Telithromycin is a semi-synthetic ketolide antibiotic, chemically related to macrolides like erythromycin. It is primarily utilized in pharmaceutical research and development as an intermediate or reference standard for studying antibacterial agents effective against respiratory tract infections caused by susceptible bacteria, including community-acquired pneumonia, acute bacterial sinusitis, and acute exacerbations of chronic bronchitis. Telithromycin inhibits bacterial protein synthesis by binding to domains II and V of the 50S ribosomal subunit, providing activity against penicillin-resistant and macrolide-resistant pathogens. This reagent is supplied as a white to off-white solid with a purity of ≥99%, confirmed by infrared spectrum and suitable for laboratory applications. Warning: For research use only; not intended for human or veterinary therapeutic use. Potential hazards include hepatotoxicity; handle with appropriate safety measures.