Triterpene Esters: Natural Products from Dorstenia arifolia (Moraceae)

The phytochemical study of Dorstenia arifolia Lam. (Moraceae) has led to the identification of 18 triterpenes esterified by fatty acids, five triterpenes without esterification, 12 triterpenes esterified by acetic acid, together with a known furanocoumarin: alpha-amyrin (1), beta-amyrin (2) alpha-amyrin acetate (3) beta-amyrin acetate (4), alpha-amyrin octanoate (5), beta-amyrin octanoate (6), alpha-amyrin decanoate (7), beta-amyrin decanoate (8), alpha-amyrin dodecanoate (9), beta-amyrin dodecanoate (10), alpha-amyrin tetradecanoate (11), beta-amyrin tetradecanoate (12), alpha-amyrin hexadecanoate (13), beta-amyrin hexadecanoate (14), glutinol (15), glutinyl acetate (16), 11-oxo-alpha-amyrin (17), 11-oxo-beta-amyrin (18), 11-oxo-alpha-amyrin acetate (19), 11-oxo-beta-amyrin acetate (20) 11-oxo-alpha-amyrin octanoate (21) 11-oxo-beta-amyrin octanoate (22), 11-oxo-alpha-amyrin decanoate (23), 11-oxo-beta-amyrin decanoate (24) 11-oxo-alpha-amyrin dodecanoate (25) 11-oxo-beta-amyrin dodecanoate (26), ursa-9(11),12-dien-3-yl acetate (27), oleana-9(11),12-dien-3-yl acetate (28), ursa-9(11),12-dien-3-yl decanoate (29), oleana-9(11),12-dien-3-yl decanoate (30), 12,13-epoxyolean-3-yl acetate (31), 12,13-epoxyolean-9(11)en-3-yl acetate (32), taraxeryl acetate (33), lupenyl acetate (34), lanosta-8,24-dien-3-yl acetate (35) and psoralen (36). The identification of the triterpene compounds isolated as isomeric mixtures obtained from the hexane extract was based mainly in mass spectra and C-13-NMR data. The long-chain alkanoic acid esters of the triterpenes alpha- and beta-amyrin; 11-oxo-alpha- and 11-oxo-beta-amyrin; ursa- and olean-9(11),12-dien-3-yl; have not been reported before in the literature as constituents of the Dorstenia genus.