The chemical structure of a novel lipid A, the major com-ponent of the lipopolysaccharide from the marine gamma-proteobacteriumMarinomonas vagaATCC 27119 T ,was determined by compositional analysis, NMR spectroscopy, and MS. It was found to be b-1,6-glucosaminobiose 1-phosphate acylated with (R)-3-[dodecanoyl(dodece-noyl)oxy]decanoic acid {C10 : 0 (3O-C12 : 0 [3O-C12 : 1])} or (R)-3-(decanoyloxy)decanoic acid [C10 : 0 (3O-C10 : 0)], (R)-3-hydroxydecanoic acid [C10 : 0 (3OH)], and (R)-3-[(R)-3-hydroxydecanoyloxy]decanoic acid (C10 : 0 {3O-[C10 : 0 (3OH)]}) at the 2, 3, and2¢positions, respectively
