RT Journal Article SR Electronic T1 Synthesis, In Vivo Antileukemic Evaluation and Comparative Study of Novel 5α-7-Keto Steroidal Esters of Chlorambucil and its Active Metabolite JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 345 OP 352 VO 22 IS 3 A1 ANNA I. KOUTSOUREA A1 MANOLIS A. FOUSTERIS A1 EVAGELIA S. ARSENOU A1 ATHANASIOS PAPAGEORGIOU A1 GEORGE N. PAIRAS A1 SOTIRIS S. NIKOLAROPOULOS YR 2008 UL http://iv.iiarjournals.org/content/22/3/345.abstract AB Recent structure-antileukemic activity studies showed that the steroidal part of complex molecules containing DNA alkylators does not play only the role of the “biological carrier”. New such compounds designed to possess an allylic 7-ketone showed enhanced antileukemic potency compared with derivatives with a simple steroidal skeleton. In order to investigate whether the enhancement of the antileukemic potency is attributed to the introduction of the 7-ketone or to the Δg5-7-keto conjugated steroidal system we decided to reduce the Δ5 double bond. The 5α-7-keto-steroidal skeletons synthesized were tethered to chlorambucil and phenyl acetic acid's nitrogen mustard and studied against leukemia P338 in vivo. The reduction of the double bond had a negative impact on the antileukemic potency since the comparative study of the novel derivatives showed that a series of very potent Δ5-7-keto-steroidal esters were converted by this modification to compounds with marginally accepted activity.