香菇精多糖乙醇沉淀规律的研究

Investigation on Ethanol Precipitation of Lentinans

目的:研究香菇多糖醇沉规律及产物分子质量分布情况。方法:采用分步醇沉和分级醇沉方法研究香菇多糖醇沉工艺,用凝胶色谱法(GPC)表征香菇多糖分子质量的分布。结果:不同醇沉时间获得的香菇多糖质量相差不大,醇沉速度随时间延长逐渐降低。分步醇沉在乙醇体积分数为30%条件下,所得到的香菇多糖的质量最大。分级醇沉所得到的香菇多糖的质量随着乙醇体积分数的升高而增加,高体积分数乙醇沉淀所得的香菇多糖的质量差别不明显。乙醇体积分数为30%、50%和80%所得到的香菇多糖,其峰位分子质量(Mp)分别为22671、18694、6011D。结论:醇沉体积分数和方式对香菇多糖得率和分子质量分布均有较大影响。

A commercial sample of lentinans was refined and subjected to ethanol fractionations in two different ways：way No.1,use of ethanol concentration gradients of 10%,20%,30% to 90%,respectively,and way No.2,adjustment of ethanol concentration in supernatant to 10%,20%,30% to 90% to understand molecular weight distribution by gel filtration chromatography.Results showed that precipitation time had no notable effect on the precipitation mass of lentinans and precipitation rate exhibited a gradual decrease with prolonged precipitation time.A maximum precipitation mass of lentinans was obtained at 30% ethanol concentration in way No.2 precipitation.With increasing ethanol concentration,the precipitation mass of lentinans progressively increased in way No.1 precipitation and then trended nearly stable after reaching a high level.The peak molecular weight （Mp） of lentinans obtained at the ethanol concentrations of 30%,50% and 80% were 22671,18649 D and 6011D,respectively.In summary,both ethanol concentration and precipitation way had significantly effects on the precipitation mass and molecular weight distribution of lentinans