Influence of drying method on content of epigoitrin and uridine in isatidis radix

OBJECTIVE: To study the influence of different drying methods on the content of epigoitrin and uridine in Isatidis Radix. METHODS: Fresh Isatidis Radix was processed by four drying methods including airing drying and drying in far infrared oven at different temperature,drying in the sun and drying in the shade. The contents of epigoitrin and uridine were determined by HPLC. RESULTS: The contents of epigoitrin as well as uridine in samples valued from 3.847 - 5.204 mg/g and 0.701 - 1.028 mg/g, respectively. CONCLUSION: The optimal drying method is airing drying at 55 degrees C, which will be serviced in the large-scale processing of Isatidis Radix.