Ultrasound-assisted extraction of four groups of Osmanthus fragrans fruit: Optimization, UPLC-Orbitrap-MS/MS characterization and anti-inflammatory activity evaluation

In this study, simultaneous optimization of ultrasound-assistant extraction (UAE) of four representative groups of Osmanthus fragrans (OF) fruit was firstly performed using the response surface methodology (RSM). Subsequently, qualitative and quantitative analysis of irioid glycosides from the optimized OF fruit extract was performed using UPLC-ESI-Orbitrap-MS/MS. A total of 13 irioid glycosides were tentatively identified, of which six compounds were identified for the first time. Finally, the anti-inflammatory activity of the optimized OF var. aurantiacus Makino (OFA) fruit extract was evaluated based on a CuSO4-induced zebra fish model. The biological results demonstrated that OFA fruit extract at a concentration of 5 μg/mL could significantly reduce the number of macrophages, but no significant activities were observed at high concentrations (10 and 50 μg/mL). These results suggest that OF fruit has the promise as a functional additive in food for health promotion.