five carbon aldose

Methyl five-carbon sugar

six carbon aldose

Six-carbon ketose

Uronic acid

Sugar alcohols (monosaccharide reduction, mostly sweet)

special

Number of monosaccharide groups

Reducibility

composition

source

Monosaccharides, oligosaccharides with small molecular weight are colorless or white crystals with a sweet taste.

Sugar alcohol colorless or white crystals

Polysaccharide amorphous powder, no sweetness

Monosaccharides and oligosaccharides are easily soluble in water, especially in hot water, soluble in dilute alcohol, and insoluble in lipophilic organic solvents

Polysaccharides are insoluble in organic solvents, most are poorly soluble in water, and a few form colloidal solutions.

All are optically active, and natural monosaccharides are mostly dextrorotatory and variable.

Monosaccharides are more polar than polysaccharides

Oxidation reaction: aldehydes, ketones, primary alcohols, secondary alcohols, vicinal diols of monosaccharides (terminal carbon > secondary carbon)

hydroxyl reaction

carbonyl reaction

Boric acid complex reaction

Molish reaction

film reaction

Doron reaction (silver mirror)

Trifluorotrichloroethane

Sevag (chloroform-n-butanol 4:1)

Paper chromatography: aqueous developing agent

TLC

Developer: sulfuric acid-containing developer is not suitable for PC

D: Right side/five carbons facing up

L

α: The oxygen at the fifth position carbon and the terminal carbon are on the same side

β