Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution
Provitamin D<sub>3</sub> is the biological precursor to naturally formed vitamin D<sub>3</sub> in humans, and its conversion is initiated via photoexcitation by near ultraviolet light. Following an initial photolysis, the primary intermediate, known as previtamin D<sub>...
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| Format: | Article |
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MDPI AG
2023-11-01
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| Series: | Photochem |
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| Online Access: | https://www.mdpi.com/2673-7256/3/4/29 |
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| author | Gordon A. Ochsner Jaren S. Meikle Jacob C. Dean |
| author_facet | Gordon A. Ochsner Jaren S. Meikle Jacob C. Dean |
| author_sort | Gordon A. Ochsner |
| collection | DOAJ |
| description | Provitamin D<sub>3</sub> is the biological precursor to naturally formed vitamin D<sub>3</sub> in humans, and its conversion is initiated via photoexcitation by near ultraviolet light. Following an initial photolysis, the primary intermediate, known as previtamin D<sub>3</sub>, is prone to light-induced isomerization or recyclization, which creates byproducts that limit the desired final thermal conversion to vitamin D<sub>3</sub>. The branching of the photochemical reaction is highly wavelength-dependent, whereby excitation toward the blue edge of the provitamin D<sub>3</sub> absorption spectrum tends to terminate the reaction with the most undesired tachysterol byproduct and the lowest previtamin D<sub>3</sub> concentration. In this work, the influence of introducing the natural amino acid phenyalanine as an excitation energy donor to the photochemical reaction is investigated. We find that the incorporation of phenylalanine into provitamin D<sub>3</sub> solution results in greater intermediate concentrations and prolonged lifetimes of the desired previtamin D<sub>3</sub> while simultaneously reducing the final concentration of tachysterol when exposing the solution to wavelengths at the blue edge of the provitamin D<sub>3</sub> spectrum. The results, coupled with quantum chemical analysis, suggest that phenylalanine indeed helps to funnel energy from shorter wavelengths more effectively into the provitamin D<sub>3</sub> precursor, while simultaneously screening those wavelengths from direct excitation, which otherwise leads to enhanced concentrations of tachysterol byproduct at the expense of previtamin D<sub>3</sub>. |
| first_indexed | 2024-03-08T20:25:45Z |
| format | Article |
| id | doaj.art-219fa56d7ccc4b698be4cb01196488fc |
| institution | Directory Open Access Journal |
| issn | 2673-7256 |
| language | English |
| last_indexed | 2024-03-08T20:25:45Z |
| publishDate | 2023-11-01 |
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| record_format | Article |
| series | Photochem |
| spelling | doaj.art-219fa56d7ccc4b698be4cb01196488fc2023-12-22T14:32:38ZengMDPI AGPhotochem2673-72562023-11-013447749410.3390/photochem3040029Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in SolutionGordon A. Ochsner0Jaren S. Meikle1Jacob C. Dean2Department of Chemistry and Physics, Southern Utah University, Cedar City, UT 84720, USADepartment of Chemistry and Physics, Southern Utah University, Cedar City, UT 84720, USADepartment of Chemistry and Physics, Southern Utah University, Cedar City, UT 84720, USAProvitamin D<sub>3</sub> is the biological precursor to naturally formed vitamin D<sub>3</sub> in humans, and its conversion is initiated via photoexcitation by near ultraviolet light. Following an initial photolysis, the primary intermediate, known as previtamin D<sub>3</sub>, is prone to light-induced isomerization or recyclization, which creates byproducts that limit the desired final thermal conversion to vitamin D<sub>3</sub>. The branching of the photochemical reaction is highly wavelength-dependent, whereby excitation toward the blue edge of the provitamin D<sub>3</sub> absorption spectrum tends to terminate the reaction with the most undesired tachysterol byproduct and the lowest previtamin D<sub>3</sub> concentration. In this work, the influence of introducing the natural amino acid phenyalanine as an excitation energy donor to the photochemical reaction is investigated. We find that the incorporation of phenylalanine into provitamin D<sub>3</sub> solution results in greater intermediate concentrations and prolonged lifetimes of the desired previtamin D<sub>3</sub> while simultaneously reducing the final concentration of tachysterol when exposing the solution to wavelengths at the blue edge of the provitamin D<sub>3</sub> spectrum. The results, coupled with quantum chemical analysis, suggest that phenylalanine indeed helps to funnel energy from shorter wavelengths more effectively into the provitamin D<sub>3</sub> precursor, while simultaneously screening those wavelengths from direct excitation, which otherwise leads to enhanced concentrations of tachysterol byproduct at the expense of previtamin D<sub>3</sub>.https://www.mdpi.com/2673-7256/3/4/29provitamin D photochemistry7-dehydrocholesterolphotoprotectionresonance energy transfer |
| spellingShingle | Gordon A. Ochsner Jaren S. Meikle Jacob C. Dean Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution Photochem provitamin D photochemistry 7-dehydrocholesterol photoprotection resonance energy transfer |
| title | Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution |
| title_full | Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution |
| title_fullStr | Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution |
| title_full_unstemmed | Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution |
| title_short | Photoprotective Steering of Previtamin D<sub>3</sub> Photochemistry by Phenylalanine in Solution |
| title_sort | photoprotective steering of previtamin d sub 3 sub photochemistry by phenylalanine in solution |
| topic | provitamin D photochemistry 7-dehydrocholesterol photoprotection resonance energy transfer |
| url | https://www.mdpi.com/2673-7256/3/4/29 |
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