Secondary metabolites from the leaves of Hymenocardia acida and their chemotaxonomic significance

The phytochemical investigation of the methanolic extract of the leaves of Hymenocardia acida (Euphorbiaceae) resulted in the isolation of twelve known secondary metabolites including flavonolignan (1), coumarin (2), chromone (3), C-glucosylated flavonoid (4), bisphenylpropanoid (5), triterpenoids (6–9) and steroids (10–12), respectively. Their structures were elucidated by comparison of their physical and spectroscopic data with those reported in literature. This is the first report on isolation of compounds 1–5 and 10 from the family Euphorbiaceae. The chemotaxonomic significance of these compounds has been discussed. Hydnocarpin (1), 7-hydroxycoumarin (2), 5,7-dihydroxy-2-n-pentacosanylchrom-4-one (3), luteolin 6-C-β-D-glucopyranoside (4), katsumadin (5) and friedelanone (6), were evaluated in vitro for their anti-free radical scavenging activity as well as inhibitory potential against the enzyme urease. Compounds 4 and 5 exhibited potent anti-free radical scavenging activity (IC₅₀ = 20.20 ± 0.19 μM and 15.60 ± 0.22 μM, respectively), while compounds 1–4 showed significant urease inhibitory activity (IC₅₀ = 25.60 ± 0.59 μM, 33.20 ± 0.73 μM, 27.60 ± 0.69 μM and 26.60 ± 0.13 μM, respectively).