Джозамицин

Josamycin is a macrolide substance having antibacterial activity produced by the growth of Streptomyces narboensis var. josamyceticus.
Josamycin appears as white to yellowish white powder, slightly hygroscopic. Josamycin is very soluble in methanol or in ethanol, and very slightly soluble in water.

As a 16-membered ring macrolide antibiotic with antimicrobial activity against a wide range of pathogens. Josamycin can be particularly used in the treatment of Mycoplasma infection.
Josamycin is used to study the modification of phagocytosis and cytokine production by macrolide antibiotics, immunomodulatory effects, the suppression of matrix metalloproteinase production as well as study bacteria protein synthesis at the level of the the 23S rRNA, 50S ribosomal subunit.

ChEBI: A macrolide antibiotic produced by certain strains of Streptomyces narbonensis var. josamyceticus.

A naturally occurring antibiotic produced by Streptomyces narbonensis var. josamyceticus and belonging to the leucomycin group of macrolides. It is formulated for oral administration.
Many Gram-positive and Gram-negative anaerobes are susceptible, including Peptostreptococcus spp., Propionibacterium spp., Eubacterium spp. and Bacteroides spp.
After a single 1 g oral dose, a peak serum concentration of 2.74 mg/L was achieved 0.75 h after dosing. The AUC was 4.2 mg.h/L, and the apparent elimination half-life 1.5 h. Several inactive metabolites could be detected. It penetrates into saliva, tears and sweat, and achieves high levels in bile and lungs. It is mostly metabolized and excreted in the bile in an inactive form. Less than 20% of the dose appears in the urine, producing levels of around 50 mg/L.
The drug is generally well tolerated, producing only mild gastrointestinal disturbance. Its uses are similar to those of erythromycin. It is of limited availability.

Josamycin inhibits bacterial protein biosynthesis by inhibiting peptidyltransferase and ribosomal translocation, and depleting the intracellular pools of aminoacyl-tRNAs available for protein synthesis by drop-off and incomplete peptidyl-tRNA hydrolase activity. It slows down formation of the first peptide bond of a nascent peptide in an amino acid-dependent way and inhibits formation of the second or third peptide bond.