Besides activity of investigated nucleoside analogs in relation to cultivated ovarian tumour cells SKOV-3 was estimated by us. In this case the chase of nucleoside derivatives were chosen, some of them had has high PARP-inhibited activity (substances II, III and VI) but other are either bad or non-inhibited PARP (substances I, IV and V). The dThd, dAde и 3-АВ were used as the substances-comparison (pic. 3).

         It was shown that 72-hour incubation of SKOV-3 cells with the 1мМ dAde or dThd leads to the almost twice decreasing of cells density in the culture comparing with the control. Their disaccharide derivatives which are contained second ribose residue in the 3’ placement – substances I and II were almost nontoxic till the 1мМ concentration (pic. 3). Besides the similar structural derivate of 5-J-deoxyuridine (substance VI) was nontoxic too. Thus it was shown that derivatives of thymidine and 5-J-deoxyuridine with the additional non-oxidized ribose residue in the 3’ placement unlike their prototypes had no toxicity in the relation to SKOV-3 cells.

         The substance III is oxidized derivate of substance II has had strong toxic activity in relation to SKOV-3 cell. It was found out that after 72-hour incubation of SKOV-3 cells with the 1мМ substance III the cells density in the culture has decreased on about 75% comparing to the control but in the concentration 0,1мМ of substance III was indifferent to the cell culture growth. The derivatives of uridine are oxidized on to saccharide residue – substances IV and V have had bigger toxicity. After 72-hour cultivation of SKOV-3 cells with the 1 мМ IV or V the cell loss was observed and in the concentration 0,1 мМ these substances have led to twice decreasing of cell dencity in the culture (pic. 3).