MODULE 2: CLASSES OF CHEMICAL CONSTITUENTS (I) PDF

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Carbohydrates - Carbohydrates are much abundant in plants, rather than in animals. - Carbohydrates are widely distributed in plants and animals and also found in green plants by the process of Photosynthesis. o This process occurs with the presence of Chlorophyll Pigment.BIOSYNTHESIS - Process in wh...

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PHARMACOGNOSY AND PLANT CHEMISTRY

Carbohydrates • Carbohydrates are much abundant in plants, rather than in animals. • Carbohydrates are widely distributed in plants and animals and also found in green plants by the process of Photosynthesis. o This process occurs with the presence of Chlorophyll Pigment. BIOSYNTHESIS • Process in which substrates are converted to more complex products. The products which are produced as a result of biosynthesis are necessary for cellular and metabolic processes deemed essential for survival. • Photosynthesis an anabolic, endergonic, carbon dioxide (CO2) requiring process that uses light energy (photons) and water (H2O) to produce organic macromolecules (glucose). o Anabolic reactions (also called anabolism) are chemical reactions in which energy is stored in molecules. o Endergonic chemical reaction that requires the absorption of energy. o LIGHT DEPENDENT REACTIONS uses light energy to make two molecules needed for the next stage of photosynthesis. o The energy storage molecule ATP and the reduced electron carrier NADPH that provides energy to fuel the Calvin cycle in the second stage of photosynthesis. o LIGHT INDEPENDENT REACTIONS or CALVIN CYCLE Reactions because they are not directly driven by light. o The energized electrons from the light-dependent reactions provide the energy to form carbohydrates from carbon dioxide molecules o The Calvin cycle uses 18 ATP and 12 NADPH molecules to produce one glucose molecule. • Glycolysis series of reactions that extract energy from glucose by splitting it into two threecarbon molecules called pyruvates. o PHASES OF GLYCOLYSIS o Energy-Requiring: The first half of glycolysis uses two ATP molecules in the phosphorylation of glucose, which is then split into two three-carbon molecules. o Energy-Releasing: The second half of glycolysis involves phosphorylation without ATP investment (step 6) and produces two NADH and four ATP molecules per glucose. o End Product: 2 ATP, 2 NADH, and 2 MOLECULES OF PYRUVATE • Citric acid cycle a series of chemical reactions used by all aerobic organisms to generate energy through the oxidization of acetate derived from carbohydrates, fats, and proteins into carbon dioxide.

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Glycogenesis biological process of forming glycogen from glucose o Glucose is transported into the liver cells by a specific glucose transporter, whereby it is immediately phosphorylated Hence, most of the glucose in a cell is in the form of glucose-6-phosphate. o Glycogenesis is stimulated by the hormone insulin. JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

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Glycogenolysis process by which glycogen is broken down into glucose (glucose-1-phosphate and glycogen) o The reaction takes place in the hepatocytes and the myocytes. The process is under the regulation of two key enzymes: phosphorylase kinase and glycogen phosphorylase. o Provide immediate energy and to maintain blood glucose levels during fasting. Gluconeogenesis it is a metabolic pathway that results in the generation of glucose from noncarbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids. o The production of new glucose

CLASSIFICATION • Classification of carbohydrates based on their molecular size • Monosaccharides simplest carbohydrate units (simple sugars) o Building blocks of carbohydrates o Cannot be hydrolyzed to simpler sugars/carbohydrates o Characteristics ▪ Crystalline compounds ▪ Soluble in water ▪ Practically insoluble in organic solvents ▪ Needs digestion in-order to be absorbed in blood stream • Examples o Based on the no of carbon atom and presence of carbonyl group o Triose simplest monosaccharides containing 3 carbon atoms. ▪ Glyceraldehyde (aldotriose) aldose with 3 carbon atoms ▪ Dihydroxyacetone (ketotriose) ketose with 3 carbon atoms o Tetrose is a monosaccharide whose molecule contains four carbon atoms ▪ Erythrulose keto-tetrose is a tetrose that has a ketone functional group attached to Carbon 2 of the straight chain, spray tan solution. o Pentoses a monosaccharide containing five atoms ▪ Xylose (Wood sugar) monosaccharide of aldopentose type. It is an attractive sugar because it can be converted to ethanol, furfural, and xylitol. • Uses: Diagnostic aid in intestinal malabsorption and diabetic sweetener in food and beverage. ▪ Ribose and Deoxyribose o Hexoses monosaccharide with six carbon atoms and most important monosaccharides ▪ Glucose (Dextrose/D-glucose/Blood sugar / grape sugar /physiologic sugar) ▪ Monosaccharide containing six carbon atoms and an aldehyde group at C1 ▪ It is found in fruits and honey and is the major free sugar circulating in the blood of higher animals. ▪ 𝛽-D-Glucose - most abundant and important • Uses: Energy storage, Dextrose excipient (glucose powder) o Fructose (Levulose) ▪ Monosaccharide containing six carbon atoms and a ketone group at C2 ▪ Occurs in sweet fruits and honey

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

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Colorless crystals, odorless powder that has a sweet taste • Uses: Ingredient in infant feeding and sugar for diabetic patients Galactose ▪ Monosaccharide and has the same chemical formula as glucose differing only in the position of one hydroxyl group ▪ Epimer (One of a pair of stereoisomers that differ in the absolute configuration of a single stereocenter) of glucose at C4 ▪ Galactosemia inherited condition in which galactose cannot be converted to glucose. • Uses: sweetener in biscuits, confectionery, and some dairy desserts.

Oligosaccharides formed by condensation of 3 – 10 monosaccharides molecules linked by glycosidic bond o Characteristics ▪ Crystalline compounds ▪ Soluble in water ▪ Sweet to taste ▪ Must be digested to monosaccharide's before absorbed and used for energy. Examples o Based on their glycosidic linkage o Reducing sugar carbohydrate that is oxidized by a weak oxidizing agent, property of reducing sugars is that, in aqueous medium, they generate one or more compounds containing an aldehyde group. (hemiacetal). o The anomeric carbon (carbon derived from the carbonyl carbon compound (the ketone or aldehyde functional group)) is not involved in a glycosidic linkage o Non reducing sugar carbohydrate that is not oxidized by a weak oxidizing agent. Property of nonreducing sugars is that, in basic aqueous medium, they do not generate any compounds containing an aldehyde group. o The anomeric carbon is involved in a glycosidic linkage o Reducing sugar o Maltose ▪ Malt sugar ▪ Disaccharides obtained from the hydrolysis of starch ▪ Made out of two glucose molecules bound together in α 1 – 4 linkage • Uses: Food and beverage sweetener o Lactose ▪ Milk sugar - from cow’s milk of Bos taurus ▪ Composed of glucose and galactose bound together in 𝛽 -1 – 4 linkage. ▪ Lactose intolerance / lactose malabsorption are unable to fully digest the sugar (lactose) in milk. As a result, they have diarrhea, gas and bloating after eating or drinking dairy products. • Uses: Filler or diluent in tablets and capsules, milk and dairy products ▪ Cow’s milk is a white, opaque liquid, being an emulsion of minute fat globules suspended in a solution of casein, albumin, lactose, and inorganic salts.

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

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Will undergo Churning meaning changing / agitation whole milk or cream on separating of fat globules • Butter - churned fat globules • Butter milk - liquid left from churned fat globules • Skimmed milk - milk left after the separation of the cream • Whey – liquid separated from the coagulum which contains lactose & inorganic salts • Cheese - skim milk treated with rennin to form a coagulum • Condensed Milk – partial evaporation of milk in a vacuum & consequent sterilization Non reducing sugar Sucrose ▪ Table sugar ▪ Composed of α- D - glucose and β – d – fructose in α -1 – 2 linkage ▪ Sources: Sugar cane (Saccharum officinarum), Sugar beet (Beta vulgaris), and Sugar maple (Acer saccharum) ▪ Molasses residual dark colored syrup after complete crystallization of sucrose, it is use in Food and ethanol industry. • Uses: Demulcent, sweetening agent (masks taste), coating agent, preservative, production of syrups, retards oxidation.

Polysaccharides long chains of monosaccharides linked by glycosidic bonds. o Large molecule made of many smaller monosaccharides. o Consists of high molecular weight polymers of large numbers of monosaccharides o Considered as non-sugar carbohydrates o Characteristics ▪ Amorphous compounds ▪ Insoluble in water ▪ Not sweet to taste ▪ They form colloidal suspensions instead of solution & must be digested before being absorbed. Examples o Homoglycans a polysaccharide when it contains only one type of monosaccharide unit. o Heteroglycans a polysaccharide when it contains two or more different monosaccharide units. o Homoglycans o Starch ▪ Polysaccharide comprising glucose monomers joined in α 1,4 linkages. ▪ The linear and helical amylose and the branched amylopectin. ▪ Temporary storage form of photosynthetic products ▪ Sources: Corn (Zea mays), Wheat (Triticum aestivum), Potato (Solanum tuberosum), Rice (Oryza sativa), Arrowroot (Maranta arundinacea) • Uses: Tablet filler, binder and disintegrant, Antidote for iodine poisoning

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

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Glycogen ▪ Branched polymer of glucose linked linearly by α-1,4 glycosidic bonds, approximately every ten residues a chain of glucose residues branches off via α-1,6 glycosidic linkages. ▪ More branched than starch ▪ Found in skeletal muscles & liver ▪ Can provide 80 – 85% of energy • Uses: Serves as a form of energy storage in animals, fungi, and bacteria. Inulin ▪ A polysaccharide which, on hydrolysis, yields mainly fructose. ▪ Source: Chicory root of Chicorum intybus (Asteraceae) • Uses: Improves digestion, ingredient in culture media, and evaluation of renal function Dextran ▪ Polysaccharide that differs from others in that its glucose units are joined together 1- 6 glucoside links. ▪ A complex branched glucan (polysaccharide derived from the condensation of glucose) ▪ Source: Lactic acid bacteria (Leuconostoc mesenteroides) • Uses: Plasma expander (Agents that have relatively high molecular weight and boost the plasma volume by increasing the osmotic pressure.) Cellulose ▪ Most abundant organic matter ▪ Most abundant polysaccharide in nature and consists only glucose units only, which are arranged in a linear chain. ▪ Principal structural element of higher plant cell walls ▪ Source: From the hair of the seeds of Gossypium hirsutum • Uses: Surgical dressing mechanical protection to absorb blood, textiles, and manufacture of explosives Homoglycans Gums ▪ Natural plant hydrocolloids that may be classified as anionic and nonionic polysaccharides or salts of polysaccharides. ▪ Produced by plants as a protective after injury ▪ Translucent and amorphous substances Karaya gum/Sterculia Gum ▪ Source: Sterculia urens, Sterculia villosa, Sterculia tragacantha, Cochlospermum gossypium ▪ Family: Malvaceae / Sterculiaceae ▪ Dried gummy exudates from: Source ▪ Gum exudes naturally or from incisions made to the hardwood.

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

Uses: Bulk laxative, as an agent forming emulsions and suspensions, and as a dental adhesive Sodium alginate/Algin ▪ Source: Macrocystis pyrifera (Giant kelp) ▪ Family: Lessoniaceae ▪ Purified marine gum product extracted from source. ▪ Uses: Suspending agent, Consists of alginic salt use as binder or thickening agent. ▪

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Agar/Japanese Isinglas ▪ Source: Gelidium cartilagineum, Gracilaria confervoides ▪ Family: Gelidaceae ▪ Dried hydrophilic, colloidal substance extracted from a marine gum such as (source). ▪ Uses: Used as laxatives, suspending agent, emulsifier, gelating agent for suppositories, surgical lubricant, tablet excipient, disintegrant, gel in bacteriologic culture media, and aid in food and industrial processes. Carageenan or Irish moss ▪ Source: Chondrus crispus (Carageenan), Gigartina mamillosa (Irish moss) ▪ Family: Gigartinaceae ▪ Hydrocolloids obtained from various red algae or seaweeds of (source) ▪ Uses: Used as demulcent, a bulk laxative, and ingredient in many food preparation Psyllium/Plantago seed ▪ Source: Plantago psyllium ▪ Family: Plantaginaceae ▪ Uses: Seeds use as cathartic, Ingredient in preparations for treatment for constipation Cydonium/Quince seed ▪ Source: Ripe seed of Cydonia vulgaris ▪ Family: Rosaceae ▪ It possesses a mucilaginous epithelium composed of celluloses ▪ Uses: Thixotropic agent Guar gum or guaran ▪ Source: Powdered endosperm of Cyamopsis tetragonolobus ▪ Family: Fabaceae ▪ Uses: Used as a bulk forming laxative, thickening agent, a tablet binder and disintegrating agent in pharmaceutical Locust bean gum/Carob pulp/St. John’s Bread ▪ Source: Hydrocolloid powdered endosperm of the seed of Ceratonia siliqua ▪ Family: Fabaceae ▪ Uses: Used as a thickener and stabilizing agent Xanthan gum

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

Source: Microbial gum prepared by the action of Xanthomonas campestris on carbohydrates ▪ Family: Xanthomonadaceae ▪ Uses: An excellent emulsifying agent with suspending properties, it has pseudoplastic properties that enables toothpaste and ointments to hold their shape and spread readily. Acacia/Gum Arabic ▪ Source: Acacia senegal ▪ Family: Fabaceae ▪ Dried gummy exudates from: Source ▪ Uses: Suspending agent, demulcent, emollient, emulsifying agent, binding agent, and stabilizing agent. Tragacanth/ Gum tragacanth ▪ Source: Astragalus gummifer ▪ Family: Fabaceae ▪ Dried gummy exudates from: Source ▪ Uses: Suspending agent, demulcent, emollient, emulsifying agent, and used in lotions & spermicidal jellies. Pectin ▪ Source: A purified carbohydrate product obtained from the dilute acid extract of the inner portion of the rind of citrus fruit. ▪ It is a course/fine powder, yellowish, white in color, odorless, and mucilaginous taste ▪ Uses: Used as a protectant, suspending agent, and ingredient in anti-diarrheal preparations. ▪

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OTHER SORUCES OF CARBHYDRATES o Product of oxidative metabolism o Cherry Juice ▪ Source: Prunus Cerasus ▪ Family: Rosaceae ▪ Liquid expressed from the fresh, ripe fruit of Prunus Cerasus ▪ Uses: Preparation of cherry syrup, a vehicle serving as disguising agent in pharmaceutical mixtures. o Citric acid ▪ First isolated from lemon juice (Citrus limon) by Swedish chemist Carl Wilhelm Scheele in 1784 ▪ Uses: Flavoring and preserving agent o Lactic acid ▪ Milk acid ▪ Uses: Acidulant in infant feeding formula, feminine wash o Tartaric acid ▪ 2,3-dihydroxybutanedioic acid

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

Uses: Improve the taste of oral medications, one of the important acids in wine, and used in foods to give a sour taste o Ferrous fumarate ▪ Uses: hematinic o Alcohol of Ethanol ▪ 95% ethanol by volume @ 15.56°C ▪ Product of fermentation ▪ Undergo the process of distillation to concentrate the alcohol content to 4055% ▪ Liquor • Brandy - produced by distilling Wine • Whiskey - Fermented Malted grain • Rum - from fermented Molasses ▪ Concentration • 70% - disinfectant • 50% - dilute alcohol ▪ Uses: In low concentration - CNS Stimulant and in high concentration - CNS depressant o Product of reductive metabolism o Mannitol ▪ D-mannitol ▪ From dried saccharine exudate of manna ash Fraxinus ornus (Oleaceae) ▪ Freely soluble in water & boiling alcohol but insoluble in cold alcohol ▪ Uses: Osmotic diuretic and laxative o Sorbitol ▪ D-glucitol ▪ A hexitol originally obtained from the ripe berries of mountain ash, Sorbus aucuparia (Rosaceae). ▪ Tastes approximately half as sweet as sucrose ▪ Uses: Manufacture of toothpastes and chewing gums EXTRACTION AND PURIFICATION • Boiling with 80% Alcohol one of the most commonly used methods of extracting low molecular weight carbohydrates. o Monosaccharides and oligosaccharides are soluble in alcoholic solutions, whereas proteins, polysaccharides and dietary fiber are insoluble. • Chromatography powerful analytical techniques for the analysis of the type and concentration of monosaccharides and oligosaccharides o Thin layer chromatography (TLC), Gas chromatography (GC) and High-Performance Liquid chromatography (HPLC) are commonly used to separate and identify carbohydrates. • Electrophoresis converts a chemical compound into a product (the reaction's derivate) of similar chemical structure ▪

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

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The carbohydrates are then separated on the basis of their size: the smaller the size of a carbohydrate molecule, the faster it moves in an electrical field.

TEST FOR CARBOHYDRATES • Lane – Eynon Method titration method of determining the concentration of reducing sugars o A burette is used to add the carbohydrate solution being analyzed to a flask containing a known amount of boiling copper sulfate solution and a methylene blue indicator. o The reducing sugars in the carbohydrate solution react with the copper sulfate present in the flask. Once all the copper sulfate in solution has reacted o Positive result: the indicator to change from blue to white. • Charring test heating in test tube or in a presence of conc. H₂SO₄ o Positive result: Produces charring with smell like burning sugar (carmel) • Molisch test o General test for carbohydrates o Molisch’s reagent: 5% alpha-naphthol solution in ethyl alcohol o Aqueous solution of drug/carbohydrate mixed with few drops Molisch reagent and conc. H₂SO₄ was added from sidewall of test tube. o Positive result: Purple colored ring at junction indicates presence of carbohydrates. o PRINCIPLE: Pentose are dehydrated to form furfural derivatives; Hexoses are dehydrated to form 5 – hydroxymethylfurfural; H₂SO₄ dehydrating agent. • Iodine test o Specific test for polysaccharides o Iodine/Lugol’s Solution soluble in alcohol and insoluble in water o When the iodine is added to the solution, the color of the solution changes. o Positive result: If blue color appears, amylase or starch is present in the solution; If reddish-purple color appears, dextrin is present; If reddish-brown color appears, glycogen is present o PRINCIPLE: The iodine test is based on the absorptive properties possessed by large polysaccharide molecules. The glucose chains in most of polysaccharides are organized to form helices. The space between the turns of the helix can hold small iodine molecules. • Barfoed test o Differentiating test to distinguish between monosaccharides and disaccharides o Test for reducing monosaccharides o Barford Solution: Copper Acetate in Glacial Acetic Acid o When the Barford’s reagent is added to the solution upon heating and letting it cool at a room temperature, precipitates are formed. o Positive result: Formation of red precipitates after the initial first 5 minutes indicates the presence of a monosaccharide; If precipitates are formed after 7 - 15 minutes, a disaccharide is present in the test solution. o PRINCIPLE: Reducing sugars will oxidize the reagent This cuprous hydroxide us converted to cuprous oxide on heating and precipitates are formed.

JOSE PHILIP G. MAGLALANG, RPh

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PHARMACOGNOSY AND PLANT CHEMISTRY

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Seliwanoff’s Test o This test is used to detect monosaccharides with a ketonic functional group o Seliwanoff’s solution: 50mg resorcinol and 33 ml of ...