Sh. Knutsen et al., MODIFIED PROCEDURES FOR EXTRACTION AND ANALYSIS OF CARRAGEENAN APPLIED TO THE RED ALGA HYPNEA-MUSCIFORMIS, Journal of applied phycology, 7(6), 1995, pp. 565-576
Dried powder of Hypnea musciformis was extracted with water at pH 7 af
ter an initial short pre-treatment with cold, diluted HCl. Carrageenan
s were isolated by alcohol precipitation after an amylase treatment an
d a filtration of the extracts. The yields at 25 and 90 degrees C were
25 and 75% (w/w) of the dry alga, with molecular weights (Mw) corresp
onding to 194 000 and 245 000, respectively. The chemical structure wa
s dominated by G4S-DA-(kappa-carrageenan or carrageenose 4'-sulphate).
A simple fractionation procedure for kappa-carrageenase hydrolysates,
based on stirring in different enthanol/water mixtures, is introduced
. NMR analysis showed that oligosaccharides with a repeating DA-G4S st
ructure were the main constituents in the enzymic hydrolysates of the
carrageenans from Hypnea musciformis. These oligosaccharides were solu
bilized in an ethanol concentration from 96 to 48% (v/v). In some enzy
me resistant fractions D6S-G4S and DA2S-G4S sequences and D2S,6S unite
s were detected by C-13-NMR.