Occurrence of 3‐keto triterpenes in the unsaponifiable matter of sal (Shorea robusta) seed fat

Abstract

The unsaponifiable matter from sal (Shorea robusta) seed fat contains, in addition to the usual sterols and triterpenes, 12% of another fraction mainly consisting of 3‐keto triterpenes. The major constituents of the keto triterpene fraction have been identified as β‐amyrenone, cycloartenone and lupenone. The structural assignments were based on physical and spectral characteristics (infrared,1H‐ and13C‐nuclear magnetic resonance, and gas chromatography‐mass spectroscopy) of the alcohol acetates obtained by reduction, acetylation and fractionation of individual components by argentation thin layer chromatography. This appears to be the first recorded instance of the occurrence of 3‐keto triterpenes in vegetable fats.