Cao ZS1, Mendoza J, Dejesus A, Giovanella B.
Acta Pharmacol Sin. 2005 Feb;26(2):235-41.AIM: To study the degrees of influence of changing side ester chains at position C20 of camptothecin on the anti-tumor activity of the molecules.METHODS: The esterification reaction of camptothecin 1 and 9-nitrocamptothecin 2 with crotonic anhydride in pyridine gave the corresponding esters 3 and 4, respectively. The acylation of 1 and 2 with cinnamoyl chloride gave products 7 and 8. Epoxidation reaction of 3 and 4 with m-chloroperoxybenzoic acid in benzene solvent gave the products 5 and 6. Read More