Effect of various water-soluble components of phospholipids on the photooxidation of chlorophyllin

Photooxidation of water-soluble chlorophyllin was measured in the presence of glycerol, phosphate, choline, phosphorylcholine, ethanolamine, phosphorylethanolamine and liposomes made from phosphatidylcholine and phosphatidylethanolamine. The choline containing compounds protected chlorophyllin from destruction while the ethanolamines enhanced degradation. The difference in activity between the two families of compounds is related to the availability of their protons. These experiments provide a further indication that in the thylakoid phosphatidylcholine may protect chlorophyll from photooxidation.