Derived Sugars

Derived Sugars

  • Oxidation of Sugar- Under mild oxidation, aldehyde group is oxidised to Aldonic Acid.
  • *Glucose to Gluconic Acid
  • Mannose to Mannonic Acid
  • Galactose to Galactonic Acid.
  • Oxidation of aldehyde group from glucose in blood glucose estimation results in Gluconic Acid.
  • Oxidation of terminal alcohol group leads to the production of Glucuronic acid.
  • Under strong oxidation-
  • Glucose to glucosaccharic acid
  • Mannose to mannaric acid
  • Galactose to mucic acid 

Sugar Alcohols-

Glucose Sorbitol  
Mannose Mannitol Reduces intracranial pressure by forced diuresis
Galactose Dulcitol/Galactitol Osmotic effect causes cataract in Galactosemia &Diabetes
Fructose Sorbitol and Mannitol  

  • Deoxy Sugar- Oxygen of the hydroxyl group may be removed to form deoxy sugars.
  • Deoxyribose– is an important part of nucleic acid.
  • Oxygen is removed from the 2nd position
  • Feulgen Staining is specific for 2-deoxy sugar(DNA) in tissues.(*Schiff’s agent)
  • L-fuctose is present in the blood antigen.               
  • Amino Sugars– Amino group substituted for hydroxyl group in the second carbon atom of monosacharides to form Amino Sugars. 
Glucosamine Seen in hyluronic acid, heparin & blood group substance.
Galactosamine (Chondrosamine) Present in chondroitin of cartilage, tendons & bone.
Mannosamine Constituent of glycoproteins.
  • An unusual amino sugar with 9 carbon atom is Sialic Acid.
  • The principal Sialic Acid found in human body is N Acetyl Neuraminic Acid (NANA) and is derivative f N-acetylmannose and pyruvic acid.
  • Erythromycin is an antibiotic which contains amino sugar.
  • GLYCOSIDES- When the monosaccharide is condensed with an alcohol, phenol or sterol by O- Glycosidic Linkage to form glycoside.
  • Digitonin is a cardiac stimulant.
  • Quabain in cardiac effect
  • Phlorhizin produces renal damage.
  • Antibiotic- Streptomycin, Puromycin.
  • Benedict’s Reaction- Standard lab test to diagnose Diabetes mellitus.

Shapes of Osazones-

  • Needle-shaped/Broomstick/sheaves of corn – Glucose, Fructose, Mannose
  • Pincushion with pins/Hedgehog/ Flower of Touch –me-not – Lactose
  • Sunflower Petal-shaped –  Maltose 


Reductometric Methods
  1. Nelson Somogyi Method
  2. Folin-Wu Method
  3. O- Toluidine Method
Enzymatic Method
  1. Hexokinase Method
  2. Glucose-Oxidase Perioxidase Method (GOD-POD)
  3. Highly specific method 
  4. Used in dry nanlysis technique                                              








General test for all carbohydrates           Molisch test
Tests for reducing substances          Benedict’s Test
Test to differentiate monosaccharides and Diasaccharides         Barfoed’s Test

        Moore’s Test

        Fehling’s Test

Test to differentiate Aldoses and Ketoses          Seliwanoff’s Test

         Rapid Furfural Test

         Fougler’s Test

Test to detect Deoxy Sugar          Feulgen Staining
Test for Pentoses           Bial’s Test
Test for Galactose           Mucic Acid Test
  • Reaction In Glucose oxidase and Perioxidase Method is- (GOD-POD)
  • Glucose + H2O2 + O2  GOD_→   Gluconic Acid + H2O2
  • 2H2O2 + 4 aminoantipyrine + PHB  POD → Quinoneminine dye + H2O (RED COLOR)

Exam Important

  • Derived Sugars include- Acid sugars, Sugar alcohols, Deoxy sugars, Amino sugars, Glycosides, Furfural derivatives.
  • The immediate precursor of Glucosamine is Fructose 6 phosphate.
Don’t Forget to Solve all the previous Year Question asked on Derived Sugars
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