Nature of Multiple Forms of the Lactobacillus bulgaricus Factor (LBF).

Abstract
Treatment of pantethine with Na sulfide, cysteine, glutathione, beta-mercaptoethylamine, or several other thiols (followed, in some cases, by oxidation with iodine) yielded a series of new compounds,apparently mixed disulfides, with growth-promoting activity for L. heiveticus 80. The natural formation of similar mixed disulfides from pantethine and other naturally occurring thiols may account in part for the presence of several chromatographically distinct forms of LBF in natural materials.