Identification of new diterpene esters from green Arabica coffee beans, and their platelet aggregation accelerating activities

Eight new ent -kaurane diterpene fatty acid esters, namely caffarolides A–H ( 1 – 8 ), were isolated from green beans of Coffea arabica . Their chemical structures were confirmed by extensive spectroscopic analysis including 1D, 2D NMR (HSQC, HMBC, 1 H– 1 H COSY, and ROESY), HRMS, IR and CD spectra and by GC-FID analysis. Interestingly, the diterpene moiety of these new compounds first occurred in genus Coffea . All the isolates were evaluated for platelet aggregation activity in vitro . As the results, caffarolides C, D and F ( 3 , 4 and 6 ) showed induction effect for platelet aggregation and the possible structure-activity relationships have been discussed briefly.