The isolation, purification and biological activity of a novel antibacterial compound produced by Pseudomonas stutzeri.
A novel compound designated zafrin [4beta-methyl-5, 6, 7, 8 tetrahydro-1 (4beta-H)-phenanthrenone] was isolated from a crude extract of a marine bacterium identified as Pseudomonas stutzeri. Zafrin showed strong antibacterial activity against both Gram-positive and Gram-negative bacteria. The compound was purified and its structure was elucidated by spectroscopic methods including 1H-nuclear magnetic resonance (NMR), 13C-NMR, 1D-NMR and 2D-NMR spectroscopy. It could be demonstrated that a purified solution of zafrin was active against several human pathogens, including Staphylococcus aureus, and Salmonella typhi. By contrast, zafrin did not inhibit the growth of eukaryotic organisms Candida albicans and Schizosaccharomyces pombe. The minimal inhibitory concentration for Gram-positive bacteria ranged from 50 to 75 microg mL(-1) and varied between 75 and 125 microg mL(-1) for Gram-negative bacteria. Zafrin lysed Bacillus subtilis cells grown in an osmotically protected medium, suggesting that it does not act upon the cell wall. Further investigation using B. subtilis indicated that the compound is bactericidal and is likely to target the cell membrane.
Uzair
Bushra
B
Centre for Molecular Genetics, University of Karachi, Karachi, Pakistan.
Ahmed
Nuzhat
N
Ahmad
Viqar Uddin
VU
Mohammad
Faryal Vali
FV
Edwards
David H
DH
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D015169:Colony Count, Microbial; D006090:Gram-Negative Bacteria / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D044223:Pseudomonas stutzeri / Q000737:chemistry* / Q000302:isolation & purification; D012568:Schizosaccharomyces / Q000187:drug effects
D000900:Anti-Bacterial Agents