Description

Circulin B CAS NO 20905-50-4 is a polypeptide antibiotic belonging to the polymyxin class, known for its potent bactericidal activity against Gram-negative bacteria. This compound is critical for research and development in microbiology and pharmaceutical sciences, particularly in studying antibiotic mechanisms and resistance. It serves as an essential tool for academic institutions, pharmaceutical R&D departments, and biotechnology companies focused on infectious disease research and novel antimicrobial discovery.

Application

• Antimicrobial Research: Used as a reference standard and active agent in microbiological studies to investigate its mechanism of action against Gram-negative pathogens like Pseudomonas aeruginosa and E. coli.
• Pharmaceutical Development: Serves as a key intermediate or model compound in R&D programs aimed at developing new polymyxin-derived antibiotics or combination therapies.
• Cell Biology Studies: Employed in laboratory research to study bacterial membrane disruption, outer membrane permeability, and the effects on lipopolysaccharides (LPS).
• Quality Control & Assay Standards: Acts as a certified reference material (CRM) in pharmaceutical quality control laboratories for potency testing and microbiological assay calibration.
• Academic & Institutional Research: Provides a critical reagent for university and institutional labs conducting fundamental research on antibiotic resistance and novel treatment strategies.

Basic Information

Product Name	Circulin B
CAS No.	20905-50-4
Molecular Formula	C58H98N16O13
Molecular Weight	~ 1203.5 g/mol
Synonyms	Circulin B; Antibiotic 136; Polymyxin P; Polymyxin P1; Circulin; Polypeptide antibiotic from Bacillus circulans; Bacillomycin P; [Dab1]Polymyxin B1; Cyclo[Dab-Dab-Dab-Dab-Dab-Dab-Thr-Dab-Dab-Dab] (cyclic decapeptide structure)
EINECS	Contact for details

Quality Control

Our Circulin B is produced and handled under strict quality management protocols. Each batch undergoes comprehensive analytical testing, including HPLC for purity and potency, to ensure it meets the high standards required for research applications. A detailed Certificate of Analysis (COA) is provided with every shipment, documenting identity, purity, and microbiological activity. We support compliance with relevant research and development guidelines.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); ensure the container is sealed tightly after each use to prevent absorption of atmospheric moisture. For long-term storage, consider desiccants or inert atmosphere.

Specification

Item	Specification
Appearance	White to off-white powder
Identification (IR)	Conforms to reference spectrum
Purity (HPLC)	≥ 95.0%
Potency (Microbiological Assay)	≥ 15,000 IU/mg
Water Content (KF)	≤ 5.0%
Residue on Ignition	≤ 1.0%
Bacterial Endotoxins	< 10.0 EU/mg

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.