Isolation of Coralmycins A and B, Potent Anti-Gram Negative Compounds from the Myxobacteria Corallococcus coralloides M23

  • J Nat Prod. 2016 Sep 23;79(9):2223-8. doi: 10.1021/acs.jnatprod.6b00294.
Yu Jin Kim  1 ,  Hyun-Ju Kim  1 ,  Geon-Woo Kim  1 ,  Kyungyun Cho  2 ,  Shunya Takahashi  3 ,  Hiroyuki Koshino  3 ,  Won-Gon Kim  1
Affiliations
  • 1. Superbacteria Research Center, Korea Research Institute of Bioscience and Biotechnology , Yusong, Daejeon 305-806, Korea.
  • 2. Department of Biotechnology, Hoseo University , Asan 336-795, Korea.
  • 3. RIKEN Center for Sustainable Resource Science , Hirosawa 2-1, Wako, Saitama 351-0198, Japan.
PMID: 27598688 DOI: 10.1021/acs.jnatprod.6b00294
Abstract

Two new potent anti-Gram negative compounds, coralmycins A (1) and B (2), were isolated from cultures of the myxobacteria Corallococcus coralloides M23, together with another derivative (3) that was identified as the very recently reported cystobactamid 919-2. Their structures including the relative stereochemistry were elucidated by interpretation of spectroscopic, optical rotation, and CD data. The relative stereochemistry of 3 was revised to "S*R*" by NMR analysis. The Antibacterial activity of 1 was most potent against Gram-negative pathogens, including Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumanii, and Klebsiella pneumoniae, with MICs of 0.1-4 μg/mL; these MICs were 4-10 and 40-100 times stronger than the Antibacterial activities of 3 and 2, respectively. Thus, these data indicated that the β-methoxyasparagine unit and the hydroxy group of the benzoic acid unit were critical for Antibacterial activity.