Identification of kahweol fatty acid esters in Arabica coffee by means of LC/MS

The diterpenes of coffee oil are responsible for various physiological effects in human subjects. They may increase the cholesterol level and also the activity of glutathione-S-transferase. For the most part, the diterpenes present in coffee oil are esterified with fatty acids (16-O-methylcafestol 12 and cafestol 14 different fatty acid esters). For kahweol, however, only five different fatty acid esters were identified by mass spectrometry. Therefore more kahweol esters are expected. The diterpene esters have now been isolated from roasted Arabica coffee by means of GPC and subsequently analyzed with the aid of LC/MS/DAD. Besides the cafestol esters already known, kahweol esters with the fatty acids C16, C17, C18 : 3, C18:2, C18 : 1, C18, C20 : 1, C20, C21, C22, C23, and C24 could be identified.