Chitosan oligosaccharide (COS) is a natural compound, a type of sugar chain, known for its unique biological properties. It consists of smaller sugar units, or oligomers, derived from a more complex substance. These short chains possess an average molecular weight below 5,000 Daltons. Unlike its larger precursors, COS is readily soluble in water, a feature that enhances its biological availability and activity in various applications.
From Shells to Soluble Fiber
The journey of chitosan oligosaccharide begins with chitin, a naturally abundant structural polymer. Chitin forms the rigid exoskeletons of crustaceans, such as shrimp and crabs, and is also found in the cell walls of fungi. To obtain chitosan, chitin undergoes a deacetylation process, which removes acetyl groups from its structure, transforming it into a linear polysaccharide.
Chitosan, while useful, is largely insoluble in water. Chitosan oligosaccharide is then produced by further breaking down chitosan through processes like chemical hydrolysis or enzymatic degradation. This depolymerization results in shorter chains of glucosamine and N-acetylglucosamine units, ranging from 2 to 20 monosaccharide units. The reduced chain length and free amino groups contribute to COS’s improved water solubility and lower viscosity compared to its parent compound. These properties, particularly its enhanced solubility, make COS more biologically active and versatile for various applications.
Agricultural and Environmental Roles
Chitosan oligosaccharide demonstrates versatile applications in agriculture and environmental management. In farming, COS functions as a natural biopesticide, helping plants defend against various pathogens. It triggers a plant’s innate defense mechanisms, enhancing its resistance to diseases caused by fungi, bacteria, and viruses. Beyond protection, COS also acts as a plant growth promoter, accelerating the development of roots, stems, leaves, and fruits, which can increase crop yield.
COS helps plants cope with environmental stresses like cold, drought, and high-salt conditions by stabilizing cell membrane structures and improving water absorption and retention. This enhances photosynthesis and strengthens the plant’s stress resistance. In environmental contexts, COS shows potential in water purification due to its strong adsorption properties. It effectively binds with harmful heavy metals, facilitating their removal from water systems.
Influence on Gut Microbiota and Digestion
Chitosan oligosaccharide plays a notable role in human health by influencing the gut microbiota. It acts as a prebiotic, a type of non-digestible carbohydrate that selectively stimulates the growth and activity of beneficial microorganisms in the colon. After ingestion, COS passes largely undigested through the upper gastrointestinal tract due to its resistance to human digestive enzymes.
Upon reaching the large intestine, COS becomes a fermentable food source for health-promoting gut bacteria. It encourages the proliferation of beneficial strains such as Bifidobacteria and Lactobacilli, while inhibiting the growth of harmful bacteria. This selective fermentation helps to rebalance and improve the gut microbiome, contributing to a healthier digestive environment. The positive impact on gut flora can also indirectly influence various metabolic activities within the host.
Biomedical and Cosmetic Functions
Beyond its impact on gut health, chitosan oligosaccharide exhibits direct biological effects on human cells and tissues, making it valuable in biomedical and cosmetic fields. COS possesses antioxidant properties, helping to neutralize harmful free radicals that contribute to cellular damage. It also demonstrates anti-inflammatory capabilities.
COS is incorporated into wound healing preparations due to its ability to promote cell proliferation and migration, facilitating tissue repair. Its antimicrobial properties also help create a protective environment for healing wounds. In cosmetic products, COS acts as an effective moisturizing agent, helping skin retain water. Its antimicrobial attributes further contribute to its use in lotions and creams, enhancing product stability and skin health.