Definition: An alkaloid isolated from the stem wood of the Chinese tree, Camptotheca acuminata. This compound selectively inhibits the nuclear enzyme DNA TOPOISOMERASES, TYPE I. Several semisynthetic analogs of camptothecin have demonstrated antitumor activity.
9-aminocamptothecin [ 9-amino-20(S)-camptothecin,9-amino-CPT,9-amino-20-camptothecin, (+-)-isomer,9-amino-20-camptothecin, (R,S)-isomer,NSC 603071 ] RN given refers to the 20(S)-isomer which is the naturally-occuring isomer