Bioactive constituents of the roots of Polyalthia cerasoides.

A new dimeric aporphine alkaloid, bidebiline E (1), and a new natural product, octadeca-9,11,13-triynoic acid (2), along with three known sesquiterpenes, alpha-humulene (3), caryophyllene oxide (4), and (-)-alpha-cadinol (5), and four known isoquinoline alkaloids, laudanosine (6), codamine (7), laudanidine (8), and reticuline (9), were isolated from the roots of Polyalthia cerasoides. The structures of compounds 1 and 2 were established on the basis of their 1D and 2D NMR spectroscopic data. Among these isolates, 1, 2, 4, 7, and 8 exhibited antimalarial activity against Plasmodium falciparum, while 1- 3 showed antimycobacterial activity against Mycobacterium tuberculosis using in vitro assays.