Structural Revision and Absolute Configuration of Burnettramic Acid A

• DOI: 10.1021/acs.orglett.9b04008
• Publication Date: 2019-12-12T19:14:16Z
• Authors: Jiao Li; Minghua Chen; Xiaomeng Hao; Shasha Li; Fang Li; Liyan Yu; Chunling Xiao; Maoluo Gan
• Keywords: 01 natural sciences; 0104 chemical sciences

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.