Table 1.
Summary of the extraction, purification, characterization methods and structural studies of acemannan.
| Source | Extraction, Fractionation, Purification | Structural Characterization Method | MW (kDa) | Monosaccharide Composition | Structural Feature | Yield | Reference |
|---|---|---|---|---|---|---|---|
| Fresh gel | Water extraction (Homogenization, centrifugation mixed with 3 volumes of ethanol, lyophilization) | LC; FT-IR; SEC; 1H-NMR | 190–220 | Man: Glc: Gal = 57:22:17 | O-(Acetyl-d-Manp)-O-(acetyl-d-Manp)-O-(d-Glap)-O-(acetyl-d-Man) | --- | [14] |
| Fresh gel | Water extraction; separation (Shodex Sugar KS-804 column) | 13C-NMR; SEM 1H-NMR; FT-IR | 150-190 | Man: Glc: Gal = 65:17:17 | Single-branched galactose at C6 of the second acetylated mannose residue | 0.04% | [33] |
| Frozen gel | Ultrafiltration cell membrane (Fractionated by ultrafiltration cell with MW cut-off membrane) | HPLC (BIOSEP SECH400 column); GC (SP2330 glass-capillary column); 1H-NMR; IR | >500 | Man: Glc = 97:3 | Galp-(1→residues link to O-2, O-3, or O-6 of →4)-β-Manp-(1→ residues, with ∽16→4)-β-Manp-(1→ residues between the side chains | 2% | [42] |
| Fresh gel | Water extraction; separation (homogenization, centrifugation, alcohol precipitation, dialysis, lyophilization) | HPLC (Shodex Sugar KS-804 column); GC–MS; 13C-NMR | ≥800 | Man (77.18%); Glc (15.3%); Gal (4.9%); Ara (0.7%); Rha (0.2%); Fuc (0.34%); Xyl (0.7%) | β-(1→4) | 0.2% | [46] |
| Fresh gel (1 year old) | Water extraction (Homogenization, centrifugation with 80% v/v alcohol, ammonium sulfate precipitation, lyophilization) | GC-MS; SEC; 13C-NMR | 1100 | Man: Glc = 15:1 | O-2, O-3, and O-6 of→4)- β-Manp-(1→residues to single α-Galp-(1→side chains | --- | [47] |
| Fresh gel | Water extraction; (Homogenization, centrifugation mixed with 3 volumes of ethanol, wash with ethanol, lyophilization) | HPGPC; FTIR; GLC-MS; TGA | 1020 | Mannose (84.9%): glucose (7.2%); galactose (3.9%) | (1→4)-Linked mannose/glucose 2,3,6-tri-O-acetyl-mannose,2,6-di-O-acetylglucose,6-acetyl-O-glucose, 3,6-di-O-acetyl-glucose |
--- | [53] |
| Frozen gel | Water extraction (Homogenization, centrifugation, alcohol precipitation, lyophilization) | GC–MS; Ion-chromatograph; 13C-NMR | 1100 | Man: Glc: Gal: GalA: Fuc: Ara: Xyl = 120:9:6:3:2:2:1 | →4)-β-Manp-(1→ and →4)-β-Glcp-(1→ residues in 15:1 ratio | --- | [60] |
| Fresh gel (3 years old)) | Water extraction (Homogenization, centrifugation, supernatant mixed with 3 volumes of ethanol, pellet) | FACE; FT-IR; SEC | 281 | Man (62.9%); Glc (13.1%); Gal (0.6%) | --- | 1.7% | [61] |
| Frozen gel | Water extraction; (depigmentation, deproteinization) | CR; GC-MS; PACE | --- | Man (86.87%); Glc (0.05%); Gal (12.68%); Ara (0.38%) | β-(1→4) | 0.32% | [62] |
Fluorophore-assisted carbohydrate electrophoresis (FACE); Congo red (CR); Liquid chromatography (LC); Size exclusion chromatography(SEC); Polysaccharide analysis by carbohydrate gel electrophoresis (PACE); Thermogravimetric analysis (TGA).