Corticosterone metabolites originating as a consequence of solvated electron (e(-)aq) emission.

Corticosterone in water-ethanol solution can eject "solvated electrons" (eaq(-)) when excited into the singlet state by monochromatic UV-light (λ=254 nm). As a consequence of this process free radicals and H(+) ions were also generated. Hence, the objectives of this study were to determine the quantum yield, Q, at different corticosterone concentrations, and elucidate the fate of the generated free radicals and the involved reaction mechanisms. Because of the formation of associates, which consume a part of the emitted eaq(-), the Q decrease with increase of cortisone concentration. Additionally the H(+) ions scavenge and convert a part of the ejected eaq(-) into H-atoms. In comparsion with progesterone, the Q of corticosterone is much higher. Evidently, this effect is due to the two OH groups of corticosterone, which act as intense emission centres for eaq(-). Thereby, the generated free radicals from corticosterone lead to formation of metabolites, which were analyzed by combination of liquid-chromatography with mass spectrometry (LC/MS) method. Two of them were identified: 5α-pregnan-3α, 21-diol-11, 20-dione and 20ß-dihydroxycortisone. Both have the same mass number of 348.230. To explain the involved, rather complicated processes, a probable reaction mechanism is suggested.

Dopamine: effect of concentration and pH on the electron emission. Reaction mechanisms.

Dopamine (DA) in airfree, aqueous solution (pH 7.4; 37°C) is able to emit e(-)(aq) when electronically excited in its singlet state by monochromatic UV light (λ=254 nm; 4.85 eV/hν). The quantum yield Q(e(-)(aq)), was studied in dependence of DA concentration and pH of the media. The DA transients resulting from the electron emission form products, which also have the ability to emit e(-)(aq), but with much lower yield. Since DA in the ground state can consume e(-)(aq), it is classified as an electron mediator. Some biological consequences based on the e(-)(aq) emission are mentioned.

Method for regeneration of hormones: 17ß-estradiol, 21α-hydroxyprogesterone and corticosterone. A pathway for a possible medical application.

The hormones 17ß-estradiol (17ßE2), 21α-hydroxyprogesterone (21α-HOPRG) and corticosterone (CORT) were used as representative models for the study. As a source for hormone excitation in singlet state serviced monochromatic UV-light (λ=254 nm), it was stated that the transients resulting by e-aq emission in air-free mixture water/ethanol 40/60, as long as they are in "status nascendi", can be regenerated by electron transfer from a potent electron donor, e.g., vitamin C. The hormone regeneration (%) strongly depends, after all, on specific hormone molecular structure, concentration, temperature, etc. Because of the large heterogenic molecular structures, the substrates dissolved in the solvent mixture form "associates" (unstable complexes) in concentrations >109 mol/L hormone. The hormones eject, but they also consume e-aq with a rather high reaction rate constant (k≈109 up to 2×1010 L/mol.s), therefore, they act as "electron mediators". It was also observed that the hormones by dissolution in aerated solvent mixture are sensitive towards oxygen. For an explanation of the results, probable reaction mechanisms are presented. The described method offers a new pathway and possibilities for application in medicine.