Enzymatic degradation of hybrid ι-/ν-carrageenan by Alteromonas fortis ι-carrageenase Original Research Article

Hybrid ι-/ν-carrageenan was water-extracted from Eucheuma denticulatum and incubated with Alteromonas fortis ι-carrageenase. The degradation products were then separated by anion-exchange chromatography. The three most abundant fractions of hybrid ι-/ν-carrageenan oligosaccharides were purified and their structures were analyzed by NMR. The smallest hybrid was an octasaccharide with a ι-ι-ν-ι structure. The second fraction was composed of two decasaccharides with ι-ι-ι-ν-ι and ι-[ι/ν]-ι-ι structures. The third fraction was a mixture of dodecasaccharides which contained at least a ι-ι-ι-ι-ν-ι oligosaccharide. The carbon and proton NMR spectra of the octasaccharides were completely assigned, thereby completely attributing the ν-carrabiose moiety for the first time.