Chemical composition of the lipophylic extract from the tunicate Botryllusschlosseri

Eighteen sterols were identified in Botryllus schlosseri, stanols being the main sterols. The sterol composition is in agreement with our recent paper on taxonomic separation of tunicates into three groups. Again;we found in invertebrates of the Black Sea sterols with a (22Z)-double bond. This confi rms the presence of such sterols in nature. The composition of the phosphol ipids appeared to be complex, and twelve groups of them were identified in Botryllus schlosseri. The main representatives of phospholipids appeared to be phosphatidylcholine and phosphatidylethanolamine. Only four volatile co mpounds were identified, which is unusual for marine invertebrates.