AUTHOR=Jia Shujie , Su Xiangdong , Yan Wensi , Wu Meifang , Wu Yichuang , Lu Jielang , He Xin , Ding Xin , Xue Yongbo 

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

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.780304

DOI=10.3389/fchem.2021.780304

ISSN=2296-2646

ABSTRACT=<p>Mangrove-derived endophytes are rich in bioactive secondary metabolites with a variety of biological activities. Recently, a fungus <italic>Pseudofusicoccum</italic> sp. J003 was first isolated by our research group from mangrove species <italic>Sonneratia apetala</italic> 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 <bold>(1)</bold>, two alkaloids <bold>(2–3)</bold>, four phenolic compounds <bold>(4–<bold>7</bold>)</bold>, and four steroid derivatives <bold>(8–11)</bold>. The new structure of <bold>1</bold> 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 <italic>in vitro</italic> AChE inhibitory, anti-inflammatory, and cytotoxic activities of the selected compounds were evaluated. The results showed that compound <bold>1</bold> showed mild AChE inhibitory activity, with an inhibition rate of 23.34% at the concentration of 50 <italic>μ</italic>M. Compound <bold>9</bold> 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 <italic>μ</italic>M, better than that of positive control L-NMMA. Compound <bold>9</bold> 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 <bold>(1–11)</bold> against <italic>Escherichia coli</italic>, <italic>Bacillus subtilis</italic>, <italic>Staphylococcus aureus</italic>, and <italic>Pseudomonas aeruginosa</italic> were also tested; however, none of them showed antimicrobial activities.</p>