Design, synthesis, and biological evaluation of indolequinone phosphoramidate prodrugs targeted to DT-diaphorase.
A series of 2- and 3-substituted indolequinone phosphoramidate prodrugs targeted to DT-diaphorase (DTD) have been synthesized and evaluated. These compounds are designed to undergo activation via quinone reduction by DTD followed by expulsion of the phosphoramide mustard substituent from the hydroquinone. Chemical reduction of the phosphoramidate prodrugs led to rapid expulsion of the corresponding phosphoramidate anions in both series of compounds. Compounds substituted at the 2-position are excellent substrates for human DTD (k(cat)/K(M) = (2-5) x 10(6) M(-1) s(-1)); however, compounds substituted at the 3-position are potent inhibitors of the target enzyme. Both series of compounds are toxic in HT-29 and BE human colon cancer cell lines in a clonogenic assay. There was a correlation found between cytotoxicity and DTD activity for the 2-series of phosphoramidates; however, there was no correlation between cytotoxicity and DTD activity in the 3-series of compounds. This finding suggests the presence of an alternative mechanism for the activation of these compounds.
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA.
Marcy
M
Hernick
Carolee
C
Flader
Richard F
RF
Borch
D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D006873:Hydroquinones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry / Q000378:metabolism*; D010752:Phosphoramide Mustards / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011355:Prodrugs / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D006873:Hydroquinones; D010752:Phosphoramide Mustards; D011355:Prodrugs; D016660:NAD(P)H Dehydrogenase (Quinone)