Study on the Chemical Constituents and Bioactivities of Acalypha Brachystachya and Daphne Genkwa
|School||Huazhong University of Science and Technology|
|Keywords||Acalypha brachystachya Daphne genkwa Chemical Constituents Cytotoxicity|
The plants of the genus of Acalypha (Euphorbiaceae) have been widely used as folk medicine and used to treat malaria, infection, skin diseases and so on, in some areas of South America and Latin America. Acalypha australis (Euphorbiaceae) is used to cure diarrhea and dysentery, and is the main component of the Xian-Cai-Huang-Lian-Su capsules in China. Literature investigation revealed that there were no reports of the chemical constitution study on Acalypha brachystachya. This dissertation mainly deals with study on the chemical constituents of Acalypha brachystachya. By means of several chromatography methods, such as low, medium and high pressure column chromatography, and the using of several chromatographic packing materials, such as silica gel, Sephadex LH-20, ODS and MCI, 17 compounds were isolated from the petroleum ether and chloroform parts of the 95% ethanol extracts of the whole plants of Acalypha brachystachya, among them 11 compounds were identified to be chrysophanol (1), physcion (2), emodin (3), 1,2-benzenedicarboxylic acid, 1,2-dibutyl ester (4), 1,2-benzenedicarboxylic acid, 1,2-bis(2-methylpropyl) ester (5), lignoceric acid salicylate (6), spinasterol (7), oleanolic Acid (8), ursolic Acid (9), 3β-hydroxyolean-11-en-28,13β-olide (10) and squalene (11) on the basis of the analysis of physical and chemical properties, NMR and MS data. Compounds 1, 2 and 4-11 were isolated from the genus of Acalypha for the first time.The ethanol extracts of dry flower buds of Daphne genkwa Sieb.et Zucc. were dissolved in water and extracted by petroleum ether, chloroform, ethyl acetate and n-butanol to afford 4 parts. 10 compounds were isolated from the ethyl acetate part by sorts of chromatographic separation methods, and 8 compounds were identified as apigenin (12), genkwanin (13), 4′-O-Methylapigenin (14), kaempferol (3-O-β-D-(6-0-trans-p-coumaroyl)-glucopyranoside (15), 4-hydroxybenzaldehyde (16), trans-p-hydroxy cinnamic methyl ester (17), p-hydroxybenzoic acid (18) and p-hydroxy cinnamic acid (19), respectively. Compounds 16-19 were isolated from Daphne genkwa for the first time.In addition, the cytotoxic activities of spinasterol (7) and 3β-hydroxyolean-ll-en-28,13β-olide (10) and kaempferol (3-O-β-D-(6-0-trans-p-coumaroyl)-glucopyranoside (15) were tested in vitro. Spinasterol (7) showed cytotoxicity to HT-29, Hep-G2 and HELA cells, and the IC50 was 37.5μg/mL, 50μg/mL, and 37.5μg/mL, respectively. 3β-Hydroxyolean-ll-en -28,13β- olide (10) had no significant cytotoxicity to Hep-G2, to HT-29, IC50>50μg/mL. Compound 15 had no inhibitory activity against HELLA cells, slightly stimulated the proliferation of HT-29 cells, and inhibited the proliferation of HepG-2 with IC50 50μg/mL.