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Review
. 2010 Jul;140(7):1363S-8S.
doi: 10.3945/jn.109.119784. Epub 2010 Jun 2.

Equol: pharmacokinetics and biological actions

Kenneth D R Setchell  1 , Carlo Clerici
Affiliations
Review

Equol: pharmacokinetics and biological actions

Kenneth D R Setchell et al. J Nutr. 2010 Jul.

Abstract

Equol [7-hydroxy-3-(4'-hydroxyphenyl)-chroman], an isoflavan produced by intestinal bacteria in response to soy isoflavone intake in some but not all humans, exhibits a wide range of biological properties. It exists as the diastereoisomers S-(-)equol and R-(+)equol. Intestinal bacteria produce exclusively S-(-)equol, which has selective affinity for estrogen receptor (ER)-beta. The evidence is conflicting on whether there is an advantage to producing S-(-)equol in response to soy isoflavone intakes, but the ability to now synthesize these diastereoisomers opens the way for future clinical trials to directly examine their potential in a number of hormone-dependent conditions. In this review, the plasma and urinary pharmacokinetics of S-(-)equol and R-(+)equol are reviewed and summarized, and some of the more recent evidence supporting potential biological effects of S-(-)equol is considered.

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Figures

FIGURE 1
FIGURE 1
A comparison of the conformation structures of estradiol, S-(-)equol, and R-(+)equol.
See this image and copyright information in PMC

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