Flavonoids from Friesodielsia discolor

Abstract Phytochemical investigation of the fresh leaves of Friesodielsia discolor (Craib) D. Das led to the isolation of four new flavonoids, 3′-formyl-2′,4′-dihydroxy-6′-methoxychalcone ( 1 ), 8-formyl-7-hydroxy-5-methoxyflavanone ( 2 ), 8-formyl-5,7-dihydroxyflavanone ( 3 ) and 5,3′-dihydroxy-7-methoxyflavone ( 6 ), together with two known compounds, lawinal ( 4 ) and tectochrysin ( 5 ). The structures of the compounds were elucidated by spectroscopic analysis, mainly 1D and 2D NMR techniques ( 1 H, 13 C, COSY, HMQC and HMBC), as well as comparison with literature data. The isolates were tested for antiplasmodial, antimycobacterial and cytotoxic activities. Compounds 1 , 2 , 5 and 6 exhibited cytotoxicity against human tumor cell lines, KB and MCF-7 with the IC 50 values in the range of 3.45–14.82 μg/ml. Compounds 1 , 2 , and 5 also showed significant antiplasmodial activity with respective IC 50 values of 2.75, 2.78 and 2.08 μg/ml.