Glycochemistry and Glycobiology Lab, CAS Key Laboratory of Receptor Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China.
School of Chinese Materia Medica, Nanjing University of Chinese Medicine, 138 Xianlin Avenue, Nanjing 210023, China.
J Agric Food Chem. 2022 Aug 17;70(32):9908-9918. doi: 10.1021/acs.jafc.2c03823. Epub 2022 Aug 4.
The fruit of is food and medicine, which has been demonstrated to have a significant neuroprotective effect. However, the effective constituent remains unknown. We speculate that the glycopeptide in the extract of the fruit has similar activity. To address this hypothesis, we isolated a novel pectin-like glycopeptide (FMP-6-S4) with a molecular weight of 11.23 kDa from the fruit. It contains about 20% of peptide comprising 17 amino acids and 80% glycan consisting of L-rhamnose (L-Rha), D-galactose (D-Gal), D-galacturonic acid (D-GalA), L-arabinose (L-Ara) and d-glucose (D-Glc) in molar ratios of 7.25:4.62:77.66:5.62:4.85. The backbone of the glycan part consisted of 1,4-linked α-D-GalA and 1, 2-linked α-L-Rha, while the branches were composed of hexenuronic acid (HexA) substituted at the C-3 position of partial galacturonic acid, and traces of galactose, glucose, and arabinose were substituted at the C-4 position of rhamnose. The experiments revealed that FMP-6-S4 might inhibit Aβ (β-amyloid peptides 42) aggregation and decrease Aβ production by modulating APP (amyloid precursor protein) processing.
的果实既是食物也是药物，已被证明具有显著的神经保护作用。然而，其有效成分仍不清楚。我们推测提取物中的糖肽具有相似的活性。为了验证这一假设，我们从该果实中分离得到一种新型的果胶样糖肽（FMP-6-S4），其分子量为 11.23 kDa。它含有约 20%的由 17 个氨基酸组成的肽和 80%的糖，由摩尔比为 7.25:4.62:77.66:5.62:4.85 的 L-鼠李糖（L-Rha）、D-半乳糖（D-Gal）、D-半乳糖醛酸（D-GalA）、L-阿拉伯糖（L-Ara）和 D-葡萄糖（D-Glc）组成。糖部分的骨架由 1,4-连接的α-D-GalA 和 1,2-连接的α-L-Rha 组成，而支链由部分半乳糖醛酸 C-3 位取代的己糖醛酸（HexA）以及少量半乳糖、葡萄糖和阿拉伯糖组成。实验表明，FMP-6-S4 可能通过调节 APP（淀粉样前体蛋白）加工来抑制 Aβ（β-淀粉样肽 42）聚集和减少 Aβ 的产生。
