Bioactive isoquinoline alkaloids from Corydalis saxicola.

Twelve isoquinoline alkaloids including two new nitro-containing tetrahydroprotoberberines, (-)-2,9-dihydroxyl-3,11-dimethoxy-1,10-dinitrotetrahydroprotoberberine (1) and (+)-4-nitroisoapocavidine (2), were isolated from the whole plant of Corydalis saxicola Bunting. The structures of the new compounds were established by spectroscopic analysis and chemical evidence. The inhibitory activity of these isolates against cholinesterase and canine parvovirus were evaluated.

Cytotoxic amide alkaloids from Piper boehmeriaefolium.

Eight new amide alkaloids (1-8) and 19 known ones were isolated from the whole plant of Piper boehmeriaefolium. Their structures were determined through spectroscopic data analyses. Cytotoxic activity of these amides against human cervical carcinoma HeLa cells was evaluated, and 1-[(9E)-10-(3,4-methylenedioxyphenyl)-9-decenoyl]pyrrolidine (9) exhibited significant inhibitory activity with an IC(50) value of 2.