Analysis of Antioxidant Properties and Major Components of the Extract of Paulownia tomentosa Steud Flowers

Paulownia tomentosa Steud flowers have been used for many therapeutic purposes in traditional pharmacopeia. The components of the extract of Paulownia tomentosa Steud flowers were separated using ethanol elution. The antioxidant properties of different components (20% component, 40% component, 60% component, and 80% component) and synthetic antioxidants (BHA and BHT) were evaluated by scavenging DPPH, superoxide anions, and hydroxyl radical methods. All components showed strong antioxidant properties, especially the 60% component, which exhibited excellent antioxidant activity. These components may be developed for use as natural antioxidants. The main compounds in these components were identified using UPLC-TOF-MS/MS and UV spectra analysis. Two compounds, abscisic acid and t-abscisic acid, were found in the 20% component. Five compounds, t-abscisic acid, luteolin, apigenin, tricin, and 4′,5,7-trihydroxy-3′-methoxyflavone, were found in the 40% component. Three compounds, t-abscisic acid, apigenin and 4′,5,7-trihydroxy-3′-methoxyflavone, were found in the 60% component. Six compounds, luteolin, apigenin, 4′,5,7-trihydroxy-3′-methoxyflavone, paulownin, 3'-methyldiplacol, and diplacone, were found in the 80% component. The antioxidant activity of these components can be attributed to the main chemical composition of the components of the extract of Paulownia tomentosa Steud flowers.