Synthesis and biological evaluation of novel biphenyl-furocoumarin derivatives as vasodilator agents.

A series of novel biphenyl-furocoumarin derivatives were synthesized based on the nuclear structure of imperatorin and identified by IR, 1H NMR, 13C NMR and MS, and evaluated for their ability to relax vessel on isolated rat mesenteric artery, basilar artery and renal artery, respectively. The majority of compounds demonstrated potent vasodilatation, and compound 8e expressed the highest activity (EC50 = 0.56 μM) in MA. Compounds with fluorine at 2-position of 5-phenyl get better activity than others with chlorine or bromine, and the compounds containing a bulky structure had relatively low activity, such as 8c (EC50 = 22.39 μM) in MA. As a follow-up, 8e, 10e, and 8c were docked into L-calcium channel (PDB code: 3G43) to explain the difference in the activity of the compounds.