Paenimacrolidin, a novel macrolide antibiotic from Paenibacillus sp. F6-B70 active against methicillin-resistant Staphylococcus aureus.
Bottom Line: Elucidation of the structure by nuclear magnetic resonance and infrared spectroscopy revealed that the active compound, paenimacrolidin (PAM), was a novel 22-membered macrolide with side-chains.The antibiotic capacity of PAM was compromised by its instability, which can be overcome significantly with addition of an anti-oxidant.To our knowledge, this is the first report of the isolation of an active macrolide from paenibacilli, which may be a promising source of novel antibiotics.
Affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China. firstname.lastname@example.orgShow MeSH
Related in: MedlinePlus
Mentions: Considering that PAM is a member of the polyene family, which is sensitive to pH, temperature, oxygen and light, we speculate that the unusual high MICs of PAM may be due to its instability. To this end, the stability of PAM in Mueller–Hinton broth at 37°C was accessed. As shown in Fig. 5A, the remaining PAM was rapidly reduced to 20.6%, 6%, 3.8%, 0% of the initial concentration (128 µg ml−1) at 6, 12, 18 and 24 h after inoculation, respectively. A similar phenomenon was observed in LB medium at 37°C or 28°C (data not shown). These data indicate that the decay of PAM appears to be exponential with a half‐life of approximately 4 h, suggesting that the chemical is unstable.
Affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China. email@example.com