Caractérisation des extraits et molécules d'intérêt 2019 2020.pdf
Biopolymères glucidiques d’origine marine I
IV-- Techniques de caractérisation
A : DS de raie
B : DS standard
Infrared spectrum of DS within the range 4000–400 cm−1 : a pattern close to that of DS standard
-Strong OH stretch at 3200–3500 cm−1 and a strong OH bend at 1620–1660 cm−1
-Thin and strong absorbance bands at 1038, 1052 and 1155 cm−1, corresponded to C–O–C, C–OH and C–C ring vibrations
and suggested the occurrence of osidic cycles.
- Uronic acids were evidenced by the two medium size bands at 1378 and 1417 cm−1 (O–C=O bending). Another absorbance
band at 1556 cm−1 can be attributed to C=O stretching in acetyl groups, probably in acetylated galactosamine residues.
-A strong and broad absorbance band at 1239 cm−1 as well as bands at 839 cm−1 corresponded to S=O stretching and C–
O–S bending, respectively and evidenced sulfate groups as substituents.