6/3-Hydroxyestrone

Bradlow HE, Davis DL, Lin G, et al. 1995. Effects of pesticides on the ratio of 16a/2-hydroxyestrone A biologic marker of breast cancer risk. Environ Health Perspect 103(Suppl. 7) 147-150. 

C. Atkinson, H.E. Skor, E.D. Fitzgibbons, D. Scholes, C. Chen, K. Wahala, S.M. Schwartz and J.W. Lampe, Urinary equol excretion in relation to 2-hydroxyestrone and 16 alpha-hydroxye-strone concentrations an observational study of young to middle-aged women.. /. Steroid Biochem. Mol. Biol. 86 (2003) 71-77. 

Since the neutral molecules of steroid hormones and metabolites are not easily ionized under either APCP or ESI+/ modes, LC-MS/MS is less sensitive when used directly in either APCP or ESI+/ modes, with LOQs at ng/mL level as shown in Table 4 [20, 21, 52], It has been observed that estrone, 16a-hydroxyestrone, 2-methoxyestrone, 4-methoxyestrone, and 2-hydroxy-3-methoxyestrone are sensitive to APCI+ mode, while 2-hydroxyestrone and 4-hydroxyestrone are sensitive to APCI- mode, and even more sensitive to ESI mode [29], Estrone, estradiol, estradiol, and estriol are sensitive to ESI" mode, and testosterone is sensitive to ESP mode [76, 77], Similarly, estrone and estradiol are sensitive to APPI" mode, and testosterone is sensitive to APPI+ mode with LOQs in a range of 1.5-10 pg/mL [22], which are comparable with those steroid hormones and metabolites derivatized with hydroxylamine or dansyl chloride, and detected under ESP mode [2, 8],... 

Representative Chemicaes 2-Hydroxyestrone 2-Hydroxyestradiol 4-Hydroxyestrone 2-Met-hoxyestrone 2-Methoxyestriol Chemicae Abstracts Service Registry Numbers CAS 362-06-1 (2-Hydroxyestrone) CAS 362-05-0 (2-Hydroxyestradiol) CAS 3131-23-5 (4-Hydroxyestrone) CAS 362-08-3 (2-Methoxy-estrone) CAS 1236-72-2 (2-Methoxyestriol) Synonyms ... 

Chemical Formulas o 2-Hydroxyestrone CigHnOs o 2-Hydroxyestradiol CigH2403 o 4-Hydroxyestrone CigH2i03 o 2-Methoxyestrone C19H24O3 o 2-Methoxyestriol C19H26O4 Chemical Structures ... 

McGuinness BJ, Power MJ, Fottrell PF. Radioimmunoassay of 2-hydroxyestrone m urine. Chn Chem 1994 40 80-5. 

The phenolic ring in estrone can be readily oxidized. Reaction of estrone with Fremy salts (peroxylamine disulfonate) affords a mixture of the two isomeric catechols. In a more controlled manner, treatment of estrone with 2-iodoxybenzoic acid (22-1) leads intially to a mixture of the 2,3-quinone (22-2) and its 3,4-isomer (22-3) (Scheme 3.22). These products are then reduced in situ with ascorbic acid to afford 2-hydroxyestrone (22-4) and 4-hydroxyestrone (22-5). 

Lu, L.-J.W M. Cree S. Josyula M. Nagamani J.J. Grady K.E. Anderson. Increased urinary excretion of 2-hydroxyestrone but not l6 aIpha -hydroxyestrone in premenopausal women during a soya diet containing isoflavones. Cancer Res. 2000b, 60, 1299—1305. 

This specific steroid is most abundantly synthesized in the human plaeenta. It has been observed that in both pregnant and nonpregnant women estriol (along-with estrone and estradiol) are duly metaboHzed to small quantum of other structural analogues viz., 2-hydroxyestrone 2-methoxyestrone 4-hydroxyestrone and 16P-hydroxy-17P-estradiol. 

UGTIAI Bilirubin, estradiol (3-hydroxy), 2-hydroxyestrone, 2-hydroxyestradiol trans-retinoic acid, catechol estrogens (2- and 4-hydroxy)... 

The formation of 2-methoxyestrogens from the estrogens requires also 2-hydroxylation of the phenolic steroids. It has recently been shown by Fishman et al. (1960a) that this reaction does in fact occur in human tissues. Following the injection of estradiol-l7 9-i5-C into a 22-year-old man, 2-hydroxyestrone was isolated from the urine. The extent of 2-hydroxylation appears to be considerable about 12% of the administered radioactivity was recovered from the urine as radioactive 2-hydroxyestrone. An extensive study on 2-hydroxylation of estriol by rat liver in vitro was carried out by King (1961 a,b). It was found that the 2-hydroxylase activity is limited to the microsomal fraction and requires either NADHj or NADPHz, and possibly a folic acid derivative ATP appears to stimulate the 2-hydroxylase. 

Since C. e. are nonestrogenic (i. e. nonuterotropic), they are generally regarded as inactivation products of the estrogens. There is, however, evidence that C. e. (in particular 2-hydroxyestrone) are hormones in their own right, and active in the suppression of prolactin secretion [J. Fishman D.Tulchinsky Science 210 (1980) 73-74],... 

Synonyoa 2,3-Dihydroxy-l,3,5[10]-estratrien-17-one-2-methyl ether 2-hydroxyestrone-2-methyl ether 3-hydroxy-2-methoxy-l,3,5[10] estratien-17-one Trade namea ... 

The fonn of conjugation of 2-hydroxyestrone in the fetal compartment is not yet established, but it is interesting to note that in the human adult, this estrogen is conjugated with both sulfuric and glucuronic acids. The conjugation with glucuronic acid takes place exclusively at Cs but that with sulfuric acid at Ca or Cs (Yoshizawa and Fishman, 1969). 

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