Studies On Synthesis, Activity And Interaction Of Polypyridyl Platinum (Ⅱ) Complexes With DNA

DNA is the classic targets for studies on platinum anticancer drugs. Because there is a large amount of duplex DNA inside the human cells, the platinum anticancer drugs killing the cancer cells should have an effect on normal cells at the same time and cause serious side effects. Therefore, it is necessary to search nonclassic targets inside the cancer cells. Fifteen polypyridyl platinum (Ⅱ) complexes have been synthesized and the interactions of those compounds with G-quadruples DNA, ct-DNA and BSA and antitumor activity have also been investigated.1. The platinum (Ⅱ) complexes’inhibitory activity for seven cancer cells and normal hepatic cell has been evaluated by MTT method. The platinum (Ⅱ) complexes have good selectivity for T-24 bladder cancer cells, complexes 8 and 9 have the strongest effects among the complexes, the IC50 values are 8.44 ± 0.41 μmol·L-1 and 5.24±0.16 μmol·L-1, respectively, their antitumor activities are better than cisplatin’s. The complexes are hypotoxicity because their inhibition activities are lower than cisplatin’s.2. The results of UV-vis assay have shown that ct-DNA abilities with complexes’binding power are not strong, complexes can give priority to binding with G-quadruples DNA. The complexes might stack onto the end of G-quadruples DNA with binding constant of 105-106M-1 and produce π-π stack with G-quadruples’plane. The results of Fluorescent Intercalator Displacement (G4-FID) have suggested that the complexes have different selectivity for different G-quadruples DNA, and their recognizing abilities for G-quadruples DNA are better than for duplex DNA (ds26).3. Fluorescent spectrum has been employed to investigate the interaction of complexes toward BSA, the results have shown that complexes interaction with BSA has been confirmed to, be static quenching. In different buffer solution, BSA’s max emission wavelength λmax=338nm can not move with the increase of complexes’ density, the result has shown that complexes interaction with BSA can not change Trp’s polar.