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Chen CH, Yu JY, Yang Z, Ke JP, Qi Y, Yang Y, Gao B, Yao G, Bao GH. Novel methylated flavoalkaloids from Echa 1 green tea inhibit fat accumulation and enhance stress resistance in Caenorhabditis elegans. Food Chem 2023; 413:135643. [PMID: 36773353 DOI: 10.1016/j.foodchem.2023.135643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 01/19/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023]
Abstract
Methylation is a common structural modification of catechins in tea, which can improve the bioavailability of catechins. Flavoalkaloids are catechin derivatives with a nitrogen containing five-membered ring at the C-6 or C-8 position. Here we isolated three new methylated flavoalkaloids from Echa 1 green tea (Camellia sinensis cv. Echa 1) and synthesized another four new methylated flavoalkaloids. The structures of the new ester-type methylated catechins (etmc)-pyrrolidinone A-G (1-7) were elucidated by various spectroscopic techniques, including nuclear magnetic resonance (NMR), optical rotation, infrared, UV-vis, experimental and calculated circular dichroism (CD) spectra, and high-resolution mass. Among them, 6 and 7 showed the strongest α-glucosidase inhibitory activity and significantly lowered lipid content of Caenorhabditis elegans with 73.50 and 67.39% inhibition rate, respectively. Meanwhile, 6 and 7 also exhibited strong antioxidant activity in vitro and stress resistance to heat, oxidative stress, and UV irradiation in nematodes.
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Affiliation(s)
- Chen-Hui Chen
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Jing-Ya Yu
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Zi Yang
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Jia-Ping Ke
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Yan Qi
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Yi Yang
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Biao Gao
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Guangmin Yao
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Guan-Hu Bao
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Healthy Effects, State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
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