3种药用石斛鉴别特征的综合分析

目的 综合分析铁皮石斛、细茎石斛和齿瓣石斛的显微和红外光谱特征，为3种药用石斛的鉴别提供依据。方法 采用徒手切片和显微测量方法观察分析3种药用石斛茎的显微特征；用傅里叶红外光谱（FT-IR）及其导数光谱法测定其红外光谱特征。结果 3种药用石斛显微特征存在一定差异，铁皮石斛的角质层比较薄，厚度约4.9μm；铁皮石斛、细茎石斛和齿瓣石斛的茎表皮细胞类型分别是不均匀加厚型、无增厚型和均匀加厚型，其中细茎石斛表皮细胞壁加厚程度不大，仅为9.1μm；齿瓣石斛的厚壁组织细胞壁加厚程度明显，厚度为30.0μm。在3种药用石斛二阶导数光谱特征中，1585、1217和1049cm-1是细茎石斛的特有峰，1569、1450、1225和1073 cm-1是铁皮石斛和齿瓣石斛的共有特征峰，1011 cm-1是细茎石斛和齿瓣石斛的共有特征峰。结论 显微和红外光谱鉴定方法的综合分析和应用能对3种药用石斛提供更为准确的鉴别信息。

Comprehensive Analysis for the Identification Characters of Three Medicinal Dendrobii

Objective Comprehensive analyze the microscopical character and Infrared Spectroscopy(IR) character of Dendrobium officinale, D. moniliforme and D. devonianum in order to provide the basis for distinguishing the three medicinal Dendrobii. Methods The freehand section and micrometer analysis were conducted to study the authentication chracters of the stems of three medicinal Dendrobii. FT-IR as well as the second order derivative FT-IR to analyze the IR characters of the three medicinal Dendrobii. Results The thickness of cuticula of D. officinale were 4.9μm that was fairly thiner than the other two species. The thickness scale for cell of stem epidermis in D. officinale is 9.1μm belong to non uniform thickness, D. moniliforme has non thickness, and D. devonianum has uniform thickness. The special peak in the second order derivative for D. moniliforme is 1585、1217 and 1049cm-1, D. officinale and D. devonianum has the same special peak of 1569、1450、1225 and 1073 cm-1, D. moniliforme and D. devonianum has the same special peak of 1011 cm-1. Conclusions Comprehensive application for the method of microscopical and IR identification can precisely distinguish the three medicinal Dendrobii.