Albafurans D-N, 2-phenylbenzofuran derivatives with anti-inflammatory activity from Morus alba.

From the root bark of Morus alba, a high-value medicinal product, eleven undescribed 2-phenylbenzofuran derivatives named albafurans D-N (1-11) including four 4 pairs of separated enantiomers (2a/2b, 6a/6b, 8a/8b and 11a/11b), along with 27 known analogues (12-38), were isolated and identified. The structures of these undescribed compounds, including their absolute configurations, were determined using a combination of spectroscopic and computational techniques. In a preliminary anti-inflammatory screening, compound 30 demonstrated potent activity in LPS-stimulated RAW264.7 macrophages, marked by significant inhibition of nitric oxide production. Further investigation revealed that compound 30 dose-dependently inhibited key inflammatory mediators, including the cytokines TNF-α and IL-6, as well as the enzymes COX-2 and iNOS. Subsequent mechanistic studies elucidated that the anti-inflammatory effects of compound 30 were attributed to the inhibition of the NF-κB signaling pathway and the activation of the Nrf2 signaling pathway.