AUTHOR=Chen Yan , Wang Huan , Ke Xin , Sang Zihuan , Kuang Min , Peng Weiwei , Tan Jianbing , Zheng Yuting , Zou Zhenxing , Tan Haibo 

TITLE=Five new secondary metabolites from an endophytic fungus Phomopsis sp. SZSJ-7B

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1049015

DOI=10.3389/fpls.2022.1049015

ISSN=1664-462X

ABSTRACT=<p>Two previously undescribed lactones, phomolides A and B (<bold>1</bold> and <bold>2</bold>), and three new sesquiterpenoids, phomenes A–C (<bold>3</bold>–<bold>5</bold>), together with one known compound, colletotricholide A (<bold>6</bold>), were isolated from the endophytic fungus <italic>Phomopsis</italic> sp. SZSJ-7B. Their chemical structures, including the absolute configurations, were comprehensively established by extensive analyses of NMR, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism powered by theoretical calculations, and X-ray diffractions. Moreover, the cytotoxic and antibacterial activities of compounds <bold>1–6</bold> were also evaluated, and the results demonstrated that compound <bold>2</bold> showed significant antibacterial effects towards methicillin-resistant <italic>Staphylococcus aureus</italic> and <italic>S. aureus</italic> strains with minimum inhibitory concentration as low as 6.25 μg/ml, which was comparable to that of the clinical drug vancomycin. Moreover, all compounds showed no cytotoxic activity.</p>