Induction of SOS-response inEscherichia coli K12 bacteria by 4-quinolones

Shul'gina, M. V.; Fadeeva, N. I.; Stebaeva, L. F.; Bol'shakova, T. N.

doi:10.1007/bf02220534

Cited by 2 publications

(5 citation statements)

References 3 publications

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“…The results obtained in this work can be summarized, together with the data reported in [8,10,11 ], in the scheme depicted in Fig. 1.…”

Section: Resultsmentioning

confidence: 70%

“…The model is It should be noted that the series of 6-quinolones available in this work contained no compounds substituted at position 8. However, both the results of our previous investigations &the properties oflomefloxacin [10,11] and the extensive published data concerning the activity of this drug both in vitro and in vivo [12,13] suggest that modification of this quinolone in position 8 may not decrease activity toward DNA replication in E. coli but expand the spectrum &action and markedly improve the pharmacokinetic characteristics of this drug. In our opinion, very good prospects from the standpoint of high antibacterial activity are offered by compound LIB-174.…”

Section: Resultsmentioning

confidence: 92%

“…(2) Inhibition of DNA synthesis not accompanied by formation of DNA chain breaks-this mechanism apparently prevails in the case of low concentrations of nitroquinolones or oxolinic acid [10].…”

mentioning

confidence: 99%

“…(1) Inhibition of DNA synthesis accompanied by formation (or stabilization) of DNA chain breaks [8] according to a mechanism proposed in [9].…”

mentioning

confidence: 99%

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Structure—Function relationships in a series of 4-quinolone-3-carboxylic acid derivatives

Shul'gina¹,

Fadeeva²,

Bol'shakova³

et al. 1999

Pharm Chem J

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“…The results obtained in this work can be summarized, together with the data reported in [8,10,11 ], in the scheme depicted in Fig. 1.…”

Section: Resultsmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 92%

mentioning

confidence: 99%

“…(1) Inhibition of DNA synthesis accompanied by formation (or stabilization) of DNA chain breaks [8] according to a mechanism proposed in [9].…”

mentioning

confidence: 99%

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Structure—Function relationships in a series of 4-quinolone-3-carboxylic acid derivatives

Shul'gina¹,

Fadeeva²,

Bol'shakova³

et al. 1999

Pharm Chem J

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“…The effect of quinolones on the viability of bacteria was determined as described in [12]. For this purpose, after an 18-h growth in a liquid nutrient medium a bacterial culture was diluted to 1/50 by the same medium and poured (in 2-ml aliquots) into tubes containing a certain amount of 4-quinolones and(or) chloramphenicol (for A versus B mechanism determination).…”

Section: Experimental Partmentioning

confidence: 99%

Mechanisms of the antibacterial activity of fluoroquinolones and nitroquinolones with respect toEscherichia coli K12

Shul'gina¹,

Fadeeva²,

Bol'shakova³

et al. 1999

Pharm Chem J

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The derivatives of 4-quinolone-3-carboxylic acid containing one (norfloxacin, pefloxacin, ciprofloxacin, grepafloxacin), two (lomefloxacin, sparfloxacin), or three (fleroxacin, tosufloxacin) fluorine atoms are known as highly active antibacterial drugs. A necessary condition for the manifestation of high antibacterial activity in this series of compounds is that one of the fluorine atoms would occupy position 6 in the aromatic part of the quinolone nucleus [1]. Another important factor is the character of the substituent in position 7 of the quinolone nucleus. Using various combinations and variations of substituents in positions 6 and 7 of the quinolone molecule (as well as of those in positions 5 and 8) is still the main point in searching for new active compounds of this class.The bactericidal effect of 4-quinolones is commonly related to their ability to inhibit bacterial topoisomerase II (DNA-gyrase)-an enzyme that promotes the reaction of negative DNA supercoiling in bacteria. Two subunits A of this enzyme act by unwinding the DNA chain, cutting one strand of the double helix, forming one more turn of the supercoil, and resealing the cut strand. Two subunits B of DNA-gyrase implement the ATP hydrolysis and provide the energy necessary for the supercoiling process [2]. At present, it is believed that 4-quinolones inhibit the reaction of DNA supercoiling by binding to the gyrase-DNA complex at the instant of the double-strand DNA breaking. Indeed, mutation . However, the bactericidal effect of drugs belonging to the 4-quinolone group is not restricted to inhibiting DNA supercoiling. It was suggested that DNA breaks formed under the action of these compounds induce an SOS response in the damaged bacterial cell, the uncontrolled development of which can result in the loss of bacteria [2,4,5]. Over a few recent years, specialists of the Center for Drug Chemistry have synthesized a series of 6-nitro derivatives of 4-quinolone-3-carboxylic acid and determined special features of their antibacterial action in comparison to that of fluorine-containing quinolones [6][7][8]. The purpose of this work was to study the relationship between the ability of inhibiting DNA synthesis and the bactericidal action of fluoroand nitroquinolones with respect to the E. coli species with intact and mutant DNA-gyrase. We have also determined the ability of these compounds to act according to bactericidal mechanisms of the A and B types inherent in quinolones. EXPERIMENTAL PARTBacterial strains and their cultivation. The experiments were performed with the E. coli K12 strains KLl6thy (Hfr P. 0.45, thi 11 thy A24) and KL166 (Hfr P.0.45, thi 11 rel I thy A24 drm 13 gyr AI3) kindly provided by B. Bachmann (E. coli Genetic Stock Center) and the strain EC 1000/pJE43 (F, A(proB--lac) thi 1 supE44 strA/colEI ~d Ap-lac) [9] carrying a multicopy plasmid with the [3-galactosidase 0091-I 50X/99/3307-0343522.00 9

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Induction of SOS-response inEscherichia coli K12 bacteria by 4-quinolones

Cited by 2 publications

References 3 publications

Structure—Function relationships in a series of 4-quinolone-3-carboxylic acid derivatives

Structure—Function relationships in a series of 4-quinolone-3-carboxylic acid derivatives

Mechanisms of the antibacterial activity of fluoroquinolones and nitroquinolones with respect toEscherichia coli K12

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