Two novel decaglycosylceramides with a blood group A-active tetrasaccharide repeat in the epithelial cells of the small intestine of inbred rats.

A novel type of blood group A-active glycosphingo-lipid was isolated from the epithelial cells of the small intestine of one strain of inbred rats. Electron-impact mass spectrometry of the permethylated and LiAlH4-reduced glycolipid indicated that it is a decaglycosylceramide with a branched oligosaccharide chain. Methylation analysis, gas chromatography-mass spectroscopy of the partially methylated alditol acetates, sequential degradation by exoglycosidases and characterization of the reaction products by TLC immunostaining with appropriate anti-A and anti-H antibodies, and 1H NMR spectrometry resulted in the characterization of a decaglycosylceramide with two variants in a 7/3 ratio. It was termed AA-10. [formula: see text] The major variant has only type 1 chains, whereas the minor one has type 2 chain in the C6-linked branch. This is a novel type of glycolipid with a blood group A-active tetrasaccharide repeat. Genetic analysis demonstrated that AA-10 is inherited as an autosomal dominant trait.