黑果枸杞多糖的分离纯化及抗氧化活性研究
发布时间：2019-01-07 20:34
【摘要】：黑果枸杞作为一种天然果实,有“软黄金”之称。国内外大量实验研究发现,黑果枸杞对机体有一定的保健效能,备受人们的关注。本论文用青海省黑果枸杞的干果为原料,通过超声波辅助法提取黑果枸杞多糖,并对黑果枸杞粗多糖进行纯化,进而对纯化后的黑果枸杞多糖进行初步结构表征以及抗氧化活性的研究。1.超声波法提取黑果枸杞多糖。研究用料液比、超声波功率、提取温度、提取时间作为单因素,并用正交试验优化提取工艺。结果表明最适宜的提取条件是料液比是1:20(g/mL)、超声波功率是150 w、提取温度是70℃、提取时间是30 min。此条件下的粗多糖得率为10.74%。2.黑果枸杞多糖的纯化。黑果枸杞粗多糖经三氯乙酸脱蛋白后,依次采用超滤、大孔树脂吸附、聚酰胺层析、分级沉淀、DEAE-52纤维素洗脱及流水透析进行纯化,再次通过DEAE-52纤维素柱来洗脱以及制备型高效液进一步对多糖进行分离纯化。结果表明:经分级沉淀后,黑果枸杞多糖由LPR-60、LPR-70、LPR-80、LPR-90四种多糖组成,含量分别为69.27%、76.07%、78.11%、74.43%。用DEAE-52纤维素柱去对其洗脱后,与制备型高效液相结果相差甚微,研究结果表明,黑果枸杞多糖由LPR-80-1、LPR-80-2、LPR-80-3和LPR-80-4四种多糖组成,含量分别为76.68%、78.59%、78.54%和77.43%。选择多糖组分LPR-80-2做后续的研究。3.黑果枸杞多糖的初步结构表征。通过紫外光谱、红外光谱、毛细管电泳、扫描电镜、原子力显微镜、质谱对多糖组分LPR-80-2的结构进行初步研究。结果表明:UV检测显示其多糖组分在260-280nm的范围内并没有明显的吸收,表明该多糖样品不含蛋白质和核酸等生物大分子;红外光谱分析表明黑果枸杞多糖含多糖的特征吸收峰,且含有吡喃环结构;而毛细管电泳结果发现,该多糖组分由鼠李糖、阿拉伯糖、葡糖糖及半乳糖4种单糖组成。其组成摩尔比为:Rha:Ara:Glc:Gal=0.3:2.2:1.0:1.5;原子力显微镜扫描显示该多糖分子分子间排列紧密,呈圆圈状堆积结构;扫描电镜显示其呈现表面粗糙的片状聚集结构。4.黑果枸杞多糖的抗氧化。研究以DPPH·、OH·和O2-·为体外抗氧化指标,对比黑果枸杞粗多糖及精制多糖的抗氧化活性,实验结果发现,黑果枸杞多糖粗品和和精制样品均具有清除自由基的能力,具有一定的抗氧化活性,且精制多糖样品的清除自由基能力略高于粗多糖,而且根据浓度的增大,抑制自由基的作用效果也随之加强,研究还发现,多糖样品均对羟基自由基的抑制作用比较显著,随浓度的变大,越来越接近于Vc对活性氧自由基的抑制能力。并通过研究黑果枸杞多糖对镉中毒小鼠肝脏的保护效果,以肝脏中MDA含量、抗氧化酶CAT和SOD含量以及NO的含量为指标,结果发现,黑果枸杞多糖能够使得MDA含量降低,CAT和SOD活性增强,NO的含量下降,证实了黑果枸杞有一定的体内抗氧化作用,能够对镉中毒小鼠的肝脏起到保护效果。
[Abstract]:Black fruit wolfberry as a natural fruit, has a "soft gold" said. A large number of experimental studies at home and abroad found that black fruit wolfberry has a certain health care efficiency, and has attracted people's attention. In this paper, the dried fruit of black fruit Lycium barbarum in Qinghai Province was used as raw material, and the polysaccharides of black fruit Lycium barbarum were extracted by ultrasonic assisted method, and the crude polysaccharide of black fruit Lycium barbarum was purified. The purified Lycium barbarum polysaccharides were characterized and the antioxidant activity was studied. 1. Extraction of Polysaccharide from Lycium barbarum by Ultrasonic method. The ratio of material to liquid, ultrasonic power, extraction temperature and extraction time were used as single factors, and the extraction process was optimized by orthogonal test. The results show that the optimum extraction conditions are 1:20 (g/mL), 150 ww ultrasonic power, 70 鈩，
本文编号：2404128
[Abstract]:Black fruit wolfberry as a natural fruit, has a "soft gold" said. A large number of experimental studies at home and abroad found that black fruit wolfberry has a certain health care efficiency, and has attracted people's attention. In this paper, the dried fruit of black fruit Lycium barbarum in Qinghai Province was used as raw material, and the polysaccharides of black fruit Lycium barbarum were extracted by ultrasonic assisted method, and the crude polysaccharide of black fruit Lycium barbarum was purified. The purified Lycium barbarum polysaccharides were characterized and the antioxidant activity was studied. 1. Extraction of Polysaccharide from Lycium barbarum by Ultrasonic method. The ratio of material to liquid, ultrasonic power, extraction temperature and extraction time were used as single factors, and the extraction process was optimized by orthogonal test. The results show that the optimum extraction conditions are 1:20 (g/mL), 150 ww ultrasonic power, 70 鈩，
本文编号：2404128
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