Analysis of nine compounds from Alpinia oxyphylla fruit at different harvest time using UFLC-MS/MS and an extraction method optimized by orthogonal design

BACKGROUND: The dried fruits of Alpinia oxyphylla Miq have been widely used as an herbal medicine for the treatment of diarrhea and enuresis in China. Medicinal chemistry studies revealed that the tepenes, diphenylheptanes and flavones were the main components. Therefore, these three kinds of components should be chosen as the bioactive marker compounds for the quality control of A. oxyphylla fruits. Moreover, multiple active components has been widely recognized to be a more feasible method for the quality control of herbal medicines. This study firstly provided a better method for comprehensive component analysis of A. oxyphylla fruits. Meanwhile, the different harvest time was also evaluated. RESULTS: The solvent-to-sample ratio was the most important factor comparing with solvent, extraction time and temperature. The highest yield of nine compounds was achieved with 70% ethanol-water and a solvent-to-sample ratio of 20:1 at 60°C for 30 min. The optimized analytical method for ultra fast high performance liquid chromatography (UFLC) was a gradient elution using water containing 0.04‰ formic acid (A) and methanol containing 0.04‰ formic acid (B), at a flow rate of 0.3 mL/min. Using this optimized method, nine compounds were simultaneously separated and quantified by UFLC coupled with tandem electro-spray ionized mass spectrometry (MS/MS). CONCLUSIONS: The contents of the six bioactive compounds were reported in A. oxyphylla for the first time. The contents of nine compounds of different harvest time fruits of A. oxyphylla were assessed under the optimized extraction and UFLC-MS/MS analytical conditions, and the 45-day culture fruit had the highest content levels.