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

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

doi:10.3389/fpls.2022.1049015

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

Front Plant Sci. 2022 Nov 14:13:1049015. doi: 10.3389/fpls.2022.1049015. eCollection 2022.

Authors

Yan Chen^{1

2

3}, Huan Wang³, Xin Ke^{1

2

3}, Zihuan Sang^{1

2

3}, Min Kuang^{1

2}, Weiwei Peng^{1

2

3}, Jianbing Tan^{1

2}, Yuting Zheng^{1

2}, Zhenxing Zou^{1

2}, Haibo Tan^{1

2

3}

Affiliations

¹ Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, China.
² Hunan Key Laboratory of Diagnostic and Therapeutic Drug Research for Chronic Diseases, Central South University, Changsha, China.
³ Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.

Abstract

Two previously undescribed lactones, phomolides A and B (1 and 2), and three new sesquiterpenoids, phomenes A-C (3-5), together with one known compound, colletotricholide A (6), were isolated from the endophytic fungus Phomopsis 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 1-6 were also evaluated, and the results demonstrated that compound 2 showed significant antibacterial effects towards methicillin-resistant Staphylococcus aureus and S. aureus 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.

Keywords: Phomopsis; antibacterial activity; cytotoxic activity; endophytic fungus; secondary metabolites.