What Is Chitosan Oligosaccharide (COS) Agricultural Elicitor? Applications, Dosage, Alternatives & Specifications

Chitosan Oligosaccharide (abbreviated as COS), also known as Chitosan Oligomer, Low Molecular Weight Chitosan, Chitooligosaccharide, and Agricultural Aminoglycan, is a natural oligosaccharide product obtained by degrading chitin or chitosan, with a degree of polymerization (DP) between 2 and 20. It is produced from abundant marine biological resources (shrimp and crab shells) through decalcification and deproteinization to obtain chitin, deacetylation of chitin to obtain chitosan, and then degradation of chitosan through biological enzymatic hydrolysis (or chemical degradation, physical degradation, and other methods). Chitosan oligosaccharide is the only cationic alkaline amino oligosaccharide carrying a positive charge in nature, known as “animal cellulose,” and is an upgraded product of chitin and chitosan products. In biological systems, chitin has a molecular weight of ≥1000 kDa, is insoluble in water and general acid and alkaline solutions, and is almost not absorbed by the body; chitosan has a molecular weight of ≥100 kDa, is only soluble in dilute acid solutions, with 1–3% absorption; while chitosan oligosaccharide has a molecular weight of ≤3000 Da, is easily soluble in water and acid and alkaline solutions, with over 99% absorption by the body. Chitosan oligosaccharide possesses unique functions such as the high solubility that chitosan lacks, complete water solubility, easy absorption and utilization by living organisms, with its effect being 14 times that of chitosan. Chitosan oligosaccharide products are available in various forms, including different degree of polymerization specifications (chitobiose to chitoeicosaose, etc.), different molecular weight specifications (≤3000 Da), different purity grades (agricultural grade, food grade, cosmetic grade, pharmaceutical grade), as well as powder and liquid formulations.

Chitosan oligosaccharide is an oligosaccharide composed of 2–20 glucosamine units connected by β-1,4 glycosidic bonds. Its molecular formula can be expressed as (C6H11NO4)n (n=2–20), and its chemical name is β-(1,4)-2-amino-2-deoxy-D-glucan. The main activity of chitosan oligosaccharide depends on its degree of polymerization distribution, degree of deacetylation, and molecular weight. Based on its molecular structure, it can be divided into three types: α, β, and γ. Typically, a degree of deacetylation ≥85% is considered chitosan oligosaccharide, while a degree of deacetylation ≤15% is considered chitin oligosaccharide. Parameter

Chitosan oligosaccharide is known as the “king of marine bioactive substances” and occupies an important position in the global natural functional ingredient market. Its most prominent core advantages include: safety assurance from natural sources, unique structure with good water solubility and high biological activity, multi-component synergistic comprehensive health benefits, regulatory flexibility of being both medicinal and edible, excellent processing adaptability, and continuously expanding global market demand.