AUTHOR=Pang Xiaoyan , Chen Weihao , Wang Xin , Zhou Xuefeng , Yang Bin , Tian Xinpeng , Wang Junfeng , Xu Shihai , Liu Yonghong 

TITLE=New Tetramic Acid Derivatives From the Deep-Sea-Derived Fungus Penicillium sp. SCSIO06868 With SARS-CoV-2 Mpro Inhibitory Activity Evaluation

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.730807

DOI=10.3389/fmicb.2021.730807

ISSN=1664-302X

ABSTRACT=<p>Three new tetramic acid derivatives (<bold>1</bold>–<bold>3</bold>) and a new polyketide (<bold>4</bold>) along with eight known compounds (<bold>5</bold>–<bold>12</bold>) were isolated from cultures of the deep-sea-derived fungus <italic>Penicillium</italic> sp. SCSIO06868. Four new structures were elucidated by analysis of one-dimensional/two-dimensional nuclear magnetic resonance (NMR) data and high-resolution electrospray ionization mass spectrometry. Their absolute configurations were established by X-ray crystallography analysis and comparison of the experimental and reported electronic circular dichroism (ECD) values or specific optical rotation. Compound <bold>3</bold> exhibited potent, selective inhibitory activities against <italic>Staphylococcus aureus</italic> and methicillin-resistant <italic>S. aureus</italic> with minimum inhibitory concentration values of both 2.5 μg/ml. Also, compound <bold>3</bold> showed weak antiviral activity against severe acute respiratory syndrome coronavirus 2 main protease, which was responsible for the coronavirus disease 2019 pandemic.</p>