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-κB/MAPK and activating Nrf2/Keap1 signaling pathways. The results suggested that bioactive naphthalene derivatives are the major pharmacodynamic substances of E. bulbosa.