Characterization and Bioactive Potential of Secondary Metabolites Isolated from Roxb.

Roxb. (Piperaceae) is a traditional medicinal plant in South-East Asian countries. The chemical investigation of leaves from this species resulted in the isolation of three previously not described compounds, namely 4″-(3-hydroxy-3-methylglutaroyl)-2″--D-glucopyranosyl vitexin (), kadukoside (), and 6--coumaroyl-D-glucono-1,4-lactone (), together with 31 known compounds. Of these known compounds, 21 compounds were isolated for the first time from . The structures were established by 1D and 2D NMR techniques and HR-ESI-MS analyses. The compounds were evaluated for their anthelmintic (), antifungal (, and ), antibacterial () and cytotoxic (PC-3 and HT-29 human cancer cells lines) activities. Methyl-3-(4-methoxyphenyl)propionate (), isoasarone (), and -asarone () demonstrated anthelmintic activity with IC values between 0.9 and 2.04 mM. Kadukoside () was most active against with IC at 5.0 µM and also induced 94% inhibition of growth at 125 µM. -asarone (), piperolactam A (), and dehydroformouregine () displayed a dose-dependent effect against from 1.5 to 125 µM up to more than 80% inhibition. Paprazine (), cepharadione A () and piperolactam A () inhibited bacterial growth by more than 85% at 100 µM. Only mild cytotoxic effects were observed.