Antitumor effects of biologic reducing agents related to 3,4-dihydroxybenzylamine: dihydroxybenzaldehyde, dihydroxybenzaldoxime, and dihydroxybenzonitrile.

This report describes a structure-activity analysis of isomers of three classes of dihydroxybenzene derivatives, including dihydroxybenzaldoxime, dihydroxybenzaldehyde, and dihydroxybenzonitrile. These derivatives were examined for their effect on ribonucleotide reductase activity, macromolecular synthesis, cell growth, and in vivo antitumor activity against the L1210 murine leukemia. One of the compounds studied exhibited significant antitumor activity against the growth of L1210 leukemia cells. A comparison of the various analogues revealed a possible correlation for 3,4-dihydroxybenzaldoxime between its potent inhibitory effect toward ribonucleotide reductase activity (IC50 = 38 microM) and its superior L1210 antitumor activity [percent increased life span (% ILS) = 100].