There are always new antibiotic drugs being approved for clinical use each year, but over use of antibiotics has already resulted in a growing number of antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Unfortunately, the rate of discovering new antimicrobial agents is slower than the rate of losing antibiotics’ efficiency. This mismatch reveals a serious challenge for human health. Therefore, there is always urgency to identify new potent and safe antimicrobial agents. Endospore-forming bacteria like Paenibacillus are well known for producing polypeptide and polyketide antibiotics. In this thesis, we discovered two types of new compounds with antibacterial activities, named paenibacillaene and...[ Read more ]

There are always new antibiotic drugs being approved for clinical use each year, but over use of antibiotics has already resulted in a growing number of antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Unfortunately, the rate of discovering new antimicrobial agents is slower than the rate of losing antibiotics’ efficiency. This mismatch reveals a serious challenge for human health. Therefore, there is always urgency to identify new potent and safe antimicrobial agents. Endospore-forming bacteria like Paenibacillus are well known for producing polypeptide and polyketide antibiotics. In this thesis, we discovered two types of new compounds with antibacterial activities, named paenibacillaene and paenialvin. Both of them were isolated from secondary metabolite of Paenibacillus. Reverse-phase C18 flash chromatography and high performance liquid chromatography (HPLC) were used to purify these compounds. To identify the chemical structures of these compounds, mass spectrometry (MS) experiments and nuclear magnetic resonance (NMR) experiments were performed. Furthermore, to evaluate antimicrobial activities of these compounds, the minimum inhibitory concentration (MIC) assay was performed. The MICs of these new compounds against Staphylococcus aureus reach to 0.8-5 μg/mL. In conclusion, we discovered one polyketide antibiotic and four polypeptide antibiotics with potential for clinical use.