C(60) Fullerene Effects on Diphenyl-N-(trichloroacetyl)-amidophosphate Interaction with DNA In Silico and Its Cytotoxic Activity Against Human Leukemic Cell Line In Vitro

New representative of carbacylamidophosphates - diphenyl-N-(trichloroacetyl)-amidophosphate (HL), which contains two phenoxy substituents near the phosphoryl group, was synthesized, identified by elemental analysis and IR and NMR spectroscopy, and tested as a cytotoxic agent itself and in combination with C(60) fullerene. According to molecular simulation results, C(60) fullerene and HL could interact with DNA and form a rigid complex stabilized by stacking interactions of HL phenyl groups with C(60) fullerene and DNA G nucleotide, as well as by interactions of HL CCl(3) group by ion-π bonds with C(60) molecule and by electrostatic bonds with DNA G nucleotide. With the use of MTT test, the cytotoxic activity of HL against human leukemic CCRF-CM cells with IC(50) value detected at 10 μM concentration at 72 h of cells treatment was shown. Under combined action of 16 μM C(60) fullerene and HL, the value of IC(50) was detected at lower 5 μM HL concentration and at earlier 48 h period of incubation, besides the cytotoxic effect of HL was observed at a low 2.5 μM concentration at which HL by itself had no influence on cell viability. Binding of C(60) fullerene and HL with minor DNA groove with formation of a stable complex is assumed to be one of the possible reasons of their synergistic inhibition of CCRF-CЕM cells proliferation. Application of C(60) fullerene in combination with 2.5 μM HL was shown to have no harmful effect on structural stability of blood erythrocytes membrane. Thus, combined action of C(60) fullerene and HL in a low concentration potentiated HL cytotoxic effect against human leukemic cells and was not followed by hemolytic effect.