Omiganan Pentahydrochloride | CAS 269062-93-3 | Cationic Antimicrobial Peptide (Research Use Only) | Knowlux

Product Description

Omiganan Pentahydrochloride, CAS 269062-93-3, is a synthetic 12-amino-acid cationic antimicrobial peptide corresponding to the pentahydrochloride salt of Omiganan, supplied by Knowlux for laboratory research use. The sequence is H-Ile-Leu-Arg-Trp-Pro-Trp-Trp-Pro-Trp-Arg-Arg-Lys-NH2, with a C-terminal lysinamide and five hydrochloride counter-ions. The molecular formula is C90H132Cl5N27O12 and the molecular weight is 1961.45 g/mol on the pentahydrochloride basis. Each lot is released with a lot-specific COA, MSDS and analytical traceability.

Salt Form and Free Peptide Distinction: Omiganan circulates in commercial catalogues as two distinct chemical entities that are frequently conflated, and the distinction is the single most consequential procurement variable for this product. CAS 269062-93-3 is the pentahydrochloride salt, with formula C90H132Cl5N27O12 and MW 1961.45, as confirmed by the USAN Council statement, the National Cancer Institute, MedChemExpress, PeptideDB, Creative Peptides, Adooq, and InvivoChem. CAS 204248-78-2 is the free peptide, with formula C90H127N27O12 and MW 1779.15, as listed by DrugBank, MedChemExpress, InvivoChem, ApexBio, and NCIt. A trifluoroacetate salt of Omiganan also exists under the free-base CAS, with formula C92H128F3N27O14 and MW 1893.17, as listed by AbMole. Some ChemicalBook listings apply CAS 269062-93-3 to material described as containing the free-peptide formula C90H127N27O12 and a molecular weight in the 1779-1815 range, which is chemically inconsistent with a pentahydrochloride salt; these entries conflate the free peptide and the pentahydrochloride registries. Knowlux specifies the salt form, counter-ion identity, and peptide content per lot on the COA. Buyers should confirm whether the quoted material is the pentahydrochloride salt (MW 1961.45) or the free peptide (MW 1779.15) before procurement, as the pentahydrochloride carries approximately 182 g/mol of additional HCl mass relative to the free base.

Structural and Mechanistic Note: Omiganan is a synthetic analogue of indolicidin, a tryptophan-rich antimicrobial peptide originally purified from the cytoplasmic granules of bovine neutrophils. The sequence retains the Trp-Pro-Trp-Trp-Pro-Trp motif that is characteristic of the indolicidin family, and the peptide is amidated at the C-terminus. Unlike the disulfide-constrained peptides in the Linaclotide, Plecanatide, and Ziconotide families, Omiganan is linear, contains no cysteine, and has no intramolecular cross-link. The peptide contains no methionine, which removes methionine sulfoxide formation as a degradation pathway; the principal structural liability is the high Trp content (four residues), which creates a strong UV absorbance at 280 nm and makes Trp oxidation the relevant oxidative consideration under forced conditions.

Product Parameters

Item	Specification
Product Name	Omiganan Pentahydrochloride
Synonyms	MBI-226; MX-226; ILRWPWWPWRRK-NH2 pentahydrochloride
CAS No.	269062-93-3 (pentahydrochloride); 204248-78-2 (free peptide)
Molecular Formula	C90H132Cl5N27O12 (pentahydrochloride); C90H127N27O12 (free peptide)
Molecular Weight	1961.45 g/mol (pentahydrochloride); 1779.15 g/mol (free peptide)
Sequence (1-letter)	ILRWPWWPWRRK-NH2
Sequence (3-letter)	H-Ile-Leu-Arg-Trp-Pro-Trp-Trp-Pro-Trp-Arg-Arg-Lys-NH2
Sequence Length	12 amino acids, linear
Key Structural Features	Trp-rich indolicidin-like motif; C-terminal Lys-NH2; pentahydrochloride counter-ion; no cysteine, no disulfide, no methionine
Appearance	White to off-white powder
Solubility	Free peptide: DMSO >=44.3 mg/mL, ethanol >=44.3 mg/mL, water >=21.9 mg/mL (see Solubility section); pentahydrochloride salt data supplier-declared
Purity	>=95.0% to >=99.0% (HPLC; supplier-dependent)
Identity	Confirmed by LC-MS and HPLC
Grade	Research grade
Counter-ion	Hydrochloride (pentahydrochloride, lot-specific)
Peptide Content	>=75.0% to >=80.0% (supplier-dependent)
Water Content	<=8.0% (supplier specification)
Single Impurity	<=2.0% (HPLC; <=1.0% available)
Bacterial Endotoxins	<=50 EU/mg (supplier specification)
Amino Acid Composition	+/-10% to +/-15% of theoretical
Storage	See Storage and Stability section
Packaging	1 mg / 5 mg / 10 mg / 25 mg / 50 mg / 100 mg vial; bulk on request
Application	Laboratory research use only
Origin	China

Product Details

1. Overview

Omiganan pentahydrochloride (formerly MBI 226, also designated MX-226) is a topical cationic antimicrobial peptide developed for the prevention of catheter-related bloodstream infections and investigated for acne and other skin infections. It is a synthetic 12-amino-acid analogue of indolicidin, a Trp-rich peptide isolated from bovine neutrophil cytoplasmic granules, and it exhibits broad-spectrum activity against gram-positive bacteria, gram-negative bacteria, and fungi, including Candida species. The peptide is rapidly microbicidal and acts primarily by interacting with and disrupting the bacterial cytoplasmic membrane; in Staphylococcus aureus it depolarizes the cytoplasmic membrane, leading to cell disruption and death, and it also produces dose-dependent inhibition of whole-cell protein, RNA, and DNA synthesis. In Escherichia coli, exposure results in outer membrane permeabilization. The material supplied under this specification is research-grade and is not intended for human administration.

2. Antimicrobial Spectrum and Mechanism

The antimicrobial activity of Omiganan pentahydrochloride has been characterized against large clinical isolate panels. The pivotal in vitro study tested 1,437 recent clinical bacterial isolates and 214 recent clinical yeast isolates; minimal bactericidal concentrations (MBCs) and minimal fungicidal concentrations (MFCs) were either equal to or two- to fourfold higher than the corresponding MICs, and kill-curve experiments showed a clear pattern of bactericidal activity. The peptide is described as a cationic peptide that interacts with the bacterial cell membrane, causing membrane destruction and bacterial death, and it is active against strains with drug-resistant phenotypes associated with catheter-associated infections. Because Omiganan's mechanism is membrane-directed rather than target-specific, resistance development through single-point target mutations is less likely than for conventional antibiotics, although membrane adaptation mechanisms are not excluded. The peptide's activity is retained against both gram-positive and gram-negative organisms, and it is also fungicidal against Candida spp. These descriptions are derived from published research and are provided for scientific reference only.

3. Research Applications

Published pharmacological characterizations and documented protocols describe the following research applications:

• Antimicrobial susceptibility testing and MIC/MBC determination against gram-positive, gram-negative, and fungal clinical isolates

• Membrane permeabilization and cytoplasmic membrane depolarization studies (Staphylococcus aureus, Escherichia coli)

• Catheter-related bloodstream infection prevention research models

• Acne and topical skin infection research contexts

• Bacterial resistance profiling against drug-resistant phenotypes

• Structure-activity relationship studies of Trp-rich indolicidin analogues

• Reference standard development for HPLC and LC-MS analytical methods

These descriptions are derived from published research and are provided for scientific reference only.

Quality Control

Test Item	Method	Acceptance Criteria
Purity	RP-HPLC	>=95.0% (entry grade); >=98.0% (standard grade); >=99.0% (high-purity grade)
Identity	LC-MS and HPLC	Consistent with structure (1961.45 +/- 1 for pentahydrochloride)
Single Impurity	RP-HPLC	<=2.0% (entry grade); <=1.0% (higher grade)
Peptide Content	Nitrogen analysis or AAA	>=75.0% to >=80.0% (supplier-dependent)
Water Content	Karl Fischer	<=8.0%
Amino Acid Composition	AAA	+/-10% to +/-15% of theoretical
Bacterial Endotoxins	LAL or chromogenic	<=50 EU/mg
Appearance	Visual	White to off-white powder

Purity specifications for Omiganan pentahydrochloride span the 95% to 99% range depending on supplier and grade. BOC Sciences specifies 98% by HPLC. ChemicalBook supplier listings from Hangzhou Gotop specify HPLC purity >=98.0%, single impurity <=2.0%, peptide content >=75.0%, water content <=8.0%, amino acid composition within +/-15%, and endotoxin <=50 EU/mg. A second ChemicalBook supplier entry tightens several of these limits: HPLC >=98.0%, water content <=8.0%, peptide content >=80.0%, endotoxin <=50 EU/mg, and amino acid composition within +/-10%. Adooq and MolCore specify >98% and NLT 98%, respectively. SciPeptide lists >=95% as an entry grade. The principal quality consideration is the salt-form ambiguity discussed in the Product Description: a lot reported at MW 1961.45 is on the pentahydrochloride basis, whereas a lot at MW 1779.15 is on the free-peptide basis. Researchers preparing molar solutions should use the peptide content value and the declared salt basis rather than the HPLC purity figure alone.

Solubility and Handling

Solubility: Solubility data for the pentahydrochloride salt are limited in the sourced literature, and the numeric values that are available are reported for the free peptide rather than the pentahydrochloride. ApexBio reports free-peptide solubility of >=44.3 mg/mL in DMSO, >=44.3 mg/mL in ethanol, and >=21.9 mg/mL in water at 25C. ChemicalBook supplier listings declare solubility as H2O/DMSO without a numeric limit for the pentahydrochloride material. The pentahydrochloride salt is expected to be more water-soluble than the free peptide because the five hydrochloride counter-ions increase ionic character, but a numeric pentahydrochloride solubility value was not identified in the sourced data. For practical stock preparation, DMSO is the solvent with the most consistent numeric support (>=44.3 mg/mL for the free peptide), and water is viable at >=21.9 mg/mL on a free-peptide basis; the pentahydrochloride salt should be expected to meet or exceed the aqueous value. Prepare solutions fresh and aliquot to avoid repeated freeze-thaw cycles.

Handling Precautions: Use powder-handling containment (glove box or fume hood with particulate control). Avoid inhalation of fine powder. Wear nitrile gloves, lab coat, and eye protection. Because the peptide contains no cysteine or methionine, reducing agents and methionine-oxidation protection measures are not required. The high Trp content makes the peptide strongly UV-absorbing at 280 nm, which is useful for concentration determination but also means Trp oxidation should be considered under forced degradation conditions. The lyophilized powder is hygroscopic; equilibrate vials to room temperature before opening.

Storage and Stability

Format	Temperature	Shelf Life
Lyophilized Powder	-20C, sealed, desiccated	3 years (InvivoChem, Creative Biolabs, Adooq)
Lyophilized Powder	4C, sealed, desiccated	2 years (InvivoChem, Creative Biolabs)
Lyophilized Powder	-80C, sealed, desiccated	2 years (MedChemExpress)
Reconstituted Solution	-80C, aliquoted, sealed	6 months (InvivoChem, MedChemExpress)
Reconstituted Solution	-20C, aliquoted, sealed	1 month (InvivoChem, MedChemExpress); 6 months (Adooq)

Storage guidance for Omiganan pentahydrochloride converges on -20C for the lyophilized powder as the standard long-term condition, with 4C acceptable for shorter-term storage and -80C as the conservative archival option. InvivoChem specifies 3 years at -20C and 2 years at 4C for powder, with solutions stable for 6 months at -80C or 1 month at -20C. Creative Biolabs specifies >98% purity with 2 years at 4C or 3 years at -20C for the powder. Adooq specifies 3 years at -20C for powder and 6 months at -20C for solutions. MolCore specifies 2 years at 20C. ChemicalBook supplier listings from Hangzhou Gotop specify -20C under freeze-dried, light-protected conditions. The lyophilized powder is hygroscopic; equilibrate vials to room temperature before opening to prevent condensation. Protect from light and moisture throughout storage.

Documentation Support

Per lot: COA, MSDS, HPLC chromatogram, and mass spectrometry data. Salt-form identity, counter-ion content, and peptide content available on request. Custom specifications and third-party inspection can be arranged on a project basis.

About Knowlux

Knowlux Biotechnology is a GMP-oriented manufacturer and supplier of peptides, APIs and fine-chemical research compounds, operating from Hubei, China. We serve research groups, CDMOs and distributors in more than 40 countries, and support contract synthesis, custom packaging and technical documentation requests.

Compliance Statement

FOR RESEARCH USE ONLY. NOT FOR HUMAN USE. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE.

This product is supplied for laboratory research use only. It is not for human or animal administration, not for diagnostic or therapeutic use, not for retail sale, and not for personal use. Omiganan Pentahydrochloride has been investigated in clinical trials for catheter-related bloodstream infection prevention and topical skin infections but is not approved as a medicinal product in the United States or the European Union; the material offered under this specification is research-grade and is not intended for clinical use. The purchaser is responsible for verifying product specifications against their specific research requirements and for compliance with all applicable institutional, local, and national regulations governing research chemical acquisition, storage, and use. Research context statements are for scientific reference only and do not constitute medical advice, promotional claims, or dosing guidance.

Data Verification Notes

The pentahydrochloride formula C90H132Cl5N27O12 and MW 1961.45 are confirmed by the USAN Council statement (which renders the formula as C90H127N27O12.5HCl and MW 1961), the National Cancer Institute (C90H127N27O12.5HCl), MedChemExpress (C90H132Cl5N27O12, 1961.45), PeptideDB (C90H132Cl5N27O12, 1961.45), Creative Peptides (C90H132Cl5N27O12, 1961.4), Adooq (C90H132Cl5N27O12, 1961.45), MolCore (C90H132Cl5N27O12, 1961.45), and InvivoChem (C90H132Cl5N27O12, 1961.45). The free peptide CAS 204248-78-2, formula C90H127N27O12, and MW 1779.15 are confirmed by DrugBank, MedChemExpress, InvivoChem, ApexBio, and NCIt. The TFA salt formula C92H128F3N27O14 and MW 1893.17 are from AbMole. ChemicalBook supplier listings that pair CAS 269062-93-3 with molecular weights of 1815.64 or 779.14 are chemically inconsistent with the pentahydrochloride salt and are treated as data entry or formula-field errors; the 779.14 figure is a decimal-shift artifact of 1779.14. The indolicidin origin and the bovine neutrophil granule source are from the Antimicrobial Agents and Chemotherapy paper. The MIC/MBC/MFC and kill-curve data are from the same paper. The membrane depolarization and macromolecule synthesis inhibition data are from the AAC paper as cited in the abstract. The solubility values (DMSO >=44.3 mg/mL, ethanol >=44.3 mg/mL, water >=21.9 mg/mL) are from ApexBio and are explicitly for the free peptide. Storage guidance divergence (-20C versus -80C for powder; 1 month versus 6 months for -20C solutions) is reported as-is; the -20C powder condition is the most widely supported archival temperature, and -80C is presented as the conservative option.

Formatting Note: All formulas, sequences, and comparison operators use plain ASCII notation to prevent character corruption on the platform. Section headings, table alignment, and spacing follow the approved product detail pattern. No trailing spaces or non-breaking characters are used; tables use consistent pipe alignment.