Isolation of an unusual ‘lipid a’ type glycolipid from Pseudomonas paucimobilis

Abstract

A new glycolipid was isolated from defatted cells of Pseudomonas paucimobilis IAM 12576, and called ‘bound lipid’. The ‘bound lipid” could not be extracted by hot phenol extraction, but could be extracted with hot chloroform/methanol after hydrolysis with 5% trichloroacetic acid. The ‘bound lipid’ was purified by thin-layer chromatography on silica gel plates using the solvent mixture CHCl 3/CH 3OH/CH 3COOOH/ H 2O (25:15:4:2, v/v). It consisted of glucosamine, 2-hydroxy mysristic acid, galactose, mannose and uronic acid with ratios of 1.0:0.75:0.77:0.44:1.5, respectively, and other fatty acids besides 2-hydroxy myristic acid were not detected in the ‘bound lipid’. 2-Hydroxy myristic acid was probably bound to glucosamine residues by amide linkage, because mild alkali treatment did not liberate the fatty acid. From these results, we discussed the possibility that the ‘bound lipid’ was some kind of lipid A of this bacteria.