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甙键的裂解反应在研究甙无的结构以及甙的糖链中各糖的联结顺序及位置方面有重要意义。常用的甙键裂解方法有酸催化水解法、酶水解法、乙酰解法、Smith降解水解法及光解法等等。很少对碱解法进行研究,一般认为甙键对碱较稳定,故碱法只用于水解某些特殊的甙类,例如酯甙、酚甙、烯醇甙等。我们在研究中发现:在适宜的反应条件下,一般甙键均可用碱法裂解。碱解法与酸解法相比,具有反应温和容易控制的特点,特别适用于甙元遇酸不安定的甙的水解。众所周知,人参皂甙元对酸很敏感,因此在用酸水解人参皂甙时,只能得到侧链环合的次生甙元,例如酸解人参皂甙-Re时,则生成人参三醇。为了制取真正的原始甙元,过去均用Smith降解水解法及酶解法。我们选择适宜的反应溶剂、碱的浓度、反应温度及反应时间,用碱法水解人参皂甙-Rg_2等,成功地得到了原人参三醇及相应的前皂甙元-人参皂甙-Rh_1。
The cleavage reaction of the oxime bond is of great importance in the study of the structure of quinones and the order and position of the saccharides in the sugar chains of quinones. Commonly used methods for the cleavage of oxime bonds include acid catalyzed hydrolysis, enzymatic hydrolysis, acetyllysis, Smith degradation hydrolysis, and photolysis. The alkaline hydrolysis method is rarely studied. It is generally believed that the hydrazone bond is relatively stable to alkali, so the alkali method is only used to hydrolyze certain special terpenes such as ester oximes, phenolphthalein, enol oximes, and the like. We found in the study: Under the appropriate reaction conditions, the general hydrazine bond can be used alkaline cleavage. Compared with the acid hydrolysis method, the alkali hydrolysis method has the characteristics that the reaction is mild and easy to control, and is particularly suitable for the hydrolysis of the unstable earthworms in the case of arsenic. It is well-known that ginsenosides are very sensitive to acids, so when the acid is used to hydrolyze ginsenosides, only side-chain cyclized secondary aglycone can be obtained. For example, when ginsenoside Re is hydrolyzed, ginsenotriol is produced. In order to obtain the real primitive cells, Smith degradation hydrolysis and enzymatic hydrolysis were used in the past. We chose the appropriate reaction solvent, base concentration, reaction temperature and reaction time, alkaline hydrolysis of ginsenoside-Rg 2 and so on, and successfully obtained the original ginseng triol and the corresponding pre-sapogenin-ginsenoside-Rh_1.