Chemical Characterization of Lipid A from Some Marine Proteobacteria

Lipids A from type and wild strains of marine Proteobacteria belonging to Alteromonadaceae (Alteromonas (1 species), Idiomarina (1 species), and Pseudoalteromonas (8 species) genera) and Vibrionaceae (Shewanella (1 species) and Vibrio (1 species) genera) families and Marinomonas genus (1 species) were isolated by hydrolysis of their respective lipopolysaccharides with 1% acetic acid. Based on thin-layer chromatography data, the lipids A studied had low heterogeneity and generated family-specific patterns varying in numbers of bands and their chromatographic mobility. Total chemical analysis of the compounds showed that they contained glucosamine, phosphate, and fatty acids with decanoate (I. zobellii KMM 231^T lipid A) or dodecanoate (lipids A of the other bacteria) and 3-hydroxy alkanoates as the major fatty acid components. Unlike terrestrial bacterial lipids A, lipids A of marine Proteobacteria had basically monophosphoryl (except V. fluvialis AQ 0002B lipid A with its two phosphate groups) and pentaacyl (except S. alga 48055 and V. fluvialis AQ 0002B lipids A which were found to have six residues of fatty acids per molecule of glucosamine disaccharide) structural types, low toxicity, and may be useful as potential endotoxin antagonists.