Abstract
Background: Dendrobium officinale (D. officinale) has been traditionally used as an herbal medicine in Eastern Asia. Because of its ambiguous chemical characteristics, an authentic quality evaluation system is urgently needed. The aim of this work is to establish a comprehensive method for the evaluation of D. officinale based on volatile constituents, methanol extracts and polysaccharide analysis.
Methods: We identify the volatile constituents via headspace solid-phase micro-extraction and gas chromatography–mass spectrometry. We establish a standard fingerprint for the methanol extracts of D. officinale leaves by high performance liquid chromatography analysis. This work also compares the content of polysaccharide using the phenol-sulfuric acid method.
Results: We identify 37 volatile constituents in D. officinale. Thirty compounds obtained in flowers, 18 in leaves, and 11 in stems. We then assess the quality of D. officinale leaves collected from four different regions by comparing volatile constituents. We further identify 22 volatile components from the sample from Anhui Huoshan, which contains more volatile components than the others. Besides, we establish a standard fingerprint for the methanol extracts of D. officinale leaves, which confirms 21 common peaks in six different regions. The results of hierarchical cluster analysis show that the samples from these six regions are classified into two main groups. The three samples from Zhejiang province are clustered into one subgroup. The sample from Zhejiang Deqing contains the most abundant polysaccharides both in stems and leaves. As the years of growth increase, the content of polysaccharide is also improved.
Conclusion: This study provides a comprehensive method for quality evaluation of D. officinale. This study also explores the possible reasons for the discrepancies in the flavor of D. officinale in production.
Keywords: Dendrobium officinale, volatile constituents, methanol extracts, polysaccharides, gas chromatography–mass spectrometry, high performance liquid chromatography.
Graphical Abstract
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