title: Determining double-bond positions in monoenoic 2-hydroxy fatty acids of glucosylceramides by gas chromatography-mass spectrometry.
abstract: We applied a gas chromatography-mass spectrometry (GC-MS) method using dimethyl disulfide (DMDS) adducts and were able to determine the double-bond positions in monounsaturated 2-hydroxy fatty acids (2-HFA). 2-HFA methyl esters, prepared from the hydrolysate of Arabidopsis thaliana leaf glucosylceramides, were acetylated and methylthiolated. GC-MS analysis of the resulting DMDS adducts showed simple mass spectra with recognizable molecular ions and a series of key fragment ions indicating the original double-bond positions in the aliphatic chain. Based on this GC-MS elucidation, we confirmed that Arabidopsis leaf glucosylceramides have C22, C23, C24, C25, and C26 chain length 2-HFA with monounsaturation, and all their double bonds are placed at the n-9 position. This procedure is simple, time efficient, and highly sensitive.
authors.affiliation: Department of Biology, Faculty of Science, Konan University, Kobe, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Imai
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: A
authors.initials: A
authors.lastname: Shibahara
authors.forename: S
authors.initials: S
authors.lastname: Miyatani
authors.forename: T
authors.initials: T
authors.lastname: Nakayama
mesh_terms: D017360:Arabidopsis / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005963:Glucosylceramides / Q000032:analysis / Q000737:chemistry*
chemical_list: D004220:Disulfides; D005227:Fatty Acids; D005963:Glucosylceramides; C021181:dimethyl disulfide