Isoflavonoids from Erythrina poeppigiana: evaluation of their binding affinity for the estrogen receptor.
Five new isoflavones, named 5,4'-dihydroxy-7-methoxy-3'-(3-methylbuten-2-yl)isoflavone (1), 5,2',4'-trihydroxy-7-methoxy-5'-(3-methylbuten-2-yl)isoflavone (2), 5,4'-dihydroxy-7-methoxy-3'-(3-methyl-2-hydroxybuten-3-yl)isoflavone (3), 3'-formyl-5,4'-dihydroxy-7-methoxyisoflavone (4), and 5-hydroxy-3''-hydroxy-2'',2''-dimethyldihydropyrano[5'',6'':3',4']isoflavone (5), as well as six known compounds, wighteone (6), 3'-isoprenylgenistein (7), isolupabigenin (8), alpinumisoflavone (9), erypoegin D (10), and crystacarpin (11), were isolated from Erythrina poeppigiana. The structures of the isolated compounds were elucidated on the basis of chemical and spectroscopic analysis. The affinity of these compounds for the estrogen receptors ERalpha and ERbeta was evaluated using a receptor binding assay. While isoprenyl and dimethylpyrano substituents in ring A reduced the affinity of binding to ERbeta ca. 100-fold compared to genistein, the isoprenyl substituent in ring B was better accommodated, allowing 7 to bind with ca. 10-fold lower affinity than genistein.
Djiogue
Sefirin
S
Division of Pharmacognosy and Natural Products Chemistry, School of Pharmacy, University of Athens, Panepistimioupoli Zografou, Athens, Greece.
Halabalaki
Maria
M
Alexi
Xanthippi
X
Njamen
Dieudonne
D
Fomum
Zacharias Tanee
ZT
Alexis
Michael N
MN
Skaltsounis
Alexios-Leandros
AL
D001838:Bolivia; D004895:Erythrina / Q000737:chemistry*; D047628:Estrogen Receptor alpha / Q000187:drug effects*; D047629:Estrogen Receptor beta / Q000187:drug effects*; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D013329:Structure-Activity Relationship
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D007529:Isoflavones; D019833:Genistein