【摘要】 苦豆子种子中含有苦豆子胶12.8%,胶的比旋度[a]^25D+173°,红外光谱图中在810及870cm^-1处有α-型和β型的糖甙键构型的特征峰。胶经完全水解后,用纸层析及酚硫酸比色法测定,主要成分为 D-半乳糖和 D-甘露糖。半∶甘=1∶2.37。用铁氰化钾法测定其总糖含量为67—70%。苦豆子胶经完全水解后,用硼氢化钠还原后再制得乙酯。经气相色谱分析,结果表明主要成分仍是 D-半乳糖和甘露糖。半∶甘=1∶1.83,并计算出其总糖含量为56%。此外,还有鼠李糖、核糖、木糖、阿拉伯糖和葡萄糖。醇离析纯化的苦豆子胶经比旋度及超速离心分析,是均质的。其沉降系数值[S⁰_20.w]为5.31s,特性粘度[η⁰]为6.25dl/g,用光散射法测定其分子量为715,000。水溶性苦豆子胶含量为49.4%。更多还原

【Abstract】 The seeds of Sophora alopecuroides L.contained 12.8 per cent of endos- perm,from which the water-soluble polysaceharide gum was isolated and purified by frac- tionation with alcohol three times.Hydrolysis of the polysaccharides with sulphuric acid produced galactose and mannose in the molar ratio of 1:2.37,as determined by the phenol- sulphuric acid method and by paper chromatographic method.The total sugar content reac- hed 67—70%. The polysaccharides,after complete hydrolysis,reduction with NaBH₄ and acetylation, yielded acetates.An analysis on them by gas-chromatography showed that they contained galactose and mannose in the molar ratio of 1:1.83,and the total sugar content reached 56%. In order to identify the linkages of the polysaccharides isolated from the seeds of So- phora alopecuroides,they were methylated by using the methods of Hokomori,Conval and Albersheim.The fully methylated polysaceharides were hydrolyzed and then reduced with NaBH₄,foflowed by acetylation.Finally they yielded acetates.An analysis on IR data,the results of acid hydrolysis,periodate oxidation and Smith type degradation,as well as the acetates by GC,GC—MS and ¹HNMR showed that the linkages of Sophora alopecuroides gum may be: The purified polysaccharides seem to be homogenous after ultracentrifugation analy- sis.The sedimentation coefficient of the gum obtained from repeated purification with alcohol was 5.31,its intrinsic viscosity was 6.25 dl/g and its molecular weight was esti- mated to be 635000.By the light-scattering method,however,its molecular weight was estimated to be 715000.The crude polysaccharides contained 44 per cent of the water-so- luble polysaccharides.更多还原