MONOSACCHARIDE DERIVATIVES
They are modified monosaccharides.
GLYCOSIDES
- They are compounds formed by condensation reaction between a sugar and hydroxyl group of another substance which may be a sugar, a sterol, glycerol, methyl alcohol, etc.
- Streptomycin is a glycoside.
- Other medicinally important ones are cardiac glycosides.
ALCOHOLIC SUGAR
- When aldehyde group of monosaccharide is converted into alcohol (OH) group, then it is called alcoholic sugar.
- Glucose → Sorbitol
- Mannose → Mannitol
- Reduction of aldehyde and ketone group converts a sugar into sugar alcohol.
- Ascorbic acid or vitamin C is sugar acid.
- Glucouronic acid and iduronic acid are components of chondroitin sulphate, cell wall and gums.
AMINO SUGARS (HEXOSAMINES)
- When -OH group of second carbon converted into -NH then it is called amino sugar.
- Glucose → Glucosamine
- They are generally formed by replacement of hydroxyl group at carbon 2 with amino group (-NH ).
- Glucosamine is the most common amino sugar that occurs in chitin, fungal wall and hyaluronic acid.
- Galactosamine is used in synthesis of cartilage.
- Mannosamine is found in mucoprotein.
- Amino sugars also occur in some antibiotics.