title: Acyclic nucleoside analogues as novel inhibitors of human mitochondrial thymidine kinase.
abstract: A series of acyclic nucleoside analogues of 5'-O-tritylthymidine have been synthesized and evaluated as potential human mitochondrial thymidine kinase (TK-2) inhibitors. In this series, the sugar moiety of the parent 5'-O-tritylthymidine has been replaced by aliphatic chains including (E)- and (Z)-butenol, butynol, or butanol. Among them the (Z)-butenyl derivative (10) showed an IC(50) against TK-2 of 1.5 microM, being 1 order of magnitude more potent than the parent 5'-O-tritylthymidine. This lead compound has been further modified by replacing the thymine base by other pyrimidine bases such as 5-iodouracil, 5-ethyluracil, 5-methylcytosine, 3-N-methylthymine, or 5,6-dihydrothymine, as well as by the purine base guanine. The trityl group has also been replaced by different aliphatic and aromatic acyl moieties including tert-butylacetyl, hexanoyl, decanoyl, and diphenylacetyl moieties. The evaluation of the compounds against TK-2 and the phylogenetically close HSV-1 TK has shown that the base moiety plays a crucial role in their interaction against these pyrimidine nucleoside kinases. Also, the presence of a lipophilic substituent, preferentially an aromatic moiety such as diphenylmethyl or triphenylmethyl, is required for efficient TK-2 inhibition. Whereas some compounds showed marked specificity for either TK-2 (i.e, the 5,6-dihydrothymine derivative, 26) or HSV-1 TK (i.e., the butynyl derivative, 11), some others, including the (Z)-and (E)-butenyl derivatives 10 and 12, showed significant inhibition against both enzymes. They also proved to be inhibitory against HSV-1 TK in intact human osteosarcoma cells that were transduced with the HSV-1 TK gene.
authors.affiliation: Instituto de Química Médica (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: Ana-Isabel
authors.initials: AI
authors.lastname: Hernández
authors.forename: Jan
authors.initials: J
authors.lastname: Balzarini
authors.forename: Anna
authors.initials: A
authors.lastname: Karlsson
authors.forename: María-José
authors.initials: MJ
authors.lastname: Camarasa
authors.forename: María-Jesús
authors.initials: MJ
authors.lastname: Pérez-Pérez
mesh_terms: D002384:Catalysis; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D018259:Herpesvirus 1, Human / Q000201:enzymology; D006801:Humans; D008928:Mitochondria / Q000201:enzymology*; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010766:Phosphorylation; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013937:Thymidine Kinase / Q000037:antagonists & inhibitors*; D014407:Tumor Cells, Cultured
chemical_list: D004791:Enzyme Inhibitors; D009705:Nucleosides; C105339:thymidine kinase 2; D013937:Thymidine Kinase