Monoterpenoid Indole Alkaloids Mediating DNA Strand Scission from Turpinia arguta

Two new monoterpenoid indole alkaloid derivatives, turpiniside (1) and 11-methoxyjavaniside (2), along with the known alkaloids, vincosamide (3), (3R)-pumiloside (4), and paratunamide C (5), were isolated from the leaves of Turpinia arguta (Lind1.) Seem. Their structures were determined on the basis of spectroscopic data. Compounds 1 and 3-5 were found to effect relaxation of the supercoiled pBR322 plasmid DNA in the presence of Cu2+.