Diol lipids. Acylated ethyleneglycol glycosides. A new type of natural glycolipid.

A new type of glycolipid has been detected in ripening corn seeds. The presence of ethyleneglycol, galactose, glucose and fatty acids was shown by degradation studies. The products of alkaline deacylation were identified as galactosyl- and glycosylethyleneglycol by thin-layer chromatography and combined gas-liquid chromatography-mass spectrometry. The native ethyleneglycol galactolipid was isolated by distribution of the total lipids between heptane and 95% methanol, following silica gel column chromatography of the methanol soluble fraction. Analysis of the alkaline deacylation products of the isolated ethyleneglycol lipid as well as examination of the mass-spectrum of its tetraacetate showed the new lipid to have the structure of 1-acyl-2-(O-beta-D-galacto-pyranosyl)ethyleneglycol with palmitic, oleic and stearic acids as the main fatty acid components. The fragmentation patterns under electron impact of trimethylsilyl ethers of synthetic ethyleneglycol glycopyranosides and of 1-palmitoyl-2-(O-beta-D-tetraacetylgalactopyranosyl)ethyleneglycol are described.