Separation of Camptothecin by Ethanol/K2CO3 Aqueous Two-Phase System Containing Tetramethylguanidine

Insoluble camptothecin was converted into the corresponding hydrosoluble analog, camptothecin carboxylate, by using 1,1,3,3-tetramethylguanidine as hydrolyzing agent. The ethanol/K 2 CO 3 /H 2 O aqueous two-phase system was established to extract the hydrosoluble camptothecin carboxylate. Through two-stage extraction from crude camptothecin of 5.4%, purity, final hydrosoluble camptothecin was obtained with a purity of 98.5% at a total yield of 78.4%.