Secondary metabolites isolated from Penicillium christenseniae SD.84 and their antimicrobial resistance effects

Abstract

A pair of new quinolone alkaloid enantiomers, (Ra)-(-)-viridicatol (1) and (Sa)-(+)-viridicatol (4), and seven known compounds, namely, 2, 3 and 5–9, were isolated from Penicillium christenseniae SD.84. The structures of 1 and 4 were determined using NMR and HRESIMS data. Theoretical calculations through CD and ECD confirmed 1 and 4 as a pair of enantiomers. The MIC values of 4 against Staphylococcus aureus and methicillin-resistant S. aureus were 12.4 and 24.7 μM, respectively, compound 1 had no inhibitory activity. Antimicrobial assays of 2, 3, and 5–7 showed a moderate activity against S. aureus and methicillin-resistant S. aureus. This study demonstrated the remarkable potential of Penicillium sp. to produce new drug-resistant leading compounds, thereby advancing the mining for new sources of antimicrobial agents.

Graphical Abstract

Keywords:

• Penicillium christenseniae SD.84
• secondary metabolites
• structural elucidation
• enantiomer
• antimicrobial activity

Disclosure statement

The authors declare no potential conflicts of interest.

Additional information

Funding

National Natural Science Foundation of China (Nos.31770024), Innovation and Development Joint Fund of Natural Science Foundation from Shandong Province (ZR2021LSW022), Exploration Innovation Team (2021GXRC062), Young Taishan Scholarship to Xuekui Xia (tsqn202103100), Natural Science Foundation from Shandong Province (ZR2021QB173), Highend Foreign Experts Recruitment Program (G2021023002L), Key innovation Project of Qilu University of Technology (Shandong Academy of Sciences) (2022JBZ01-06).