The Influencing Factors on Gastrodin Content in the Herbal Materials of Gastrodia elata (Orchidaceae)

The influencing factors on gastrodin content in the crude materials of Gastrodia elata were investigated by HPLC analysis. The results indicated that the preparing method of post harvest is a more important factor for the gastrodin content, comparing to those brought about by the growing areas and herbal varieties. Among the different processing methods, steaming produced the most impact effect on the increment of gastrodin in the herbal material. The possible mechanism of gastrodin formation during the crude process was also discussed.