LAUSR

Abstract Heterophragma adenophyllum (Wall. ex G.Don) Seem belong to family Bignoniacea. To find a safe, effective and economical drugs candidate, the screening of chemical constituents for various biological actions is essential. The isolated compounds (1–3), such as, 2-hydroxy-3-(3-methylbut-2-enyl)naphthalene-1,4-dione (1), methyl 1,2-dihydroxy-2-(3-methylbut-2-enyl)-3-oxo-2,3-dihydro-1H-indene-1-carboxylate (2), 2,2-dimethyl-3,4-dihydro-2H-benzo[g]chromene-5,10-dione (3) were characterized with 1H-NMR, 13C-NMR, EI-MS and UV spectroscopy. The pure constituents have shown significant inhibition potential against phosphodiesterase-1 (PDE-1) with percentage inhibition 98.4, 92.4 and 88.4%, respectively. The IC50 value of the compounds was calculated in which all the three compounds have shown potent activity against clinically important enzyme PDE-1 (IC50 = 21.9 ± 1.12 to 112.4 ± 2.08 µM). When these values were compared with standard EDTA (IC50 = 265.5 ± 2.25 µM), then it is concluded that H. adenophyllum can be used for the treatment of vasoconstriction and various inflammatory conditions. Molecular docking was performed to explore the possible role of isolated bioactive compounds into active sites of snake venom and human PDE-1. The data obtained in terms of binding energy values from docking studies of both snake venom and human PDE-I agrees with the experimental PDE-1 inhibition.