Biotransformation of chalcones by the endophytic fungus Aspergillus flavus isolated from Paspalum maritimum trin

The fungus Aspergillus flavus isolated as endophytic of the plant Paspalum maritimum Trin. was evaluated for its potential application in biotransformation reactions. The compounds chalcone (1), 3,4,5-trimethoxychalcone (2) and 2,3,4,4'-tetramethoxy chalcone (3) were biotransformed, respectively, in dihydrochalcone (4), 3,4,5-trimethoxydihydrochalcone (5) and 2,3,4,4'-tetramethoxydihydrochalcone (6). The structures were elucidated by spectroscopic methods including 1D and 2D NMR techniques, and MS analysis. The dihydrochalcones 5 and 6 are new compounds. (author)