Structure and Vasorelaxant Activity of Floranol, a Flavonoid Isolated from the Roots of Dioclea grandiflora

✍ Scribed by Virgínia S. Lemos; Steyner F. Côrtes; Marcelo H. dos Santos; Javier Ellena; Maria E. C. Moreira; Antônio C. Doriguetto

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 268 KB
• Volume: 3
• Category: Article
• ISSN: 1612-1872
• DOI: 10.1002/cbdv.200690066

✦ Synopsis

The structure of the prenylated flavanonol, floranol (1 ¼ (2R,3R)-3,5,7-trihydroxy-2-(2-hydroxyphenyl)-6-methoxy-8-(3-methylbut-2-enyl)-4H-1-benzopyran-4-one), isolated from the roots of Dioclea grandiflora (Fabaceae), was unambiguously determined by X-ray analysis. The compound was tested for vasorelaxant activity. In endothelium-containing aortic rings, floranol (1) induced a concentrationdependent vasodilator effect in vessels precontracted with 0.1 mm phenylephrine with an IC 50 value of 19.9 AE 2.4 mm. The removal of endothelium or pretreatment of vessels with the NO-synthase inhibitor l-NAME did not change the IC 50 and E max values for floranol-induced vasorelaxation. We conclude that floranol (1) should be acting directly in the rat-aorta smooth muscle cells to produce its vasorelaxant effect. The structure -activity relationship was discussed in terms of the 3-D floranol structure determined by X-ray crystallography.