New aromatic polyketides from the marine-derived fungus Pseudopithomyces maydicus PSU-AMF350 and their antimicrobial activity

Abstract

Four new aromatic polyketides including two diphenyl ethers (pseudopithoethers A–B, 1-2), one benzofuranone (pseudopithonone, 3) and one xanthone (pseudopithoxanthone, 4), along with two known compounds (5-6) and one new naturally occurring hydroquinone (α,2,5-trihydroxyacetophenone, 7) were isolated from the marine-derived fungus Pseudopithomyces maydicus PSU-AMF350. Their structures were identified by analysis of spectroscopic data. All isolated compounds were tested for antimicrobial activity. Only compound 7 displayed antibacterial activity against methicillin-resistant Staphylococcus aureus with the MIC value of 128 µg/mL and against S. aureus, Acinetobacter baumannii NPRC005 and A. baumannii NPRC007 with the same MIC value of 200 µg/mL.

Keywords:

• Pseudopithomyces maydicus
• marine-derived fungus
• diphenyl ether
• benzofuranone
• xanthone
• hydroquinone
• antimicrobial activity

Acknowledgments

V. Rukachaisirikul thanks the NSTDA Chair Professor grant (the fourth Grant) of the Crown Property Bureau and the National Science and Technology Development Agency, Thailand. B. N. S. Ningsih would like to express gratitude for Thailand's Education Hub for the Southern Region of ASEAN Countries (TEH-AC) Scholarship from Prince of Songkla University (Contract No. TEH-AC 029/2018), and to the Center of Excellence for Innovation in Chemistry (PERCH-CIC), Ministry of Higher Education, Science, Research and Innovation, Thailand and the Graduate School, Prince of Songkla University for partial support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the NSTDA Chair Professor grant (the Fourth Grant) of the Crown Property Bureau and National Science and Technology Development Agency, and Thailand's Education Hub for the Southern Region of ASEAN Countries (TEH-AC) Scholarship from Prince of Songkla University (Contract No. TEH-AC 029/2018).