The synthesis of a series of isonicotinoylamino acids (II-XI) and some of their corresponding methyl esters (XII-XVIII), hydrazides (XXI-XXVI), dipeptide methyl esters (XXVII-XLII), the di- and tri-glycine peptides (XIX-XX) is described. Sixteen of various isonicotinoylamino acid and dipeptide derivatives were found to possess specific antimicrobial activities towards different microorganisms.