Pristinamycin IIA is a naturally occurring Streptogramin A antibiotic component and one of the principal components of the pristinamycin antibiotic complex. It is also known as Virginiamycin M1, Mikamycin A, Ostreogrycin A, and Streptogramin A. Pristinamycin IIA works synergistically with Streptogramin B components such as Pristinamycin IA to inhibit bacterial protein synthesis.
Pristinamycin IIA is chemically distinct from Pristinamycin IA. The exact API described on this page is Pristinamycin IIA, CAS 21411-53-0, rather than the pristinamycin combination or Pristinamycin IA.
Pristinamycin IIA, CAS 21411-53-0, has the molecular formula C₂₈H₃₅N₃O₇ and molecular weight 525.60 g/mol. PubChem, ChEBI and other chemical databases identify it as a macrolide antibiotic belonging to the Streptogramin A subclass.
The compound is associated with Streptomyces pristinaespiralis, the microorganism responsible for production of pristinamycin. The pristinamycin complex contains Streptogramin A and B components that act synergistically against susceptible bacteria.
| Parameter | Details |
|---|---|
| Product Name | Pristinamycin IIA |
| Synonyms | Virginiamycin M1, Mikamycin A, Ostreogrycin A, Streptogramin A |
| CAS Number | 21411-53-0 |
| Molecular Formula | C₂₈H₃₅N₃O₇ |
| Molecular Weight | 525.60 g/mol |
| UNII | 8W4UOL59AZ |
| ChEBI | CHEBI:9997 |
| DrugBank | DB01669 |
| Compound Class | Macrolide antibiotic / Streptogramin A |
| Appearance | White to yellow / yellow-tan solid or powder, depending on reference material |
| Physical State | Solid |
| Solubility | Soluble in DMF and DMSO; slightly/partially soluble in ethanol and methanol; poorly soluble in water |
| Light Sensitivity | Light sensitive |
The identity and molecular characteristics are supported by PubChem and ChEBI, while commercial reference materials describe Pristinamycin IIA as a solid with the above solvent-solubility profile.
Pristinamycin IIA is a Streptogramin A component of pristinamycin and acts on bacterial protein synthesis through interaction with the bacterial 50S ribosomal subunit. Its activity is particularly important when combined with Streptogramin B components, producing synergistic antibacterial activity.
Pristinamycin IIA has been studied against Gram-positive bacterial organisms and is associated with activity against organisms including staphylococci and streptococci. The pristinamycin combination has also demonstrated activity against resistant Gram-positive organisms.
For analytical and pharmaceutical research, purified Pristinamycin IIA is used as an individual component/reference material for chromatographic identification, assay development, impurity profiling, pharmacological studies and research into streptogramin antibacterial mechanisms. Validated HPLC methods have been reported for analysis of pristinamycin and its components.
Pristinamycin IIA is a complex natural-product antibiotic, and publicly available sources do not establish a current universal USP/BP/Ph Eur API monograph with complete numerical release specifications for the isolated component. Therefore, numerical values below are clearly identified as commercial/reference-material specifications rather than pharmacopoeial limits.
| Detailed Specification | Value |
|---|---|
| Identification | Complies — HPLC / LC-MS / IR / NMR |
| Assay / Purity | NLT 95.0% by HPLC — commercial reference specification |
| LOD | N/A — no universal pharmacopoeial numerical limit publicly verified |
| Residue on Ignition | N/A — no universal pharmacopoeial numerical limit publicly verified |
| Heavy Metals | N/A — no universal pharmacopoeial numerical limit publicly verified |
| pH (1% Solution) | N/A — no verified universal API pH specification |
| Individual Impurity | N/A — no universal numerical limit verified |
| Total Impurities | N/A — no universal numerical limit verified |
| Water Content | N/A — no universal numerical API limit verified |
| Specific Rotation | −218° (D20, c=0.34, ethanol) — reported reference physical property |
| Melting Point | 165–167°C — reported reference physical property |
| Solubility | Soluble in DMSO/DMF; slightly soluble in ethanol/methanol; poorly soluble in water |
| Appearance | White to yellow / yellow-tan solid or powder |
Cayman Chemical lists ≥95% purity for Pristinamycin IIA/virginiamycin M1, while Sigma-Aldrich likewise lists Virginiamycin M1 at ≥95% HPLC. A commercial chemical reference reports a melting range of 165–167°C and specific rotation of −218° (D20, c=0.34, ethanol).
A separate highly purified research reference reports approximately 99% HPLC purity, demonstrating that higher-purity material is commercially available, but this should not be represented as a universal pharmacopoeial API assay requirement.
Pristinamycin IIA API can be manufactured and characterized as an individual Streptogramin A component using controlled analytical procedures. Quality control should emphasize identity confirmation, chromatographic purity, related-substance monitoring, residual solvents, moisture, microbial quality where applicable, and appropriate storage stability.
Analytical characterization can include HPLC/UPLC, LC-MS, IR, NMR and chromatographic impurity profiling. HPLC methods have specifically been developed for quantitative analysis of pristinamycin and its components, including Pristinamycin IIA.
Because Pristinamycin IIA is an individual component rather than the complete pristinamycin mixture, its specification and documentation should clearly identify CAS 21411-53-0 and distinguish it from Pristinamycin IA, Pristinamycin IIB and the pristinamycin combination.
Pristinamycin IIA should be packaged in well-closed, light-protective containers appropriate for pharmaceutical or analytical materials. Protection from excessive moisture, heat and light is recommended because available reference information identifies the material as light sensitive. Commercial research material is commonly stored under refrigerated or frozen conditions depending on formulation and intended use.
Recommended storage condition for controlled API/reference material: 2–8°C or validated frozen storage according to the applicable product stability data.
Typical pharmaceutical/API documentation may include:
Pristinamycin IIA requires accurate component identification because it is only one constituent of the broader pristinamycin antibiotic complex. A reliable manufacturing program should distinguish Pristinamycin IIA (CAS 21411-53-0) from Pristinamycin IA and the pristinamycin mixture, while maintaining controlled chromatographic purity and complete analytical documentation.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | Complies — HPLC / LC-MS / IR / NMR |
| Assay (HPLC) | NLT 95.0% by HPLC |
| Specific Rotation | −218° (D20, c=0.34, ethanol) — reported reference physical property |
| Melting Point | 165–167°C — reported reference physical property |