Triterpenoids and Flavonoids from the Leaves of Astragalus membranaceus and Their Inhibitory Effects on Nitric Oxide Production.

Four new cycloartane triterpenes, named huangqiyegenins V and VI and huangqiyenins K and L (1-4, resp.), together with nine known triterpenoids, 5-13, and eight flavonoids, 14-21, were isolated from a 70%-EtOH extract of Astragalus membranaceus leaves. The structures of the new compounds were elucidated by detailed spectroscopic analyses, and the compounds were identified as (9ß,11α,16ß,20R,24S)-11,16,25-trihydroxy-20,24-epoxy-9,19-cyclolanostane-3,6-dione (1), (9ß,16ß,24S)-16,24,25-trihydroxy-9,19-cyclolanostane-3,6-dione (2), (3ß,6α,9ß,16ß,20R,24R)-16,25-dihydroxy-3-(ß-D-xylopyranosyloxy)-20,24-epoxy-9,19-cyclolanostan-6-yl acetate (3), and (3ß,6α,9ß,16ß,24E)-26-(ß-D-glucopyranosyloxy)-16-hydroxy-3-(ß-D-xylopyranosyloxy)-9,19-cyclolanost-24-en-6-yl acetate (4). All isolated compounds were evaluated for their inhibitory activities against LPS-induced NO production in RAW264.7 macrophage cells. Compounds 1-3, 14, 15, and 18 exhibited strong inhibition on LPS-induced NO release by macrophages with IC50 values of 14.4-27.1 µM.

[Study on lignans of Gentianella acuta].

OBJECTIVE: To study the lignans from the whole plant of Gentianella acuta. METHODS: The compounds were isolated by various chromatographic techniques and indentified by spectroscopic methods. RESULTS: Nine compounds were isolated and identified as (7R,8S) -dehydrodiconiferyl alcohol-4,9'-O-beta-D-glucopyranoside (1), alaschanisoside A (2), citrusin A (3), olivil-4'-O-beta-D-glucopyranoside (4), leptolepisol D (5), acanthoside D (6), (+) pinoresinol-4-O-beta-D-glucopyranoside (7), (+) 8-hydroxypinoresinol-4-O-beta-D-glucopyranoside (8), and (+) pinoresinol-8-O-beta-D-glucopyranoside (9). CONCLUSION: Compounds 1 - 9 are isolated from this plant for the first time, compounds 1 and 9 are isolated from Gentianella genus for the first time,and compounds 2, 3 and 5 - 8 are isolated from Gentianaceae family for the first time.