Chitosan Oligosaccharide

CAS No:	148411-57-8
EINECS No:	604-631-8
Synonyms:	Chitooligosaccharide, chitooligomer, chitosan oligos, COS, deacetylated chitin oligosaccharide, oligochitosan

Product Summary

Chitosan oligosaccharide (COS) is a low-molecular-weight, water-soluble derivative of chitosan with excellent biocompatibility, biodegradability, and bioactivity. Its small size and cationic nature enable superior solubility, improved bioavailability, and versatile functionality in biomedical, food, agricultural, and cosmetic research. Mechanistically, COS exerts its effects via electrostatic membrane disruption, metal ion chelation, antioxidant activity, and immune modulation. These properties make it a prominent subject in the development of drug delivery systems, natural antimicrobials, and bio-based functional materials.

Function

Unlike high-molecular-weight chitosan, COS is readily absorbed in the gastrointestinal tract due to its small molecular size. Composed of short chains of D-glucosamine units, COS is highly water-soluble. In acidic to neutral environments, its amino groups become protonated (–NH₃⁺), imparting a strong cationic charge that enables electrostatic interactions with negatively charged biological surfaces. This property allows COS to inhibit a broad spectrum of bacteria, fungi, and some viruses by disrupting cell membranes, chelating essential metal ions, and interfering with microbial metabolism. Beyond its antimicrobial effects, COS modulates inflammatory pathways, promotes the production of anti-inflammatory mediators, and enhances both innate and adaptive immunity by activating macrophages, dendritic cells, and natural killer cells.

Mechanism of Action

Electrostatic interaction with microbial membranes: Protonated amino groups (–NH₃⁺) in COS bind to negatively charged microbial cell walls and membranes, altering permeability and causing leakage of intracellular contents.
ROS scavenging & antioxidant effect: Chitosan oligosaccharide possesses free amino (–NH₂) and hydroxyl (–OH) groups, which can act as hydrogen or electron donors. These functional groups react with reactive oxygen species (ROS)—such as superoxide anion (O₂⁻•), hydroxyl radical (•OH), and hydrogen peroxide (H₂O₂)—neutralizing them before they can damage cellular components.
Immunomodulation: COS can act as an immune stimulant by interacting with pattern recognition receptors (PRRs), leading to the upregulation of pro-inflammatory cytokines (e.g., TNF-α, IL-1β, IL-6) and chemokines. COS also enhances macrophage phagocytic activity, stimulates the production of immunoglobulins (IgA, IgG) and activates natural killer (NK) cells. Through these combined actions, COS supports both innate immunity and adaptive immunity.
Chelation of metal ions: By binding essential metal cofactors (Fe²⁺, Zn²⁺, Cu²⁺), COS effectively starves microorganisms of essential nutrients, impairing growth and virulence. In addition to antimicrobial effects, the metal-binding ability of COS contributes to its antioxidant properties by limiting metal-catalyzed free radical generation via Fenton-type reactions.
Signal pathway modulation: COS is reported to influence NF-κB, MAPK, and other signaling pathways, leading to anti-inflammatory or anti-proliferative effects.

Applications in Scientific Research

Mucoadhesive drug delivery: COS exhibits strong adhesion to mucosal surfaces, and its excellent water solubility and biocompatibility make it ideal for use in oral tablets, nasal sprays, eye drops, and transdermal patches, enabling controlled or targeted drug release.
Gene therapyIn non-viral gene delivery, COS electrostatically complexes with DNA or RNA to form stable polyplexes, protecting nucleic acids from degradation and enhancing cellular uptake.
Wound healing: COS acts as both an antimicrobial and a hemostatic agent, reducing infection risk and promoting clot formation, tissue regeneration, and faster wound closure.
Food preservation: Serves as a natural antioxidant and antimicrobial agent, extending shelf life by preventing microbial growth and oxidative spoilage.
Prebiotic function: Supports beneficial gut microbiota, improving digestive health and nutrient absorption.
Functional food ingredient: Demonstrated potential in lowering cholesterol and improving lipid metabolism.
Plant immunity & growth stimulation: Enhances plant defense responses and stimulates growth through signaling pathway activation.
Biocontrol applications: Effective against various fungal and bacterial phytopathogens, reducing the need for synthetic pesticides.
Skin care applications: Used as a moisturizing and skin-repair additive in creams, serums, and masks; its antioxidant activity helps protect against oxidative stress, supporting anti-aging effects and improved skin barrier function.

Packaging & Storage

Sources: Produced by enzymatic hydrolysis or chemical depolymerization of chitosan
White to off-white powder
Storage: at room temperature, protect from moisture

References

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Aam BB, et al. 2010: Production of chitooligosaccharides and their potential applications in medicine, Mar Drugs. 8(5): 1482-517.
Naveed M, et al. 2019: Chitosan oligosaccharide (COS): An overview, Int J Biol Macromol. 129: 827-843.
Wang L, et al. 2024: Chitosan oligosaccharide improves intestinal homeostasis to achieve the protection for the epithelial barrier of female Drosophila melanogaster via regulating intestinal microflora, Microbiol Spectr. 12(4): e0363923.
Lan R, et al. 2024: Chitosan oligosaccharide improves intestinal function by promoting intestinal development, alleviating intestinal inflammatory response, and enhancing antioxidant capacity in broilers aged d 1 to 14, Poult Sci. 103(2): 103381.
Jeong S, et al. 2019: Chitosan oligosaccharide (GO2KA1) improves postprandial glycemic response in subjects with impaired glucose tolerance and impaired fasting glucose and in healthy subjects: a crossover, randomized controlled trial, Nutr Diabetes. 9(1): 31.
Jahan M, et al. 2022: Chitosan oligosaccharide supplementation affects immunity markers in ewes and lambs during gestation and lactation, Animals (Basel). 12(19): 2609.
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Chotphruethipong L, et al. 2023: Chitooligosaccharide from pacific white shrimp shell chitosan ameliorates inflammation and oxidative stress via NF-κB, Erk1/2, Akt and Nrf2/HO-1 pathways in LPS-induced RAW264.7 macrophage cells, Foods. 12(14): 2740.