Access to N-Acetylated Chitohexaose with Well-Defined Degrees of Acetylation

Abstract

Chitohexaose has attracted wide interest due to its special bioactivities and these potential activities are significantly related to N-acetylation. Herein, six chitohexaose fractions with different degrees of acetylation were prepared by selective N-acetylation and ion-exchange chromatography and further analyzed by ESI/MS. It is revealed that all the six N-acetylated chitohexaoses were of single molecular weight, the molecular weights of which were exactly assigned to 1026.44 Da, 1068.44 Da, 1110.48 Da, 1152.48 Da, 1194.49 Da, and 1236.48 Da, respectively. These results suggested that the six prepared N-acetylated chitohexaoses were N-acetylchitohexaose (D5A1), di-N-acetylchitohexaose (D4A2), tri-N-acetylchitohexaose (D3A3), tetra-N-acetylchitohexaose (D2A4), penta-N-acetylchitohexaose (D1A5), and hexa-N-acetylchitohexaose (A6), respectively, which are of great significance to screen their bioactivities and discover well-defined chitooligosaccharide molecules as potential drugs.

Chitin and Chitosan Fragments Responsible for Plant Elicitor and Growth Stimulator

“…The separation of a homogeneous oligosaccharides series of chitin and chitosan is relatively easy, which could be achieved by size exclusion chromatography but with a small loading sample. , Considering the cationic property of chitosan oligosaccharides, ion-exchange chromatography takes advantage of large sample load and high resolution and is efficient to separate glucosamine oligomers . Ion-exchange chromatography could also be applied for the preseparation of heterogeneous GlcN/GlcNAc oligosaccharides according to their numbers of amino group, such as D 5 A 1, D 4 A 2, D 3 A 3, D 2 A 4, and D 1 A 5 . Concerning specific GlcN/GlcNAc sequences, enzymatic deacetylation is a potential alternative before the application of advancing separation techniques, because chitin deacetylases allows for a controlled process resulting in an oligosaccharide with well-defined patterns of acetylation .…”

“…Chitosan could be classified by molecular weight (MW), degree of polymerization (DP), degree of acetylation (DA), and pattern of acetylation (PA). , This heterogeneity greatly affects the physicochemical properties of chitosan, thus governing its biological applications. , Therefore, which fragments are responsible for the observed biological effects of chitin and chitosan is a matter of continuing concern. In recent years, with the rapid development of separation and purification technology, more and more chitin and chitosan fragments with well-defined structures are available and used for bioassays to understand the biological roles of chitin and chitosan. − Herein, we review the current and ongoing research on the structure–function relationship of chitin and chitosan fragments in the field of agriculture, such as eliciting plant immunity, inducing plant resistance against abiotic stress, promoting plant growth, and activating symbiotic signaling between plant and beneficial microbes. The preparation of chitin and chitosan fragments and their action mode for plant protection and growth (strengthening) are also discussed.…”

Effect of chitin and chitosan hexamers on growth and photosynthetic characteristics of wheat seedlings

“…The selective N-acetylation of chitosan hexamer was performed according to previous method (Li et al 2017). Briefly, 30 mg of chitosan hexamer was dissolved in 5 mL of a methanol/ water (50:50, v/v) solution.…”

Characterization of the Specific Mode of Action of a Chitin Deacetylase and Separation of the Partially Acetylated Chitosan Oligosaccharides

“…Due to its special biological activity, partially acetylated chitosan oligosaccharides have attracted wide interest, and these potential activities are significantly correlated with the degree of polymerization and degree of acetylation of chitooligosaccharides [ 14 , 42 ]. However, the method of preparing and isolating high-purity chitooligosaccharides is time consuming and labor intensive, which severely limits the large-scale production of partially acetylated chitooligosaccharides [ 43 ].…”