College of Ecological and Environmental Engineering, Qinghai University, Xining 810016, China.
State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China.
Molecules. 2022 Jul 8;27(14):4385. doi: 10.3390/molecules27144385.
The extraction and characterization of new bioactive plant-derived polysaccharides with the potential for use as functional foods and medicine have attracted much attention. In the present study, A novel acidic polysaccharide (RPP-3a) with a weight-average molecular weight (Mw) of 88,997 Da was isolated from the raspberry pulp. RPP-3a was composed of rhamnose, arabinose, galactose, glucose, mannose, and galacturonic acid at a molar ratio of 13.1:28.6:16.8:1.4:6.2:33.9. Structural analysis suggested that the RPP-3a backbone was composed of repeating units of →4)--Gal-(1→3,4)--Rha-(1→[4)--GalA-(1→4)--GalA-(1→] with branches at the C-4 position of rhamnose. The side chain of RPP-3a, containing two branch levels, was comprised of -Ara-(1→, →5)--Ara-(1→, →3,5)--Ara-(1→, →3)--Gal-(1→, →3,6)--Gal-(1→, →4)--Glc-(1→, and →2,6)--Man-1→ residues. RPP-3a exhibited moderate reducing power and strong hydroxyl and superoxide anion radical scavenging abilities. RPP-3a significantly promoted the viability of RAW264.7 macrophages by increasing the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) at both the expression and transcriptional levels. In summary, the immunostimulatory and antioxidant activities make RPP-3a a viable candidate as a health-beneficial functional dietary supplement.
从树莓果肉中分离得到一种新型酸性多糖（RPP-3a），其重均分子量（Mw）为 88997 Da。RPP-3a 由鼠李糖、阿拉伯糖、半乳糖、葡萄糖、甘露糖和半乳糖醛酸以摩尔比 13.1:28.6:16.8:1.4:6.2:33.9 组成。结构分析表明，RPP-3a 的骨架由重复单元→4)--Gal-(1→3,4)--Rha-(1→[4)--GalA-(1→4)--GalA-(1→]组成，在鼠李糖的 C-4 位带有支链。RPP-3a 的侧链含有两个支化水平，由-Ara-(1→, →5)--Ara-(1→, →3,5)--Ara-(1→, →3)--Gal-(1→, →3,6)--Gal-(1→, →4)--Glc-(1→和→2,6)--Man-1→残基组成。RPP-3a 具有中等的还原能力和较强的羟基和超氧阴离子自由基清除能力。RPP-3a 通过增加 RAW264.7 巨噬细胞中一氧化氮（NO）、肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）和白细胞介素-1β（IL-1β）的表达和转录水平，显著促进其活力。综上所述，RPP-3a 的免疫刺激和抗氧化活性使其成为一种有前途的、有益健康的功能性膳食补充剂。
