ABSTRACT
OBJECTIVE: To evaluate the antimalarial activity of Isodon yuennanensis for the development of neo-style antimalarial drugs or lead compounds from plants. METHODS: The crude extract and compounds from I. yuennanensis were screened for antimalarial activities by β-hematin formation inhibition assay, and the results were expressed as IC50 values. RESULTS: The crude extract, as well as some compounds, showed β-hematin formation inhibition activities in different degrees. CONCLUSION: The ethyl acetate fraction derived from the 70% acetone extract of I. yuennanensis and the compounds 2, 12, and 13 obtained from the ethyl acetate fraction are worthy of deeper research due to their significant antimalarial activities.
ABSTRACT
Objective: To study the chemical constituents from the roots of Astragalus englerianus, and to determine their anti-oxidative activities. Methods: The compounds were isolated and purified by silica gel, RP18, and Sephadex LH-20 column chromatography, then their structures were elucidated on the basis of spectral data and physicochemical properties, and anti-oxidative activities were tested by DPPH method. Results: Twenty-nine compounds were obtained from the ethyl acetate fraction of the methanol extract from the roots of A. englerianus and identified as isoliquiritigenin (1), 4'-hydroxy-2, 4-dimethoxychalcone (2), xenognosin (3), formononetin (4), calycosin (5), prunetin (6), (3R)-vestitol (7), liquiritigenin (8), (6aR, 11aR)-medicarpin-3-O-β-D-glucopyranoside (9), olean-12-en-3β, 22β, 24-triol (10), friedelin (11), β-sitosterol (12), stigmasterol (13), 7β-hydroxysitosterol (14), 7-oxositosterol (15), 3β-sitosteryl (9'Z)-9'-heptadecenoate (16), stigmast-4-en-3-one (17), 5α, 8α-epidioxy-ergosta-6, 9, 22E-trien-3β-ol (18), 5α, 8α-epidioxy-ergosta-6, 22E-dien-3β-ol (19), D-2-O-methylinositol (20), octacosanol (21), methyl stearate (22), eicosanoic acid (23), heneicosanoic acid (24), oleic acid (25), linoleic acid (26), α-linolenic acid (27), tripalmitin (28), and trilinolein (29). The ethyl acetate soluble portion, compounds 1 and 3 showed DPPH free radical scavenging activity with IC50 values of (66.0 ± 1.8), (64.3 ± 0.4), and (57.1 ± 1.2) μg/mL, respectively. Conclusion: This is the first report on the compounds 2, 3, 6, 10, 11, 14-22, and 28 from the plants of Astragalus Linn., and all the compounds are obtained from A. englerianus for the first time. A. englerianus is found to possess the potent anti-oxidative activity.