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Cleavage of glycosidic bond in alcoholic alkali metal solution

碱金属醇溶液中糖苷键的断裂

基本信息

批准号：
62470140
负责人：
OGIHARA Yukio
金额：
$ 2.94万
依托单位：
Nagoya City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-62470140/
关键词：
alcoholic alkali metal cleavage of glycosidic bond saikosaponin a saikosaponin c saikosaponin d corticosterone-secretion hemolysis 赤血球膜への吸着 saikosaponin a saikosaponin c saikosaponin d 消化管内代謝物赤血球溶血態細胞膜への吸着 20(S)ーginsenosideーR

项目摘要

To know the active forms of saikosaponin a (sa), saikosaponin c (sc) and saikosaponin d (sd) after the oral administration, metabolites in alimentary tract were derived from sa, sc and sd chemically and studied their pharmacological activities. Since th aglycones of sa, sc and sd have ether ring which is unstable in acidic conditions, alcoholic alkali metal degradation of hlycosidic bond was studied to get intestinal metabolites which have genuine aglycones. The conditions of the reaction were as follows; solvent: notmal butanol for spectra analysis, metal: Na (> 10 equivalent mole). temperature: 60-80 c. alkaline degradation gave intestinal metabloites which were obtained by the partial hydrolysis at a high yield, although its reaction mechanism is unknown except that the alkaline degradation was the indirect cleavage of glycosidic bond due to the degradation of terminal sugars. This possibility was explained by the inactivity of the permethylate of sa against the alcoholic alkali metal.The corticosterone-secretion activities of 30 kinds of gastric and intestinal metabolites of sa, sc and sd were studied in vivo. Sd and its intestinal product, prosaikogenin G (PSG), showed a remarkable activity. The activity of sa and its intestinal product, prosaikogenin F (psF), which have -OH at C-16 (sd and psG have -OH at C-16) were weaker than that of sd and psG. The gastric products which have diene structure in aglycone by the by the cleavage of ether ring showed a little or no corticosterone-secretion activity. These activities were corresponded with their hemolytic activities and the adsorbability to the cell membrane to some extent.Consequently, the polar valance between the sugar moiety (polar part) and the aglycone moiety (nonpolar part) should be important for their pharmacological activities.

为了解柴胡皂苷a（sa）、柴胡皂苷c（sc）和柴胡皂苷d（sd）口服后的活性形式，采用化学方法对sa、sc和sd在消化道中的代谢产物进行了衍生，并对其药理活性进行了研究。由于sa，sc和sd的苷元含有醚环，在酸性条件下不稳定，因此研究了醇碱金属降解糖苷键以获得含有真正苷元的肠代谢产物。反应条件如下：溶剂：用于光谱分析的正丁醇，金属：Na（> 10当量摩尔）。温度：60-80 ℃。碱性降解产生肠代谢物，其通过部分水解以高产率获得，尽管其反应机理未知，但碱性降解是由于末端糖的降解而导致的糖苷键的间接断裂。这一可能性是由于水杨酸的过甲基化产物对醇碱金属无活性所致。在体研究了水杨酸、sc和sd的30种胃肠代谢产物的皮质酮分泌活性。Sd及其肠内产物原柴胡皂苷元G（PSG）具有显著的活性。16位有-OH的sa及其肠产物prosaikogenin F（psF）（sd和psG的16位有-OH）的活性较sd和psG弱。通过醚环断裂使糖苷配基中具有二烯结构的胃产物显示出很小的或没有皮质酮分泌活性。这些活性在一定程度上与它们的溶血活性和对细胞膜的吸附性相对应，因此糖基（极性部分）和糖苷配基（非极性部分）之间的极性价态对它们的药理活性可能是重要的。