Characterization of lipids from chloroplast envelopes.

The major neutral, glycolipids and phospholipids from envelopes of spinach chloroplasts were analyzed with respect to proportions, positional distribution and pairing of fatty acids. All specificities in the diacylglycerol portions of lipids known from previous analyses of lipids from whole leaves were also found in envelope lipids. Diacylglycerols and galactolipids share a common diacylglycerol portion. The only exception is digalactosyl diacylglycerol, which contains 18:3/16:0 but lacks 18:3/16:3 species reverting the distribution in other galactolipids. Phosphatidylcholine, phosphatidylglycerol and sulfoquinovosyl diacylglycerol are distinct from the galactolipids, because each one has a unique diacylglycerol profile. The diacylglycerol species present in phosphatidylcholine and galactolipids or free diacylglycerols do not provide evidence for a biogenetic relation between phosphatidylcholine and galactolipids at the level of envelopes.