The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers
Polyphenols are key free radical scavengers in tea. This study screened the antioxidant active groups of catechins and dimers and analyzed the effects of the degree of oxidative polymerization and oxidative dimerization reaction on their antioxidant activities. ABTS<sup>+·</sup> free rad...
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MDPI AG
2023-11-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/12/23/4207 |
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| author | Wei Wang Ting Le Wei-Wei Wang Jun-Feng Yin He-Yuan Jiang |
| author_facet | Wei Wang Ting Le Wei-Wei Wang Jun-Feng Yin He-Yuan Jiang |
| author_sort | Wei Wang |
| collection | DOAJ |
| description | Polyphenols are key free radical scavengers in tea. This study screened the antioxidant active groups of catechins and dimers and analyzed the effects of the degree of oxidative polymerization and oxidative dimerization reaction on their antioxidant activities. ABTS<sup>+·</sup> free radical scavenging activity, DPPH free radical scavenging activity, and total antioxidant capacity of catechins and polymers were systematically analyzed and compared in this study. Results manifested antioxidant activities of catechins were dominated by B-ring pyrogallol and 3-galloyl, but were not decided by geometrical isomerism. 3-galloyl had a stronger antioxidant activity than B-ring pyrogallol in catechins. The number, not the position, of the galloyl group was positively correlated with the antioxidant activities of theaflavins. Theasinensin A has more active groups than (−)-epigallocatechin gallate and theaflavin-3,3′-digallate, so it had a stronger antioxidant activity. Additionally, the higher the degree of oxidation polymerization, the weaker the antioxidant activities of the samples. The oxidative dimerization reaction hindered the antioxidant activities of the substrate–catechin mixture by reducing the number of active groups of the substrate and increasing the molecular structure size of the product. Overall, pyrogallol and galloyl groups were antioxidant active groups. The degree of oxidative polymerization and the oxidative dimerization reaction weakened the antioxidant activity. |
| first_indexed | 2024-03-09T01:51:27Z |
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| id | doaj.art-05e0e966500448af84a49d9d44ea8df0 |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-09T01:51:27Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foods |
| spelling | doaj.art-05e0e966500448af84a49d9d44ea8df02023-12-08T15:15:18ZengMDPI AGFoods2304-81582023-11-011223420710.3390/foods12234207The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and PolymersWei Wang0Ting Le1Wei-Wei Wang2Jun-Feng Yin3He-Yuan Jiang4Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Xihu District, Hangzhou 310008, ChinaKey Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Xihu District, Hangzhou 310008, ChinaKey Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Xihu District, Hangzhou 310008, ChinaKey Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Xihu District, Hangzhou 310008, ChinaKey Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Xihu District, Hangzhou 310008, ChinaPolyphenols are key free radical scavengers in tea. This study screened the antioxidant active groups of catechins and dimers and analyzed the effects of the degree of oxidative polymerization and oxidative dimerization reaction on their antioxidant activities. ABTS<sup>+·</sup> free radical scavenging activity, DPPH free radical scavenging activity, and total antioxidant capacity of catechins and polymers were systematically analyzed and compared in this study. Results manifested antioxidant activities of catechins were dominated by B-ring pyrogallol and 3-galloyl, but were not decided by geometrical isomerism. 3-galloyl had a stronger antioxidant activity than B-ring pyrogallol in catechins. The number, not the position, of the galloyl group was positively correlated with the antioxidant activities of theaflavins. Theasinensin A has more active groups than (−)-epigallocatechin gallate and theaflavin-3,3′-digallate, so it had a stronger antioxidant activity. Additionally, the higher the degree of oxidation polymerization, the weaker the antioxidant activities of the samples. The oxidative dimerization reaction hindered the antioxidant activities of the substrate–catechin mixture by reducing the number of active groups of the substrate and increasing the molecular structure size of the product. Overall, pyrogallol and galloyl groups were antioxidant active groups. The degree of oxidative polymerization and the oxidative dimerization reaction weakened the antioxidant activity.https://www.mdpi.com/2304-8158/12/23/4207antioxidant activitystructureoxidative dimerizationcatechinspolymers |
| spellingShingle | Wei Wang Ting Le Wei-Wei Wang Jun-Feng Yin He-Yuan Jiang The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers Foods antioxidant activity structure oxidative dimerization catechins polymers |
| title | The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers |
| title_full | The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers |
| title_fullStr | The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers |
| title_full_unstemmed | The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers |
| title_short | The Effects of Structure and Oxidative Polymerization on Antioxidant Activity of Catechins and Polymers |
| title_sort | effects of structure and oxidative polymerization on antioxidant activity of catechins and polymers |
| topic | antioxidant activity structure oxidative dimerization catechins polymers |
| url | https://www.mdpi.com/2304-8158/12/23/4207 |
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