Flavonoids from Chiococca braquiata (Rubiaceae)

The genus Chiococca (Rubiaceae) with 22 species is endemic of the American Continent, and occurs from North America to Brazil. Several Chiococca species have been traditionally used in these regions for the treatment of numerous human ailments including inflammation, antivirus, anti-edema and as aphrodisiac. Other plants belonging to the Rubiaceae family have yielded a number of interesting biologically active compounds, including seco-iridoids with mild DNA-activity isolated from Chiococca alba. C. braquiata, however, has not been subjected to phytochemical analysis or assayed for any biological activity. In an ongoing quest to identify biologically active compounds from the Brazilian Rubiaceae plant species, antifungal evaluation using Cladosporium sphaerospermum and C. cladosporioides was performed on CH 2 Cl 2 -MeOH (2:1, v/v) extract from C. braquiata leaves, which exhibited strong antifungal activity. Bioassay-guided fractionation of the bioactive extract led to the isolation of the inactive flavonoids 4’methoxykaempferol-7-(acetyloxy)-3,5-O-L-rhamnoside (1), apigenin, 7-O-methoxyquercetrin and quercetrin. The triterpenes -amirin, -amirin, ursolic and oleanolic acids were also isolated. The structure of the new derivative 1 and the known compounds were elucidated by spectroscopic methods, mainly 2D NMR and MS.