A novel antitumour compound from the mucus of a coral, galaxea fascicularis, inhibits topoisomerase I and II

Abstract

S2 isolated from the mucus of G. fascicularis contains anti- topoisomerase activity, causing cytotoxicity to a multiple-drug resistant leukaemia cell line, P388/VCR. It inhibits DNA relaxation catalysed by topoisomerase I and II. S2 stabilised the topoisomerase I-DNA cleavable complex, thereby inhibiting the DNA replication machinery, leading to cell death. The active centre of S2 probably contains a Galβ(1-4)GlcNAc dissacharide linkage. S2 has potentials of being developed into a new anticancer therapeutic.