极大螺旋藻多糖IPⅡA、IPⅡB的理化特性及抗肿瘤活性研究

Physicochemical Properties and Anti tumor Activities of Polysaccharides IP ⅡA、IP ⅡB from Spirulina maxima

极大螺旋藻（Ｓｐｉｒｕｌｉｎａｍａｘｉｍａ）经碱性热水抽提，酶解和Ｓｅｖａｇ法结合脱蛋白，醇沉淀得胞内多糖ＩＰⅠ．ＩＰⅠ经ＤＥ－５２和ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５柱层析得到组分多糖ＩＰⅡＡ和ＩＰⅡＢ，糖含量分别为７４．９％和６８．４％，ＩＰⅡＡ分子量为１．３×１０６，ＩＰⅡＢ分子量为５．０×１０５．以完全酸水解、薄层层析、气相层析、红外光谱、核磁共振氢谱对二者进行化学结构分析，证明均为酸性杂多糖；ＩＰⅡＡ糖苷键为α型，ＩＰⅡＢ中同时存在α和β型糖苷键．离体条件下，ＩＰⅠ与血癌细胞ＨＬ６０和Ｕ９３７分别共同培养，半固体琼脂培养法检测，结果表明，ＩＰⅠ对二者的作用具有选择性，同时ＩＰⅠ的促进和抑制作用均表现出一般药物所具有的剂量效应．

An intracellular polysaccharide IPⅠ was extracted with hot alkaline solution from the whole cells of Spirulina maxiam, deproteinized by Sevag's method and precipitated with ethanol.IPⅠ was further purified by loading on DE 52 and then DEAE Sephadex A 25,two pure fractions IP ⅡA and IP ⅡB were obtained.They were identified to be homogenous,with contents of polysaccharides 74 9% and 68 4% respectively.The molecular weight of the IP ⅡA was 1 3×10 6,and that of IP ⅡB 5 0×10 5.The composition identified by TLC and GC showed that the two fractions were both composed of hexuronic acid and different hexoses.IP ⅡA contained α glycosidic bond,while both α and β glycosidic bonds were present in IP ⅡB. In vitro anti tumor assays indicated that intracellular polysaccharide IPⅠ could selectively inhibit or promote the growth of human leucocytoma HL60 and U937 with dose respose relationship.