Effects of various treatments and influencing factors on catalpol in Rehmannia glutinosa

Objective To study the effect of different storage methods, processing methods, temperatures, pH values, and enzymes on the content of catalpol in Rehmannia glutinosa. Methods To investigate the content change of catalpol in different processed R. glutinosa under the different storage conditions by HPLC. And the content of catalpol was determined after being stored under different temperatures, pH values, and enzymes. Results The content of catalpol in fresh R. glutinosa was significantly higher than that in the processed ones. The content of catalpol in frozen under vacuum was almost unchanged. The content of catalpol was obviously influenced by pH value, especially in strong acid and alkali, and the change was enhanced at higher temperature. Meanwhile, the content of catalpol was easily influenced by β-glucosidenzyme. Conclusion Catalpol is stable to high temperature, while unstable to acid, alkali or β-glucosidenzyme.