Inhibition of deoxyribonucleic acid synthesis in vitro by anticancer platinum pyrimidine greens against Daudi cells

Platinum pyrimidine greens inhibited the deoxyribonucleic acid (DNA) synthesis of tumor cells in the S phase of the cell cycle and exerted antitumor activity. Clear differences were observed in the activity between the samples prepared at 40 degrees C and at 75 degrees C. Using 3H-thymidine incorporation assay and cell cycle analysis we confirmed that the former had much stronger and more specific inhibitory activity against DNA synthesis than the latter. Reactivity of the 40 degrees C sample with deoxyguanosine monophosphate (dGMP) and deoxyadenosine monophosphate (dAMP) was, respectively, two and three times larger than that of the 75 degrees C sample.