10-Methoxycamptothecin, a natural bioactive derivative of camptothecin (CPT) isolated from *Camptotheca acuminata*, exhibits potent anti-cancer properties.

Camptothecin (CPT) belongs to the alkaloid group of natural products and is a specific DNA topoisomerase I (Topo I) inhibitor (IC50=679 nM) with specificity. Camptothecin has antitumor activity and induces apoptosis.

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+.

9-Methoxycamptothecin (MCPT) has antitumour activities through topoisomerase inhibition.

(S)-10-Hydroxycamptothecin (10-HCPT) is a DNA topoisomerase I inhibitor used as a clinical therapeutic agent against hepatoma.

(±)-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.

1. 7-Ethylcamptothecin has the superior antitumor activity than CPT. (a). 7-Ethylcamptothecin has a stronger growth-inhibiting activity against tumor cells. (b). 7-Ethylcamptothecin remains in the intestinal tract for a longer time and in higher amounts when administered in vivo.

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.