黑穗醋栗果实多糖的制备、结构鉴定及生物活性研究

以黑穗醋栗果实为原料,采用超声波法提取黑穗醋栗果实粗多糖。利用大孔树脂D4006,阴离子交换剂Q-Sepharose FF和葡聚糖凝胶Sephadex G-100对粗多糖进行分离纯化,得到均一黑穗醋栗多糖(black currant polysaccharide,BCP)。高效液相色谱法测定BCP的重均分子质量为16 329 k D。气相色谱法测定BCP单糖组成及物质的量比为:n(半乳糖醛酸)∶n(鼠李糖)∶n(阿拉伯糖)∶n(木糖)∶n(甘露糖)∶n(葡萄糖)∶n(半乳糖)=0.31∶0.66∶1.63∶0.36∶0.23∶0.31∶1.00。傅里叶变换红外光谱分析表明BCP含有多糖的特征吸收峰,紫外光谱和定性实验表明BCP不含花色苷、蛋白质、核酸和淀粉。刚果红实验表明BCP不具有三螺旋结构。生物活性研究结果表明:在0.2~1.2 mg/m L范围内,BCP对1,1-二苯基-2-三硝基苯肼自由基、·OH、超氧阴离子自由基(O2-·)均有较明显的清除作用,随着质量浓度增大,清除率明显升高。BCP对糖基化反应3个阶段产物(Amadori产物、二羰基化合物和糖基化终产物)的形成均表现出良好的抑制作用,抑制率高于阳性对照氨基胍,且随质量浓度的增加,抑制率升高。BCP对α-淀粉酶具有一定的抑制活性,但抑制效果低于阳性对照阿卡波糖。

Preparation,Structural Identification and Bioactivities of Polysaccharides from Black Currant Fruits

A homogeneous polysaccharide (BCP) from black currant fruits was obtained by ultrasound-assisted extraction followed by successive purification using macroporous resin D4006, anion-exchange Q-Sepharose FF and Sephadex G-100 columns. The molecular weight of BCP was determined as 16 329 kD by HPLC. BCP consisted of galacturonic acid, rhamnose, arabinose, xylose, mannose, glucose, and galactose at a molar ratio of 0.31:0.66:1.63:0.36:0.23:0.31:1.00 as determined by gas chromatography (GC). Fourier transform infrared (FTIR) spectra revealed that BCP had the characteristic absorption peaks of polysaccharides. Qualitative tests and UV spectra indicated the absence of protein, nucleic acid, starch, and pigment. Congo red test showed that BCP lacked triple helix structure. In the concentration range of 0.2–1.2 mg/mL, BCP presented high scavenging activities toward 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), hydroxyl, superoxide anion radicals in a concentration-dependent manner. BCP exhibited a significant ability to inhibit the formation of glycation products at three stages which was in a concentration-dependent manner and higher than that of the control aminoguanidine. Moreover, BCP showed inhibitory activity against α-amylase lower than that of the control acarbose.