Pharmacognosy: Carbohydrates - Advanced Theory

 Course Title Pharmacognosy-IIA (Advanced) [Theory] Course Code PHARM 513-T Topic : Carbohydrates 2 Course Incharge Sidrah Talib  Learning Objectives Sugars D and L configurations...

 Course Title Pharmacognosy-IIA (Advanced) [Theory] Course Code PHARM 513-T Topic : Carbohydrates 2 Course Incharge Sidrah Talib  Learning Objectives Sugars D and L configurations Cyclic structures Linear and ring forms of glucose α-D-Glucose and β-D-Glucose Pyranose & Furanose Dextrose Liquid glucose Calcium gluconate Calcium gluceptate and calcium levulinate Ferrous gluconate  Previous Lecture Metabolites are products of metabolism and perform various functions. Metabolites can be categorized into Primary metabolites and secondary metabolites. Carbohydrates are aldehyde or ketone alcohols containing carbon, hydrogen and oxygen Monosaccharides are the compounds that cannot be hydrolyzed to simpler sugars. The monosaccharides are subdivided as trioses, tetroses, pentoses, hexoses Oligosaccharides sugars which yield 2 to 10 monosaccharide units on hydrolysis.Disaccharides Carbohydrates, which upon hydrolysis yield two molecules of monosaccharides Trisaccharides liberate three molecules of monosaccharides on hydrolysis. Raffinose & Gentianose Stachyose, a tetrasaccharide, yields on hydrolysis, four molecules of monosaccharide, found in manna On hydrolysis they give an indefinite number of monosaccharides.  Sugars D and L configurations When the hydroxyl groups on carbons 4 and 5 are to the right side of the fischer projection, glucose is D- configuration. When the hydroxyl groups on carbons 4 and 5 are to the left side of the fischer projection, glucose is L-sugar.  CYCLIC STRUCTURES Open-chain form of D-Glucose called as Aldehydo-D- Glucose is taken, and condense the aldehyde group on carbon-1, with the alcoholic-OH group on carbon-5, two different forms of glucose are formed. When the OH group extends to right, it is α-D-Glucose and it extends to left, it is β-D-Glucose  Dextrose α-D(+)-glucopyranose or D-glucose is a sugar that occurs naturally in grapes and other fruits. It is usually obtained by controlled enzymatic hydrolysis of starch. High-conversion hydrolysates are subjected to rigorous purification procedures to yield crystalline dextrose that is 99.5 to 100% pure and suitable for parenteral use. USES. Dextrose is a nutrient and may be given by mouth, by enema, by subcutaneous injection, or by intravenous injection, as required. It also is present in anticoagulant citrate dextrose  Liquid glucose It is a product obtained by the incomplete hydrolysis of starch. It consists chiefly dextrose but also contains dextrins, maltose, and water. Liquid glucose is usually prepared by controlled acid hydrolysis of corn starch. The washed starch is mix with diluted hydrochloric acid and heated for 22 minutes at about 30 lb pressure, the acid is neutralized, and the neutral liquid is centrifuged and filtered until clear. This clear liquid is then evaporated to the syrupy condition. It is a colorless or yellowiish, thick, syrupy liquid Uses It is used as an agent of pharmaceutic necessity. Calcium gluconate is the calcium salt of gluconic acid. Gluconic acid is obtained by the oxidation of dextrose. Calcium gluconate is soluble in cold water and less irritating for parenteral use than calcium chloride. An electrolyte replenisher, calcium gluconate is used to obtain the therapeutic effects of calcium. Calcium gluceptate and calcium levulinate are calcium salts of 7- and 5-carbon acids that are prepared semisynthetically from carbohydrates. The salts are calcium are used parenterally to obtain the therapeutic effects of calcium. Ferrous gluconate is the ferrous salt of gluconic acid. It is classed as a hematinic and is employed in iron deficiency anemia.  Summary Hydroxyl groups are on carbons 4 and 5 to the right side and to the left side of the fischer projection, glucose is D and L-sugar respectively. Two different cyclic forms of glucose are formed, α-D-Glucose OH extends to right and it extends to left, it is β-D-Glucose. Six membered ring of glucose called Pyranose & five membered ring of glucose is Furanose D-glucose is a sugar that occurs naturally in grapes and other fruits. Dextrose is a nutrient and is present in anticoagulant citrate dextrose solution for the storage of whole blood Liquid glucose is usually prepared by controlled acid hydrolysis of corn starch. It is employed as a sweetening agent, as a substitute for sucrose in syrups, and as a tablet binder and coating agent. Calcium gluconate, Calcium gluceptate and calcium levulinate are used parenterally to obtain the therapeutic effects of calcium. Ferrous gluconate is the ferrous salt of gluconic acid, classed as a  Further reading and references Evans WC, Trease GE, Evans D. Trease and Evan’s Pharmacognosy. 16th Ed. Elsevier Health Sciences Publisher; 2009 Tyler VE, Brady LR, Robbers JE. Pharmacognosy. 10th Ed. Lea and Febiger; 2001 Kar A. Pharmacognosy and Pharmacobiotechnology, Revised - expanded Second edition, new age international (p) limited, publishers. Shah and Seth. Textbook of Pharmacognosy and Phytochemistry. First Edition 2010ELSEVIER. A division of Reed Elsevier India Private Limited