title: Synthesis, conformational analysis, and biological activity of new analogues of thiazole-4-carboxamide adenine dinucleotide (TAD) as IMP dehydrogenase inhibitors.
abstract: Thiazole-4-carboxamide adenine dinucleotide (TAD) analogues T-2'-MeAD (1) and T-3'-MeAD (2) containing, respectively, a methyl group at the ribose 2'-C-, and 3'-C-position of the adenosine moiety, were prepared as potential selective human inosine monophosphate dehydrogenase (IMPDH) type II inhibitors. The synthesis of heterodinucleotides was carried out by CDI-catalyzed coupling reaction of unprotected 2'-C-methyl- or 3'-C-methyl-adenosine 5'-monophosphate with 2',3'-O-isopropylidene-tiazofurin 5'-monophosphate, and then deisopropylidenation. Biological evaluation of dinucleotides 1 and 2 as inhibitors of recombinant human IMPDH type I and type II resulted in a good activity. Inhibition of both isoenzymes by T-2'-MeAD and T-3'-MeAD was noncompetitive with respect to NAD substrate. Binding of T-3'-MeAD was comparable to that of parent compound TAD, while T-2'-MeAD proved to be a weaker inhibitor. However, no significant difference was found in inhibition of the IMPDH isoenzymes. T-2'-MeAD and T-3'-MeAD were found to inhibit the growth of K562 cells (IC(50) 30.7 and 65.0muM, respectively).
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Camerino, 62032 Camerino, Italy.
authors.forename: Palmarisa
authors.initials: P
authors.lastname: Franchetti
authors.forename: Loredana
authors.initials: L
authors.lastname: Cappellacci
authors.forename: Michela
authors.initials: M
authors.lastname: Pasqualini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Petrelli
authors.forename: Vetrichelvan
authors.initials: V
authors.lastname: Jayaprakasan
authors.forename: Hiremagalur N
authors.initials: HN
authors.lastname: Jayaram
authors.forename: Donald B
authors.initials: DB
authors.lastname: Boyd
authors.forename: Manojkumar D
authors.initials: MD
authors.lastname: Jain
authors.forename: Mario
authors.initials: M
authors.lastname: Grifantini
mesh_terms: D000227:Adenine Nucleotides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007168:IMP Dehydrogenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D020014:K562 Cells; D008968:Molecular Conformation
chemical_list: D000227:Adenine Nucleotides; D004791:Enzyme Inhibitors; C038167:thiazole-4-carboxamide adenine dinucleotide; D007168:IMP Dehydrogenase