[QSAR-modeling of desoxyuridine triphosphatase inhibitors in a series of some derivatives of uracil]. / QSAR-modelirovanie ingibitorov dezoksiuridintrifosfatazy v riadu nekotorykh proizvodnykh uratsila.

Due to the widespread prevalence, deoxyuridine triphosphatase (UTPase) is considered by modern biochemists and physicians as a promising target for the development of drugs with a wide range of activities. The therapeutic effect of these drugs will be due to suppression of DNA biosynthesis in various viruses, bacteria and protozoa. In order to rationalize the search for new dUTPase inhibitors, domestic and foreign researchers are actively using the QSAR methodology at the selection stage of hit compounds. However, the practical application of this methodology is impossible without existence of valid QSAR models. With the use of the GUSAR 2013 program, a quantitative analysis of the relationship between the structure and efficacy of 135 dUTPase inhibitors based on uracil derivatives was performed in the IC50 range of 30¸185000 nmol/L. Six statistically significant valid consensus models, characterized by high descriptive ability and moderate prognostic ability on the structures of training and test samples, are constructed. To build valid QSAR models for dUTPase inhibitors can use QNA or MNA descriptors and their combinations in a consensus approach.

[Express evaluation of antioxidant activity of uracil derivatives].

Using photometric methods the antioxidant activity of 19 uracil derivatives has been analyzed. The test using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals can be applied for the rapid assessment of antioxidant activity of uracils. Among uracil derivatives studied the compounds possesing a proton-donor group in C-5 position--free or alkylated amino group, as well as hydroxyl group were the most active: 5-aminouracil (IC50 3 mg/ml), 5-amino-6-methyluracil (IC50 of 5 mg/ml), 5-hydroxy-6-methyluracil (IC50 of 15 mg/ml), 5-hydroxy-1,3,6-trimethyluracil (IC50 of 15 mg/ml), 5-ethylamino-6-methyluracil (IC50 of 20 mg/ml), 5-methylamino-6-methyluracil (IC50 of 20 mg/ml), 5-allylaminouracil (IC50 of 20 mg/ml), 5-amino-1,3,6- trimethyluracil (IC50 of 25 mg/ml). These uracil derivatives were more active than the reference compounds ionol (IC50 of 30 mg/ml) and a-naphthylamine (IC50 of 45 mg/ml), but less active than ascorbic acid (IC50 0.8 mg/ml). There was a correlation between the results of DPPH test (IC50) and coupling constants of uracil derivatives with peroxide radicals of 1,4-dioxane (fk7). Uracil with proton-donor group at C-5 also showed high ferrum-reducing activity as determined by FRAP.