Separation and analysis of flavonoid chemical constituents in flowers of Juglans regia L. by ultra-high-performance liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry.

The flowers of Juglans regia L. have demonstrated their medicinal value as a part of edible plants. In this study, an analytical methodology for identification of flavonoid chemical constituents in flowers of Juglans regia L. was established using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). Thirty-six flavonoid compounds were identified based on highly accurate mass measurements, and the mass spectrometric fragmentation pathways of eleven representative compounds were proposed, which was helpful for the identification of different types of flavonoids. The study has laid the foundation for the research and development of effective drugs from flowers of Juglans regia L.