Inhibitory effects of phenylpropanoids and lignans isolated from the bark of Cinnamomum cassia L. on soluble epoxide hydrolase: Spectroscopic, kinetic, molecular docking, and molecular dynamics studies

Cinnamomum cassia L., commonly known as cinnamon, is a widely used aromatic spice and medicinal plant with a rich history of culinary and therapeutic applications. In this study, a new phenylpropanoid, named di(1,3-dioxane)cassin A (4), and 13 known compounds (1‒3, 5‒14), were isolated from the bark of C. cassia. Their structures were successfully elucidated using modern spectroscopic techniques, such as nuclear magnetic resonance, high-resolution mass spectrometry, and circular dichroism spectroscopy. In addition, isolated compounds were evaluated for their inhibitory effects on soluble epoxide hydrolase (sEH). Compound 4 exhibited sEH inhibition with an IC₅₀ value of 28.80 µM. Enzyme kinetics experiment indicated that compound 4 acted as a competitive sEH inhibitor. In silico methods, including molecular docking and molecular dynamics simulations, were employed to determine and understand the binding mechanism and dynamics behavior of this active compound with sEH.