CARBOHYDRATE CHEMISTRYDR ROHINI C SANE

PROFESSOR

DEPARTMENT OF BIOCHEMISTRY

DR D Y PATIL MEDICAL COLLEGE

EBENE

CARBOHYDRATE CHEMISTRY

• Definition :Polyhydroxy aldehydes or ketones

• Empirical formula : (CH2O) n----Hydrates of carbon

• C2H4O2---ACETIC ACID---NOT CARBOHTRATE

• C3H6O3 ---LACTIC ACID ---NOT CARBOHTRATE

PHYSICAL PROPERTIES

• SWEET TASTE

• WATER SOLUBLE

• SMELL OF BURNT SUGAR ON BURNING

• CRYSTALLINE

CARBOHYDRATE CHEMISTRYFUNCTIONS

ENERGY –4KCAL/GM

PRECURSORS OF ORGANIC COMPOUNDS—FAT ,AMINO ACIDS

STORAGE FORM OF ENERGY –GLYCOGEN

STRUCTURAL COMPONENTS OF MEMBRANE

STRUCTURAL COMPONENTS OF CELLULOSE,EXOSKELETON,CELL WALL OF MICRO-ORGANISMS

INDUSTRIAL—PAPER, TEXTILE

CLASSIFICATION OF CARBOHYDRATES• Monosaccharides –ONE SAKCHARON---SUGAR

• BASED ON FUNCTIONAL GROUPS

• ALDOSES— CHO

• KETOSES— C=O

DISACCHARIDES =C n(H2O)n-1• α GLUCOSE + α GLUCOSE = MALTOSE

• α GLUCOSE + β FRUCTOSE = SUCROSE

• β GLUCOSE + β GALACTOSE = LACTOSE

α D GLUCOSYL (1 4) α D GLUCOSE

β- D galactosyl (14) β- D glucose

α D glucosyl (12 ) β D fructose

C6H12O6 +C6H12O6 ---- >C12H22O11 +H20

MALTOSE LACTOSE SUCROSE

GLUCOSE (1)+GLUCOSE 4 GALACTOSE 1+ GLUCOSE 4 GLUCOSE 1 + FRUCTOSE 2

PANCREATIC AMYLASE INTESTINAL LACTASE SUCRASE

GLYCOSIDIC BONDGLUCOSE α (1--->4)

β GAL(1---4) β GLUCOSE α GLUCOSE (1- 2)β FRUCTOSE

REDUCING SUGAR REDUCING SUGAR NON REDUCING SUGAR

SUNFLOWER SHAPED OSAZONES LADY POWDER PUFF OSAZONES NO OSAZONES

SOURCE –DIGESTION OF STARCH MILK SUGAR CANE SUGAR,BEET SUGAR

DISACCHARIDES ---CRYSTALLINE, WATER SOLUBLE ,SWEET TASTE ,FORM OSAZONES (EXCEPT SUCROSE )

POLYSACCHRIDESHIGH MOLECULAR WEIGHTTASTE LESSCOLLOIDAL

STARCH ,CELLULOSE ,GLYCOGENHETEROGLYCANS

HEPARIN,CHONDROTIN SULPHATEHYALURONIC ACIDDERMATAN SULPHATEKERATAN SULPHATE

AMYLOSE AMYLOPECTIN

MOLECULAR WIGHT > 400000 MOLECULAR WIGHT 1 MILLION

SOLUBLE IN HOT WATER INSOLUBLE IN HOT WATER

200- 1000 UNITS α(1 4)LINKAGE 1000 UNITS IN α(1 4)& α(1 6)LINKAGE

INNER LINEAR OUTER PORTION BRANCHED

STARCH ,CELLULOSE , GLYCOGEN ---GLYCANS----POLYMERS OF GLUCOSEINULIN ---FRUCTOSANCELLULOSE ---PAPER

STARCH • HYDROLYSIS- WITH ACIDS –END PRODUCT –GLUCOSE

• HYDROLYSIS- WITH ENZYMES –END PRODUCT –MALTOSE(HYDROLYSIS WITH MALTASE YEILDS GLUCOSE )

• STARCH + IODINE> BLUE

• AMYLODEXTRINS >VIOLET

• ERYTHRODEXTRINS -RED

• ACRODEXTRINS > >COLORLESS

• MALTOSE –COLORLESS

• NO BRANCHING IN PROTEINS & NUCLEIC ACIDS

STARCH CELLULOSE GLYCOGEN INULIN

ORIGIN PLANT PLANT ANIMAL PLANT

HOMOPOLYSACCHARIDE OF

GLUCOSE GLUCOSE GLUCOSE FRUCTOSE

GLYCOSIDIC BONDS α(1--->4 )&α(1--->6 ) β (1--->4 ) α(1--->4 )&α(1--->6 )INTENSE BRANCHING

FATE CAN BE DIGESTED CANNOT BE DIGESTED LIVER GLYCOGEN-GLYCOGENOLYSIS ….>>GLUCOSEMUSCLES GLYCOGEN-GLYCOGENOLYSIS ….>>GLUCOSE 6 P(GLYCOLYSIS)

CANNOT BE DIGESTED

ENZYME INVOLVED IN METABOLISM

α AMYLASE CELLULASE GLYCOGEN PHOSPORYLASE

NOT METABOLISED

END PRODUCT OF ENZYME ACTION

MALTOSE β GLUCOSE GLUCOSE/GLUCOSE 6 P

FUNCTION DIETARY SOURCEFOR ANIMALS

PLANT CELLWALL STORAGE FOERM OF CABOHYDRATES IN LIVER,MUSCLES

Used for measuring GLOMERULAR FILTRATION RATE (GFR )

CELLULOSE• NOT DIGESTED IN HUMAN BODY

• WITHIODINE RED COLOR

• UNBRANCHED

• CONSTIUENT OF COTTON (90%),WOOD (50%),HAY (40%)

• MAJOR CONSTITUENT OF FIBRE

• SOURCES ---FRUITS ,LEAFY VEGETABLES,WHOLE WHEAT LEGUME, RICE BRAN

ADVANTAGES OF DIETARY FIBRES(CELLULOSE ,HEMICELLULOSE ,LIGNIN,PECTINS)

IMPROVES GLUCOSE TOLERANCE(DIMINISHED RATE OF ABSORPTION OF GLUCOSE )

DECREASED ABSORPTION OF CHOLESTEROL FROM INTESTINE >>>>REDUCE PLASMA

CHOLESTEROL LEVELS

FIBRES BIND WITH BILE SALTS & REDUCE ENTERO HEATIC CIRCULATION >>>DEGRADATION

OF CHOLESTEROL TOBILE SALTS & ITS DISPOSAL FROM BODY IS INCREASED

PREVENTS CONSTIPATION (INCREASING BULK OF FAECES BY ABSORBING WATER )

ELEMINATES BACERIAL TOXINS (ADSORPTION OF TOXIC COMPOUNDS )

LOWER INCIDENCE OF GIT CANCER

SATIETY VALUE –SENSETION OF STOMATCH FULLNESS , SATIETY WITHOUT CONSUMPTION

OF EXCESS CALORIES

ADVERSE EFFECTS OF FIBRE

DIGESTION & ABSORPTION OF PROTEINS ARE ADVERSLY AFFECTED

INTESTINAL ABSORPTION OF MINERALS CALCIUM ,MAGNESIUM ,PHOSPHOROUS

DECREASED

INTESTINAL BACTERIA FERMENT FIBRES CAUSING FLATULANCE

DEXTRINS

• BREAKDOWN PRODUCTS OF STARCH (WITH ACIDS OR ENZYMES)

• STARCH +IODINE (ADSORPTION -BLUE COLOR )

• AMYLODEXTRIN –(VIOLET COLOR)

• ERYTHRODEXTRINS (RED COLOR)

• ACHRODEXTRINS (NO COLOR )

• MALTOSE (NO COLOR )

• GLUCOSE (NO COLOR )

DEXTRANS• HOMOPOLYSACCHARIDE

• SYNTHESIZED BY YEAST & BACTERIA

• LINEAR CHAIN α(16 )GLYCOSIDIC LINKAGE

• BRANCHING 1,2

1,3

1,4 GLYCOSIDIC LINKAGES

INTRAVENOUS ADMISTRATION AS PLASMA SUBSTITUTE DURING BLEEDING ,DIARRHOEA,SURGERY ,ACCIDENTS (DONOT GO OUT OF VASCULAR TISSUE THEREFORE TREATMENT OF HYPOVOLUMIC SHOCKS)

DENTAL PLAQUES

INDUSTRY ----SEPHADEX (CROSS LINKED DEXTRANS)

• DEXTRINS –PARTIALLY DIGESTED PRODUCTS OF STARCH

• DEXTRAN---HYPOVOLUMIC SHOCKS

• DEXTROSE –BEDSIDE MEDICINE

• CHITIN –STRUCTURAL POLYSACCHARIDE FOUND IN EXOSKELETONS OF INVERTEBRATES

• N- acetyl D-glucosamine

AGAR• SEA WEED

• HETEROPOLYSACCHARIDE –SULPHATED GALACTOSE/GLUCOSE/OTHER SUGARS

• DISSOLVES IN WATER (SET ON COOLING )

• BACTERIA DONOT UTILIZE AGAR –THEREFORE CULTURE MEDIUM

• USED IN IMMUNO-DIFFUSION ,IMMUNO-ELECTROPHORESIS

• TRATMENT OF CONSTIPATION (INCREASE BULK OF FAECES)

• AGAROSE –PRODUCED BY BACTERIA WHEN GROWN ON SUCROSE MEDIUM –(GALACTOSE+3,6 ANHYDROGALACTOSE )

Heteropolysaccharides

• GLYCOSAMINOGLYCANS(GAG )/MUCOPOLYSACCHARIDES/HETEROGLYCANS

• REPEATING ALTERNATE UNITS OF SULPHATED AMINOSUGARS & URONIC ACID

• RICH IN SULPHATES ,CARBOXYL GROUPS = ACIDIC MUCOPOLYSACCHARIDES

• Mucoproteins =proteoglycans (95% carbohydrates +5% proteins )

• Occurrence ---1.extra cellular spaces in tissue

• 2 cartilage ,skin ,blood vessels ,tendon,ground tissue in connective tissue

• Presence of charged groups-attracts water ---viscous solution

•

Heteropolysaccharides

Functions Of Hyaluronic acid

• present in synovial fluid, ground tissue in connective tissue

• Lubricant & shock absorbent

• Gel around ovum

• Enzyme hyaluronidase is present in acrosome of spem,snake venoms ,insect venoms ,bacteria

Functions Of HEPARIN

• Anticoagulant –inactivates anti-thrombin III,FACTOR IX, FACTOR X

HETEROPOLYSACCHARIDE

OCCURRENCE FUNCTIONS CHEMICAL COMPONENTS

Hyaluronic acid synovial fluid, ground tissue in connective

tissue,SORROUNDINGOVUM ,

LUBRICANTS ,SHOCK ABSORBANT

Repeating Disaccharide units of (D -GLUCORONIC ACID ,

N ACETYL GLUCOSAMINE )

Chondroitin-6- sulphate Bone,cartilage,tendon,heart

valves ,cornea

LUBRICANTS ,SHOCK ABSORBANT

D -GLUCORONIC ACID ,N acetyl Galactosamine -4- sulphate

HEPARIN Anticoagulant –activates antithrombinIII,FACTOR IX, FACTOR X

N-sulpho D glucosamine -6 sulphate & gluconate -2 sulphate

Dermatan sulphate skin LUBRICANTS ,SHOCK ABSORBANT

L-induronic acid N acetyl galactosamine

Keratan sulphate Keratin of hair LUBRICANTS ,SHOCK ABSORBANT

D-galactosamineN ACETYL GLUCOSAMINE 6 sulphate

D GLUCORONIC ACID BY INVERSION GIVES L

INDURONIC ACID

• Gum acacia –Gal+ Arabinose +glucoronic acid

• Pectins –galactose +uronic acid (citrous fruits ,apples )

Mucopolysaccridoses

Deposition of muco-polysaccharides in lysosomes of various tissues

Mental retardation

Skeletal deformties

Corneal opacity

Urinary excretion of particular mucopolysaccharide

Mucopolysaccridoses

Type of mcopolysaccridosis

Enzyme defect manifestation

Hurler’s syndrome Induronidase Accumulation of Dermatan sulphate &heparin

sulphate in tissue & excretion in urine

Hunter’s syndrome Induronate sulphtase Accumulation of Dermatan sulphate &heparin

sulphate in tissue & excretion in urine

Marquio syndrome GalactosidaseGalactosamine

sulphtase

Accumulation excretion of keratan sulphate &

chondroitin sulphate in urine

Glycoproteins• Carbohydrates ( 1-90%)+proteins = glycoproteins • 4% carbohydrate content mucoproteins• CARBOHYDRATES are mannose, galactose ,xylose,l-fucose +Nacetyl

glucosamine+ Nacetyl galactosamine• Enzymes • Hormones • Transport proteins • RBC blood group antigens (N ACETYL GALACTOSAMINE +GALACTOSE+

FUCOSE ,SIALIC ACID+GLYCOLIPID• Structural proteins• ANTI -FREEZE PROTEINS FROM ANTARTIC FISHES LOWER FREEZING OF

PLASMA AT LOW TEMP (ALA—ALA—THR ___GAL____(1-3 )Nacetylgalactosamine

Reactions of Monosaccharides

• Tauto-merization –shifting of carbon atom from one carbon to another

• Glucose/fructose /mannose ---undergo tautomerization when placed in alkaline medium to form enendiol (intermediate of highly reducing agent )

• Benedict's test

• Sugar -alkaline medium enendiol

• CuSO4 -CUPRIC CU2+Cu+2 Cu (OH)Cu2O(YELLOW PPT)+2H2O

• BENEDICT’S test -- CuSO4& Na corbonate ,Na –citrate--+reducing monosaccharides /disaccharides

• Barfoed’s test---copper acetate /acetic acid + monosaccharides /-vedisaccharides

Dehydration • Glucose /fructose /lactose /maltose + conc H2SO4 FURFURAL

• FURFURAL + PHENOLIC COMPOUND COLOR COMPLEX

• PHENOLIC COMPOUND---

PHENOLIC COMPOUND-

COLOR TEST APPLICATION

ALPHA NAPHTOL VIOLET MOLISCH’S GROUP TEST FOR CARBOHYDRATES

RECERCINOL CHERRY RED SELIWAOFF’S KETOSES (FRUCTOSE /SUCROSE+VE)

ALPHA NAPHTOL VIOLET RAPID FURFURAL KETOSES (FRUCTOSE /SUCROSE+VE)

OSAZONE FORMATION• GLUCOSE /FRUCTOSE/LACTOSE /MALTOSE –REDUCING SUGAR WITH

FREE ALDEHYDE GROUP FORM OSAZONES ( YELLOW CRYSTALLINE SUBSTANCE WITH SPECIFIC SHAPE

OSAZONE FORMATION• The reaction is stepwise;

DERIVATIVES OF MONOSACCHARIDES

SUGAR ACIDS

• GLUCOSE (C1 )-> GLUCONIC ACID

• GLUCOSE (C6 )-> GLUCORONIC ACID

• GALACTOSE > MUCIC ACID

SUGAR ALCOHOL

GLUCOSE SORBITOL

MANNOSE MANNITOL

GALACTOSE DULCITOL

RIBOSE RIBITOL

DERIVATIVES OF MONOSACCHARIDES

ALDITOLS

• MONOSACCHARIDES ---POLY HYDROXY ALCOHOL

• GLYCEROL (COMPONENT OF TG )

• MYO-INISITOL(SECONDARY MESSENGER )

• RIBITOL (FLAVIN )

• XYLITOL(SWEETENER)

AMINO SUGARS

• OH OF SUGAR AMINO SUGAR

• GLUCOSE GLUCOSAMINE

FORMATION OF ESTERS –GLUCOSE ESTERIFICATION GLUCOSE -6 P

DERIVATIVES OF MONOSACCHARIDESAmino Sugar on acetylation acetylated amino sugar

• Glucosamine N-acetyl Glucosamine

• N acetyl mannose + pyruvic acid N- acetyl neuraminic acid (NANA)—COMPONENTOF GLYCOPROTEIN/GLYCOLIPID

• NANA +NANA –DERIVATIVES SIALIC ACID

DEOXY RIBOSE SUGAR

SUGAR DE-OXYSUGAR (CHOH –O =CH2 )—DEOXY RIBOSE –DNA

CH2OH CH3

RHAMNOSE /L-FUCOSE POLYSACCHARIDE

ASCORBIC ACID –VITAMIN C –DERIVED FROM GLUCOSE IN LOWER ANIMALS

OPTICAL ACTIVITY

• COMPOUND WITH ASYMMETRICAL CARBON ATOMS –PLANE OF POLARIZED LIGHT TOWARDS LEFT (LAEVO ROTATORY )/RIGHT(DEXTRO-ROTATORY )

• CHARACTERISTIC FEATURE OF COMPOUND WITH ASYMMETRICAL CARBON ATOM

• D(+) ,D (-) ,L(+) ,L (-)

• RECEMIC MIXTURE (NO OPTICAL ROTATION )

• DETRO ROTATORY + LAEVO ROTATORY = ZERO OPTICAL ROTATION

• (-Xο

)+ (+Xο

)= 0

EPIMERS

• Monosaccharides which differ in configuration

around one specific C-atom are called epimers of

one another

• C-2 epimers

• glucose and mannose

• C-4 epimers

• glucose and galactose

H C O

H C OH

HO C H

H C OH

H C OH

CH2OH

D-GLUCOSE

H C O

HO C H

HO C H

H C OH

H C OH

CH2OH

D-MANNOSE

CARBON-2 EPIMERS

CARBON-4 EPIMERS

H C O

H C OH

HO C H

H C OH

H C OH

CH2OH

D-GLUCOSE

H C O

H C OH

HO C H

HO C H

H C OH

CH2OH

D-GALACTOSE

STEREOISOMERS OF MONASACCHARIDES • SAME STRUCTURAL FORMULA DIFFER IN THEIR SPACIAL

ARRANGEMENT/ CONFIGURATION

• Asymmetrical carbon atoms –attached to four different groups

• Number of possible isomers of given compound 2 n (n =number of asymmetric carbon atoms within molecule )

• Glucose 4 asymmetric carbon atoms –2 4 =16 isomers

• D-Glucose –OH GROUP on penultimate carbon atoms is on right side

• L- Glucose –OH GROUP on penultimate carbon atoms is on LEFT side

• Glyceraldehyde is simplest reference carbohydrate -D & L ISOMERS USED FOR COMPARISION

• Naturally occurring monosaccharide in mammalian tissue –D configuration

• Enzymes present to metabolise D isomer =dextro -rotatory

• ANOMERIC CARBON ATOM

The carbon atom which is part of the carbonyl group

Alpha(α) and Beta(β) anomers differ from each other

only in respect to configuration around anomeric

carbon atom.

ISOMERISM IN SUGARS

• Isomers/Stereo-isomers: Compounds having the

same chemical formulae but differing in the

arrangement of their atoms in space and having

different physical properties are called isomers.

Mutarotation

• Alpha ,beta have diffirent optical activity

• GLUCOSE CRYSTALLIZED FROM WATER & ALCOHOLALPHA D –GLUCOSE(+112.2ο ))

• GLUCOSE CRYSTALLIZED FROM WATER ABOVE 98ο & PYRIDINEBETA D GLUCOSE (+18.8 ο )

• In aqueous solution the beta form of D glucose is more stable & predominant

• Definition –change in the specific optical rotation representing the interconversion of alpha & beta form of D glucose to specific equilibrium mixture.( 52.7% ).This conversion takes place through straight chain /linear form.

• Inter conversion is faster in alkaline form.

• equilibrium mixture-has 63% of beta form,36% of alpha form& 1% 0pen chain form.

MUTAROTATION OF FRUCTOSE

• PYRANOSE (SIX MEMBER RING ) FUNAROSE (FIVE MEMBER RING )

• CHAIR & BOAT CONFIRMATION OF FRUCTOSE

BOAT CHAIR

(LESS STABLE ) (MORE STABLE )

AXIAL EQUATORIAL ARRANGEMENT

PARALLEL HEAVY GROUPS PERPENDICULAR HEAVY GROUPS

INVERSION OF SUGARSUCROSE (+66.5

ο)+ SUCRASE /HCL α D-GLUCOPYRINOSE (+52.5

ο)

+

β D-FRUCTO FUNAROSE (-92 ο

)

DEXTRO –ROTATORY (SUCROSE ) LAEVO ROTATORY HYDROLYSATE (-39.5)

NON- REDUCING (BENEDICT’S NEGATIVE ) REDUCING (BENEDICT’S POSITIVE)

• SUCROSE –INVERT SUGAR ,SUCRASE –INVERTASE

• SWEETNER

• MAJOR CARBOHYDRATE– PHOTOSYNTHESIS

• STORAGE & TRANSPORT FORM IN PLANTS ,ROOTS ,TUBERS

OXIDATION OF MONOSACCHARIDES • Oxidation –CHO COOH (MILD OXIDATION/BROMINE )

• GLUCOSEGLUCONIC ACID (C1 )

• GLUCOSE GLUCORONIC ACID (C6)

• GLUCOSE GLUCOSACCHARIC ACID ( C1,C6)WITH STRONG ACIDS HNO3

• FUNCTION OF GLUCORONIC ACID (C6)---DETOXIFICATION ,SYNTHSESIS OF MUCOPOLYSACCHARIDES

• GALACTOSE MUCIC ACID –DIAGNOSIS OF GALACTOSE INTOLERENCE

ESTIMATION OF GLUCOSE BY GOD –POD METHOD

• GLUCOSE GLUCONIC ACID +H2O2

• H2O2 -POD H20 +(O)

• CHROMOGENIC SUB+(O)-COLOR COMPLEX

REDUCTION OF MONOSACCHARIDES

• CHO CH2OH ALCOHOLS (WITH SODIUM AMALGAM)

• GLUCOSE SORBITOL

• GALACTOSE DULCITOL

• MANNOSE MANNITOL

• FRUCTOSE MANNITOL & SORBITOL

• RIBOSE RIBITOL

Glycosides

• Hemiacetal +R2OH OH

R 1 -- C -- H

OR2• HEMI ACETAL HYDROXY GROUP OF ANOMERIC CARBON OR HEMIKATAL

HYDROXY GROUP OF ANOMERIC CARBON+

• HYDROXY GROUP OF ANOTHER CARBOHYDRATE OR NON CARBOHYDRATE CARBOHYDRATE + CARBOHYDRATE ---GLYCOSIDE (LINKING WITH

GLYCOSIDIC BOND)• HEMI ACETAL HYDROXY GROUP OF GLUCOSE + HYDROXY GROUP OF

ANOTHER GLUCOSE-MALTOSE• OH FROM ANOMERIC CARBON –GLYCOSIDES /GLUCOSIDES/GALACTOSIDESOF MONOSACCHARRIDESCARBOHYDRATE +NON CARBOHYDRATES (AGLYCAN)GLYCOSIDES OH FROM ANOMERIC CARBON + OH OF METHANOL /ETHANOL/STEROL(AGLYCAN)

Physiologically important Glycosides • Glucovanilin----vanilla flavor

• Cardiac glycosides –muscle contraction

• digitoxin & digoxin—pumping of heart

• Streptomycin—antibiotic for tuberculosis

• ERYTHROMYCIN—DIMETHYL AMINO SUGARS • Quabain – inhibitors of Na+k+ ATPase

SUGAR AGLYCAN GLYCOSIDE FUNCTION

GLUCOSE PHLORETIN PHLORIZIN(ROSE BARK ) RENAL DAMAGE

GALACTOSE & XYLOSE DIGITOGENINE DIGITONIN CARDIAC STIMULANT

GLUCOSE INDOXYL PLANT INDICAN STAIN

Pentose sugars

• RIBOSE –RNA /ATP/NAD

• RIBULOSE HMP SHUNT INTERMEDIATE

• ARABINOSECHERRIES

• XYLOSEPROTEOGLYCANS

• XYLULOSEURONIC ACID PATHWAY

Aminated sugar

N acetyl Glucosamine—Hyaluronic acid

• Nacetyl Galactosamine---chondroitoin sulphate

• Glycoprotein –carbohydrate (< 10% )+ protein

• Mucoprotein =mucopolysaccharides (>10%)+protein

• Mucopolysaccharidesuronic acid + amino sugar