银杏黄酮测定时水解条件的研究

目的:寻找水解率高、耐用性好的银杏黄酮测定的水解条件。方法:在预防氧化降解反应方面,比较不同保护措施的效果;在充分的保护措施下考察不同的加热方式、盐酸浓度、甲醇浓度、加热时间等水解条件。结果:预防氧化降解的发生能有效提高水解液的稳定性,并使密封加热在优选的条件下,测得量比回流加热水解高10%以上。结论:溶剂脱气、充氮气排除接触供试液的空气中的氧、避光等可有效防止氧化降解反应的发生;水解方式采用密封加热优于回流加热。

Flavonoids hydrolysis conditions in EGb quantification

Aim: To optimize the hydrolysis conditions in flavonoid aglycone quantification in extract of Ginkgo biloba(EGb).Methods: In the quantification process of flavonoids,it has to be hydrolyzed first into flavonoid aglycones.However,oxidation could occur and the stability of flavonoid aglycone is affected.Hence measures have to be taken to minimize the oxidative degradation in the hydrolysis.Conditions such as the heating method,the heating time,and the concentrations of hydrochloride and methanol were assessed.Results: It was found that boiling the solvent under a reflux condenser to remove the dissolved gases,introducing inert gas to protect the test solution and protecting the reaction from light greatly suppressed the oxidation in the hydrolysis of flavonoid aglycones.Conclusion: We obtained the better conditions of hydrolysis of flavonoid aglycones while minimizing oxidative degradation.However,pressurizing is better than boiling under a reflux condenser.