S-equol

(S)-Equol

Identifiers
IUPAC name (3S)-3-(4-Hydroxyphenyl)-3,4-dihydro-2H-chromen-7-ol
CAS Number	531-95-3
PubChem CID	91469
ChemSpider	82594
Chemical and physical data
Formula	C15H14O3
Molar mass	242.26986 g/mol
3D model (Jmol)	Interactive image
SMILES C1C(COC2=C1C=CC(=C2)O)C3=CC=C(C=C3)O
InChI InChI=1S/C15H14O3/c16-13-4-1-10(2-5-13)12-7-11-3-6-14(17)8-15(11)18-9-12/h1-6,8,12,16-17H,7,9H2/t12-/m1/s1 Key:ADFCQWZHKCXPAJ-GFCCVEGCSA-N

(S)-Equol, or (S)-(–)-4',7-isoflavandiol, is the (S)-enantiomer of the naturally occurring isoflavandiol estrogen, equol. It is a non-steroidal, selective agonist of ERβ (K_i = 16 nM), with 13-fold selectivity for ERβ over ERα. Relative to (S)-equol, (R)-equol is less potent and, in contrast, binds to ERα (K_i = 50 nM) with 3.5-fold selectivity over ERβ. Under the code name AUS-131, (S)-equol is under development for the treatment of menopausal symptoms such as hot flashes and benign prostatic hyperplasia.[1] Human intestinal bacteria metabolize the soy isoflavone daidzein into (S)-equol, and it has been determined that (S)-equol is exclusively produced.