ABSTRACT
It has been found that melatonin reacts rapidly with hypochlorous acid in phosphate-buffered, ethanol-water solutions to produce 2-hydroxymelatonin. The rate law, d[2 - HOMel]/dt - kHOCl[Mel][HOCl] - kOCl-[Mel][OCl-], was obtained. At 37 degrees C and at a water concentration of 23.5 M, kOCl- = 6.0 x 10(2) L. mol-1. s-1, and kHOCl was found to be a function of the water concentration, kHOCl = 11 +/- 3 L3. mol-3. s-1. [H2O]2, indicating that the availability of water at the site of the reaction plays a significant role. The part that the structural components of melatonin play in determining the reaction pathway was examined by comparing the rate of deactivation of HOCl by melatonin to that of the model compounds indole, 5-methoxyindole, and 3-methylindole. The relative reactivity is explained in terms of steric and electronic effects, and it was found that the presence of the substituent at the 3-position influences the nature of the oxidation product. Melatonin and 3-methylindole yielded hydroxylated products, whereas indole and 5-methoxyindole produce chlorinated products.
Subject(s)
Hypochlorous Acid/metabolism , Melatonin/metabolism , Antioxidants/chemistry , Antioxidants/metabolism , Antioxidants/pharmacology , Binding Sites , Chlorine/metabolism , Chlorine/pharmacology , Free Radical Scavengers/chemistry , Free Radical Scavengers/metabolism , Free Radical Scavengers/pharmacology , Hydrogen/metabolism , Hydrogen-Ion Concentration , Hydroxylation , Indoles/chemistry , Indoles/metabolism , Indoles/pharmacology , Kinetics , Magnetic Resonance Spectroscopy , Mass Spectrometry , Melatonin/chemistry , Melatonin/pharmacology , Models, Chemical , Oxidants/metabolism , Reactive Oxygen Species/metabolism , Skatole/analogs & derivatives , Skatole/chemistry , Skatole/metabolism , Skatole/pharmacology , Solvents , Static Electricity , Water/metabolismABSTRACT
The attitudes of women (1) toward a woman in menopause, (2) comparable male and non-menopausal female stimulus figures, (3) and themselves were compared using a vignette approach. Vignettes depicting a middle-aged female and a middle-aged male were presented to 152 women between the ages of 18 and 55. The women were asked to rate the vignette subjects on a semantic differential. Approximately half of the women received a vignette of a woman who was identified as being menopausal, and half received the identical vignette without the menopausal condition. Participants then completed a semantic differential rating of themselves and the Tennessee Self Concept Scale (TSCS). There was no difference in the semantic differential ratings of the menopausal vs. the nonmenopausal vignette characters, nor in the male vs. the female characters. Although the participants ranked themselves higher than both the female and male characters, there was no difference in the ratings of the vignettes or the self by women with lower vs. higher self-esteem.
