Large scale preparation of single chitin oligomers by the combination of homogeneous acid hydrolysis and reversed phase preparative chromatography

Chitin oligomers received increased research and commercial attention recently because of their many excellent biological activities. However, most of these studies were based on heterogeneous oligomer mixtures. In order to study systematically their structure-function relationships, it is essential to prepare highly purified chitin oligomers with single degree of polymerization (single chitin oligomers). In this study, firstly chitin oligomer compositions (CHOS) were prepared by homogeneous acid hydrolysis by using superfine grinded chitin (SFG-chitin) as the starting materials. The CHOS analysis using LC-MS indicated that the main component of composition was chitin oliogmers with 2–7 of polymerization. Afterwards, the CHOS were separated by preparative liquid chromatography based on silica-carbon composite materials, and five highly purified (71.3–96.4%) single chitin oligomers (GlcNAc)2–(GlcNAc)6 were obtained at gram scale. The preparation was performed in reversed phase chromatography mode with lower organic solvent consumption, which made it suitable for large scale preparation of single chitin oligomers.