Quantitative Comparison and Chemical Profile Analysis of Different Medicinal Parts of Perilla frutescens (L.) Britt. from Different Varieties and Harvest Periods

Perilla frutescens (L.) Britt. is a plant that has been classified as one of the "One Root of Medicine and Food", and it can be used both as medicine and as food. To explore the influence of different varieties and harvest periods on the quality of different medicinal parts of P. frutescens, a comprehensive study on the chemical constituents of P. frutescens based on plant metabolomics was conducted. A total of 57 nonvolatile chemical components and 105 volatile chemical components of P. frutescens were characterized by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC-MS). Furthermore, 35, 27, and 2 nonvolatile constituents as well as 16, 16, and 18 volatile constituents were identified as potential markers for discriminating P. frutescens between different medicinal parts, different varieties, and different harvest periods, respectively. Besides, 22 bioactive compounds of P. frutescens were quantitatively determined by a new sensitive UPLC-MS/MS method. This study comprehensively compares the differences and similarities of P. frutescens among the different medicinal parts, different varieties, and different harvest periods, and the results of this study may provide a theoretical basis and guidance for studying the quality evaluation and the optimization of the harvest period of this plant.