Biological potency of organic selenium compounds. III. Phenyl-, benzyl-, and phenylethylseleno-car☐ylic acids, and related compounds

Abstract

Several 2,4-dinitrophenylseleno-car☐ylic acids, a number of unsubstituted and 4-substituted benzylselenocar☐ylic acids, and some phenylethylseleno-car☐ylic acids have been investigated with regard to their potency in the prevention of dietary liver necrosis. The potency was strongly influenced by the structure of the alkanoic moiety of the molecule and the distance between the car☐yl group and the selenium atom. An alternating effect of the length of the car☐ylic acid carbon chain was obvious in 2,4-dinitrophenylseleno-car☐ylic acids, unsubstituted benzylseleno-n-car☐ylic acids, and 4-nitrobenzylseleno-car☐ylic acids, as previously described for aliphatic monoseleno-dicar☐ylic acids and selena-car☐ylic acids. Presence of a quaternary carbon atom in the chain eliminated potency almost entirely. Substituents in the aromatic ring also exerted a strong influence. In the benzylseleno-car☐ylic acid series, introduction of methyl or nitro groups in the 4 position of the ring decreased biopotency. The effect of bromine substitution in this position was basically different: The alternating effect was abolished, and a pattern of activity arose which was similar to that of the diseleno-dicar☐ylic acids. The results are discussed in the light of structural activity relationships found previously in aliphatic mono- and diseleno-dicar☐ylic acids and selena-car☐ylic acids.