NSC 660028 is a novel γ-lactone ring modified arylamino etoposide analogram with strong antitumor activity as an inhibitor of human DNA topoisomerase II.
Costatolide is isolated from Calophyllum lanigerum var austrocoriaceum and Calophyllum brasiliense, it exhibits potent activity against HIV-1 reverse transcriptase. It has a role as a HIV-1 reverse transcriptase inhibitor and a plant metabolite. It is a delta-lactone, a cyclic ether, a secondary alcohol and an organic heterotetracyclic compound.