The recently discovered antibiotic burnettramic acid A (1) and three new congeners, burnettramic acids C-E (2-4), were identified from the co-cultures of two marine Aspergillus strains. The structure of burnettramic acid A was revised on the basis of reinterpretation of the nuclear magnetic resonance (NMR) data and chemical derivatization. The full absolute configurations of burnettramic acids were established using the Mosher ester method and Marfey's analysis, combined with density functional theory calculation of NMR and electric circular dichroism data.
NMR, absolute configuration, Aspergillus, burnettramic acids
NCBI PubMed ID: 31829608Publication DOI: 10.1021/acs.orglett.9b04008Journal NLM ID: 100890393Publisher: American Chemical Society
Correspondence: Gan M
Institutions: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
Methods: 13C NMR, 1H NMR, NMR-2D, HR-ESI-MS, antibacterial assay, derivatization, antifungal activity test, ECD, chiral LC-MS