Abstract: The proposed structure of galantin I, a peptide antibiotic isolated from Bacillus puluifaciens as a mixture of congeners (la with the wmithine residue and lb with plysine; la/lb= 9/1), was shown to be incorrect by total synthesis. The substructure 3a, named galantinic acid, was an artifact, and its correct structure was assumed to be the hydroxylated form, 2Oa or 2Ob, by spectroscopic comparisons of synthetic la with natural galantin I. The ...