Structural characteristics of flavanones and flavones from Cudrania tricuspidata for neuraminidase inhibition

The structural characteristics of. avonoids (1-3 and 6-8) from the root of Cudrania tricuspidata required for neuraminidase inhibition were studied and compared with commercially available. avonoids (4, 5, and 9-12). Alkylated flavanones (1-3) display better inhibition than the corresponding parent compound 4. Importantly, flavanone 1 bearing a C-8 hydrated prenyl group showed extremely high inhibition with IC50 of 380 nM. On the other hand, the parent flavone 5 was more effective than alkylated analogues (6-8). Isolated inhibitors (1-3 and 6-8) showed noncompetitive inhibition in kinetic studies. The binding affinity of. avanones (1-4) for neuraminidase in in silico docking experiments correlated well with their IC50 values and noncompetitive inhibition mode. (C) 2009 Elsevier Ltd. All rights reserved.