Biochemistry of the sphingolipids. XIV. Inositol lipids of flaxseed

Abstract

Abstract A study has been made of the inositol‐containing lipids of flaxseed phosphatides. Solvent fractionation procedures have been developed for the preparation of an inositol lipid fraction from the oil‐free phosphatide. By countercurrent extraction, the inositol lipid fraction was separated into a crude phosphatidyl inositol fraction and a second fraction containing long‐chain base nitrogen. The phosphatidyl inositol was shown to exist as a mixed magnesium‐calcium salt and evidence is presented that nitrogenous impurities (mainly phosphatidylethanolamine) may be bound to phosphatidyl inositol through a chelated salt linkage. The long‐chain base fraction was shown to contain phosphatidyl inositol and two phytoglycolipids, one similar to that from corn and soybean; the other of a novel type in which the oligosaccharide portion contains galactose, arabinose and fucose. The long‐chain base in flax phosphatides was shown to be dehydrophytosphingosine. It was suggested that phytoglycolipid may exist in a loose complex with phosphatidyl inositol (possibly as a chelated magnesium and/or calcium salt).