R)-3-oxo-7-hydroxy-3,7-seco-dihydrorhynchohylline (1), (+)-(7S)-3-oxo-7-hydroxy-3,7-seco-dihydrorhyncho-hylline (2), (+)-(7R)-3-oxo-7-hydroxy-3,7-seco-rhynchohylline (3) and (+)-(7S)-3-oxo-7-hydroxy-3,7-seco-rhynchohylline (4), and a β-carboline alkaloid 1,2,3,4-tetrahydro-1-oxo-β-carboline (5). Among them, 1 and 2 are new compounds, 3 and 4 are new natural products that were semi-synthesized from isorhynchohylline with incorrect specific rotations, and 5 is isolated for the first time from the genus Uncaria.

Triterpenoids from leaves of Ilex chinensis / 中草药

Objective: To study the triterpenoids from the leaves of Ilex chinensis. Methods: The constituents were isolated and purified by various chromatographic methods, and the structures were elucidated by spectroscopic analysis. Results: Thirteen triterpenoid saponins were isolated from 70% ethanol extracts in the leaves of I. chinensis and identified as 3β, 23-dihydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranoside (1), quadranoside IV (2), mussaendoside R (3), monepaloside F (4), ilexoside XXVII (5), ilexoside XXXVII (6), ilexoside XXXVIII (7), ilexoside XLI (8), niga-ichigoside F1 (9), kalidiumoside D (10), chikusetsusaponin Iva (11), oblonganoside M (12), and 23-hydroxy-betulinic acid-28-O-β-D-glucopyranoside (13). Conclusion: Compounds 1, 10, and 13 are isolated from the genus Ilex for the first time. Compounds 2-8, 11, and 12 are isolated from this plant for the first time.

Influence of STAT3 on promoting Warburg effect probably by upregula-ting GLUT2 expression in the malignant transformation of WB-F344 rat hepatic oval cells / 中国病理生理杂志

AIM:To investigate the influence of signal transducer and activator of transcription 3(STAT3)on Warburg effect in the malignant transformation of WB-F344 rat hepatic oval cells.METHODS:The WB-F344 cells were treated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)and hydrogen peroxide(H2O2)to induce the malignant trans-formation.Evaluation of the transformed cells were measured by the soft agar colony formation assay and DNA aneuploidy with flow cytometry.The levels of glucose and lactate in the culture medium of the cells were detected by chromatography. The protein levels of alpha-fetoprotein(AFP),STAT3,p-STAT3 and glucose transporter 2(GLUT2)in the cells were ex-amined by Western blot analysis.The cell proliferation were evaluated by WST-1 assay,viable cell counting,measuring the S-phase fraction(SPF)and proliferation index(PI)using the data from flow cytometry analysis,and detecting proliferating cell nuclear antigen(PCNA)protein expression by Western blot.RESULTS:Compared with the control cells,the forma-tion of colonies in soft agar(P<0.05)and DNA aneuploidy(P<0.01)were elevated in transformed cells,and the ex-pression level of AFP was also augmented(P<0.05).The increases in the level of both glucose consumption(P<0.05) and lactate production(P<0.01)show that Warburg effect was enhanced in transformed cells.Meanwhile, the protein levels of GLUT2(P<0.01)and p-STAT3(P<0.01)in transformed cells were higher than those in the control cells.The cell proliferation parameters including SPF(P<0.01),PI(P<0.01), viable cell number and PCNA expression(P<0.01)in transformed cells were also elevated as compared with the control cells.Interestingly, stattic, an inhibitor of STAT3 activation,resulted in declines in glucose consumption(P<0.05)and lactate production(P<0.01)in the trans-formed cells.In addition,compared with transformed cells,formation of colonies in soft agar(P<0.01),DNA aneuploidy (P<0.01),AFP(P<0.05), GLUT2(P<0.05), and cell proliferation parameters including SPF(P<0.01), PI (P<0.01),viable cell number(P<0.05)and PCNA expression(P<0.05)were also decreased following stattic treat-ment in transformed cells.CONCLUSION:STAT3 promotes Warburg effect and cell proliferation probably by upregula-ting GLUT2 expression in the malignant transformation of hepatic oval cells.