Optimization of Ultrasound-Assisted Extraction of Leaves: Maximal Phenolic Yield and Antioxidant Capacity.

() is a medicinal plant with secondary metabolites such as phenolics, flavonoids, glycosides, saponins, and alkaloids. This study was designed to optimize the ultrasonic-assisted extraction (UAE) parameters to enhance the phenolic content and characterize the phenolic compounds using ultra-high-performance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-QTOF-MS/MS), and antioxidant activities in extract. Extraction time, sample-to-solvent ratio, and extraction temperature were considered for UAE optimization.