Fatty acid composition of seed oils from six Adansonia species with particular reference to cyclopropane and cyclopropene acids

Abstract

The oil content of six Adansonia species (Bombacaceae family) of Madagascar (Adansonia grandidieri, A. za, A. digitata, A. fony, A. madagascariensis and A. suarenzensis) and Africa (A. digitata) ranges from 8 to 46%. All the oils give a positive response to the Halphen test. Malvalic, sterculic and dihydrosterculic acids were detected using gas liquid chromatography-mass spectrometry (GLC-MS). Epoxy or hydroxy fatty acids were not found in these oils. Fatty acid composition was determined by GLC using glass capillary columns coated with BDS and Carbowax 20 M. Results obtained for cyclopropenic fatty acids (CPEFA) were compared to those given by glass capillary GLC after derivatization with silver nitrate in methanol, by hydrogen bromide titration and by proton magnetic resonance (PMR). Good agreement was observed for the results given by the various methods. Malvalic acid content ranges from 3 to 28%, sterculic acid from 1 to 8% and dihydrosterculic acid from 1.5 to 5.1%. Odd-numbered fatty acids (Pentadecanoic and hepatadecanoic) were also observed in minute amounts (0.1-1.1%). Among the normal fatty acids, we observed mainly palmitic (21-46%), oleic (15-40%) and linoleic (12-32%). The relationship between fatty acid composition and Adansonia species is discussed. © 1982 American Oil Chemists' Society.