Structure of a major glycophosphoceramide from tobacco leaves, PSL-I: 2-deoxy-2-acetamido-D-glucopyranosyl(α1 → 4)-D-glucuronopyranosyl(α1 → 2)myoinositol-1-O-phosphoceramide

Abstract

The chemical structure of a major glycophosphoceramide from tobacco [Nicotiana tabacum] leaves, called PSL-I, has now been characterized as 2-deoxy-2-acetamido-D-glucopyranosyl-(.alpha.1 .fwdarw. 4)D-glucuronopyranosyl(.alpha.1 .fwdarw. 2)myoinositol-1-O-phosphoceramide. Sites of glycosidic linkage were determined by methylation analysis on a trisaccharide isolated by degradation of carboxyl-reduced PSL-I and periodate oxidation experiments on PSL-I. The resulting products were identified with gas chromatography/mass spectrometry. Anomeric configurations were determined by resistance of the sugars in the peracetylated trisaccharide to chromium trioxide treatment.