1-Piperazineacetic acid, 4-ethyl-3,4,12,14-tetrahydro-3,14-dioxo-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-4-yl ester, dihydrochloride, (S)- CAMPTOTHECIN, 20-O-(1-PIPERAZINO)ACETYL-2HCL NSC374026