Oxylipin vanillyl acetals from Solanum lyratum.

Four undescribed oxylipin vanillyl acetals with four stereogenic carbons were isolated from the herbs of Solanum lyratum. A comprehensive set of spectroscopic methods were used to elucidate the structures and relative configurations of 1–4. The absolute configurations of the naturally occurring compounds are assigned as 7S, 9′S, 10′S, 11′R at the site of six-membered cyclic acetal attachment by electronic circular dichroism (ECD) calculations and the modified Mosher's method. Compounds 1 and 3 displayed moderate selective inhibition against Hep3B and HepG2 cells, respectively. Further Annexin V-FITC/PI staining assay revealed that 1 and 3 might have inhibitory effects on hepatoma cells through induction of apoptosis.