番石榴叶中多糖分离纯化工艺研究

Study on the optimal extraction and purification technology for polysacchrides from the guava leaves

为了筛选出番石榴叶多糖的最佳分离纯化工艺,本文了采用正交设计试验筛选番石榴叶多糖的提取的最佳工艺。结果表明番石榴叶多糖最佳提取工艺为:按1:30的料水比进行加热,在80℃恒温下3h回流提取,重复3次。番石榴叶粗多糖的进一步的精制方法为醇沉法和Diaion HP-20大孔吸附树脂吸附法,并且考察了Diaion HP-20大孔树脂对番石榴叶粗多糖的纯化能力。首先采用酒精-水系统作为Diaion HP-20大孔树脂洗脱液纯化粗多糖,然后将所得的多糖通过酒精-水溶液沉淀,干燥,最后通过苯酚-硫酸法对所得的多糖进行含量测定。结果表明醇沉法以及Diaion HP-20大孔吸附树脂吸附法相结合的纯化过程对番石榴叶多糖分离纯化效果良好,Diaion HP-20大孔树脂对番石榴叶粗多糖的吸附效果良好,吸附量为50g/L,能够有效吸附番石榴叶多糖,此外该方法收率高,能够得到纯度为95.64%的多糖化合物。

In order to find out the best method of isolation and purification of polysaccharide from the guava leaves,the best extraction method was determined by orthogonal design.The result showed that the best extraction and purification method for the polysaccharide was determined as follows：At first,the guava leaves was soaked in water for 3 hours at 80 ℃ and extracted for three times.The ratio of the solvent（water）and the material（guava leaves）was 30 ∶1（w/w）.The crude polysacchride was further purified by the extraction of ethanol and followed by the absorbtion.We also studied the ability of purifying polysaccaride from the guava leaves by macroporous absorption resin.First,the crude polysaccaride was purified by macroporous absorption resin（Diaion HP-20）using the ethanol/H2O system;then,the polysaccaride was purified by ethanol/H2O system and dried.The amount of the polysaccaride was determined by phenol-sulphuric acid method.The results showed that the purification was higher by the absorbtion of macroporous absorption resin（Diaion HP-20）and the extraction of ethanol.The macroporous absorption resin（Diaion HP-20）showed a good ability of absorption of polysaccaride（50g/L）.It can effectively absorb the polysaccaride.Furthermore,the method showed a good ability of recovery of polysaccharide.Under this condition,the content of polysaccaride in the final product was 95.64%.