Abstract
Various analogues of pantothenic acid which contained the pantoyl group inhibited the growth of microorganisms which did not synthesize pantothenic acid. This inhibition was competitive since it occurred only when the ratio of the conc. of the analogue to that of pantothenic acid surpassed a given value, but was independent of the absolute amt. of analogue present. Two compds. promoted growth slightly in the absence of pantothenic acid, but inhibited growth induced by added pantothenic acid to the level of their own activity. In each of the compds. used, the amino compd. condensed with the lactone contained an asymmetric C atom. Crude reaction mixts. were tested throughout. The organisms used were Lactobacillus casei, L. arabinosus and L. jermentum. The analogues were dl-pantothenyl alcohol, N-pantoyl-4-amino-2-butanol, sodium N-pantoyl-[beta]-aminobutyrate, N-pantoylisoserine and sodium N-pantoyl-[beta]-aminoisobutyrate.