Silyl modification of biologically active compounds 5. Hydrolytic stability and biological activity of the trialkylsilyl derivatives of some heterocyclic bases

The kinetics of the desilylation of the triorganosilyl derivatives of some biologically active heterocyclic bases and uridine were investigated by¹H NMR spectroscopy. A correlation was established between the relative rates of desilylation and the steric environment of the silicon atom. In trials on locomotor activity and muscular tone, the effect on memory processes, and the Porsolt test it was found that tris(tert-butylmethylsilyl)barbituric acid has higher sedative activity than barbituric acid. In contrast to uridine, 5-O-tert-butyldimethylsilyluridine exhibits antitumor activity, suppressing the development of fibrosarcoma in human lungs (HT-1080) and fibroblasts in mice.For communication 4, see [1].Latvian Institute of Organic Synthesis, Riga, Latvia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1253–1258, September, 1998.