鱿鱼内脏多糖的分离纯化、理化性质及抗氧化活性研究

Studies on Isolation, Purification, Characterization and Antioxidant Activity of Polysaccharides Extracted from Squid Viscera

以秘鲁鱿鱼内脏副产物为原料,经水提醇沉法提取鱿鱼内脏多糖,利用DEAE Sepharose Fast Flow离子交换色谱和Sephadex G-100凝胶色谱对鱿鱼内脏多糖进行分离纯化;通过高效凝胶渗透色谱法进行纯度鉴定和分子质量测定,并用离子色谱、红外光谱进行结构组成分析;由差示扫描量热法分析多糖热稳定性;采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基和羟自由基(·OH)体系对不同质量浓度多糖的抗氧化活性进行评价。结果表明,由鱿鱼内脏粗多糖(SVP)纯化得到两个纯度均较好的组分,SVP-1是分子质量为12.39 ku的中性多糖,SVP-2是分子质量为22.83 ku的含硫酸基酸性多糖。SVP-1的单糖组成为岩藻糖、阿拉伯糖、半乳糖、葡萄糖和木糖,其物质的量比为11.6∶30.4∶22.4∶11.4∶13.9;SVP-2的单糖组成为岩藻糖、阿拉伯糖、半乳糖、葡萄糖和甘露糖,其物质的量比为9.5∶23.7∶35.7∶16.2∶8.3;两者常温热稳定性良好,红外光谱分析表明,两者都具有多糖的特征吸收峰,且含有β-吡喃糖环结构,其中SVP-2具有明显的硫酸基吸收峰;SVP-1和SVP-2对DPPH自由基清除率的IC50分别为3.93 mg/mL和2.05 mg/mL,对·OH清除率的IC50分别为3.38 mg/mL和3.05 mg/mL,说明SVP-1和SVP-2均具有一定的抗氧化活性,可为高值化利用鱿鱼内脏、开发多糖产品提供理论依据。

Squid viscera polysaccharides (SVP) were extracted by water and precipitated by ethanol from squid (Dosidicus gigas) viscera, and then purified by chromatography of DEAE Sepharose Fast Flow and Sephadex G -100.Their purities and molecular weight were detected by HPGPC.The thermal stability was analyzed by DSC.The composition and structure were studied by ion chromatogram and infrared spectral.The antioxidant activity of polysaccharides with different mass concentration were tested by DPPH and hydroxyl radicals.The results showed that:two fractions were homogeneity and separated from SVP, SVP-1 was neutral polysaccharide with molecular weight of 12.39 ku, and SVP-2 was acidic polysaccharide with molecular weight of 22.83 ku which also had sulfuric radicals.Besides, they were thermal stable and the monosaccharide composition of SVP-1 was fucose, arabinose, galactose, glucose and xylose with the molar ratio of 11.6:30.4:22.4:11.4:13.9,whereas that of SVP- 2 was fucose, arabinose, galactose, glucose and fucose with the molar ratio of 9.5:23.7:35.7:16.2:8.3,respectively.Infrared spectroscopy revealed that they had typical peeks of polysaccharides with β-pyranose rings and that SV P-2 might contain sulfuric radicals.IC50 of the scavenging rate of DPPH radicals of SVP-1 and SVP-2 were 3.93 mg/mL and 2.05 mg/mL, while IC50 of the scavenging rate of hydroxyl radicals of them were 3.38 mg/mL and 3.05 mg/mL.It revealed that SVP-1 and SVP-2 do have some antioxidant activity, which might be a reference to develop the high-valued products of squid viscera polysaccharides.