16 Questions
Which antibiotic binds reversibly to the 30S subunit, blocking the binding of tRNA to the acceptor site on the mRNA-ribosome complex?
Tetracyclines
What is the chemical structure of tetracyclines?
octahydronaphthacene ring as a scaffold
How does resistance to tetracyclines develop?
Preventing accumulation of the drug inside the bacterial cell
What type of activity do tetracyclines exhibit?
Broad spectrum of activity (Gram + and Gram -, protozoa, ricketsie)
Which region of the tetracycline structure carries out chelation of divalent atoms by c11 and c12 oxygen atoms?
Metal ion binding region
What predominates at physiological pH in the structure of tetracycline?
Zwitterionic tetracycline
Which modification makes the drug more water soluble and prone to hydrolysis in vivo?
Aminoalkylation of N
What renders the drug inactive or produces toxic products due to a photochemical reaction?
Metal ion binding face modification
What is the impact of the presence of 5-OH on the drug?
Affects pharmacokinetics but not activity
What is the effect of the removal of the tertiary amine substituent on the drug's activity?
Reduces activity
Which generation of tetracycline is more stable to acidic pH due to the absence of C6-OH?
3rd generation
What is the role of Mannich reaction in tetracycline derivatives?
Increases water solubility and hydrolysis in vivo
What characteristic is associated with semisynthetic tetracyclines analogues such as doxycycline and minocycline?
Oral administration
What are tetracycline derivatives like Rolitetracycline and Mepicycline known for?
Low toxicity but high G.I side effects
What is the impact of adding small alkyl groups to tetracycline?
Reduces activity
What is the role of aminoalkylation of the amide nitrogen in tetracycline derivatives?
Increases water solubility and hydrolysis in vivo
Test your knowledge of antibiotics that inhibit protein synthesis in bacterial ribosomes. Explore topics like Tetracyclines, Aminoglycosides, Macrolides, Streptogramins, Lincosamides, Chloramphenicol, Fusidic acid, and Oxazolidinones.
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