6-Methylenetetracyclines. III.1 Preparation and Properties2

Blackwood, Robert K.; Beereboom, John J.; Rennhard, Hans H.; Wittenau, M. Schach von; Stephens, Charles R.

doi:10.1021/ja00907a010

Cited by 46 publications

(12 citation statements)

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“…The frequencies were respectively shifted to 1560 cm -~ and 1550 cm -1 and diminish in intensity for the HA complex. For ISO, the intense band found at 1740 cm -1 was characteristic for the lactone structure [27]. During complex formation this absorption diminishes in intensity.…”

Section: Resultsmentioning

confidence: 98%

IR absorption spectrophotometric analysis of the complex formed by tetracycline and synthetic hydroxyapatite

Myers

Tochon-Danguy²,

Baud³

1983

Calcif Tissue Int

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The infrared (IR) spectra of KBr pellet preparations of tetracycline (TC) complexes with hydroxyapatite (HA) indicated that the binding of the antibiotic to bone mineral can occur independently at each of two ligands. The shifts in the IR spectrum occur for the keto-enol ligand of rings B and C and for the tricarbonylmethane grouping of ring A. Analogs that lack one or the other of these groups are able to form complexes with HA in which the common portion resembles that of the parent molecule.

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Section: Resultsmentioning

confidence: 98%

IR absorption spectrophotometric analysis of the complex formed by tetracycline and synthetic hydroxyapatite

Myers

Tochon-Danguy²,

Baud³

1983

Calcif Tissue Int

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“…Non-enzymatic oxidation reactions of tetracyclines at C11a are known. In 1963 Blackwood et al (15) prepared several C11a-halogenated derivatives of various tetracyclines. These included 11a-fluorotetracycline, 11a-fluorooxytetracycline, 11a-chlorotetracycline, and 11a-chlorooxytetracycline.…”

Section: Table II Mic Values Of Tetracycline Antibiotics With E Colimentioning

confidence: 99%

TetX Is a Flavin-dependent Monooxygenase Conferring Resistance to Tetracycline Antibiotics

Yang

Moore²,

Koteva³

et al. 2004

Journal of Biological Chemistry

281

238

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The tetracycline antibiotics block microbial translation and constitute an important group of antimicrobial agents that find broad clinical utility. Resistance to this class of antibiotics is primarily the result of active efflux or ribosomal protection; however, a novel mechanism of resistance has been reported to be oxygen-dependent destruction of the drugs catalyzed by the enzyme TetX. Paradoxically, the tetX genes have been identified on transposable elements found in anaerobic bacteria of the genus Bacteroides. Overexpression of recombinant TetX in Escherichia coli followed by protein purification revealed a stoichiometric complex with flavin adenine dinucleotide. Reconstitution of in vitro enzyme activity demonstrated a broad tetracycline antibiotic spectrum and a requirement for molecular oxygen and NADPH in antibiotic degradation. The tetracycline products of TetX activity were unstable at neutral pH, but mass spectral and NMR characterization under acidic conditions supported initial monohydroxylation at position 11a followed by intramolecular cyclization and non-enzymatic breakdown to other undefined products. TetX is therefore a FAD-dependent monooxygenase. The enzyme not only catalyzed efficient degradation of a broad range of tetracycline analogues but also conferred resistance to these antibiotics in vivo. This is the first molecular characterization of an antibiotic-inactivating monooxygenase, the origins of which may lie in environmental bacteria.

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“…The TCs are amphoteric and can be manufactured as both acidic and basic salts. 1 The macrolide antibiotics most commonly used in agriculture are tylosin and erythromycin. Macrolide antibiotics are used in veterinary medicine to treat respiratory diseases, or as feed additives to promote growth.…”

Section: Introductionmentioning

confidence: 99%

X-Ray Powder Diffraction Patterns for Certain β-Lactam, Tetracycline and Macrolide Antibiotic Drugs

Thangadurai¹,

Abraham

Srivastava

et al. 2005

ANAL. SCI.

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X-ray powder diffraction (XRD) data for eight β-lactam viz., ampicillin sodium, ampicillin trihydrate, penicillin G procaine, benzathine penicillin, benzyl penicillin sodium, cefalexin, cefotaxime sodium and ceftriaxone sodium; three tetracyclines viz., doxycycline hydrochloride, oxytetracycline dihydrate and tetracycline hydrochloride; and two macrolide viz., azithromycin and erythromycin estolate antibiotic drugs were obtained using a powder diffractometer. The drugs were scanned from Bragg angles (2θ) of 10˚ to 70˚. The obtained data were tabulated in terms of the lattice spacing (Å) and relative line intensities (I/II). This new information may be useful for identifying these drugs from confiscated materials, which has been frequently encountered in forensic laboratories.

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6-Methylenetetracyclines. III.¹ Preparation and Properties²

Cited by 46 publications

References 0 publications

IR absorption spectrophotometric analysis of the complex formed by tetracycline and synthetic hydroxyapatite

IR absorption spectrophotometric analysis of the complex formed by tetracycline and synthetic hydroxyapatite

TetX Is a Flavin-dependent Monooxygenase Conferring Resistance to Tetracycline Antibiotics

X-Ray Powder Diffraction Patterns for Certain β-Lactam, Tetracycline and Macrolide Antibiotic Drugs

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