A novel sulfonic-acid analogue of ceramide is the major extractable lipid of the gram-negative marine bacterium Cyclobacterium marinus WH

Abstract

The extractable lipids of the gram-negative, sea-water bacterium Cyclobacterium marinus strain WH contain about 94% of polar components which consist of two phospholipids, phosphatidylethanolamine (29% of the total lipids) and phosphatidylcholine (7%), and two phosphorus-free lipids. One of the latter has been shown to be a novel sulfonic-acid analogue of ceramide, 2- d-(2′- d-hydroxy-13′-methyltetradecanoyl) amino-3- d-hydroxy-15-methylhexadec-4 (E)-en-1-sulfonic acid (48%), and other is a lipodipeptide, N-[3- d-(13′-methyltetradecanoyloxy)-15-methylhexadecanoyl] glycyl- l-serine (11%), which has so far been found only in a Flavobacterium sp. strain. The dominant fatty acid residues of the phospholipids are iso-15:0, n-16:0, 16:1 and 18:1, the acyl residues linked to the sn-1 carbon of the glycerol moiety being somewhat more saturated as compared with those located at the sn-2 position. A new procedure for determination of the absolute configuration of 2- and 3-hydroxy fatty acids is briefly described.