Recueil des Travaux Chimiques des Pays-Bas · 1960 · 18 citations · 9 references
Life SciencesBiochemistryChemistryMetabolismSpectroscopySteroid BiochemistryPhotochemical KineticsPhotochemistrySteroid BiosynthesisSteroid Hormone BiochemistrySteroidogenic EnzymesSterol MetabolismPhotoisomerization KineticsPhotosensitizing CompoundsSterol CompositionUltraviolet Light ExposureUltraviolet PhotochemistryVitamin D Biosynthesis
Abstract Kinetic experiments on the photoisomerisation of ergosterol were carried out using different sources of light. New methods of analysis for pre‐ergocalciferol and tachysterol 2 had to be developed. The quantum yield of the photoisomerisation of ergosterol with ultraviolet light of 2537 Å was found to be 0.31 at 20°. This value was obtained when ether, ethanol and petroleum ether were used as solvents. Tachysterol 2 is not formed from ergosterol during irradiation, but originates exclusively from pre‐ergocalciferol. Excited ergosterol falls back to its ground state (69%) or transforms to pre‐ergocalciferol (26%) and to unidentified products (5%).
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