Phenolic compounds from the roots of Ochna schweinfurthiana and their antioxidant and antiplasmodial activities

摘要

An investigation of compounds extracted from Ochna schweinfurthiana roots with ethyl acetate led to the isolation of three new compounds 4'''-methoxylophirone A (1), 4,4',4'''-trimethoxylophirone A (2) and (4E;7Z)-3,8-dicarboxy-1-(O-beta-D-glucopyranosyl-(1 ! 6)-O-beta-D-glucopyranosyl-2,9-dihydroxyhexeicosa- 4,7-diene (3). Six known compounds were also identified, including Calodenone (4), Calodenine B (5), Lophirone A (6), Gerontoisoflavone A(7), 16 alpha,17-dihydroxy-ent-kauran-19-oic acid (8) and 3 beta-O-D-glucopyranosyl-beta-sitosterol (9). This report describes the first time that compounds 4-8 have been isolated from this plant, while 8 has never been identified in the genus Ochna. Some of the isolated compounds were evaluated for their antiplasmodial activity against the chloroquine-sensitive Plasmodium falciparum strain 3D7 and antioxidant activity using DPPH radical scavenging and Ferric reducing-antioxidant power (FRAP) assays. Compound 5 exhibited prominent radical scavenging and FRAP activities, while 7 had weak activity. Compound 1 showed good in vitro anti-plasmodial activity. The structures of the isolated compounds were elucidated by spectroscopic methods and comparisons with prior data in the literature. (C) 2016 Phytochemical Society of Europe. Published by Elsevier Ltd. All rights reserved.