Gilvocarcin V is the major analogue of a complex of C-glycoside antitumor actives isolated from a Streptomyces sp. Gilvocarcin V contains a vinyl group in the 8-position, and is the most potent analogue of the complex. It is thought to act as an inhibitor of the catalytic activity of human topoisomerase II. The metabolite displays potent antibacterial, antifungal, antiviral and antitumor activity. Recent research suggests that the gilvocarcins act as photoactivated cross-linkers of DNA to histones.