First report on mangiferin (C-glucosyl-xanthone) isolated from leaves of a wild coffee plant,Coffea pseudozanguebariae(Rubiaceae)

Bean biochemical composition has been extensively analyzed in Coffea species because of its impact on coffee beverage quality. C. pseudozanguebariae appeared as an interesting wild species because of its low caffeine and chlorogenic acid content, compounds involved in coffee bitterness. Extending the study to its leaves revealed the presence of two unknown phenolic compounds. Isolation, then identification by MS and NMR analysis proved that these compounds are two C-glucosyl-xanthones: mangiferin and isomangiferin. HPLC analyses indicated very high mangiferin content in young leaves. This class of compounds is described for the first time not only in coffee plants but also in the Rubiaceae family. The interest of mangiferin identification in the Coffea genus is discussed.