Synthesis of 2-hydroxy-ethynylestradiol and 4-hydroxy-ethynylestradiol

ESR identification of free radicals formed from the oxidation of catechol estrogens by Cu2+

Catechol estrogens are genotoxic, indirectly through redox cycling mechanisms leading to oxidative DNA damage and directly by formation of quinone-DNA adducts. Previously, we demonstrated that Cu2+ can oxidize estradiol (E2) catechols, establishing a copper redox cycle leading to the formation of DNA strand breaks. The goal of this study was to use electron spin resonance techniques to identify the free radical intermediates formed. The 2- and 4-OH catechols of E2 and ethinyl estradiol (EE) were oxidized to semiquinone intermediates, stabilized by Mg2+, when incubated with Cu2+. The 4-OH-EE semiquinone decayed more slowly than the 2-OH-EE semiquinone. Using the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone, 4-OH-E2 plus Cu2+ generated hydroxyl radicals at a greater rate than 2-OH-E2 plus Cu2+. Formation of hydroxyl and methyl radical adducts was detected, using 5,5-dimethyl-1-pyrroline-N-oxide as the spin trap, when 2-OH-E2 was incubated with Cu2+ and 1% dimethyl sulfoxide. This was inhibited by the Cu1+ chelator bathocuproinedisulfonic acid and catalase. These data demonstrate that the oxidation of estrogen catechols by Cu2+ leads to a Cu-dependent mechanism of hydroxyl radical production via a hydrogen peroxide intermediate and suggest a mechanism for estrogen-associated site-specific DNA damage and mutagenesis.

A new efficient synthetic method for 2- and 4-hydroxy-17 alpha-ethynylestradiol

The reaction of ethyl magnesium bromide and 17 alpha-ethynylestradiol with formaldehyde in the presence of triethyl phosphate or hexamethylphosphoramide gave the 2- and 4-formyl-17 alpha-ethynylestradiol in high yield. Treatment of the formyl derivatives with an alkaline solution of hydrogen peroxide in tetrahydrofuran afforded the corresponding catechols in almost quantitative yield. This new synthetic method was far superior to other methods, especially concerning simplicity, selectivity, and high yields.

Formation and metabolism of catecholestrogens in depressed patients

The evidence that catecholestrogens are formed in the brain and exert behavioral effects in animal models suggest that these steroids might have psychotropic activities. In the present investigation, the formation and metabolism of catecholestrogens were studied in depressed patients. Twenty-four-hr urine samples were collected from 6 male patients (59 +/- 8 years) with endogenous retarded depression (subtype primary, endogenous, and recurrent according to Research Diagnostic Criteria) and from 12 male control subjects (51 +/- 4 years). The patients were treated with the monoamine oxidase inhibitor tranylcypromine (10-40 mg/day for 3-4 weeks). The concentrations of primary estrogens, 4- and 2-hydroxyestrogens and 2-methoxyestrogens, were measured in the urine samples after multiple chromatographic separation steps by radioimmunoassay. In the depressed patients, the excretion rates of 4-hydroxyestrogens were significantly lower than in control subjects. The ratio 2-methoxyestrogens:2-hydroxyestrogens as an index for 2-O-methylation was 3.8 +/- 1.6 in patients and 1.8 +/- 0.7 in controls. The increased methylation and reduced 4-hydroxylation rates of patients were not affected by treatment with tranylcypromine though the psychopathological state was improved by 46%. Therefore, it seemed unlikely that the observed alterations were pathognomonically relevant in these depressed patients. The alterations in the formation and methylation of catecholestrogens show that the depressed patients exhibited remarkable metabolic disturbances. The functional role of these disturbances remains to be clarified.

Convenient large scale preparation of catechol estrogens

2-Hydroxyestrone, 2-hydroxyestradiol-17beta, 2-hydroxy-17alpha-ethynylestradiol, 2-hydroxyestriol, 4-hydroxyestrone, 4-hydroxyestradiol-17beta, 4-hydroxy-17alpha-ethynylestradiol and 4-hydroxyestriol are prepared on a preparative scale from the corresponding aminophenols using a new inverse oxidation procedure. By the synthesis described both the 2- and 4-hydroxylated estrogens are available in high yields.

Metabolism of 4-3-H- and 4-14-C-17alpha-ethynylestradiol 3-methyl ether (mestranol) by women

A mixture of 4-3-H and 4-14-C-mestranol was administered orally to four women. Reactions involving position 4 were no greater than 1.7-3% of the dose as measured by liberation of 3-H into body water. The extent of de-ethynylation in vivo was no greater than 1-2% of the dose as measured by urinary estrone metabolites. Mestranol (0.7 and 0.32% of the dose), 17alpha-ethynylestradiol (6.6 and 11.3%) and 2-hydroxy-17alpha-ethynylestradiol (0.64 and 0.7%) were identified as metabolite aglycons by reverse isotope dilution after Ketodase hydrolysis of the urine from two of the women.