SN-38 is a pyranoindolizinoquinoline derivative with the structure (4S)-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14-dione, substituted with ethyl groups at positions 4 and 11, and hydroxy groups at positions 4 and 9. It is the active metabolite of irinotecan, approximately 1000 times more potent than the parent compound. SN-38 functions as an apoptosis inducer, a DNA topoisomerase (EC 5.99.1.2) inhibitor, a drug metabolite, and an antineoplastic agent. It belongs to the classes of pyranoindolizinoquinolines, delta-lactones, tertiary alcohols, and phenols.
