ABSTRACT
A range of triazoloacridin-6-ones functionalized at C5 and C8 have been synthesized and evaluated for ability to inhibit NQO1 and NQO2. The compounds were computationally docked into the active site of NQO1 and NQO2, and calculated binding affinities were compared with IC(50) values for enzyme inhibition. Excellent correlation coefficients were demonstrated suggesting a predictive QSAR model for this series of structurally similar analogues. From this we have identified some of these triazoloacridin-6-ones to be the most potent NQO2 inhibitors so far reported.
Subject(s)
Acridines/pharmacology , Enzyme Inhibitors/pharmacology , NAD(P)H Dehydrogenase (Quinone)/antagonists & inhibitors , Quinone Reductases/antagonists & inhibitors , Triazoles/pharmacology , Acridines/chemical synthesis , Acridines/chemistry , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , DNA/drug effects , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Male , Models, Molecular , Molecular Structure , Salmon , Spermatozoa/chemistry , Structure-Activity Relationship , Transition Temperature , Triazoles/chemical synthesis , Triazoles/chemistryABSTRACT
The synthesis is reported here of two novel series of inhibitors of human NAD(P)H quinone oxidoreductase-1 (NQO1), an enzyme overexpressed in several types of tumor cell. The first series comprises substituted symmetric dicoumarol analogues; the second series contains hybrid compounds where one 4-hydroxycoumarin system is replaced by a different aromatic moiety. Several compounds show equivalent or improved NQO1 inhibition over dicoumarol, both in the presence and in the absence of added protein. Further, correlation is demonstrated between the ability of these agents to inhibit NQO1 and computed binding affinity. We have solved the crystal structure of NQO1 complexed to a hybrid compound and find good agreement with the in silico model. For both MIA PaCa-2 pancreatic tumor cells and HCT116 colon cancer cells, dicoumarol shows the greatest toxicity of all compounds. Thus, we provide a computational, synthetic, and biological platform to generate competitive NQO1 inhibitors with superior pharmacological properties to dicoumarol. This will allow a more definitive study of NQO1 activity in cells, in particular, its drug activating/detoxifying properties and ability to modulate oncoprotein stability.
Subject(s)
4-Hydroxycoumarins/chemical synthesis , 4-Hydroxycoumarins/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , NAD(P)H Dehydrogenase (Quinone)/antagonists & inhibitors , 4-Hydroxycoumarins/chemistry , 4-Hydroxycoumarins/toxicity , Animals , Cattle , Cell Line, Tumor , Crystallography, X-Ray , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/toxicity , Humans , Inhibitory Concentration 50 , Models, Molecular , Molecular Conformation , NAD(P)H Dehydrogenase (Quinone)/chemistry , Quantitative Structure-Activity RelationshipABSTRACT
An array of novel analogues of the marine oxylipins, the manzamenones and plakoridines, have been prepared in divergent fashion using an approach modelled on a biogenetic theory. Many of the target compounds show potent inhibition of DNA polymerases alpha and beta and human terminal deoxynucleotidyl transferase (TdT).
