Abstract
Of the phenazine derivatives tested, phenazine-di-N-oxides produced the most marked prolongation of the survival time of mice bearing Ehrlich ascites carcinoma. Phenazine-mono-N-oxides were only moderately effective. The di-N-oxide compounds, however, were ineffective against the solid form of Ehrlich carcinoma. Other phenazine derivatives exhibited no effect on the growth of tumor cells. The degrees of inhibition of glycolysis (aerobic or anaerobic) and respiration of tumor cells by these compounds were in the same order as their antitumor activities. So, the following general structure-activity relationships were observed with the series of compounds tested : appreciable antitumor activity was found only among compounds with the 〓N→O moiety. Possible parallels between the antitumor activities of these compounds and the degrees of their inhibition of energy-generating systems of tumor cells were shown.
