4-Methoxyestriol Explained

4-Methoxyestriol (4-MeO-E3) is an endogenous estrogen metabolite.^{[1] [2] [3] [4]} It is the 4-methyl ether of 4-hydroxyestriol and a metabolite of estriol and 4-hydroxyestriol. 4-Methoxyestriol has very low affinities for the estrogen receptors. Its relative binding affinities (RBAs) for estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) are both about 1% of those of estradiol. For comparison, estriol had RBAs of 11% and 35%, respectively.

See also

• 2-Methoxyestradiol
• 2-Methoxyestriol
• 2-Methoxyestrone
• 4-Methoxyestradiol
• 4-Methoxyestrone

Notes and References

1. Gerhardt K, Ludwig-Köhn H, Henning HV, Remberg G, Zeeck A . Identification of oestrogen metabolites in human urine by capillary gas chromatography and mass spectrometry . Biomed. Environ. Mass Spectrom. . 18 . 2 . 87–95 . February 1989 . 2706375 . 10.1002/bms.1200180202 .
2. Gaikwad NW . Ultra performance liquid chromatography-tandem mass spectrometry method for profiling of steroid metabolome in human tissue . Anal. Chem. . 85 . 10 . 4951–60 . May 2013 . 23597399 . 10.1021/ac400016e .
3. Fujii Y, Teranishi M, Nakada K, Yamazaki M, Kishida S, Miyabo S . Radioimmunoassay for the determination of 2-methoxyestriol concentration in plasma of pregnant women . Chem. Pharm. Bull. . 40 . 2 . 410–3 . February 1992 . 1606638 . 10.1248/cpb.40.410 . free .
4. Zhu BT, Han GZ, Shim JY, Wen Y, Jiang XR . Quantitative structure-activity relationship of various endogenous estrogen metabolites for human estrogen receptor alpha and beta subtypes: Insights into the structural determinants favoring a differential subtype binding . Endocrinology . 147 . 9 . 4132–50 . September 2006 . 16728493 . 10.1210/en.2006-0113 .