2-Methoxyestriol

2-Methoxyestriol (2-MeO-E3) is an endogenous estrogen metabolite.[1][2][3] It is specifically a metabolite of estriol and 2-hydroxyestriol.[1][2][3] It has negligible affinity for the estrogen receptors and no estrogenic activity.[4] However, 2-methoxyestriol does have some non-estrogen receptor-mediated cholesterol-lowering effects.[5]

Selected biological properties of endogenous estrogens in rats

Estrogen	ER RBA (%)	Uterine weight (%)	Uterotrophy	LH levels (%)	SHBG RBA (%)
Control	–	100	–	100	–
Estradiol	100	506 ± 20	+++	12–19	100
Estrone	11 ± 8	490 ± 22	+++	?	20
Estriol	10 ± 4	468 ± 30	+++	8–18	3
Estetrol	0.5 ± 0.2	?	Inactive	?	1
17α-Estradiol	4.2 ± 0.8	?	?	?	?
2-Hydroxyestradiol	24 ± 7	285 ± 8	+^b	31–61	28
2-Methoxyestradiol	0.05 ± 0.04	101	Inactive	?	130
4-Hydroxyestradiol	45 ± 12	?	?	?	?
4-Methoxyestradiol	1.3 ± 0.2	260	++	?	9
4-Fluoroestradiol^a	180 ± 43	?	+++	?	?
2-Hydroxyestrone	1.9 ± 0.8	130 ± 9	Inactive	110–142	8
2-Methoxyestrone	0.01 ± 0.00	103 ± 7	Inactive	95–100	120
4-Hydroxyestrone	11 ± 4	351	++	21–50	35
4-Methoxyestrone	0.13 ± 0.04	338	++	65–92	12
16α-Hydroxyestrone	2.8 ± 1.0	552 ± 42	+++	7–24	<0.5
2-Hydroxyestriol	0.9 ± 0.3	302	+^b	?	?
2-Methoxyestriol	0.01 ± 0.00	?	Inactive	?	4
Notes: Values are mean ± SD or range. ER RBA = Relative binding affinity to estrogen receptors of rat uterine cytosol. Uterine weight = Percentage change in uterine wet weight of ovariectomized rats after 72 hours with continuous administration of 1 μg/hour via subcutaneously implanted osmotic pumps. LH levels = Luteinizing hormone levels relative to baseline of ovariectomized rats after 24 to 72 hours of continuous administration via subcutaneous implant. Footnotes: ^a = Synthetic (i.e., not endogenous). ^b = Atypical uterotrophic effect which plateaus within 48 hours (estradiol's uterotrophy continues linearly up to 72 hours). Sources: See template.

2-Methoxyestriol

Names
IUPAC name (8R,9S,13S,14S,16R,17R)-2-methoxy-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,16,17-triol
Other names 2-MeO-E3
Identifiers
CAS Number	1236-72-2
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL1908077
ChemSpider	92169
PubChem CID	102031
InChI InChI=1S/C19H26O4/c1-19-6-5-11-12(14(19)9-16(21)18(19)22)4-3-10-7-15(20)17(23-2)8-13(10)11/h7-8,11-12,14,16,18,20-22H,3-6,9H2,1-2H3/t11-,12+,14-,16+,18-,19-/m0/s1 Key: PEXPJFWTSZLEAQ-YSYMNNNUSA-N
SMILES C[C@]12CC[C@H]3[C@H]([C@@H]1C[C@H]([C@@H]2O)O)CCC4=CC(=C(C=C34)OC)O
Properties
Chemical formula	C19H26O4
Molar mass	318.413 g·mol^−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

See also

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

References

1. Fishman J, Gallagher TF (October 1958). "2-Methoxyestriol: a new metabolite of estradiol in man". Arch. Biochem. Biophys. 77 (2): 511–3. doi:10.1016/0003-9861(58)90097-3. PMID 13584013.
2. King RJ (May 1961). "Oestriol metabolism by rat- and rabbit-liver slices. Isolation of 2-methoxyoestriol and 2-hydroxyestriol". Biochem. J. 79: 355–61. doi:10.1042/bj0790355. PMC 1205847. PMID 13756104.
3. Fujii Y, Teranishi M, Nakada K, Yamazaki M, Kishida S, Miyabo S (September 1988). "Radioimmunoassay of 2-methoxyestriol in pregnancy plasma". Horm. Metab. Res. 20 (9): 599–600. doi:10.1055/s-2007-1010895. PMID 3198067.
4. Martucci CP (July 1983). "The role of 2-methoxyestrone in estrogen action". J. Steroid Biochem. 19 (1B): 635–8. doi:10.1016/0022-4731(83)90229-7. PMID 6310247.
5. Kono, Shinzo; Higa, Hiroaki; Sunagawa, Hajime (1989). "Hypocholesterolemic Effect of Long-Term Continuous Administration of 2-Methoxyestriol in Dietary Hypercholesterolemic Rats". Journal of Clinical Biochemistry and Nutrition. 6 (1): 49–56. doi:10.3164/jcbn.6.49. ISSN 1880-5086.