It is a streptogramin group antibiotic, similar to virginiamycin, derived from the bacterium Streptomyces pristinaespiralis.

Each compound binds to the bacterial 50 S ribosomal subunit and inhibits the elongation process of the protein synthesis, thereby exhibiting only a moderate bacteriostatic activity.

However, the combination of both substances acts synergistically and leads to a potent bactericidal activity that can reach up to 100 times that of the separate components.

The pristinamycin biosynthetic gene cluster is the largest antibiotic supercluster known so far, with a size of ~210 kb, wherein the PI and PII biosynthetic genes are not clustered individually but are scattered across the complete sequence region.

Its usefulness for severe infections, however, may be limited by the lack of an intravenous formulation owing to its poor solubility.