Amburanins A and B from Amburana cearensis: Daphnodorin-type biflavonoids that modulate human neutrophil degranulation

Two new biflavonoids 3,5,7,4'-tetrahydroxyflavanone-(2→O→4': 3→3')-2',4',6',4- tetrahydroxydihydrochalcone (1) and 3,5,7,4'- tetrahydroxyflavanone-(2→O→7:3→8)-3,4',5,7- tetrahydroxyflavone (2), named as amburanin A and amburanin B, respectively, were isolated from the trunk bark of Amburana cearensis, and their structures elucidated on the basis of spectroscopic analysis and by comparison with literature data. The effects of 1 and 2 on the pro-inflammatory response of human neutrophils were investigated (0.1; 1; 25; 50 e 100 μg mL-1). At concentration higher than 25 μg mL-1, both compounds suppressed nearly 92% of the neutrophil degranulation and 53% of myeloperoxidase activity, thus indicating that they are potential anti-inflammatory lead compounds. © 2014 Sociedade Brasileira de Química.