Purification and Characterisation of κ-Carrageenan Oligosaccharides Prepared by κ-Carrageenase from Thalassospira sp. Fjfst-332

• Published in: Carbohydrate polymers Vol. 180; pp. 314 - 327
• Main Authors: Guo, Juanjuan, Zheng, Zhichang, Lu, Xu, Zeng, Shaoxiao, Chen, Chi, Zhang, Longtao, Zheng, Baodong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.01.2018
• Subjects: Anti-inflammatory; MPLC-ELSD; ROS; Structure-function relationship; κ-Carrageenan oligosaccharides; Anti-inflammatory; Structure-function relationship; κ-Carrageenan oligosaccharides; MPLC-ELSD; ROS
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2017.10.043

•MPLC-ELSD is a macroscopic flash chromatography system for κ-carrageenan oligosaccharides.•Separation of KCOs by MPLC-ELSD was optimized and a high level of purity was achieved.•The structural sequence of each KCO was clearly determined.•Anti-inflammatory activity of KCOs with various Dp and sulfate groups was compared. κ-Carrageenan oligosaccharides (KCOs) are promising agents for treating inflammatory diseases. However, the lack of purification and structural elucidation of KCOs has limited structure-function evaluation. In this study, using a system coupling medium pressure liquid chromatography (MPLC) with an evaporative light scattering detector (ELSD), four types of KCOs were separated. The total yield of the four KCO powders was ∼5.02% after purification (KCOs/κ-carrageenan, w/w). Their structural identities were characterised by ESI-MS, CID-MS/MS and NMR, as κ-neocarrabiose (α-DA-1,3-G4Srα/β), κ-neocarratetraose (α-DA-1,3-β-G4S-1,4-α-DA-1,3-G4Srα/β), κ-neocarrahexaose (α-DA-1,3-β-G4S-1,4-α-DA-1,3-β-G4S-1,4-α-DA-1,3-G4Srα/β) and heterozygous κ/ι-neocarrahexaose (α-DA/DA2S-1,3-β-G4S-1,4-α-DA-1,3-β-G4S-1,4-α-DA-1,3-G4Srα/β). KCOs showed no cytotoxicity in RAW264.7 macrophages, and the anti-inflammatory activity was closely correlated with the degree of polymerisation and the number of sulfated groups. κ/ι-Neocarrahexaose exhibited the highest inhibition of ROS (Reactive Oxygen Species) production in LPS-induced RAW264.7 macrophages. The MPLC-ELSD system provides a platform for large-scale fabrication of purified KCOs and affords a route to these compounds that may regulate immune defense.