Demonstration of long-chain n-alkyl caffeates and Δ7-steryl glucosides in the bark of Acacia species by gas chromatography-mass spectrometry

The GC-MS identification of several abundant long-chain aliphatic n-alkyl caffeates, together with other phydroxycinnamic acid esters, in the dichloromethane extracts of the bark of Acacia dealbuta and A. melanoxylon, is reported. In addition, the unambiguous differentiation between two Delta(7)-steryl glucosides (namely, spinasteryl glucoside and dihydrospinaster-yl glucosides) and the homologous Delta(5)-steryl glucosides was achieved based on the EI-MS fragmentation features of their trimethylsilyl derivatives. Copyright (c) 2007 John Wiley & Sons, Ltd.