A novel acidic polysaccharide (RTFP-3) was isolated and purified from Rosa roxburghii Tratt fruits. Structural analyses revealed that RTFP-3 is a homogeneous polysaccharide with a molecular weight of 67.2 kDa and mainly consists of arabinose (37.20%), galactose (34.40%), glucose (10.02%) and fucose (18.30%). The structural chain of RTFP-3 was proven to be composed of →6)-α-D-Galp-(1→, →4)-α-D-GalpA-(1→, →5)-α-L-Araf-(1→, →4)-β-D-Glcp-(1→, β-D-Glcp-(1→ and →3,4)-β-L-Fucp-(1→ residues by periodate oxidation–Smith degradation, methylation, and 1D- and 2D-NMR analyses. Bioassay results showed that RTFP-3 exerted favorable mixed type inhibitory activities against α-glucosidase, and its half inhibitory concentration (IC₅₀) value was determined as 4.15 mg mL⁻¹. RTFP-3 showed static type quenching of the intrinsic fluorescence of α-glucosidase, during which the binding process induced the conformational change of α-glucosidase. These results suggest that RTFP-3 has the potential to be a novel α-glucosidase inhibitory agent for use in functional foods.

中文翻译：

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从一种新颖的酸性多糖的结构表征刺梨刺梨果实及其α葡萄糖苷酶抑制活性†

从Rosa roxburghii Tratt果实中分离并纯化了一种新型酸性多糖（RTFP-3）。结构分析表明，RTFP-3是分子量为67.2 kDa的均一多糖，主要由阿拉伯糖（37.20％），半乳糖（34.40％），葡萄糖（10.02％）和岩藻糖（18.30％）组成。证明RTFP-3的结构链由→6）-α- D -Gal p-（1→，→4）-α- D- Gal p A-（1→，→5）-α-组成L -Ara f-（1→，→4）-β- D -Glc p-（1→，β- D -Glc p-（1→和→3,4）-β- L- Fuc p- （1个→残基通过高碘酸盐氧化-Smith降解，甲基化，和1D-和2D-NMR分析生物测定结果表明，RTFP-3施加有利混合型的抑制活性对α葡糖苷酶和其半抑制浓度（IC ₅₀）测定值为4.15 mg mL ^-1，RTFP-3显示出α-葡糖苷酶固有荧光的静态猝灭，在此过程中结合过程诱导了α-葡糖苷酶的构象变化，这些结果表明RTFP-3具有潜在的作用。是用于功能性食品的新型α-葡萄糖苷酶抑制剂。