Ostreogrycin A (Mikamycin A, Pristinamycin IIA, Stephylo

Ostreogrycin A also commonly referred to as virginiamycin M1 or streptogramin A is the major component of the "virginamycin complex". In the 1950s this complex was independently discovered so many times the literature became highly confusing. Ostreogrycin A is a macrocyclic lactone antibiotic that acts syngeristically with the structurally unrelated cyclic depsipeptides more commonly known as the virginiamycins B (ostreogrycin B or streptogramin B) and S to inhibit peptide elongation. This is achieved by blocking formation of a peptide bond between the growing peptide chain (peptidyl-tRNA) linked to the 50S ribosome and aminoacyl-tRNA. Ostreogrycin A has proven to be highly active against Gram positive bacteria, particularly methicillin-resistant S. aureus. Solubility: Soluble in DMSO and DMF, partially soluble in methanol and ethanol, poorly soluble in water , Storage and Stability: Lyophilized powder may be stored at -20°C. Lyophilized product is stable for 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.