The macrocyclic lactone ring is the basis of the chemical structure of all macrolide antibiotics. Classification involves the division into 14, 15 and 16-membered. These antibiotics are considered the least toxic.
Macrolides. Classification by type of origin
Natural macrolides:
Macrolide "Erythromycin" is the first bacteriostatic antibiotic that laid the foundation for a large group. It was obtained in 1952 from Streptomyces erythreus - soil actinomycete. Due to the fact that the erythromycin macrolide has the property of reversibly binding to the ribosomal 50S subunit, it disrupts the formation of peptide bonds between amino acid molecules and blocks protein synthesis of various microorganisms. Moreover, the antibiotic "Erythromycin" does not affect the synthesis (compound) of nucleic acids. In large doses, it can have a bactericidal effect on certain types of bacteria.
Spiramycin macrolide is an antibiotic derived from actinomycete Streptomyces ambofaciens, it is the first representative of the 16-membered macrolide group. The lactone ring is the structural basis of Spiramycin. It consists of 16 carbon atoms (C), to which 3 carbohydrate residues are attached: mycrosis, forosamine and mycaminosis. Preparations containing the active substance spiramycin, are common in Canada, Latin America and Europe.
Macrolide "Josamycin" is an antibiotic, a member of the 16-membered macrolide group. Produced by Streptomyces narbonensis. It has a bactericidal effect. It inhibits the synthesis of protein compounds, prevents the fixation of RNA (transport) and binds to the 50S subunit of the ribosomal membrane, thereby blocking the exchange of peptides from center A. It is allowed in the treatment of diseases during pregnancy.
Semi-synthetic macrolides:
Macrolide Roxithromycin is the first semi-synthetic 14-membered atibiotic. It was obtained from the erythromycin macrolide. Features of the structure give it higher resistance to acids, improved microbiological and pharmacokinetic parameters.
Clarithromycin Macrolide is a 14-membered antibiotic derived from the erythromycin macrolide. It has increased resistance to acids and improved pharmacokinetic and antibacterial properties.
Natural macrolide antibiotics are highly active against gram-positive, some gram-negative and intracellular microorganisms. And such modern macrolides as semi-synthetic ones are more active against pseudomonads, enterobacteria, anaerobic microflora and influenza bacillus.
And finally, azalides are macrolides of the latest generation:
The antibiotic "Azithromycin" refers to a subclass of azalides, which differ somewhat in structure from ordinary macrolides. The ring at the macrolide "Azithromycin" is not lactone, but 15-membered. Acid resistance in this case increases by 300 times compared with the antibiotic Erythromycin.
Macrolides. Generational classification:
1st - preparations "Oleandomycin", "Erythromycin";
2nd - macrolides "Roxithromycin", "Spiramycin", "Josamycin", "Midecamycin", "Clarithromycin";
3rd - macrolide "Azithromycin".
Indications for the use of antibiotics of the macrolide group. Classification by disease
Those that affect the respiratory system: acute sinusitis, streptococcal tonsillopharyngitis, community-acquired pneumonia, exacerbation of bronchitis, whooping cough, diphtheria.
Skin and soft tissues: syphilis, chlamydia, venereal lymphogranuloma, soft chancre, acne.
Oral cavity: periostitis and periodontitis.
Digestive system: campylobacter gastroenteritis, gastric ulcer.
Macrolides are also used to prevent the following diseases: whooping cough, meningitis, rheumatism, endocarditis.