LectureLecture №30 №30

General characteristic of the General characteristic of the carbohydrates, their sources of carbohydrates, their sources of

getting, properties, qualitative and getting, properties, qualitative and quantitative analysis, storage and quantitative analysis, storage and

usage. Tannins.usage. Tannins.

prepared: assist. Logoyda Lprepared: assist. Logoyda L..S.S.

Carbohydrates  are carbon compounds that contain large Carbohydrates  are carbon compounds that contain large quantities of hydroxyl groups . The presence of the hydroxyl quantities of hydroxyl groups . The presence of the hydroxyl groups allows carbohydrates to interact with the aqueous groups allows carbohydrates to interact with the aqueous environment and to participate in hydrogen bonding. environment and to participate in hydrogen bonding. Carbohydrates can combine with lipid to form Carbohydrates can combine with lipid to form glycolipids or or with protein to form with protein to form glycoproteins. They have a wide range of functions including providing a They have a wide range of functions including providing a significant fraction of the energy in the diet of most significant fraction of the energy in the diet of most organism , acting as a storage form of energy in the body and organism , acting as a storage form of energy in the body and serving as cell membrane components.serving as cell membrane components. Also carbohydrates serve as a structural component of many Also carbohydrates serve as a structural component of many organisms including cell walls of bacteria. organisms including cell walls of bacteria. Carbohydrates serve as metabolic intermediate ( e.g Glucose Carbohydrates serve as metabolic intermediate ( e.g Glucose 6 phosphate, fructose 1,6 diphosphate).6 phosphate, fructose 1,6 diphosphate).Ribose ,deoxyribose play a major role in the synthesis DNA Ribose ,deoxyribose play a major role in the synthesis DNA and RNA.and RNA.all life activities are dependent upon carbohydrates. When all life activities are dependent upon carbohydrates. When insufficient carbohydrates are available from the diet, the insufficient carbohydrates are available from the diet, the body converts fat reserves to carbohydrates for its use, and body converts fat reserves to carbohydrates for its use, and amino acids are utilized as carbohydrates instead of being amino acids are utilized as carbohydrates instead of being used to make body protein. Carbohydrates, along with used to make body protein. Carbohydrates, along with proteins and fats, comprise the major components of living proteins and fats, comprise the major components of living matter and are used for maintenance of cellular functional matter and are used for maintenance of cellular functional activities and as reserve and structural materials for cellsactivities and as reserve and structural materials for cells

• Carbohydrates with an aldehyde group are called aldoses Carbohydrates with an aldehyde group are called aldoses where those with a keto group are called ketoses. For where those with a keto group are called ketoses. For example , glyceraldehyde is an aldose, whereas, example , glyceraldehyde is an aldose, whereas, dihydroxyacetone is a ketose. dihydroxyacetone is a ketose.

• Disaccharides: contain two monosaccharides units. Disaccharides: contain two monosaccharides units. Maltose , sucroseMaltose , sucrose

• Oligosaccharides : contain from three to about 12 Oligosaccharides : contain from three to about 12 monosaccharides units. For example, Blood group antigens.monosaccharides units. For example, Blood group antigens.

• Polysaccharides : contain more than 12 monosaccharides Polysaccharides : contain more than 12 monosaccharides units and can be hundreds of sugar units in length. units and can be hundreds of sugar units in length. Starch , celluloseStarch , cellulose

• All carbohydrates All carbohydrates can be hydrolyzed (broken down) into can be hydrolyzed (broken down) into two or more monosaccharides.two or more monosaccharides.

• For further understanding of these different classifications For further understanding of these different classifications of carbohydrates, the monosaccharides and disaccharides of carbohydrates, the monosaccharides and disaccharides can be grouped together and compared with the can be grouped together and compared with the polysaccharides. This can be done because polysaccharides. This can be done because monosaccharides and disaccharides have certain things in monosaccharides and disaccharides have certain things in common.common.

• They are both water soluble. In addition, they have a sweet They are both water soluble. In addition, they have a sweet taste and a crystalline structure.taste and a crystalline structure.

Simple sugars, starches and cellulose are organic compounds that have the approximate formula C(H2O)n, which accounts for the name carbohydrate (or hydrate of carbon) that is usually applied to this group of compounds They are not truly hydrates of carbon but are polyhydroxy (alcohol) compounds that contai an aldehyde or ketone functional group. These functional groups give the carbohydrates some of their chemical properties that will be studied in this lab.

Monosaccharides

Simple sugars & cannot be hydrolysed further. They are further classified on the basis of number of carbon atoms present as well as on the presence of functional groups.

Carbon atoms Examples Functional groups

Trioses (3 carbon) GlyceraldehydeDihydroxy acetone

Aldehyde (aldotriose)Ketone (Ketotriose)

Tetroses (4 carbon) Erythrose Aldehyde (aldotetrose)

Pentoses (5 carbon RiboseXyloseXylulose

Aldehyde(Aldopentose)Aldehyde(Aldopentose)Ketone (Ketopentose)

Hexoses (6 carbons) GlucoseGalactoseFructose

Aldehyde (Aldohexose)Aldehyde (Aldohexose)Ketone (Ketohexose)

Disaccharides.

•Contain two molecules of same or different monosaccharide units. On hydrolysis they give two monosaccharide units. Monosaccharide units are joined by glycosidic bond.

Examples Product formedUpon hydrolysis

GlycosidicLinkage

Sources

Maltose glucose + glucose

α 1-4 Malt

Lactose galactose + glucose

β 1-4 Milk

Sucrose glucose + Fructose

β 1-2 Sugar cane

Isomaltose glucose + glucose

α 1-6 Digestion ofamylopectin

Oligosaccharides

Contain - molecules of monosaccharide units.

E.g. Maltotriose. (Glucose + Glucose + Glucose)

The The DD Aldose Family Aldose Family

CarbohydratesCarbohydrates

Isomers and epimersIsomers and epimers• Compounds that have the same chemical formula but have Compounds that have the same chemical formula but have

different structures are called isomers. For example different structures are called isomers. For example Fructose, glucose , mannose and galactose are all isomers Fructose, glucose , mannose and galactose are all isomers of each other having the same chemical formula C6H12O6. of each other having the same chemical formula C6H12O6. If two monosaccharides differ in configuration around only If two monosaccharides differ in configuration around only one specific carbon atom , they are defined as epimers of one specific carbon atom , they are defined as epimers of each other. For example, glucose and galactose are C4 each other. For example, glucose and galactose are C4 epimers, their structures differ only in the position of the epimers, their structures differ only in the position of the hydroxyl group at C4 ( Note , the carbons in sugar are hydroxyl group at C4 ( Note , the carbons in sugar are numbered beginning at the end that contain the aldehyde numbered beginning at the end that contain the aldehyde or ketone group.or ketone group.

• Glucose and mannose are C2 epimers. However, galactose Glucose and mannose are C2 epimers. However, galactose and mannose are not epimers they differ in the position of and mannose are not epimers they differ in the position of the hydroxyl group at two carbon 2 and 4 and therefore, the hydroxyl group at two carbon 2 and 4 and therefore, defined only as isomers.defined only as isomers.

• Enantiomers: Enantiomers: A special type of isomerism is found in A special type of isomerism is found in the pairs of structures that are mirror images of each the pairs of structures that are mirror images of each other. These mirror images are called enantiomers. The other. These mirror images are called enantiomers. The two members of the pair are called as D and L sugars. The two members of the pair are called as D and L sugars. The majority of the sugars in human are D sugars.majority of the sugars in human are D sugars.

Anomeric carbonAnomeric carbon• Formation of a ring results in the creation of an Formation of a ring results in the creation of an

anomeric carbon at C1 of an aldose or C2 of a anomeric carbon at C1 of an aldose or C2 of a ketose. These structures are called the ketose. These structures are called the αα and andββ configuration of the sugar . For example configuration of the sugar . For example αα-D -D glucose and glucose and ββ-D-glucose. These two sugars are -D-glucose. These two sugars are both glucose but they are anomers of each other. both glucose but they are anomers of each other. Enzymes are able to distinguish between these Enzymes are able to distinguish between these two structures and use one or the other two structures and use one or the other preferentially. For example glycogen is preferentially. For example glycogen is synthesised from synthesised from αα-D -D ––glucosepyranose whereas, glucosepyranose whereas, cellulose is synthesised from cellulose is synthesised from ββ-D-glucopyranose. -D-glucopyranose. The cyclic The cyclic αα and and ββ anomers of a sugar in solution anomers of a sugar in solution are in equilibrium with each other and can be are in equilibrium with each other and can be spontaneously interconverted in a process called spontaneously interconverted in a process called mutarotation.mutarotation.

Optical activity

The compounds having asymmetric carbon atoms can rotate the beam of plane polarized light and are said to be optically active. An isomer which can rotate the plane of polarized light to the right is called as dextrorotatory and is designated as (d) or (+) Example: D- (d)-glucose or it is also known as dextrose. While the isomer which rotates the plane of polarized light to left is known as levorotatory, and is identified as (l) or (-). Example: D-(l)-fructose.

A levorotatory (–) substance rotates polarized light to the left. [E.g., l-glucose; (-)-glucose] A dextrorotatory (+) substanc rotates polarized light to the right. [E.g., d-glucose; (+)-glucose]

Molecules which rotate the plane of of polarized light are optically active. Most biologically important molecules are chiral, and hence are optically active. Often, living systems contain only one of all of the possible stereochemical forms of a compound. In some cases, one form of a molecule is beneficial, and the enantiomer is a poison (e.g., thalidomide).

Polarimetry

monochromator

sample cellpolarizerlight source

Glucose cyclic formed by Glucose cyclic formed by reaction of CHO with -OH on reaction of CHO with -OH on C5C5..

GlucoseGlucose

• Ribose and deoxyriboseRibose and deoxyribose

AnomersAnomers

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MutarotationMutarotation

Reducing SugarsReducing Sugars• If the oxygen on the anomeric carbon of a sugar If the oxygen on the anomeric carbon of a sugar

is not attached to any other structure that sugar is not attached to any other structure that sugar is a reducing sugar .A reducing sugar can react is a reducing sugar .A reducing sugar can react with chemical reagents ( Benedicts solution ) and with chemical reagents ( Benedicts solution ) and reducing the reactive component with the reducing the reactive component with the anomeric carbon becoming oxidized ( Note only anomeric carbon becoming oxidized ( Note only oxygen on the anomeric carbon determines if the oxygen on the anomeric carbon determines if the sugar is reducing or non-reducing .sugar is reducing or non-reducing .

• Glucose :Glucose :

• This monosaccharide is the most important carbohydrate in This monosaccharide is the most important carbohydrate in human nutrition because it is the one that the body fuses human nutrition because it is the one that the body fuses directly to supply its energy needs. Glucose is formed from directly to supply its energy needs. Glucose is formed from the hydrolysis of di- and polysaccharides, including starch, the hydrolysis of di- and polysaccharides, including starch, dextrin, maltose, sucrose and lactose; from the dextrin, maltose, sucrose and lactose; from the monosaccharide fructose largely during absorption; and monosaccharide fructose largely during absorption; and from both fructose and galactose in the liver during from both fructose and galactose in the liver during metabolism.metabolism.

• Glucose is the carbohydrate found in the bloodstream, and Glucose is the carbohydrate found in the bloodstream, and it provides an immediate source of energy for the body's it provides an immediate source of energy for the body's cells and tissues. Glucose is also formed when stored body cells and tissues. Glucose is also formed when stored body carbohydrate (glycogen) is broken down for use.carbohydrate (glycogen) is broken down for use.

• Fructose :Fructose :

• Fructose, a monosaccharide, is very similar to another Fructose, a monosaccharide, is very similar to another monosaccharide, galactose. These two simple sugars share monosaccharide, galactose. These two simple sugars share the same chemical formula; however, the arrangements of the same chemical formula; however, the arrangements of their chemical groups along the chemical chain differ. their chemical groups along the chemical chain differ. Fructose is the sweetest of all the sugars and is found in Fructose is the sweetest of all the sugars and is found in fruits, vegetables and the nectar of flowers, as well as fruits, vegetables and the nectar of flowers, as well as molasses and honey. In humans, fructose is produced molasses and honey. In humans, fructose is produced during the hydrolysis of the disaccharide, sucrose.during the hydrolysis of the disaccharide, sucrose.

• GalactoseGalactose

• Galactose differs from the other simple sugars, glucose and Galactose differs from the other simple sugars, glucose and fructose, in that it does not occur free in nature. It is fructose, in that it does not occur free in nature. It is produced in the body in the digestion of lactose, a produced in the body in the digestion of lactose, a disaccharidedisaccharide..

DisaccharidesDisaccharides   . . The linkage of two monosaccharides to form disaccharides involves The linkage of two monosaccharides to form disaccharides involves

a glycosidic bond by dehydration . Several physiogically important a glycosidic bond by dehydration . Several physiogically important disaccharides are sucrose, lactose and maltose.disaccharides are sucrose, lactose and maltose.

• Sucrose Sucrose • prevalent in sugar cane and sugar beets, is composed of glucose prevalent in sugar cane and sugar beets, is composed of glucose

and fructose through an a-(1,2)and fructose through an a-(1,2)ββ -glycosidic bond. -glycosidic bond.• Lactose  Lactose  • is found exclusively in the milk of mammals and consists of is found exclusively in the milk of mammals and consists of

galactose and glucose in a galactose and glucose in a ββ -(1,4) glycosidic bond. -(1,4) glycosidic bond.• This disaccharide is found only in milk. Human milk contains about This disaccharide is found only in milk. Human milk contains about

4.8 g per 100 ml and cow's milk contains approximately 6.8 g per 4.8 g per 100 ml and cow's milk contains approximately 6.8 g per 100 ml. When lactose is hydrolyzed it yields one unit of the 100 ml. When lactose is hydrolyzed it yields one unit of the monosaccharide glucose and one unit of the monosaccharide monosaccharide glucose and one unit of the monosaccharide galactose. The enzyme lactase is needed to digest lactose.galactose. The enzyme lactase is needed to digest lactose.

• Maltose : This involved C1 and C4 , this special bond is called 1-4 Maltose : This involved C1 and C4 , this special bond is called 1-4 glycosidic bond. glycosidic bond. Maltose occurs in the body as an intermediate Maltose occurs in the body as an intermediate product of starch digestion. (Starch is a polysaccharide.) When product of starch digestion. (Starch is a polysaccharide.) When maltose is hydrolyzed, it yields two molecules of glucosemaltose is hydrolyzed, it yields two molecules of glucose..

SucroseSucrose

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LactoseLactose

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MaltoseMaltose

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Polysaccharides Polysaccharides • Most of the carbohydrates found in nature occur Most of the carbohydrates found in nature occur

in the form of high molecular weight polymers in the form of high molecular weight polymers called polysaccharides . The building blocks used called polysaccharides . The building blocks used to generate polysaccharides can be varied; to generate polysaccharides can be varied; however, the predominant monosaccharide found however, the predominant monosaccharide found in polysaccharides is D-glucose. When in polysaccharides is D-glucose. When polysaccharides are composed of a single polysaccharides are composed of a single monosaccharide building block, they are termed monosaccharide building block, they are termed homopolysaccharides. Polysaccharides composed homopolysaccharides. Polysaccharides composed of more than one type of monosaccharide are of more than one type of monosaccharide are termed heteropolysaccharides. Many termed heteropolysaccharides. Many polysaccharides unlike sugars are insoluble in polysaccharides unlike sugars are insoluble in water. Dietary fiber include polysacchaides and water. Dietary fiber include polysacchaides and oligosaccharides that are resistant to digestion oligosaccharides that are resistant to digestion and absorption in the human small intestine but and absorption in the human small intestine but which are completely or partially fermented by which are completely or partially fermented by microorganisms in the large intestine.microorganisms in the large intestine.

•    

• Glycogen :Glycogen :• Glycogen is the major form of stored carbohydrate in animals. Glycogen is the major form of stored carbohydrate in animals.

This molecule is a homopolymer of glucose in a-(1,4) linkage; it is This molecule is a homopolymer of glucose in a-(1,4) linkage; it is also highly branched, with a-(1,6) branch linkages occurring every also highly branched, with a-(1,6) branch linkages occurring every 8-10 residues. Glycogen is a very compact. This compactness 8-10 residues. Glycogen is a very compact. This compactness allows large amounts of carbon energy to be stored in a small allows large amounts of carbon energy to be stored in a small volume. volume. Glycogen is the reserve carbohydrate in humans. Glycogen is the reserve carbohydrate in humans. Glycogen is very similar to amylopectin, having a high molecular Glycogen is very similar to amylopectin, having a high molecular weight and branched-chain structures made up of thousands of weight and branched-chain structures made up of thousands of glucose molecules. The main difference between glycogen and glucose molecules. The main difference between glycogen and amylopectin is that glycogen has more and shorter branches, amylopectin is that glycogen has more and shorter branches, resulting in a more compact shape.resulting in a more compact shape.

• Glycogen is stored primarily in the liver and muscles of animals. Glycogen is stored primarily in the liver and muscles of animals. About two-thirds of total body glycogen is stored in the muscles About two-thirds of total body glycogen is stored in the muscles and about one-third is stored in the liver.and about one-third is stored in the liver.

• Starch is the major form of stored carbohydrate in plant cells. Its Starch is the major form of stored carbohydrate in plant cells. Its structure is identical to glycogen, except for a much lower degree structure is identical to glycogen, except for a much lower degree of branching (about every 20-30 residues). Unbranched starch is of branching (about every 20-30 residues). Unbranched starch is called amylose; branched starch is called amylopectincalled amylose; branched starch is called amylopectin

• Amylose : Molecules consist of 200- 20,000 glucose units Amylose : Molecules consist of 200- 20,000 glucose units which form helix as a result of the bond angles between which form helix as a result of the bond angles between the glucose units.( the glucose units.( αα- 1,4 glycosidic linkage).- 1,4 glycosidic linkage).

• Amylopectin : Differs from amylose is being highly Amylopectin : Differs from amylose is being highly branched. Short side chains of about 30 glucose units are branched. Short side chains of about 30 glucose units are attached with attached with αα 1-6 linkage approximately every 20- 30 1-6 linkage approximately every 20- 30 glucose unit along the chain . Amylopectin molecules may glucose unit along the chain . Amylopectin molecules may contain up to 2 million glucose units.contain up to 2 million glucose units.

• Dextran : Is a polysaccharides similar to amylopectin but Dextran : Is a polysaccharides similar to amylopectin but the main chains are formed by the main chains are formed by αα1-6 glucosidic linkages and 1-6 glucosidic linkages and the side branches are attached by the side branches are attached by αα1-3 or 1-3 or αα 1-4 linkages. 1-4 linkages. Dextran is an oral bacterial product that adheres to the Dextran is an oral bacterial product that adheres to the teeth , creating a film called plague. It is used teeth , creating a film called plague. It is used commercially as food additives .commercially as food additives .

• Cellulose : Is composed of chains of D-glucose unit joined Cellulose : Is composed of chains of D-glucose unit joined by by ββ 1-4 glycosidic linkages. The chains are linear 1-4 glycosidic linkages. The chains are linear unbranched .It is a structural polysaccharides of plant unbranched .It is a structural polysaccharides of plant cells. cells. Like starch and glycogen, cellulose is composed of Like starch and glycogen, cellulose is composed of thousands of glucose molecules. It is the structural thousands of glucose molecules. It is the structural constituent of the cell walls of plants. Cellulose is, constituent of the cell walls of plants. Cellulose is, therefore, the most abundant naturally-occurring organic therefore, the most abundant naturally-occurring organic substance. It is characterized by its insolubility and its substance. It is characterized by its insolubility and its physical rigidity. This polysaccharide can be digested by physical rigidity. This polysaccharide can be digested by cows, sheep, horses, etc., as these animals have bacteria cows, sheep, horses, etc., as these animals have bacteria in their rumens (stomachs) whose enzyme systems break in their rumens (stomachs) whose enzyme systems break down cellulose molecules. Humans do not have the enzyme down cellulose molecules. Humans do not have the enzyme needed to digest cellulose, so it is passed through the needed to digest cellulose, so it is passed through the digestive tract unchanged.digestive tract unchanged.

AmyloseAmylose

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AmylopectinAmylopectin

CelluloseCellulose

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• Amino sugarsAmino sugars Glucosamine, Galactosamine Glucosamine, Galactosamine

• Sugar acidsSugar acids Ascorbic acid, Glucuronic acid Ascorbic acid, Glucuronic acid

• Sugar alcoholSugar alcohol D-Sorbitol from D-glucose D-Sorbitol from D-glucose

• D- Mannitol from D- MannoseD- Mannitol from D- Mannose

• D-Dulcitol from D- GalactoseD-Dulcitol from D- Galactose

• Glycoprotein Glycoprotein Component of cell wall and Component of cell wall and membranemembrane

• Blood group antigensBlood group antigens: Specific oligosaccharides : Specific oligosaccharides bound to proteins , lipids on membrane bound to proteins , lipids on membrane surfaces. surfaces.

• Disease Conditions Related To Carbohydrate ConsumptionDisease Conditions Related To Carbohydrate Consumption

1. 1. Lactose intoleranceLactose intolerance

2. Galactosemia2. Galactosemia

3. Dental caries3. Dental caries

4. Diabetes mellitus4. Diabetes mellitus

5. Hypoglycemia.5. Hypoglycemia.

Functions of carbohydrates• 1. Most abundant dietary source of energy

(4Cal/g)• 2. They are precursors for many organic

compounds (fats, amino acids)• 3. Carbohydrates (glycoprotein, glycolipids)

participate in the structure of cell membrane and cellular functions

• 4. Structural components of many organisms. These include the fibers (cellulose) of plant, exoskeleton of some insects and the cell wall of microorganisms.

• 5. Serve as the storage form of energy (glycogen) to meet the immediate energy demands of the body.

Qualitative Tests for Carbohydrates

Reducing sugars are usually detected with Benedict's reagent, which contains Cu2+ ions

in alkaline solution with sodium citrate added to keep the cupric ions in solution. The alkaline

conditions of this test causes isomeric transformation of ketoses to aldoses, resulting in all monosaccharides and most disaccharides reducing the blue Cu2+ ion to cuprous oxide (Cu2O), a brick red-orange precipitate. This solution has been used in clinical laboratories for testing urine.

Barfoed's solution contains cupric ions in an acidic medium. The milder condition allows oxidation of monosaccharides but does not oxidize disaccharides. If the time of heating is carefully controlled, disaccharides do not react while reducing monosaccharides give the positive result (red Cu2O precipitate). Ketoses do not isomerize with this reagent. Carbohydrates are dehydrated in the presence of nonoxidizing acids to form furfural and hydroxymethylfurfural.

Seliwanoff's reagent contains resorcinol in 6 M hydrochloric acid. Hexoses undergo dehydration when heated in this reagent to form hydroxymethylfurfural, that condenses with resorcinol to give a red product. Ketohexoses (such as fructose) and disaccharides containing a ketohexose (such as sucrose) form a cherry-red condensation product. Other sugars may produce yellow to faint pink colors.

Bial's reagent contains orcinol (5-methylresorcinol) in concentrated HCl with a small amount of FeCl3 catalyst. Pentoses are converted to furfural by this reagent, which form a bluegreen color with orcinol. This test is used to distinguish pentoses from hexoses.

Iodine forms a deep blue color in the presence of starch. Potassium iodide is added to the reagent solution in order to make the iodine more soluble in water. Some forms of starch may yield a greenish color. Simple carbohydrates (mono- and disaccharides) and cellulose do not cause any change in the orange-brown color of the iodine reagent.

Glucose anhydrousGlucose anhydrous

Appearance. The crystalline powder of white color with sweet taste.

Solubility. Easily soluble in water R, moderately soluble in 96% alcohol R.

IDENTIFICATIONIDENTIFICATION

1.1. TLCTLC

2.2. Reaction with reagents Feling. 0.1 g of the substance is dissolved in 10 Reaction with reagents Feling. 0.1 g of the substance is dissolved in 10 ml of ml of water Rwater R, 3 ml , 3 ml solution of copper tartratic solution of copper tartratic R is added and it is R is added and it is heated; red sediment is formed:heated; red sediment is formed:

3. 3. TTo the 0,02 g of the substance are added o the 0,02 g of the substance are added a few crystals of a few crystals of resorcinol Rresorcinol R, 1-2 ml of , 1-2 ml of dilute hydrochloric acid Rdilute hydrochloric acid R and it is and it is heated till boiling; there appears pink heated till boiling; there appears pink color.color.

4. To 0,01 g of the substance is added 4. To 0,01 g of the substance is added 0.01 g 0.01 g thymol Rthymol R, 5-6 drops of , 5-6 drops of sulphate sulphate acidacid RR and R 1-2 drops of and R 1-2 drops of water Rwater R; there ; there appears dark red color.appears dark red color.

TEST ON PURITYTEST ON PURITY

• Irrelevant sugars, soluble starch, Irrelevant sugars, soluble starch, dextrinsdextrins. 1.0 g of the substance is . 1.0 g of the substance is dissolved by boiling in 30 ml of dissolved by boiling in 30 ml of alcohol (90% v / v) Ralcohol (90% v / v) R then it is then it is cooled; the solution must remain cooled; the solution must remain transparent.transparent.

QUANTITATIVE QUANTITATIVE DETERMINATIONDETERMINATION

• State Pharmacopoeia of Ukraine does not State Pharmacopoeia of Ukraine does not provide quantitative determination of provide quantitative determination of glucose in the substance.glucose in the substance.

• Iodometry, the reverse titrationIodometry, the reverse titrationApproximately 0.1 g of substance (exact batch), Approximately 0.1 g of substance (exact batch), is placed in a flask capacity 250 ml, it is dissolved is placed in a flask capacity 250 ml, it is dissolved in 10 ml of in 10 ml of water Rwater R. It is added 20.0 ml of 0.05 M . It is added 20.0 ml of 0.05 M solution of iodinesolution of iodine, 10.0 ml of 1% , 10.0 ml of 1% solution of solution of sodium hydroxide Rsodium hydroxide R and left for 15 min. Then the and left for 15 min. Then the solution is acidified by 10 ml solution is acidified by 10 ml dilutedilute acid sulphate acid sulphate RR and titrated by 0.1 M and titrated by 0.1 M solution of sodium solution of sodium thiosulfatethiosulfate (indicator - (indicator - starch solution Rstarch solution R). In ). In parallels a control experiment is conducted.parallels a control experiment is conducted.

• II22 + 2NaOH → NaI + NaIO + H + 2NaOH → NaI + NaIO + H22O;O;

• NaIO + NaI + HNaIO + NaI + H22SOSO44 → I → I22 + Na + Na22SOSO44 + + HH22O;O;

• II22 + 2Na + 2Na22SS22OO33 → 2NaI + Na → 2NaI + Na22SS44OO66..• Em = М. м./2Em = М. м./2

STORAGESTORAGE

In tightly closed container. In tightly closed container.

APPLICATIONAPPLICATION

During various diseases of heart, During various diseases of heart, liver, at shock treatment, collapse, as liver, at shock treatment, collapse, as a source of nutrition, which is easily a source of nutrition, which is easily assimilated by organism and assimilated by organism and improves the functions of different improves the functions of different organs.organs.

• Tannins can be modified to change their solubility properties or to eliminate the reactive phenolic functional groups. The modified tannins do not retain the characteristic chemical or biological reactivities of native tannins.

Acetylation

• Puts an acetyl group on each hydroxyl group of the starting material. Polarity of the tannin is diminished, and it is insoluble in aqueous solvents. Slowly drip a mixture of 5 mL pyridine and 5 mL fresh acetic anhydride into a flask containing 2 g tannic acid. Pour the solution into water; a solid should form. The solid is washed with dilute acetic acid (to remove the pyridine) and then with water. It can be freeze dried. Its IR spectrum shows loss of the phenolic OH group.

Methylation

• Converts each hydroxyl group to its methyl ester. Polarity of the tannin is diminished and its solubility altered. We have not attempted this procedure. To methylate tannin, mix it with excess methyl iodide, reagent acetone and solid potassium carbonate. Reflux the mixture overnight and purify the product.

Thank you for attention!Thank you for attention!