球花石斛茎中香豆素类成分的定位与相对定量

目的探讨不同生长年限、不同部位球花石斛 (Dendrobium thyrsiflorum Rchb. f.)茎中香豆素类(coumarins)成分的分布与相对含量变化，为合理评价及利用药用石斛提供科学依据。方法利用激光共聚焦显微技术(laser scanning confocal microscopy, LSCM)观察二月份采收的球花石斛1-3龄茎的基部、中部和顶部的香豆素类成分。所记录数据经正态性、方差齐性检验后进行方差分析(ANOVA)，并使用Tukey′s检验作多重比较。结果 香豆素类成分主要分布在球花石斛茎的维管束部位并以维管束外侧纤维的壁较多。统计分析显示香豆素类成分的含量在不同年龄茎的各个部位之间差异极显著或显著，显著值分别为：基部P=0.004(<0.01)；中部P=0.009(<0.01)；顶部P=0.036(<0.05)。结论若以利用香豆素类成分为目的，建议二月采收时，宜选择2龄茎。

Location and relative quantity of coumarins in the stem of Dendrobium thyrsiflorum

AIM: To determine the location and relative quantity of coumarins in the stem of Dendrobium thyrsiflorum Rchb. f. , and to provide a scientific basis for evaluating and utilizing the famous medicinal plant. METHODS: The stems of one, two and three years old, separately, were collected in February. Location and relative quantity of coumarins in the top, middle and basal parts of each stem sample were determined by using laser scanning confocal microscopy (LSCM). ANOVA and Tukey's test were employed in the statistical analysis. RESULTS: The coumarins located mainly in vascular bundles, especially on the walls of the outer fiber cells. There was significant difference or great significant difference exist in every part of the stem from different ages. The values of significant difference were as follows: basal part P = 0.004 (< 0.01); middle part P = 0.009 (< 0.01); top part P = 0.036( < 0.05). CONCLUSION: Two years old stem could be the best choice when collecting Dendrobium thyrsiflorum in Feburary.