Pharmaceutical Compounds Quiz

Ferrous Gluconate and Calcium Gluconate

• Ferrous gluconate (orally or intravenously) is used to treat iron deficiency.
• Calcium gluconate (intravenously or orally) is used to treat calcium deficiency.

Sorbitol

• Sorbitol is prepared by the reduction of glucose.
• Sorbitol is used as a mild laxative.
• Sorbitol is used in the preparation of spans and tweens.
• Sorbitol is used in the pharmaceutical industry as a nitrated form for angina treatment.
• Sorbitol is used in the food, chewing gum, and cosmetic industries (toothpaste).

Mannitol

• Mannitol is prepared by reduction of mannose.
• Mannitol is used as an osmotic diuretic.
• Mannitol is used as a vasodilator (mannitol hexanitrate).
• Mannitol is used in the laboratory diagnosis of kidney function because it is not metabolized when administered intravenously.

Ascorbic Acid

• Ascorbic acid (vitamin C) is synthesized both biochemically and industrially from D-glucose.

Oligosaccharides

• Oligosaccharides are crystalline, soluble in water, and have a sweet taste.
• Oligosaccharides can be hydrolyzed by acids or specific enzymes to yield 2-10 molecules of monosaccharides.
• Most oligosaccharides crystallize as hydrates, except for sucrose.
• The monosaccharide units are linked through glycosidic linkages.
• The type of glycosidic bond is based on the orientation of the hydroxyl group at the anomeric position.

Melibiose

• Melibiose is a reducing disaccharide formed by an α-1,6 linkage between galactose and glucose.
• Melibiose is formed by invertase-mediated hydrolysis of raffinose, producing melibiose and fructose.

Maltose (Malt Sugar)

• Maltose is not commonly found in nature except in malt and germinating cereals.
• Maltose is a hydrolytic product of polysaccharides like starch and dextrin.
• Maltose can be obtained from starch by:
  • Acid hydrolysis, which is random and yields a low amount of product.
  • β-amylase, which yields 80% of the product.
• Maltose reduces Fehling's solution but not Barfoed's solution.
• Maltose forms a characteristic osazone that looks like rosettes of plates.
• Maltose is hydrolyzed by maltase enzyme (α-glucosidase).
• Maltose is used as a mild sweetener in foods and pharmaceuticals.
• Maltose is used as a parenteral injectable for the slow release of D-glucose.

Cellobiose

• Cellobiose is not found in nature.

D-Mannose

• D-Mannose is a C2-epimer of glucose.
• D-Mannose is a constituent of polysaccharides, but is not found free in nature.
• D-Mannose is prepared by acid hydrolysis of seeds from dates and coffee.
• D-Mannose is used to prevent urinary tract infections and treat carbohydrate-deficient glycoprotein syndrome.

D-Galactose

• D-Galactose is a C4-epimer of glucose.
• D-Galactose is found in many glycosides and polysaccharides like agar and linseed mucilage.
• D-Galactose is prepared by acid hydrolysis of agar and linseed mucilage.
• D-Galactose is used to determine liver function because its spillage in urine indicates liver dysfunction.

Galactosemia

• Galactosemia is a genetic metabolic disorder where individuals cannot metabolize galactose properly.
• Toxic levels of galactose-1-phosphate accumulate in various tissues.
• Signs and symptoms include lethargy, vomiting, diarrhea, failure to thrive, jaundice, hepatomegaly, cirrhosis, renal failure, cataracts, brain damage, and ovarian failure.
• Treatment involves eliminating lactose and galactose from the diet.

Fructose (Levulose, Fruit Sugar)

• Fructose is found free in honey and fruit juices, as well as in the disaccharide sucrose and polysaccharides like inulin.
• Fructose is the sweetest of all natural sugars (1.73 times sweeter than sucrose).
• Fructose is a colorless crystal that is freely soluble in water.
• Fructose reduces Fehling's and Barfoed's reagents.
• Fructose forms an osazone similar to glucose and mannose.
• Fructose gives a positive rapid furfural test (resorcinol test) for ketoses.

Physical Properties of Carbohydrates

• Monosaccharides like glucose and fructose, and most disaccharides like sucrose, are white crystalline solids that melt sharply.
• Higher polysaccharides like starch and cellulose are amorphous solids and do not melt sharply.
• Low molecular weight sugars are sweet, but there are different degrees of sweetness.
• Sucrose is the reference point for sweetness and has a sweetness value of 1.

Solubility

• Monosaccharides are soluble in cold water and hot alcohol.
• Gums are soluble in water but insoluble in alcohol.
• Mucilage, pectins, starch and glycogen are soluble in hot water but not in cold water or alcohol.
• Hemicellulose is insoluble in cold and hot water but soluble in dilute alkalis.
• Cellulose is insoluble in all of the above solvents.

Optical activity of sugars

• A compound is optically active when in solution it can rotate the plane of polarized light either to the right or left.
• Compounds that rotate the plane of polarized light to the right are called dextrorotatory and are denoted by a (+) symbol or d.
• Compounds that rotate the plane of polarized light to the left are called levorotatory and are denoted by a (-) symbol or l.
• Monosaccharides and water-soluble oligosaccharides are optically active and are measured by a polarimeter.

Monosaccharides

• Monosaccharides are the simplest carbohydrates and are made up of only one unit.
• Monosaccharides cannot be further hydrolyzed.
• Monosaccharides are white crystalline solids.
• Monosaccharides contain a single aldehyde or ketone functional group.
• All monosaccharides are optically active.
• Most monosaccharides found in nature are in the D- configuration.
• Naturally occurring monosaccharides contain 3 – 7 carbon atoms.

Reactions of Monosaccharides

• Monosaccharides undergo reactions similar to other carbonyl compounds and alcohols, and also have specific reactions unique to carbohydrates.

Reactions similar to carbonyl compounds

• Glycoside formation: Carbohydrate acetals are called glycosides. The acetals of glucose are called glucosides.
• Oxidation: Aldoses can be oxidized to aldonic acid by mild oxidizing agents, and to aldaric acid by strong oxidizing agents. Aldoses can also be oxidized to alduronic acids by controlled oxidation at C-6. Glucuronic acid is important because the body uses it to detoxify foreign alcohols and phenols.
• Reduction: Aldoses can be reduced to alditols.

Reactions specific to carbohydrates

• Osazone formation:
• Action of mineral acids: Form furfural and its derivatives which form colored complexes with phenolic compounds and amines. These colored complexes can be used for qualitative and quantitative determination of monosaccharides.
• Effect of alkalis: Strong alkalis cause polymerization of monosaccharides, while weak alkalis cause isomerization. For example, glucose can be isomerized to fructose or mannose by the action of weak alkalis.
• Reaction with oxidizing cations: All monosaccharides and reducing disaccharides are oxidized by metal ions in alkaline medium.

Hexoses

• D-Mannose is a C2-Epimer of glucose and is found in many glycosides and polysaccharides, it is used to prevent urinary tract infections and treat carbohydrate-deficient glycoprotein syndrome
• D-Galactose is a C4-Epimer of glucose and is found in many glycosides and polysaccharides such as agar and linseed mucilage, it is used to determine liver function, spillage of galactose in urine indicates liver dysfunction
• Galactosemia is a genetic metabolic disorder that affects inidividuals ability to properly metabolize galactose, causing toxic levels of galactose-1-phosphate in various tissues
• Signs and symptoms include lethargy, vomiting, diarrhea, failure to thrive, jaundice, hepatomegaly, cirrhosis, renal failure, cataracts, brain damage and ovarian failure
• Treatment involves eliminating lactose and galactose from the diet
• Fructose (levulose, fruit sugar) is found free in honey and fruit juices, in disaccharide sucrose and in polysaccharides such as inulin, it is the sweetest of all natural sugars
• It is a colorless crystal that is freely soluble in water and reduces Fehling’s and Barfoed’s reagents
• Fructose forms an osazone similar to that of glucose and mannose and gives a positive Resorcinol test for ketoses
• Fructose can be prepared on a large scale from sucrose by acid or enzyme hydrolysis, or from inulin by acid hydrolysis and from Glucose by alkali action
• Fructose is used as a diabetic food due to its low glycemic factor, as a food additive for infant feeding formulae, and for diet control

Deoxy Sugars

• 2-Deoxy-D-Ribose is a 2-Deoxy Pentose that is part of nucleic acids (DNA)
• α-L-Rhamnose is a 6-Deoxy Hexose found in many glycosides and in gum acacia, it gives a yellow color when tested with aniline acetate paper
• Digitoxose and Cymarose are 2,6-Deoxy Hexose sugars found in many cardiac glycosides, they are positive when tested with Killer Killiani’s test
• They are sugar parts in many cardiac glycosides

Sugar Derivatives

• Gluconic acid is produced from glucose by mild oxidation using dilute HNO3, Br2/Na2CO3, electrically or by fermentation using Acetobacter aceti
• Gluconic acid salts are more easily absorbed than other Ca or Fe salts
• Ferrous gluconate is used orally or by intravenous injection to treat iron deficiency
• Calcium gluconate is used orally and intravenously to treat calcium deficiency
• Sorbitol is prepared by reduction of glucose, has laxative properties, is used in the preparation of Span and Tweens and is used in cosmetic and food industries
• Mannitol is prepared by reduction of mannose, is used as an osmotic diuretic and vasodilator due to its property as a hexanitrate
• Mannitol is used in the laboratory diagnosis of kidney functions, it is not metabolized when given intravenously
• L-Ascorbic acid (vitamin C) is synthesized industrially and biochemically from D-glucose

Oligosaccharides

• Oligosaccharides are crystalline, soluble in water, sweet and yield 2-10 molecules of monosaccharides when hydrolyzed by acids or enzymes
• Most oligosaccharides crystallize as hydrates except sucrose
• Monosaccharide units are linked through glycosidic linkages
• The type of glycosidic bond is based on the orientation of hydroxyl group at the anomeric position

C1-C6 Dihexoses

• Melibiose is a reducing disaccharide formed by an α-1,6 linkage between galactose and glucose, it can be formed by invertase-mediated hydrolysis of raffinose

C1-C4 Dihexoses

• Maltose (malt sugar) is not common in nature, it is found in malt and germinating cereals and is a product of hydrolysis of starch and dextrin
• Maltose is obtained from starch by either acid hydrolysis for a low yield or β-amylase for a higher yield of up to 80%
• It reduces Fehling’s solution but not Barfoed’s solution and forms characteristic osazone rosettes of plates
• It is hydrolyzed by maltase enzyme (α-glucosidase) and is used as a mild sweetener in food and pharmaceuticals and as an injectable for slow release of D-glucose
• Cellobiose is not found in nature and is obtained from cellulose by careful acid hydrolysis or using the enzyme cellulase
• Lactose (milk sugar) is found naturally in milk, it provides 40% of the energy obtained during nursing and must be broken down to D-glucose and D-galactose
• It is produced from cow’s milk using heat or renin enzymes, whey is then filtered and concentrated to yield crystalline lactose
• Lactose reduces Fehling’s but not Barfoed’s solution, forms characteristic osazone needles aggregated in clusters and is hydrolyzed by β-glucosidases
• Lactose is a nutrient in infant food