Structural characterization of a novel diglycosyl diacylglyceride glycolipid from Rhizobium trifolii ANU843.
A novel glycolipid was isolated by chloroform-methanol extraction of Rhizobium trifolii ANU843 cells. Compositional analysis, methylation studies, 1H NMR and spectroscopies led to the identification of a diglycosyl diacylglyceride: 1,2-di-O-acyl-3-O-[alpha-D-glucopyranosyl-(1----3)-O-alpha-D- mannopyranosyl]glycerol. Iso-hexadecanoic and anteiso-heptadecanoic acids were the predominant fatty acids esterifying the glyceryl moiety, but a microheterogeneity in fatty acid composition was found, resulting in at least five distinct molecular species of the glycolipid. Although widespread in plants, animals and Gram-positive bacteria, glycosyl glycerides have been seldom reported in Gram-negative bacteria and this work is the first evidence of their occurrence in the bacterial family Rhizobiaceae.
Orgambide
G G
GG
Department of Microbiology, Michigan State University, East Lansing 48824.
Hollingsworth
R I
RI
Dazzo
F B
FB
D002240:Carbohydrate Sequence; D004075:Diglycerides / Q000737:chemistry*; D008745:Methylation; D008969:Molecular Sequence Data; D012231:Rhizobium / Q000737:chemistry*; D013057:Spectrum Analysis
D004075:Diglycerides