Note
A cytotoxic pigment, makaluvamine G (5), biogenetically derivable from tryptamine and tyramine and structurally related to the discorhabdins, was isolated from a sponge of the genus Histodermella collected in Indonesia. The compound displays significant in vitro cytotoxicity to several tumor cell lines and is a moderate inhibitor of topoisomerase-I, DNA, RNA, and protein synthesis. Makaluvamine G (5) was isolated from the sponge Histodermella sp. The compound shows significant in vitro cytotoxicity to several human tumor cell lines and inhibits topoisomerase-I (IC50 = 3 μM), RNA (15 μM), DNA (15 μM) and protein (21 μM) synthesis