Total synthesis of the proposed structure of baulamycin A was performed. The spectral properties of the synthetic compound differ from those reported for the natural product. On the basis of comprehensive NMR study, we proposed two other possible structures for natural baulamycin A. Total syntheses of these two substances were performed, which enabled assignment of the correct structure of baulamycin A. Key features of the convergent and fully stereocontrolled route include Evans Aldol and Brown allylation reactions to construct the left fragment, a prolinol amide-derived alkylation/desymmetrization to install the methyl-substituted centers in the right fragment, and finally, a Carreira alkynylation to join both fragments. In addition, we have determined the inhibitory activities of novel baulamycin A derivatives against the enzyme SbnE. This SAR study provides useful insight into the design of novel SbnE inhibitors that overcome the drug resistance of pathogens, which cause life-threatening infections.
Bibliographical noteFunding Information:
This work was supported by the Korea Institute of Science and Technology, the KU-KIST Graduate School of Converging Science and Technology Program, and KRF (Korea Research Fellowship) program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (NRF-2015R1D1A1A01056815).
© 2017 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Organic Chemistry