title: Structural studies on the non-toxic lipid A from Rhodopseudomonas sphaeroides ATCC 17023.
abstract: The lipid A isolated from Rhodopseudomonas sphaeroides ATCC 17023 has been investigated. A sequence of analyses indicated beta-D-glucosaminyl-1,6-D-glucosamine as the sugar backbone carrying phosphate groups at C-1 of the reducing glucosamine and C-4 of the non-reducing glucosamine. Both 3-(7-tetradecenoyl)oxytetradecanoic and 3-oxotetradecanoic acid are linked to the NH2 groups. Two residues of 3-hydroxydecanoic acid are linked to hydroxy groups at C-3 of both reducing and non-reducing glucosamine, and the hydroxy group of 3-hydroxydecanoic acid is free. In free lipid A, the hydroxy group at C-4 of the reducing glucosamine and at C-6 of the non-reducing glucosamine are unsubstituted. The latter probably arises from a 3-deoxy-D-manno-octulosonate linkage. The structural similarities and dissimilarities existing between lipid A of R. sphaeroides, which is non-toxic, and lipid A types such as those from Salmonella, which are toxic, are discussed.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002845:Chromatography / Q000379:methods; D005227:Fatty Acids / Q000032:analysis; D008055:Lipids / Q000302:isolation & purification*; D013058:Mass Spectrometry; D010710:Phosphates / Q000032:analysis; D012242:Rhodobacter sphaeroides / Q000032:analysis*; D013329:Structure-Activity Relationship
chemical_list: D005227:Fatty Acids; D008055:Lipids; D010710:Phosphates