Cyanolipids ofKoelreuteria paniculata Laxm. seed oil

Koelreuteria paniculata Laxm. (Sapindaceae) seed oil is a mixture of cyanolipids (42%) and ordinary triglycerides. The cyanolipid portion contains two classes of components. One of these (25% of the oil) is a mixture of diesters composed of two fatty acid moieties (predominantly C18 and C20 monoenoic) esterified with an unsaturated five-carbon dihydroxynitrile (1-cyano-2-hydroxymethylprop-1-ene-3-ol). The other class (17% of the oil) consists of cyanolipids having one fatty acid moiety (predominantly C20 monoenoic) esterified with 1-cyano-2-methylprop-1-ene-3-ol. Monoesters based on this same hydroxynitrile were previously isolated fromStocksia brahuica seed oil and characterized. Hydrogenation of the diesters was accompanied by varying degrees of hydrogenolysis of the ester groups. The hydrogenated diester was reduced with lithium borohydride and the dihydroxynitrile portion was isolated. Acetolysis of the hydrogenated diester in glacial acetic acid with sulfuric acid catalyst yielded an acetylated γ-lactone. The double bond of the dihydroxynitrile moiety in the diester does not react with bromine in carbon tetrachloride.