Effects of nitrogen mustard on the physicochemical properties of mouse fibroblast deoxyribonucleic acid.

agents has received considerable experimental at tention during the last few years, and a variety of mechanisms of action have been postulated to ac count for the effect. Much of this investigation has centered on the interaction of these agents with deoxyribonucleic acid (DNA) (1, 3, 4, 9, 11, 13, 19—9292)following the initial suggestion by Elmore et at. (8) that sulfur mustard probably attacked the phosphate moieties of the DNA molecule. Rut man et at. (14) have suggested that the biological effectiveness of the mustards may not bear any quantitative relation to the extent of alkylation; rather, the specific type of reaction may be more important than the gross extent of the reaction. Drysdale et at. (6) and Trams et a!. (19), however, have discussed the possibility that the attack on the DNA molecule may not represent the specific mechanism of action of these cytotoxic compounds and that other reactions may be of more impor tance. It must be conceded, therefore, that the specific chemical reaction with the DNA molecule or other cellular constituent that is responsible for the growth-inhibitory and cytotoxic effects of