Studies on the Pharmaceutical Potentiation of Drugs. I. p-Aminosalicylic Acid Derivatives

Nine series of ω-substituted PAS alkyl esters, namely, ω-chloroalkyl, ω-aminoalkyl, ω-diethylaminoalkyl, ω-phenylethylaminoalkyl, ω-morpholinoalkyl, ω-pyrrolidinylalkyl, ω-piperidinoalkyl p-aminosalicylates and alkylene bis-p-aminosalicylates in which the alkyl length varied from ethyl to decyl were synthesized and their evaluations were made with testing their tuberculostatic activities and with measuring their physicochemical properties such as partition coefficients and degrees of protein binding that might considerably influence biological effects of these substances when administered in animal body. These synthesized derivatives have activities as same extent as the parent compound and are more lipid soluble and some of them are less protein bound than PAS. From these observations, it is considered that some of the defects of the parent compound are improved by these chemical modifications. Relationship between structures and these characteristics are also revealed.