title: Design, synthesis, and enzymatic evaluation of multisubstrate analogue inhibitors of Escherichia coli thymidine phosphorylase.
abstract: A series of acyclic phosphonate derivatives of thymine has been synthesized and tested as multisubstrate analogue inhibitors of Escherichia coli thymidine phosphorylase. The compounds synthesized include 1-(phosphonoalkyl)thymines with six to nine methylenes (1-4, respectively); 1-[(Z)-4-phosphonomethoxy-2-butenyl]thymine (5) and its butyl and 2,3-cis-dihydroxybutyl derivatives (6 and 7, respectively); 1-[(Z)-(4-(phosphonomethoxy)methoxy)-2-butenyl]thymine (8) and also its butyl and 2,3-cis-dihydroxybutyl analogues (9 and 10); and 1-[((Z)-4-(phosphonomethoxy)-2-butenoxy)methyl]thymine (11). Evaluation of these compounds against E. coli revealed significant enzymatic inhibition by 2, 3, 4, 6, and 8 at a concentration of 1000 microM, 3 and 4 being the most potent. Replacement of the thymine base in 3 by 6-amino-5-bromouracil and 7-deazaxanthine afforded compounds 12 and 13, which showed a pronounced improvement of TPase inhibition, comparable to 7-deazaxanthine. When inorganic phosphate was used as a variable substrate, compounds 12 and 13 displayed competitive kinetics with respect to phosphate, indicating a direct interaction of these compounds with the phosphate binding site. Also compounds 12 and 13 were found to be competitive inhibitors of TPase against thymidine as a variable substrate. These results are consistent with the compounds being multisubstrate analogue inhibitors of E. coli TPase, and they represent the first example of such TPase inhibitors.
authors.affiliation: Instituto de Química Médica, C.S.I.C., Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Esteban-Gamboa
authors.forename: J
authors.initials: J
authors.lastname: Balzarini
authors.forename: R
authors.initials: R
authors.lastname: Esnouf
authors.forename: E
authors.initials: E
authors.lastname: De Clercq
authors.forename: M J
authors.initials: MJ
authors.lastname: Camarasa
authors.forename: M J
authors.initials: MJ
authors.lastname: Pérez-Pérez
mesh_terms: D002851:Chromatography, High Pressure Liquid; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D063065:Organophosphonates / Q000138:chemical synthesis* / Q000737:chemistry; D011744:Pyrimidinones / Q000138:chemical synthesis* / Q000737:chemistry; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D013936:Thymidine / Q000737:chemistry; D013939:Thymidine Phosphorylase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D014498:Uracil / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: C406232:1-(8-phosphonooctyl)-2,4-dioxopyrrolo(2,3-d)pyrimidine; C406231:6-amino-5-bromo-1-(8-phosphonooctyl)uracil; D004791:Enzyme Inhibitors; D063065:Organophosphonates; D011744:Pyrimidinones; D014498:Uracil; D013939:Thymidine Phosphorylase; D013936:Thymidine