The Simultaneous Determination of Sample and Blank by Means of Dual and Differential Colorimetry in the Continuous Analysis of Penicillin in Fermentation Media

Russo-Alesi, Frank M.; Sherman, Constance; Kelly, Joseph F.; Ferrari, Andrés

doi:10.1111/j.1749-6632.1960.tb23240.x

Cited by 5 publications

(2 citation statements)

References 4 publications

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“…Concentrations were determined by scanning the plates with a spectrodensitometer (model SDA 3000, Schoeffel Instrument Corp.). Alternatively, these antibiotics were separated by paper chromatography using a propanolpyridine-acetic acid-acetonitrile-water (45:30:9:40:36) mixture or a methanol-n-propanol-water (6:2:1) mix- (9). The difference between untreated and penicillinase-treated samples measured the amount of penicillin N. In addition, penicillin N was determined biologically by a plate assay previously described (2) and by placing the dried paper chromatograms on plates seeded with Salmonella gallinarum and plates seeded with S. gallinarum plus penicillinase.…”

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confidence: 99%

Synthesis of Deactoxycephalosporin C by a Mutant of Cephalosporium acremonium

Queener

Capone

Radue

et al. 1974

Antimicrob Agents Chemother

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A number of Cephalosporium acremonium mutants blocked in the synthesis of cephalosporin C were investigated for accumulation of other ,3-lactam compounds. The non-cephalosporin C producers were isolated after exposing the superior cephalosporin C-producing strain M8650-4 to ultraviolet light (268 nm). One of the blocked mutants, MH63, accumulated deacetylcephalosporin C (0.4 mg/ml), deacetoxycephalosporin C (1.5 mg/ml), and penicillin N (2.7 mg/ml). In contrast, the parent of MH63 produced high levels of cephalosporin C as well as deacetylcephalosporin C (2.2 mg/nal) and penicillin N (1.0 mg/ml), but only traces of deacetoxycephalosporin C (about 0.1 mg/ml). Deacetoxycephalosporin C was isolated from the mutant strain and identified by ultraviolet light, nuclear magnetic resonance, bioactivity spectrum, and co-migration with authentic standard in three chromatography systems.

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confidence: 99%

Synthesis of Deactoxycephalosporin C by a Mutant of Cephalosporium acremonium

Queener

Capone

Radue

et al. 1974

Antimicrob Agents Chemother

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“…In addition, the automated system provides a continuous blank for the turbidity of the brei fractions and for auto-oxidation of the reduced cytochrome c substrate. It is thus apparent that automated enzymatic assays are most satisfactorily performed in systems based on double-beam optical equipment (21) which record directly the difference between reactions run for various time intervals.…”

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confidence: 99%

Studies on Isolated Cell Components

Schuel

Tipton

Anderson

1964

The Journal of Cell Biology

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The zonal ultracentrifuge was used to separate the subcellular components of rat liver brei into soluble phase, microsomal, mitochondrial, membranous fragments, and nuclear fractions during a single centrifugafion. The centrifuge was run at 10,000 to 30,000 RPM for 15 to 240 minutes, and the rotor contained a 1200 ml sucrose gradient, varying linearly with radius from 17 to 55 per cent sucrose with a "cushion" of 66 per cent sucrose at the rotor edge. The distribution of the mitochondria was determined using cytochrome oxidase as the marker enzyme. An automated assay system for cytochrome oxidase was developed utilizing reduced cytochrome c as substrate, modules of the Technicon Autoanalyzer, and the Beckman DB Spectrophotometer. All of the cytochrome oxidase activity was restricted to a single peak in the gradient, and no activity could be detected in the zones occupied by the m:.crosomes and nuclei. The mitochondrial fraction was isolated from rat liver brei in 0.25 M sucrose by differential centrifugation, and then run in the zonal ultracentrifuge. This fraction behaved in the zonal ultracentrifuge in the same way as mitochondria separated directly from intact brei. Observations of the isolated fractions in the phase contrast microscope indicated that a wide variety of granules was present in the mitochondrial zone in addition to the true mitochondria. Under the conditions employed, the mitochondria were sedimented essentially to their isopycnic position in the gradient at approximately 43.8 per cent sucrose, density 1.20 gm/cc.

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High‐Performance Liquid Chromatographic Analysis of Ampicillin

Tsuji

Robertson

1975

Journal of Pharmaceutical Sciences

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The Simultaneous Determination of Sample and Blank by Means of Dual and Differential Colorimetry in the Continuous Analysis of Penicillin in Fermentation Media

Cited by 5 publications

References 4 publications

Synthesis of Deactoxycephalosporin C by a Mutant of Cephalosporium acremonium

Synthesis of Deactoxycephalosporin C by a Mutant of Cephalosporium acremonium

Studies on Isolated Cell Components

High‐Performance Liquid Chromatographic Analysis of Ampicillin

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