Arachidonic, 5, 11, 14, 17-eicosatetraenoic and related acids in plants—Identification of unsaturated fatty acids

Arachidonic and related fatty acids which normally are found only in animals or microorganisms have been isolated and identified from several mosses and ferns. Fatty acids with a double bond in position 5, separated by more than one methylene group from other double bonds, have been found inGinkgo biloba andEquisetum. Analyses of fatty acids from numberous plants, in particular their chlorophyll containing parts, are listed according to components. The experimental part gives details on structure determination of the usual methylene-interrupted fatty acids by ozonization-hydrogenation-GLC. Alkaline isomerization combined with these procedures was applied to determine the unusual double bond structures. The method permits positional identification of an internal double bond.