Abstract
Hybrid κ-/μ-carrageenan, water-extracted from Kappaphycus alvarezzi, was incubated with Pseudoalteromonas carrageenovora κ-carrageenase. The five most abundant hybrid κ-/μ-carrageenan oligosaccharides were purified and their structure was determined by NMR and mass spectrometry. Since the enzyme-resistant fraction was small, these five oligosaccharides were representative of the distribution of the μ-carrabiose moieties along the carrageenan chain. Three main distributions of μ-carrabiose were found: -μ-, -μ-μ- and -μ-μ-μ-. Interestingly, the chemical shifts of the anomeric proton and carbon were strongly influenced by the identity of the adjacent carrabiose, which explains the asymmetrical D6S-H1 NMR signal that we observed. Although μ-carrabiose chemical shifts are usually attributed to blocks of μ-carrabiose as expected in ideal μ-carrageenan, we demonstrate that they are in fact due to μ-carrabiose units positioned between κ-carrabiose units. Using NMR and chromatography to monitor the alkaline conversion of μ- to κ-carrabiose, we found that the μ-carrabiose distribution (-μ-, -μ-μ-, -μ-μ-μ-) did not influence the conversion rate.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
