Inhibition of Human Topoisomerases I and II by Simocyclinone D8

Simocyclinone D8 is an antibiotic isolated from Streptomyces antibioticus T 6040 that inhibits the supercoiling activity of DNA gyrase. It also exhibits an inhibitory effect on human topoisomerase II and an antiproliferative activity,against, some cancer cell lines. Our biochemical studies have revealed that simocyclinone. D8 can inhibit the catalytic activity of human topoisomerase I. Thus,. simocyclinone. D8 is a dual Catalytic inhibitor of human topoisomerases I and II.