Harnessing Functional Food Sources: Deriving Anti-Inflammatory and Antibacterial Naphthalene Derivatives from the Edible Bulbs of Eleutherine bulbosa

The red bulbs of Eleutherine bulbosa, commonly used as a daily dietary ingredient in cooking, are well-known for their rich nutritional profile and potential medicinal properties. This study focused on identifying bioactive components from E. bulbosa by a bioactivity-guided approach combined with global natural products' social molecular networking, which led to the characterization of 12 new naphthalene derivatives, eleuthalenes A-L (1-12), and 22 known analogues. The structures of these compounds were determined through spectroscopic data, X-ray crystallography, and quantum chemical calculations. The anti-inflammatory and antibacterial activities of these compounds were evaluated, with some demonstrating significant anti-inflammatory and moderate antibacterial activities. Further studies revealed that the most potent compound 5 displayed an anti-inflammatory effect in LPS-induced RAW 264.7 cells by suppressing the NF-kappa B/MAPK and activating Nrf2/Keap1 signaling pathways. The results suggested that bioactive naphthalene derivatives are the major pharmacodynamic substances of E. bulbosa.