Process: monosaccharide chiral reagent → diastereomeric → TMS

Method: D, L-monosaccharide reacts with a single configuration of chiral reagent (L-); 1 monosaccharide reacts with 2 chiral reagents (D, L-)

Chiral reagent: (S)-(-)-1-phenylethylamine

Hydrolyze with 90% HCOOH first, then 0.05 M H2SO4 or CF3COOH

CH3OH solution: Sometimes it will cause methylation of the sugar connection site, so use it sparingly!

Sevag method: CHCl3 pentanol (butanol) polysaccharide aqueous solution 5: 1: 25 → shake vigorously for 20 minutes → centrifuge to remove denatured proteins between the two phases. Trifluorotrichloroethane method: Polysaccharide aqueous solution CF3-CCl3 1:1 → Stir for 10 min → Centrifuge and collect the water layer, twice. Trichloroacetic acid method: Add 3.13COOH dropwise to the polysaccharide aqueous solution → until it no longer becomes turbid → overnight at 5~10°C → centrifuge to remove the precipitate. Enzymatic hydrolysis: polysaccharide aqueous solution pepsin, trypsin, papain, pronase, etc.

Features: Emulsifier, can form a precipitate with acidic polysaccharides; form a precipitate with neutral polysaccharides: increase the pH of the solution, or contain borax buffer (increased acidity). Commonly used quaternary ammonium salts: CTAB/CP-OH. Operation: 1~10% CTAB or CP-OH, add dropwise to 0.1~1% polysaccharide solution with stirring (pH<9, no borax); control the quaternary ammonium salt concentration to separate different acidic polysaccharides

Sugar solution, gradually add ethanol (acetone) → each part ↓

Made into etherification and acetylation products, soluble in alcohol

Elution sequence: water → organic solvent (EtOH): H2O → 10% → 20% → 30% → 50% → 70% EtOH, The most water-soluble ones come out first: inorganic salts → monosaccharides → disaccharides → trisaccharides → polysaccharides

As the acidic groups in polysaccharide molecules increase, the adsorption force increases; for linear molecules, those with larger molecular weights are easier to adsorb; straight chains are easier to adsorb.

The order of exiting the column is that large molecules exit the column first, and small molecules exit the column later.

The upper end is the positive electrode and the lower end is the negative electrode.