Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions
Ultraviolet B (UVB) photosensitivities of eight catechins were screened. In both water and ethanol, epicatechin (EC, 575 μM) and catechin (C, 575 μM) exhibited low photostabilities under 6 h UVB radiation with the generation of yellow photoproducts, while other catechins (epigallocatechin gallate, e...
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MDPI AG
2016-10-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/21/10/1345 |
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| author | Meng Shi Ying Nie Xin-Qiang Zheng Jian-Liang Lu Yue-Rong Liang Jian-Hui Ye |
| author_facet | Meng Shi Ying Nie Xin-Qiang Zheng Jian-Liang Lu Yue-Rong Liang Jian-Hui Ye |
| author_sort | Meng Shi |
| collection | DOAJ |
| description | Ultraviolet B (UVB) photosensitivities of eight catechins were screened. In both water and ethanol, epicatechin (EC, 575 μM) and catechin (C, 575 μM) exhibited low photostabilities under 6 h UVB radiation with the generation of yellow photoproducts, while other catechins (epigallocatechin gallate, epigallocatechin, epicatechin gallate, gallocatechingallate, gallocatechin, catechin gallate) were relatively UVB-insensitive. Photoisomerization and photolysis were two important UVB-induced reactions to EC whereas photolysis was the dominant reaction for C. The influencing factors of time (2–10 h), solvent (water, ethanol) and substrate concentration (71.875–1150 μM) on UVB-induced chemical conversions of EC and C were investigated, and eight photoproducts were identified through ultra performance liquid chromatography-diode array detection-tandem mass spectrometry (UPLC-DAD-MS/MS) and 1H nuclear magnetic resonance (1H-NMR analysis). Photolysis reaction involved two pathways, including radical reaction and photo-induced electron transfer reaction. The 2,2-diphenylpicrylhydrazyl (DPPH) scavenging abilities of eight catechins did not change upon 6 h UVB irradiation. EC and C are photosensitive catechins among eight catechins causing deep color. |
| first_indexed | 2024-04-12T03:05:15Z |
| format | Article |
| id | doaj.art-b8833e88f10841499a0359998ef6028f |
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| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-04-12T03:05:15Z |
| publishDate | 2016-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-b8833e88f10841499a0359998ef6028f2022-12-22T03:50:31ZengMDPI AGMolecules1420-30492016-10-012110134510.3390/molecules21101345molecules21101345Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical ConversionsMeng Shi0Ying Nie1Xin-Qiang Zheng2Jian-Liang Lu3Yue-Rong Liang4Jian-Hui Ye5Tea Research Institute, Zhejiang University, Hangzhou 310058, ChinaTea Research Institute, Zhejiang University, Hangzhou 310058, ChinaTea Research Institute, Zhejiang University, Hangzhou 310058, ChinaTea Research Institute, Zhejiang University, Hangzhou 310058, ChinaTea Research Institute, Zhejiang University, Hangzhou 310058, ChinaTea Research Institute, Zhejiang University, Hangzhou 310058, ChinaUltraviolet B (UVB) photosensitivities of eight catechins were screened. In both water and ethanol, epicatechin (EC, 575 μM) and catechin (C, 575 μM) exhibited low photostabilities under 6 h UVB radiation with the generation of yellow photoproducts, while other catechins (epigallocatechin gallate, epigallocatechin, epicatechin gallate, gallocatechingallate, gallocatechin, catechin gallate) were relatively UVB-insensitive. Photoisomerization and photolysis were two important UVB-induced reactions to EC whereas photolysis was the dominant reaction for C. The influencing factors of time (2–10 h), solvent (water, ethanol) and substrate concentration (71.875–1150 μM) on UVB-induced chemical conversions of EC and C were investigated, and eight photoproducts were identified through ultra performance liquid chromatography-diode array detection-tandem mass spectrometry (UPLC-DAD-MS/MS) and 1H nuclear magnetic resonance (1H-NMR analysis). Photolysis reaction involved two pathways, including radical reaction and photo-induced electron transfer reaction. The 2,2-diphenylpicrylhydrazyl (DPPH) scavenging abilities of eight catechins did not change upon 6 h UVB irradiation. EC and C are photosensitive catechins among eight catechins causing deep color.http://www.mdpi.com/1420-3049/21/10/1345photostabilitycatechinsphotoisomerizationphotolysisphotoproducts |
| spellingShingle | Meng Shi Ying Nie Xin-Qiang Zheng Jian-Liang Lu Yue-Rong Liang Jian-Hui Ye Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions Molecules photostability catechins photoisomerization photolysis photoproducts |
| title | Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions |
| title_full | Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions |
| title_fullStr | Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions |
| title_full_unstemmed | Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions |
| title_short | Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions |
| title_sort | ultraviolet b uvb photosensitivities of tea catechins and the relevant chemical conversions |
| topic | photostability catechins photoisomerization photolysis photoproducts |
| url | http://www.mdpi.com/1420-3049/21/10/1345 |
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