Polyprenylated isoflavanone and isoflavonoids from Ormosia henryi and their cytotoxicity and anti-oxidation activity.

A rare naturally-occurring polyprenylated isoflavanone, designated ormosinol (1), and a new isoflavonoid glycoside, named ormosinoside (2), along with 21 known compounds were isolated from the root bark of Ormosia henryi Prain. The structures of compounds 1 and 2 were determined as 5,7,2′,4′-tetrahydroxyl-6,8,5′-tri-(γ,γ-dimethylallyl)isoflavanone and isoprunetin-7-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside on the basis of a combination of 1D-, 2D-NMR and mass spectroscopic measurements. Compound 1 showed significant anti-oxidation activity against DPPH radicals (IC50 28.5μM) and cancer cell line (A549, LAC, and HepG2) growth inhibitory activity with IC50 ranging from 4.25 to 7.09μM, while compound 2 found to be inactive to both testing systems.