AUTHOR=Zhao Dong-Lin , Zhang Xi-Fen , Huang Rui-Huan , Wang Dan , Wang Xiao-Qiang , Li Yi-Qiang , Zheng Cai-Juan , Zhang Peng , Zhang Cheng-Sheng 

TITLE=Antifungal Nafuredin and Epithiodiketopiperazine Derivatives From the Mangrove-Derived Fungus Trichoderma harzianum D13

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.01495

DOI=10.3389/fmicb.2020.01495

ISSN=1664-302X

ABSTRACT=<p>A new polyketide derivative, nafuredin C (<bold>1</bold>), a novel heterocyclic dipeptide, trichodermamide G (<bold>3</bold>), together with four known biogenetically related compounds nafuredin A (<bold>2</bold>), trichodermamide A (<bold>4</bold>), aspergillazin A (<bold>5</bold>), and peniisocoumarin H (<bold>6</bold>), were isolated from the mangrove-derived fungus <italic>Trichoderma harzianum</italic> D13. Their structures, including their absolute configurations, were determined by spectroscopic analysis and time-dependent density functional theory-electronic circular dichroism (ECD) calculations. Trichodermamide G was found to be a novel epithiodiketopiperazine derivative with an unprecedented cyclic system containing a sulfur bridge, and nafuredin C represented the third nafuredin derivative of these homologous compounds. The new compound nafuredin C exhibited obvious antifungal activity against <italic>Magnaporthe oryzae</italic> with a minimum inhibitory concentration (MIC) of 8.63 μM, which is on the same order of magnitude as the positive control carbendazim (MIC = 3.27 μM).</p>