Isolation And Identification Of Micro-constituent In Systhetic Gastrodin Semifinished Product

Gastrodia elata Blume (Orchidaceae) is a saprophyte widespread in Chinese Province Yun-nan, Si-chuan, Shan-xi, Gui-zhou, etc. Its steamed and dried tubers of the plant are commonly used as a folk medicine in long term. This drug is considered to have very beneficial properties. In clinical practice, this plant is used to treat vertigo , blackout, headache, hemiplegia, rheumatism, neuralgia, paralysis, lumbago and other neuralgic and nervous affections and it also has sedative and anticonvulsant actions. Gastrodin is a major constituent in Gastrodia elata. So gastrodin content is usually determined to assess the quality of a series of products in which Gastrodin is major active constituent by UV, TLC and HPLC etc. In the course of groping for high performance liquid chromatographic conditions suitable for quality analysis of systhetic Gastrodin products, one impurity was found in Gastrodin and preparations of Gastrodin. This impurity was never referred to in the previous documents and wasn't found by TLC. And also it wasn't recorded in Chinese pharmacopoeia. Because it was found by HPLC newly, what is it like and is it secure? So the study was carried out on the basis of this. The main works are as follows:1. The new high performance liquid chromatographic conditions was set up by studying, which the impurity was good separated from Gastrodin. The method proved to be good repeatability , convenient and fast by Performing of determintion of recovery yield , precision and stability experiments etc.2. Distinguishing by HPLC and analysis of synthetic Gastrodin semifinished product by HPLC. At the moment, we speculated this impurity might be the hydrolysis aglycon of gastrodioside-p-hydroxybenzylalcohol. So distinguishing of standard preparation of Gastrodin, Gastrodin material and p-hydroxybenzylalcohol was performed by HPLC using chosen conditions. Retention time of this impurity and p-hydroxybenzylalcohol is different. So the possibility was denied. And synthetic Gastrodin semifinished product was analysed by HPLC and the impurity that we were looking for was in it.3. Analysis by TLC. Analysis of synthetic Gastrodin semifinished product was carried out by TLC. Contrasting of some adsorbents, developping agents and developers, finally, silicaGF254, chloroformu methanol and water (7:3:0. 2 v/v) and 50%H2SO4C2H5OH was chosen asadsorbent , developping agent and developer, respectively. In addition, 254nm ultraviolet detector was also used to fix location of samples. At the same time, the another unknown compound with little content was found. And also suitable mobile phase was found for CC.4. Isolation by CC (Column Chromatography) and identification of compounds. Semifinished product was isolated and prepared by CC. Besides Gastrodin, two unknown compounds, 1 and 2, were isolated from synthetic Gastrodin semifinished product. The two compounds were examined by determining melting point , TLC and HPLC. Their structures were identified by IR, 1HNMR, 13CNMR and FAB-MS.