Levels of cafestol, kahweol, and related diterpenoids in wild species of the coffee plant Coffea

Coffee beans of commercially important Coffea species contain the diterpene cafestol, which raises serum cholesterol in humans. Coffee diterpenes also have shown anticarcinogenic properties in experimental animals. We determined levels of cafestol and other diterpenes in nine wild African Coffea species, in a search for a species without the cholesterol-raising cafestol. In addition, data on diterpene profiles might assist in the taxonomic grouping of Coffea species. Each Coffea species we investigated contained cafestol. Kahweol concentrations may be related to the geographical distribution of the Coffea species. 16-O-Methylcafestol was only present in Coffea canephora, Coffea stenophylla, and Coffea liberica var. dewevrei. A new diterpene was found in C. stenophylla and tentatively identified as 16-O-methylkahweol, Another four new diterpenes, which seem to contain an additional double bond compared to kahweol, were found in Coffea salvatrix and Coffea pseudozanguebariae, suggesting that these two species are closely related. In conclusion, cafestol is universally present in Coffea species. Amounts of kahweol, 16-O-methylcafestol, 16-O-methylkahweol, and the four newly found diterpenes present in various coffee beans may prove useful in the taxonomic classification of Coffea species.