Antibiotics

Sterigmatocystin is a mycotoxin, which is a secondary metabolite primarily produced by certain species of the fungi Aspergillus and Bipolaris. This compound exhibits its mode of action by interfering with DNA, RNA, and protein synthesis, ultimately disrupting cellular processes. As a precursor to the well-known aflatoxins, sterigmatocystin shares a similar structure and exhibits carcinogenic properties.

Leptomycin B is a bacterial secondary metabolite, which is derived from the bacterium Streptomyces sp. This compound is a potent nuclear export inhibitor with a mechanism of action that targets and inhibits the export receptor CRM1 (Chromosomal Maintenance 1), also known as Exportin 1. By binding irreversibly to CRM1, Leptomycin B prevents the nuclear export of proteins and RNA, disrupting the nuclear-cytoplasmic transport essential for cell function.

Doripenem is a carbapenem antibiotic with action on bacterial cell wall synthesis and is used for treating complicated bacterial infections like intra-abdominal infections and urinary tract infections.

Natamycin is a polyene macrolide antifungal agent with action on fungal cell membranes by binding to sterols and is used for treating fungal infections and as a food preservative.

Ceftobiprole medocaril sodium is a broad-spectrum cephalosporin antibiotic, which is a synthetically derived prodrug of ceftobiprole. Upon administration, ceftobiprole medocaril is rapidly converted into its active form, ceftobiprole, by the body's endogenous esterases. The mode of action involves binding to penicillin-binding proteins (PBPs) in the bacterial cell wall, leading to the inhibition of cell wall synthesis and ultimately the death of the bacteria. This action is effective against a wide range of gram-positive and gram-negative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae.

Doxorubicin Impurity 2 is a chemical impurity of doxorubicin with no direct therapeutic action but used in research and quality control.

Erythromycin C is a macrolide antibiotic, which is a type of product derived from the bacterium *Saccharopolyspora erythraea*. It functions by binding to the 50S subunit of the bacterial ribosome, inhibiting protein synthesis through blocking translocation of peptidyl-tRNA. This mode of action effectively prevents bacterial growth and replication, making it a potent bacteriostatic agent.

Oleandomycin is a macrolide antibiotic, which is derived from the bacterium *Streptomyces antibioticus*. This antibiotic functions by binding to the 50S subunit of the bacterial ribosome, thereby inhibiting protein synthesis. The interruption of this essential process ultimately leads to the cessation of bacterial growth and replication.