6-Epicastanospermine, a novel indolizidine alkaloid that inhibits alpha-glucosidase.
6-Epicastanospermine, a novel indolizidine alkaloid that inhibits alpha-glucosidase.
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6-Epicastanospermine，一种新型吲哚里西啶生物碱，可抑制 α-葡萄糖苷酶。
DOI：
10.1016/0003-9861(86)90351-6
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发表时间：
1986
影响因子：
3.9
通讯作者：
Elbein,AD
中科院分区：
文献类型：
--
作者：
Molyneux,RJ;Roitman,JN;Dunnheim,G;Szumilo,T;Elbein,AD
第二种吲哚里西啶生物碱，与栗精胺差向异构，已从澳大利亚树Castanospermum australe的种子中分离出来。通过质子和碳-13核磁共振光谱和质谱确定其结构为6-epicastanospermine。6-研究发现，Epicastanospermine是淀粉葡糖苷酶（一种外切-1，4-α-葡糖苷酶）的有效抑制剂，是β-半乳糖苷酶的弱抑制剂，但不抑制β-葡糖苷酶和α-甘露糖苷酶。这些结果表明，糖苷酶抑制活性不能通过与适当糖的结构和立体化学比较来预测，因为6-epicastanospermine是甘露糖而不是葡萄糖的类似物。发现淀粉葡糖苷酶的抑制是竞争性的，并且在较高的pH值下更有效。栗精胺和6-epicastanospermine不同的影响绿豆加工酶，葡萄糖苷酶I和II，因为前者是一个有效的抑制剂，而后者是一个非常差的抑制剂。因此，这些生物碱立体化学的微妙改变可以使其生物活性产生显着变化。
A second indolizidine alkaloid, epimeric with castanospermine, has been isolated from seeds of the Australian treeCastanospermum australe. The structure was established as 6-epicastanospermine by proton and carbon-13 nuclear magnetic resonance spectroscopy and mass spectrometry. 6-Epicastanospermine was found to be a potent inhibitor of amyloglucosidase, (an exo-1,4,-α-glucosidase), a weak inhibitor of β-galactosidase, and not to inhibit β-glucosidase and α-mannosidase. These results indicate that glycosidase inhibitory activity cannot be predicted by comparison of the structure and stereochemistry with the appropriate sugars, since 6-epicastanospermine is an analog of mannose and not of glucose. The inhibition of amyloglucosidase was found to be competitive and to be more effective at higher pH values. Castanospermine and 6-epicastanospermine differed in their effect upon the mung bean processing enzymes, glucosidase I and II, in that the former is a potent inhibitor whereas the latter is a very poor inhibitor. Subtle alterations in stereochemistry of these alkaloids can therefore produce significant changes in their biological activity.