Chemical constituents from aerial parts of Leonurus macranthus / 中草药

Objective: To investigate the chemical constituents from the aerial parts of Leonurus macranthus. Methods: The chemical constituents were separated and purified by silica gel, Sephadex LH-20, ODS column chromatographies, and semi-preparative HPLC. Their structures were determined by physicochemical properties and spectroscopic data. Results: Nineteen compounds were isolated from the CH2Cl2 layer of 70% aqueous acetone extract in the aerial parts of L. macranthus, and identified as (+)-syringaresinol (1), (+)-1-hydroxysyringaresinol (2), rayalinol (3), erythro-guaiacylglycerol-β-O-4'-coniferyl ether (4), (7R, 7'R, 7″S, 8S, 8'S, 8″S)-3', 4″- dihydroxy-3, 5, 4', 5″-tetramethoxy-7, 9': 7', 9-diepoxy-4, 8″-oxy-8, 8'-sesquineo-lignan-7″, 9″-diol (5), (7R, 7'R, 7″S, 8S, 8'S, 8″S)-4', 5″- dihydroxy-3, 5, 3', 4″-tetramethoxy-7, 9': 7', 9-diepoxy-4, 8″-oxy-8, 8'-sesquineo-lignan-7″, 9″-diol (6), genkwanin (7), 3'-hydroxy- genkwanin (8), eriodictyol (9), isoscopoletin (10), p-coumaric acid (11), caffeic acid methyl ester (12), trans-ferulic acid (13), syringic aldehyde (14), vanillic acid (15), oct-1-en-3-yl β-glucopyranoside (16), 5-hydroxy-2-pyrrolidone (17), pterolactam (18), and nicotinamide (19), respectively. Conclusion: Compounds 1-6 and 9-19 are isolated from the plants of genus Leonurus Linn. for the first time, and compounds 7 and 8 are found from L. macranthus for the first time.

Inhibitory effect of different species of hydroxygenkwanin on UGTs and UGT1A1 activities / 中国中药杂志

To predit the mechanism of metabolic drug-drug interactions of hydroxygenkwanin with other drugs, we investigated the inhibition inhibitory effect of hydroxygenkwanin on UGTs and UGT1A1 activities of different liver microsomes. In the present study, 4-nitrophenol (4-NP) and β-estradiol were elected as substrates to determine activities of UGTs and UGT1A1 by UV and HPLC, respectively. The results showed that, hydroxygenkwanin significantly inhibited UGTs activity in rat, mouse and human liver microsomes. UGT1A1 activity was inhibited by hydroxygenkwanin to varying degrees, with IC₅₀ about 190, 10.93, 20.07, 76.31 μmol•L⁻¹ in mouse liver microsome(MLM), rat liver microsome (RLM) and recombinant UGT1A1, and human liver microsome (HLM), respectively. The inhibition types were competitive inhibition (RLM, HLM) and linear mixed-typed linear inhibition (recombinant UGT1A1). The order for the inhibitory intensity was RLM>rUGT1A1>HLM>MLM. In conclusion, hydroxygenkwanin has an inhibitory effect on UGTs and UGT1A1 activities of different liver microsomes, with differences in species, indicating its potential drug interactions based on UGT1A1 enzyme. This study aims to provide a reliable experimental basis for its further research and development of hydroxygenkwanin, and provide theoretical reference for the clinic drug combination research.