Konstitution von Dihydrophenazin‐Derivaten

Birkofer, Leonhard

doi:10.1002/cber.19520851108

Cited by 19 publications

(2 citation statements)

References 11 publications

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“…3; R = H), do show long-wavelength bands at 350 and 450 nm. Birkofer (2) has suggested that these long-wave bands arise from quinonoid structures; quinonoid species are planar molecules, unlike the nitrogen-cross-linked dimer proposed by Gurusiddaiah et al (6). The second problem with the dimeric structure proposed by Gurusiddaiah et al…”

Section: Resultsmentioning

confidence: 98%

Revised structure for the phenazine antibiotic from Pseudomonas fluorescens 2-79 (NRRL B-15132)

Brisbane

Janik

Tate

et al. 1987

Antimicrob Agents Chemother

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A phenazine antibiotic (mp, 243 to 244°C), isolated in a yield of 134 ,ug/ml from cultures of Pseudomonas fluorescens 2-79 (NRRL B-15132), was indistinguishable in all of its measured physicochemical (melting point, UV and infrared spectra, and gas chromatography-mass spectrometry data) and biological properties from synthetic phenazine-1-carboxylic acid. Weller and Cook (10) reported that the wheat root disease take-all, which is caused by Gaeumannomyces graminis var.tritici, can be suppressed by inoculating wheat seeds with Pseudomonas fluorescens 2-79 (NRRL B-15132). Gurusiddaiah et al. (6) characterized an antibiotic (mp, 242°C) produced by this culture and considered to be significant in this suppressive activity as having an unusual phenazine-1-carboxylic acid dimer structure. However, the physicochemical properties (UV and infrared [IR] spectra and the melting point) of this compound are similar to those of the phenazine-1-carboxylic acid (mp, 238 to 241°C), isolated from P. aeruginosa by Chang and Blackwood (4), and also to the properties of a material (mp, 243 to 244°C) isolated from P. fluorescens 2-79 in our laboratory. These similarities warranted a critical assessment of the data and a direct comparison with synthetic phenazine-1-carboxylic acid. MATERIALS AND METHODSOrganisms. Bacillus cereus, Escherichia coli HB101, and fluorescent pseudomonad strains A37, 2-79, K2-79, and PGPR were routinely maintained on tryptic soy agar (8) or nutrient agar (Difco Laboratories). For long-term storage, bacteria were kept in 40% glycerol at -12°C. The fungi G. graminis var. tritici 500 and Rhizoctonia solani Rh2l were maintained on half-strength PDA medium (potato-dextrose agar powder [Oxoid Ltd.] Antibiosis bioassays. The PDA medium was adjusted by the addition of a suitable pH buffer (20 mM phosphate, 20 mM citrate) instead of water. Bacteria were mixed in 5 ml of molten 2% agar containing 0.1% (wt/vol) peptone and poured over the PDA medium. Portions of the 1.5 mM phenazine-1-carboxylic acid in ethanol were evaporated on sterile paper disks (11-mm diameter) and applied to the agar. Fungi were centrally inoculated onto buffered PDA plates with 3-mm agar plugs obtained from the outer perimeter of actively growing mycelia, and the paper disks treated with phenazine-1-carboxylic acid were applied 2 to 3 days later.Sources. P. fluorescens 2-79 (10) was kindly supplied by

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Section: Resultsmentioning

confidence: 98%

Revised structure for the phenazine antibiotic from Pseudomonas fluorescens 2-79 (NRRL B-15132)

Brisbane

Janik

Tate

et al. 1987

Antimicrob Agents Chemother

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“…Retention times for PCN and PCA were 7.45 and 8.17 min, respectively. Concentrations of PCN and PCA were estimated by using an extinction coefficient at 368 nm (ε 368 ) of 17,600 that was calculated by measuring the absorption spectra of a PCN and of a phenazine solution of known concentration and assuming the same extinction coefficient for phenazine and PCN at 250 nm (5).…”

Section: Methodsmentioning

confidence: 99%

Phenazines and Other Redox-Active Antibiotics Promote Microbial Mineral Reduction

Hernández¹,

Kappler

Newman

2004

Appl Environ Microbiol

361

227

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Natural products with important therapeutic properties are known to be produced by a variety of soil bacteria, yet the ecological function of these compounds is not well understood. Here we show that phenazines and other redox-active antibiotics can promote microbial mineral reduction. Pseudomonas chlororaphis PCL1391, a root isolate that produces phenazine-1-carboxamide (PCN), is able to reductively dissolve poorly crystalline iron and manganese oxides, whereas a strain carrying a mutation in one of the phenazine-biosynthetic genes (phzB) is not; the addition of purified PCN restores this ability to the mutant strain. The small amount of PCN produced relative to the large amount of ferric iron reduced in cultures of P. chlororaphis implies that PCN is recycled multiple times; moreover, poorly crystalline iron (hydr)oxide can be reduced abiotically by reduced PCN. This ability suggests that PCN functions as an electron shuttle rather than an iron chelator, a finding that is consistent with the observation that dissolved ferric iron is undetectable in culture fluids. Multiple phenazines and the glycopeptidic antibiotic bleomycin can also stimulate mineral reduction by the dissimilatory iron-reducing bacterium Shewanella oneidensis MR1. Because diverse bacterial strains that cannot grow on iron can reduce phenazines, and because thermodynamic calculations suggest that phenazines have lower redox potentials than those of poorly crystalline iron (hydr)oxides in a range of relevant environmental pH (5 to 9), we suggest that natural products like phenazines may promote microbial mineral reduction in the environment.

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The Bacterial Pigments

1957

Chemistry of Heterocyclic Compounds: A Series of Monographs

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Konstitution von Dihydrophenazin‐Derivaten

Cited by 19 publications

References 11 publications

Revised structure for the phenazine antibiotic from Pseudomonas fluorescens 2-79 (NRRL B-15132)

Revised structure for the phenazine antibiotic from Pseudomonas fluorescens 2-79 (NRRL B-15132)

Phenazines and Other Redox-Active Antibiotics Promote Microbial Mineral Reduction

The Bacterial Pigments

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