A mixture of two lyse isomers of a galactolipid was obtained from Dictyonema glabratum. Aqueous hydrolysis gave rise to galactose and glycerol in a 3.1 molar ratio. ESI-MS spectroscopy gave. in the positive-ion mode, a pseudomolecular ion at mlz 839 and daughter ions with mlz 677, 600, 515 and 353, suggesting three galactosyl units linked to a glycerol moiety, substituted by one O-acyl group. 1D and 1D NMR experiments were used to characterize the glycolipid, and HMQC examination showed three anomeric signals, corresponding to two α-Galp, and one β-Galp residue liked to glycerol. The glycolipid structure was shown to be O-α-D-Galp-(1→6)-O-α-D-Galp-(1→6)-O-β-D-Galp-(1<→1)-2- and -3-monoacyl-D-glycerol, the latter structures not having been previously found in nature. The fatty acid composition was determined by GC-MS of derived methyl esters: that of palmitic acid C-16:0 was the most abundant, although the presence of C-12:0, C-14:0, C-16:1 and C-18:0 esters was observed. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, lichenized fungus, Dictyonema glabratum, trigalactosylmonoacylglycerol
NCBI PubMed ID: 11164300Publication DOI: 10.1111/j.1574-6968.2001.tb09461.xJournal NLM ID: 7705721Publisher: Blackwell Publishing
Correspondence: iacomini@bio.ufpr.br
Institutions: Departamento de Bioquímica, Universidade Federal do Paraná, CP 19046, 81531-990, Curitiba PR, Brazil, Departamento de Bioquímica, Universidade Federal do Paraná, Curtiba, Brazil
Methods: 13C NMR, 1H NMR, NMR-2D, GC-MS, TLC, ESI-MS, acid hydrolysis, NMR-1D, extraction, TOCSY, NaBH4 reduction, HMQC, COSY
Found