Novel methylated flavoalkaloids from Echa 1 green tea inhibit fat accumulation and enhance stress resistance in Caenorhabditis elegans.
Novel methylated flavoalkaloids from Echa 1 green tea inhibit fat accumulation and enhance stress resistance in Caenorhabditis elegans.
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DOI：
10.1016/j.foodchem.2023.135643
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发表时间：
2023-02
期刊：
影响因子：
8.8
通讯作者：
Chen-Hui Chen-Chen-Hui-Chen-120896932;Jingying Yu;Zi Yang;Jia-ping Ke;Yan Qi;Yi Yang;Biao Gao;Guangmin Yao;Guan‐Hu Bao
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文献类型：
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作者：
Chen-Hui Chen-Chen-Hui-Chen-120896932;Jingying Yu;Zi Yang;Jia-ping Ke;Yan Qi;Yi Yang;Biao Gao;Guangmin Yao;Guan‐Hu Bao
甲基化是茶叶中儿茶素类常见的结构修饰，可以提高儿茶素类的生物利用度。黄酮类生物碱是在C-6或C-8位具有含氮五元环的儿茶素衍生物。本文从茶1号绿色茶（Camellia sinensisscv.Echa 1）中分离得到三个新的甲基化黄酮生物碱，并合成了另外四个新的甲基化黄酮生物碱。通过核磁共振（NMR）、旋光、红外、紫外-可见光谱、实验和计算的圆二色谱（CD）以及高分辨质谱等多种光谱技术对新的酯型甲基化儿茶素（etmc）-吡咯烷酮A-G（1-7）的结构进行了鉴定。其中6和7对α-葡萄糖苷酶的抑制作用最强，对秀丽隐杆线虫脂肪含量的抑制率分别为73.50%和67.39%。同时，6和7还表现出较强的体外抗氧化活性和线虫对热、氧化胁迫和紫外线辐射的抗性。
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 sinensiscv.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,6and7showed the strongestα-glucosidase inhibitory activity and significantly lowered lipid content ofCaenorhabditis eleganswith 73.50 and 67.39% inhibition rate, respectively. Meanwhile,6and7also exhibited strong antioxidant activityin vitroand stress resistance to heat, oxidative stress, and UV irradiation in nematodes.