(±) Pestalactone D and pestapyrone F, two new isocoumarins from an endolichenic Pestalotiopsis rhododendri

• Published in: Journal of antibiotics 2023-11, Vol.76 (11), p.678-681
• Main Authors: Wang, Mengyuan, Luo, Mengna, Ding, Xiaotian, Chang, Shanshan, He, Ning, Hong, Bin, Xie, Yunying
• Format: Article
• Language: English
• Subjects: 45; 631/326/193/2541; 692/308/153; Antibiotics; Antimicrobial agents; Bacteriology; Bioinformatics; Biomedical and Life Sciences; Bioorganic Chemistry; Biosynthesis; Brief Communication; Coronaviruses; Crystallography, X-Ray; Enantiomers; Genomes; Heterocyclic Compounds, 3-Ring - chemistry; Heterocyclic Compounds, 3-Ring - pharmacology; Humans; Isocoumarins - chemistry; Isocoumarins - pharmacology; Life Sciences; Magnetic Resonance Spectroscopy; Medicinal Chemistry; Microbiology; Molecular Structure; NMR; Nuclear magnetic resonance; Organic Chemistry; Pestalotiopsis; Planar structures; Single crystals; X-ray diffraction
• ISSN: 0021-8820; 1881-1469; 1881-1469
• DOI: 10.1038/s41429-023-00646-7

Three isocoumarins, including two new compounds, (±) pestalactone D ( 1 ) and pestapyrone F ( 2 ), as well as one known compound, pestapyrone D ( 3 ), were isolated from the culture of the endolichenic Pestalotiopsis rhododendri LF-19-12. The planar structures of all compounds were elucidated by NMR and MS spectra. And the absolute configurations of 1 were confirmed by single crystal X-ray diffraction analysis, indicative of it as a racemate of 4 S /12 S and 4 R /12 R enantiomers. Compound 1 exhibited weak anti-coronaviral activity against human coronavirus HCoV-229E with an EC 50 of 77.61 μM. Based on the bioinformatics analysis, the biosynthetic pathway of 1 has been proposed.