Optimized determination of phenolic compounds in Dendrobium officinale stems by reverse-phase high performance liquid chromatography.

Introduction: Phenolic compounds have been widely credited as an important part in various human ailments and plants’ disease resistances. Few studies, however, focused on the method to extract and detect the contents of phenolic compounds in the stems of Dendrobium officinale, a prized medicinal plant and functional food in China. Materials and methods: In this work, a very rapid, sensitive and reliable reverse-phase high-performance liquid chromatography (RP-HPLC) method was established for the separation and quantification of two phenolic compounds, i.e., quercetin and erianin in D. officinale stems, but also an optimized extraction process. Result and discussion: Results showed that quercetin and erianin were eluted before around 35 min, providing a time-saving separation. Furthermore, the steeper gradient rate in the range of 2.66-4.85% acetonitrile/min was the best for the elution. Meanwhile, the maceration of 30 min by the extraction solvent should be performed for removing polysaccharides that interfered the detection of phenolic components and resulted in the blockage of the chromatographic column, followed by a shorten ultrasonic-assisted extraction time of 30 min. The solid-liquid ratio was 1:100. Conclusions: This method is broadly applicable for chemical analyses of phenolic components in other Dendrobium species, for which similar problem may emerge. [ABSTRACT FROM AUTHOR]