Irinotecan (CPT-11), a derivative of camptothecin, is an inhibitor of DNA topoisomerase I (Topo I). Irinotecan has antitumor activity by preventing DNA strand reattachment through binding to the Topo I complex, resulting in double-stranded DNA breaks and cell death.

Topotecan hydrochloride (NSC609699) is an antineoplastic agent used to treat ovarian cancer.

SN-38 (NK012) is the active metabolite of Irinotecan, a DNA topoisomerase I (Topo I) inhibitor, which inhibits DNA and RNA synthesis (IC50=0.077 1.3 μM). SN-38 has antitumor activity and induces autophagy.

9-Hydroxycampothecin is a camptothecin derivative with anticancer activity.

Irinotecan hydrochloride trihydrate (CPT-11 HCl Trihydrate) keeps DNA from unwinding by inhibiting topoisomerase 1.

Topotecan (NSC-609669) is a Topoisomerase I inhibitor,and is an antineoplastic agent used to treat ovarian cancer that works by inhibiting DNA topoisomerases.

Vincosamide is an alkaloid from Psychotria leiocarpa extract, inhibits the acetylcholinesterase (AChE) activity with anti-inflammatory activity. Vincosamide can effect relaxation of the supercoiled pBR322 plasmid DNA in the presence of Cu2+.

Irinotecan Hydrochloride (CPT-11 hydrochloride) is the hydrochloride salt of a semisynthetic derivative of camptothecin. Irinotecan, a prodrug, is converted to a biologically active metabolite 7-ethyl-10-hydroxy-camptothecin (SN-38) by a carboxylesterase-converting enzyme. One thousand-fold more potent than its parent compound irinotecan, SN-38 inhibits topoisomerase I activity by stabilizing the cleavable complex between topoisomerase I and DNA, resulting in DNA breaks that inhibit DNA replication and trigger apoptotic cell death. Because ongoing DNA synthesis is necessary for irinotecan to exert its cytotoxic effects, it is classified as an S-phase-specific agent.

(±)-10-Hydroxycamptothecin (Hydroxy Camptothecine) is an alkaloid isolated from the stem wood of the Chinese tree, Camptotheca acuminata. This compound selectively inhibits the nuclear enzyme DNA topoisomerase, type I. Several semisynthetic analogs of camptothecin have demonstrated antitumor activity.

12-Ethyl-9-hydroxycamptothecin (SN38) is the active metabolite of irinotecan, a topoisomerase I inhibitor, with potential anticancer activity for use in the study of colon and rectal cancer.

10-Nitro-camptothecin is a natural product

2β,3β,23α-Trihydroxy-12-oleanen-28-oic acid shows cytotoxic activities to human lung adenocarcinoma(A-549)cell lines. 2α,3β,23-Trihydroxyolean-12-en-28-oic acid and 2α,3β,23-trihydroxyurs-12-en-28-oic acid exhibit cytotoxicity in vitro against the growth of human cancer cells lines HepG-2,with IC50 values of 16.13 ± 3.83, 15.97 ± 2.47 uM, respectively.