7-Ethyl-10-hydroxycamptothecin

7-Ethyl-10-hydroxy-camptothecin (SN-38) is a water insoluble biologically active metabolite of water soluble irinotecan hydrochloride (CPT-11) [I0714]. SN-38 has a topoisomerase-I inhibitory activity and is approximately 100-1000-fold more cytotoxic in vitro than CPT-11. Camptotecin and its derivatives interfere with DNA synthesis by inhibiting the enzyme topoisomerase-I. In order to prevent and correct of topological problems caused by the DNA double helix, topoisomerase-I catalyzes the relaxation of negatively supercoiled DNA, the knotting and unknotting DNA and the linking complementary rings of single-stranded DNA into double-stranded rings. Then the inhibition action induces breaks in single strand DNA. Eventually, this leads to double-strand DNA breaks and apoptosis or cell death. Recently, the use of polyethyleneglycolylated nanographene oxide for drug delivery of SN-38 has received widespread attention. (The product is for research purpose only.)