Structure elucidation and vasodilator activity of methoxy flavonols from Calycotome villosa subsp. intermedia

Abstract

Abstract Two flavonols identified as 3,5,7,4′-tetrahydroxy-3′-methoxyflavone ( 1 ) and 3,5,7,4′-tetrahydroxy-8-methoxyflavone ( 2 ) were isolated from the seeds of Calycotome villosa subsp. intermedia . The structure elucidation of the isolated compounds was performed by the spectroscopic methods (UV, IR, 1 H NMR, 13 C NMR and MS) and also by a single crystal X-ray analysis in the case of compound ( 2 ). Vasodilator activity of compound ( 2 ) was demonstrated in isolated rat aorta contracted with high KCl or with noradrenaline.