西藏冬虫夏草的X射线衍射鉴定及质量控制探讨

Identification on Tibet Cordyceps via X-ray Diffraction and Discussion on Quality Control

目的:建立一种反映西藏冬虫夏草(藏草)的X射线衍射(XRD)鉴别方法。方法:采用粉末XRD技术,获得1种藏草和3种市售廉价的冬虫夏草(廉价虫草)的虫体部位和真菌子座的X射线衍射谱及特征标记峰。运用有机分子晶体的XRD谱模拟方法,鉴别藏草和廉价虫草中XRD峰的成分来源。结果:藏草的XRD谱由一系列清晰而分立的尖峰构成,被证实起源于α-D-甘露醇和δ-D-甘露醇,与人工合成的甘露醇结晶相截然不同;且虫体部位甘露醇含量为真菌子座的3倍。廉价虫草XRD峰主要起源于衣康酸和少量的甘露醇,后者低于藏草甘露醇含量的31%。在廉价虫草的全部真菌子座和1种虫体中没有甘露醇存在。藏草成分与XRD的关系、甘露醇的多晶型现象以及藏草的质量控制被探讨。结论:XRD技术是能够提供藏草真伪识别的一种快速、准确而有效的工具,对于有机分子晶体含量较高的中药材的鉴定和质量标准研究具有广阔的应用前景。

Objective ：To set up a method for identifying and distinguishing Tibet Cordyceps （TC）using X-ray diffraction （XRD）. Methods ： The power XRD technique were used to obtain the XRD patterns and their characteristic peaks for polypide and fungal stroma in one kind of TC and three kinds of inexpensive Cordyeepses（IC）. Simulation of organic molecular crystals was applied to identify the constituent origin of XRD peaks of TC and IC. Results ： The XRD spectra of IC consisted of a series of clear and discrete sharp peaks, which were confirmed to originate from ^-D-mannitol and ^-D-mannitol ,which was different from artificial mannitol in crystalline phase; the content of mannitol in polypide of TC was three times that in fungal stroma. The XRD peaks of IC arose mainly from itaconic acid and a small amount of mannito]. The content of mannitol in IC was lower than 31% of that in TC. No mannitol existed in fungal stroma in all kinds of ICs and in polypide in one kind of IC. The link between constituents in TC and XRD, polymorphy phenomenon of manni- tol,and quality control of TC ,were discussed. Conclusion：XRD technique can provide an efficient means for rapidly and accurately identifying TC, and it has broad application prospects for identification and quality standard research of Chinese medicinal materials with higher-content organic molecular crystals.