| Spectroscopic and analytical analyses |
Observation |
Interference/Remark |
| FTIR |
Band at 3391.22 cm-1 |
-OH stretching of the hydroxyl group |
| peaks between 2880.45 and 2967.51 cm-1 |
-CH stretching of methyl and methylene groups |
| 1743.28cm-1 |
-C=O stretching of the acetate group |
| peaks at 615.68 cm-1 and 1455.54 cm-1 |
-COO groups |
| strong signals at 1401.12 cm-1 and 1252.95 cm-1 |
carboxylate asymmetric stretching and -C=O acetate deformation |
| absorption peaks between 928.25-745.16 cm-1 |
β- glycoside linkages |
| absorption peaks at 1671.52 cm-1 |
pyruvate group |
| absorption peaks at 1743.28 cm-1 |
acetyl group |
| 1H NMR |
1.44 |
pyruvate |
| 2.12 ppm |
acetate groups |
| 13C NMR |
107 to 95 ppm |
quaternary C2 of pyruvate |
| C1 carbon of glucose, galactose and glucuronic acid |
| 175.04 ppm |
carbonyl carbons of proteins, fatty acids and exopolysaccharide |
| 107.8 and 75.9 ppm |
carbons of the glucose and ketal group of pyruvic acid and polymeric chain of glucose |
