Quinolone antibiotics

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Basic structure of all quinolone antibiotics: the residue R drawn in blue is usually piperazine ; if the compound contains fluorine (red), it is a fluoroquinolone

Quinolone antibiotics (often short, but not unique: quinolones ) are a chemically related substance group of antibiotics known as active principle the inhibition of gyrase - enzyme use (so-called gyrase inhibitors ). Structurally, the quinolone antibiotics are derived from quinoline , which has a carbonyl group and a carboxylic acid group on the nitrogen-containing ring system . A fluorine atom on the benzene ring leads to the fluoroquinolones . Quinolone antibiotics very often also contain a piperazine substituent.

Quinolone antibiotics bind to the complex of the enzyme gyrase and DNA in the bacterial cell . This prevents the reassembly of a cut DNA strand by the enzyme that is responsible for supercoiling (twisting) the DNA.

Changing the twisted state of their DNA is essential for bacteria to copy the genetic material during cell division . The bacteria are therefore no longer able to multiply, and the DNA strand breaks that are caused are likely to have a direct fatal effect. However, an inhibition of DNA replication cannot adequately explain the bactericidal effect of the quinolone antibiotics, which is why other mechanisms of action are assumed.

Representative

The first-generation quinolone antibiotics (1960s and 1970s) were poorly absorbed and had a narrow spectrum of activity. They are hardly of any importance today, while the second generation of gyrase inhibitors are of particular importance when resistance to other drugs is observed.

The fluoroquinolone antibiotics are a subgroup of the quinolone antibiotics. The quinolone antibiotics used today are based on the most important improvement that was chemically made to the first-generation quinolone antibiotics: A fluorine atom was incorporated ( fluoroquinolones , name ending '-floxacin'). The selectivity and spectrum of activity were later improved (initially against chlamydia , pneumococci , mycoplasma , and later against anaerobic bacteria).

Individual evidence

  1. ↑ David C. Hooper: Mechanisms of Action of Antimicrobials: Focus on Fluoroquinolones . In: Clinical Infectious Diseases . tape 32 , Supplement_1, March 15, 2001, p. S9-S15 , doi : 10.1086 / 319370 .
  2. ↑ Karl Drlica, Muhammad Malik, Robert J. Kerns, Xilin Zhao: quinolone-Mediated Bacterial Death . In: Antimicrobial Agents and Chemotherapy . tape 52 , no. 2 , February 1, 2008, p. 385–392 , doi : 10.1128 / aac.01617-06 , PMID 17724149 ( asm.org [accessed March 5, 2018]).

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