Synthesis and Functions of Branched Cyclodextrins

支化环糊精的合成及功能

• 批准号: 60560143
• 负责人: HIZUKURI Susumu
• 金额: $ 1.09万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60560143/
• 关键词: Pullulanase; Cyclodextrin derivatives; Branched Cyclodextrins; イソアミラーゼ

The conditions for the synthesis of branched cyclodextrins (CDs) by the reverse action of Klebsiella pullulanase, the procedures for isolation of the branched CDs from reaction mixtures, and their properties were investigated.The rates for the formation of branched CDs with pullulanase were in the order of <gamma> -> <alpha> -> <beta> -CD, while those with Pseudomonas isoamylase were in <gamma> -> <beta> -> <alpha> -CD. Maltose ( <G_2> ) is the better substrate than maltotriose ( <G_3> ) for <alpha> -CD as to the counter substrate but <G_2> and <G_3> were equally effective substrates for <beta> - and <gamma> -CDs. The optimal conditions for the formation of <G_2> - <gamma> -CD were as follows : <gamma> -CD 0.4 M, <G_2> 1.8 M, pH 6.0 and temperature 50゜C. Under these conditions, 37% of <gamma> -CD was converted into <G_2> - <gamma> -CD by incubation for 36 hrs with 21.6 U/ml pullulanase.The two minor products, di <G_2> - <gamma> -CD and branched maltoteraose (B <G_4> ) were also found besides <G_2> - <gamma> -CD by the above reaction and these products were identified by <^(13)C> -NMR spectra and chemical and enzymic analyses. The water solubility of <gamma> -CD was enhanced about 6-fold by binding a side-chain and the hemolytic activity for human red blood cells was reduced to about a half. These results suggest that the modification of CDs to branched CDs is useful for their applications.

研究了普鲁兰聚糖酶催化合成支化环糊精(CDS)的条件、从反应混合物中分离支化环糊精的方法及其性质。普鲁兰聚糖酶催化合成支化环糊精的速率为&lt；γ&gt；-lt；α&gt；-lt；-gt；-lt；-lt；-gt；-β&gt；-cd，而含有假单胞菌异淀粉酶的支化环糊精的形成速率为-lt；-γ&gt；-gt；-lt；-CD。对于~lt；α&>CD，麦芽糖(&lt；G_2&>t；)是比麦芽三糖(&lt；G_3&>t；)更好的底物，而&lt；α&>-CD和&lt；β&>-CD和&lt；β&>G_3&>-CD是同样有效的底物。生成&lt；G_2&>-Cd的最佳条件为：-Cd 0.4M，&lt；G_2&Gt；1.8M，pH 6.0，温度50゜C。在此条件下，37%的&lt；G_2&Cd被转化为&lt；G_2&gt；-&lt；-Cd与21.6U/ml的普鲁兰酶孵育36小时后，在上述反应中还发现了两个次要产物，即Dilt；G2&gt；-lt；G4&gt；-Cd和支链麦芽糖(B&lt；G4&gt；-lt；G_2&gt；-&lt；G4&gt；-Cd)，这些产物经~lt；^(13)C&gt；-核磁共振波谱及化学和酶分析进行了鉴定。通过结合侧链，~lt；γ&Gt；-Cd的水溶性提高了约6倍，而对人红细胞的溶血活性降低了约一半。这些结果表明，将硫化镉修饰成支化的硫化镉对其应用是有益的。

项目成果

檜作進: 澱粉科学.

日泽进：淀粉科学。