An Ultra-High Performance Liquid Chromatography-Mass Spectrometry Method Based on Solid-Phase Extraction Developed for the Analysis of Polyphenols in Prunus Mume Sieb. et Zucc.

Background: Prunus mume Sieb. et Zucc. (P. mume) is rich in various phenolic compounds; however, there is a lack of effective quality evaluation methods.

Objective: The aim of this study was to establish and validate a quality evaluation method that combines composition and activity to evaluate P. mume.

Methods: Phenolic compounds were quantified using an ultra-high performance liquid chromatography-diode array detector (UPLC-DAD) and identified using quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). A solid-phase extraction (SPE) method was used for enrichment and purification. An Eclipse Plus-C18 (2.1 × 50 mm, 5 μm) column was used for separation at a flow rate of 0.25 mL/min, column temperature of 30°C, and detection wavelength of 325 nm. 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and ferric ion-reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity of P. mume. In addition, tyrosinase inhibitory activity (TIA) was verified for the first time.

Results: Twelve major phenolic compounds were identified, among which taxifolin and ferulic acid were first detected in P. mume. The established UPLC-DAD method exhibited a strong linear relationship (R2 = 0.9999). The limit of detection and limit of quantitation of the standard compounds were in the ranges of 0.001-0.014 ng/g and 0.009-0.048 ng/g, respectively. The method exhibited good linearity, precision, stability, and repeatability. The phenolic compound content was in the range of 0.38-75.88 mg/g. In addition, P. mume extract showed excellent ABTS•+ radical scavenging capacity (half maximal inhibitory concentration (IC50) = 108.93 ± 9.43 μg/mL), FRAP (10.23 ± 0.11 μM), and TIA (IC50 = 4.79 ± 0.08 mg/mL).

Conclusion: The established QC method based on composition and activity is dependable and can be used for QC of P. mume.

Highlights: The chromatographic analysis method is reliable and can provide a reference for QC methods for the determination of ingredients and activity in flower-based foods.