Acorenone C: A New Spiro-Sesquiterpene from a Mangrove-Associated Fungus, sp. J003.

Mangrove-derived endophytes are rich in bioactive secondary metabolites with a variety of biological activities. Recently, a fungus sp. J003 was first isolated by our research group from mangrove species Buch.-Ham. The subsequent chemical investigation of the methanol extract of the culture broth of this strain has led to the isolation of a new sesquiterpenoid named acorenone C , two alkaloids , four phenolic compounds , and four steroid derivatives . The new structure of was established by extensive spectroscopic analysis, including 1D, 2D NMR spectroscopy, and HRESIMS. Its absolute configuration was elucidated by experimental ECD and ECD calculation. The AChE inhibitory, anti-inflammatory, and cytotoxic activities of the selected compounds were evaluated. The results showed that compound showed mild AChE inhibitory activity, with an inhibition rate of 23.34% at the concentration of 50 M. Compound exerted a significant inhibitory effect against nitric oxide (NO) production in LPS-stimulated RAW 264.7 mouse macrophages, with an inhibition rate of 72.89% at the concentration of 25 M, better than that of positive control L-NMMA. Compound also displayed obvious inhibition effects on the growth of two human tumor cell lines, HL-60 and SW480 (inhibition rates 98.68 ± 0.97% and 60.40 ± 4.51%, respectively). The antimicrobial activities of the compounds against , , , and were also tested; however, none of them showed antimicrobial activities.