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Structure and Vasorelaxant Activity of Floranol, a Flavonoid Isolated from the Roots of Dioclea grandiflora
Author(s) -
Lemos Virgínia S.,
Côrtes Steyner F.,
dos Santos Marcelo H.,
Ellena Javier,
Moreira Maria E. C.,
Doriguetto Antônio C.
Publication year - 2006
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.200690066
Subject(s) - chemistry , phenylephrine , vasodilation , flavonoid , vascular smooth muscle , stereochemistry , endothelium , smooth muscle , pharmacology , aorta , traditional medicine , biochemistry , medicine , antioxidant , blood pressure
The structure of the prenylated flavanonol, floranol ( 1 =(2 R ,3 R )‐3,5,7‐trihydroxy‐2‐(2‐hydroxyphenyl)‐6‐methoxy‐8‐(3‐methylbut‐2‐enyl)‐4 H ‐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 concentration‐dependent vasodilator effect in vessels precontracted with 0.1 μ M phenylephrine with an IC 50 value of 19.9±2.4 μ M . 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.