a novel class of methyl esters of substituted 4 - oxo - 2 - butenoic acids and their derivatives are disclosed along with the surprising use property of these compounds as a bacteriostatic agents for humans or non - humans against mycobacteria . these compounds include : 4 -- 2 -- 4 - oxo - but - 2 - enoic acid methyl ester ; 4 -- 2 -- 2 - hydroxy - 4 - oxo - butyric acid methyl ester ; 2 -- 5 , 5 - dimethyl - 4 - oxo - hex - 2 - enoic acid methyl ester ; a pharmaceutical composition is disclosed as well as the method of treating human and non - humans infected with m . tuberculosis and related mycobacteria .