Inhibitory activity and docking studies of cathepsin V for isoflavanoids from Dalbergia miscolobium Benth

Plant extracts from Dalbergia genus have demonstrated a wide range of biological activities including, analgesic, antidiabetic, anti-inflammatory, and antimicrobial. In this work, the chemical study of the extracts from the leaves and branches of Dalbergia miscolobium led to the isolation and identification of five isoflavonoids: prunetin, di-O-methyldaidzein, 8-O-methylretusin, duartin and sativan employing nuclear magnetic resonance data. The inhibition activity of these isoflavonoids was screened against cathepsin V at a concentration of 100 μM. Duartin and sativan showed remarkable activity against cathepsin V displaying 89% and 88% inhibition values, respectively. Also, docking simulations to predict the binding mode of isoflavonoids into this protein were performed and results showed that the duartin is nicely bound to the cathepsin V and stabilized by two hydrogen bonds. The isoflavans duartin and sativan showed a significant inhibition percentage of cathepsin V, which can be considered as targets into cathepsin V inhibitors investigation and further chemical study of Dalbergia species may afford novels isoflavonoids cathepsin inhibitors. (author)