title: Two new members of streptothricin class antibiotics from Streptomyces qinlingensis sp. nov.
abstract: Four streptothricin-group antibiotics (1~4) were isolated from the fermentation broth of Streptomyces qinlingensis sp. nov. Along with the known antibiotics streptothricins F (1) and D (3), two new members of this class (2, 4) were identified as 12-carbamoyl derivatives of 1 and 3, respectively, mainly by analysis of the IR, HR-MS and NMR spectral data. The antibacterial activities of 1~4 against Escherichia coli (MICs 3.1, 25.0, 3.1 and 12.5 microg/ml), Bacillus subtilis (MICs 6.3, 25.0, 3.1 and 50 microg/ml), Staphylococcus aureus (MICs 12.5, >100.0, 6.3, >100.0 microg/ml), Bacillus cereus (MICs 25.0, 50.0, 25.0 and 50.0 microg/ml) and Pseudomonas aeruginosa (MICs 50.0, >100.0, 50.0, >100.0 microg/ml) were assayed by micro-broth dilution. The results based on MIC data indicated that 2 and 4 exhibited significantly less potent antibacterial activities when compared to that of 1 and 3.
authors.affiliation: Institute of Pesticide Science, Northwest Agricultural & Forestry University, Yangling, Shaanxi, China.
authors.forename: Zhiqin
authors.initials: Z
authors.lastname: Ji
authors.forename: Mingan
authors.initials: M
authors.lastname: Wang
authors.forename: Jiwen
authors.initials: J
authors.lastname: Zhang
authors.forename: Shaopeng
authors.initials: S
authors.lastname: Wei
authors.forename: Wenjun
authors.initials: W
authors.lastname: Wu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects; D001412:Bacillus subtilis / Q000187:drug effects; D002853:Chromatography, Liquid; D004926:Escherichia coli / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013055:Spectrophotometry, Infrared; D013211:Staphylococcus aureus / Q000187:drug effects; D013302:Streptomyces / Q000378:metabolism*; D013309:Streptothricins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D013309:Streptothricins