PST Level 5 Semester 2

NTA Level 5 • Semester 2 • PST05210 Introduction to Volatile Oils and Resins Basic Pharmacognosy • Source Session/Topic 30 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 30: Introduction to Volatile Oils and Resins Total Session Time: 120 minutes Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • List characteristics of volatile oils • Describe the composition of volatile oils • Classify volatile oils • Describe extraction of volatile oils • List therapeutic uses of volatile oils Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • LCD Projector and Laptop SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |25 minutes |Presentation |Characteristics of Volatile Oils | | | | |and Resins | |3 |20 minutes |Presentation |Composition of Volatile Oils | | | |Brainstorm | | |4 |15 minutes |Presentation |Classification of Volatile Oils | |5 |30 minutes |Presentation |Extraction of Volatile Oils | |6 |15 minutes |Presentation |Therapeutic Uses of Volatile Oils | | | |Small group | | |7 |05 minutes |Presentation |Key Points | | 8|05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Characteristics of Volatile Oils (25 minutes) • Volatile oils, also known as essential oils, are concentrated, odoriferous liquids that entirely or almost entirely volatile in steam • Volatile oils are referred to as "essential" in the sense that they carry a distinctive scent, or essence of the plant • Essential oils do not as a group need to have any specific chemical properties in common, beyond conveying characteristic fragrances (Essential oils should not be confused with essential fatty acids) • Volatile oil originates from plants, possess a unique odour or flavour, mainly used in perfumes and flavourings • Essential oils have the following general characteristics o They evaporate under atmospheric pressure at room temperature o They are soluble in alcohol and other organic solvents o They are insoluble in water o They have high refractive index o They are optically active o Most of them are colourless or pale yellow o They are odoriferous o They are sensitive to air (resinify on exposure to air) o Most of them are terpenoid in nature • Resins o Resins are hydrocarbon secretions of many plants, more or less solid amorphous products of complex chemical nature o Resin produced by most plants is a viscous liquid o Resins may be associated with volatile oils or gum or may be found in irregular masses which are insoluble in water but soluble in alcohol o Resins, oleoresins (resins associated with oils) and gum resins (resins associated with gums) are usually secreted into secretory cavities or ducts STEP 3: Composition of Volatile Oils (20 minutes) |Activity: Brainstorming (10 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | | | |What is composition of volatile oils? | | | |ALLOW students to discuss for 15 minutes | | | |ALLOW few groups to present and the rest to add points not | |mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • Volatile oils are chemically derived from terpenes (mainly from mono and sesqui terpenes) o Terpenoids are hydroxycarbons of plant origin with general formula (C5H8) n i.e. isoprene units o Terpenoids are naturally occurring and give plants and flowers their fragrance • Many oils are terpenoid in origin, some oils such as cinnamon and clove contain principally aromatic (benzene) derivatives mixed with terpenes • With the exception of oils derived from glycosides (e.g. bitter almond oil and mustard oil), volatile oils are mixtures of hydrocarbons and oxygenated compounds derived from these hydrocarbons • Some oils are acyclic, aromatic or contain sulphur or nitrogen • In some oils (e.g. Oil of turpentine) the hydrocarbons predominate and only limited amount of oxygenated constituents are present, other volatile oils (e.g. Oil of cloves) the bulk of the oil consists of oxygenated compounds STEP 4: Classification of Volatile Oils (15 minutes) • Volatile oils can be classified based on extraction method into; o Concretes ▪ Uses solvent e.g. hexane and waxes or resins to contact the plant materials and then the solvent removed by gent heating e.g. jasmine oil o Pomades ▪ Obtained by enfleurage (hot or cold) e.g. oils from flowers o Resinoids ▪ Extraction with resinous materials i.e. to prolong effect of fragrance o Absolutes ▪ Remains after alcoholic extraction from pomades or concretes • Volatile can be classified on the basis of their functional groups into; o Hydrocarbon volatile oils e.g. turpentine o Alcoholic volatile oils e.g. peppermint, cardamom and coriander oils o Aldehydic volatile oils e.g. lemon oil, orange oil, cinnamon o Ketonic volatile oils e.g. camphor, spearmint oils o Phenolic volatile oils e.g. clove, anise, nutmeg oils o Phenolic ether volatile oils e.g. fennel oil o Oxide volatile oils e.g. rosemary oil STEP 5: Extraction of Volatile Oils (30 minutes) • The following methods are used as general extractions for volatile oils; o Distillation ▪ Water (Simple) distillation (for dry plant materials, materials not destroyed by boiling e.g. turpentine oil) ▪ Water and steam distillation (for dry plant materials not destroyed by direct heating e.g. clove and cinnamon oils) ▪ Steam distillation (for fresh plant materials e.g. peppermint and spearmint oils) • Simple steam distillation • Saturated steam distillation • Hydrodifusion o Scarification ▪ Sponge extraction ▪ Ecuelle method ▪ Enzymatic hydrolysis o Soxhlet extraction o Solvent extraction ▪ Extraction by non-volatile solvents • Enfleurage (hot or cold) • Maceration • Spraying or pneumatic method o Extraction by

NTA Level 5 • Semester 2 • PST05210 Anthraquinone Glycosides Basic Pharmacognosy • Source Session/Topic 29 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 29: Anthraquinone Glycosides Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define anthraquinone glycosides • Explain natural sources and uses of Senna • Explain natural sources and uses of Cascara • Explain natural sources and uses of Aloe • Explain natural sources and uses of Rhubarb Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • LCD Projector and Laptop SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |20 minutes |Presentation |Introduction to Anthraquinone | | | | |Glycosides | |3 |20 minutes |Presentation |Natural Sources and Uses of Senna | |4 |20 minutes |Presentation |Natural Sources and Uses of | | | | |Cascara | |5 |25 minutes |Buzzing |Natural Sources and Uses of Aloe | | | |Presentation | | |6 |20 minutes |Presentation |Natural Sources and Uses of | | | | |Rhubarb | |7 |5 minutes |Presentation |Key Points | |8 |5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Introduction to Anthraquinone Glycosides (20 minutes) • Are glycosides in which the aglycone portion contains an anthracene ring structure and attached to glycone portion • They are found in drugs such as cascara, rhubarb, senna, aloes • They are used as cathartics or stimulant laxative • They act by increasing the tone of the smooth muscle in the walls of the colon and stimulate the secretion of water and electrolytes STEP 3: Natural Sources and Uses of Senna (20 minutes) • Definition o Senna consists of the dried leaflets of Casssia senna (Alexandrian senna) and Cassia angustifolia (Tinnevelly senna), family Fabaceae (Leguminosae) o Cassia senna is indigenous to tropical Africa and is cultivated in Sudan o Cassia angustifolia is indigenous to Somaliland, Arabia, Pujab and is cultivated in South India • Constituents o The basic constituents of senna are the anthraquinone glycosides; ▪ Sennoside A ▪ Sennoside B o Other constituents include; ▪ Aloe-emodin ▪ Rhein • Uses o Laxative ▪ Senna is a useful purgative either for habitual constipation or on occasional use ▪ Senna increases the peristaltic movements of the colon by its local action upon the intestinal wall STEP 4: Natural Sources and Uses of Cascara (20 minutes) • Definition o Cascara consists of the dried bark of Rhamnus purshianus, family Rhamnaceae o Requires long storage to destroy compounds called anthrones in the fresh bark, which cause vomiting • Constituents o Cascaroside A o Cascaroside B o Cascaroside C o Cascaroside D o Tannins o Volatile oils • Uses o Purgative ▪ Used in the form of liquid extract/elixir/as tablets prepared from dry extract STEP 5: Natural Sources and Uses of Aloe (25 minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are Aloes? | | | |ALLOW few pairs to respond and let other pairs to add on points not| |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | • Definition o Aloes consists of a solid residue obtained by evaporating the liquid which drains from the transversely cut leaves of various species of aloe, family Liliaceae o The species that yield aloe are: ▪ Aloe barbadensis ▪ Aloe ferox ▪ Aloe perryi ▪ Aloe vera • Constituents o The most important constituents of Aloes are the two Aloins: ▪ Barbaloin ▪ Isobarbaloin • Barbaloin is the major constituent of the plant o Other constituents are resins and Aloe-emodin • Uses o Stimulant purgative o Anthelminthic STEP 6: Natural Sources and Uses of Rhubarb (20 minutes) • Definition o Rhubarb consists of the dried underground parts of Rheum palmatum or R. officinale, family Polygonaceae • Constituents o Rhubarb contains free anthraquinone ▪ Rhein ▪ Emodin ▪ Aloe-emodine ▪ Emodin monomethylether • Uses o Rhubarb can be used as a strong laxative o Rhubarb has an astringent effect on the mucous membranes of the mouth and the nasal cavity STEP 7: Key Points (5 minutes) • Anthraquinones are glycosides in which the aglycone portion contains an anthracene ring structure and attached to glycone portion • Anthraquinone glycosides are obtained from sources including cascara, rhubarb, senna, aloes • Anthraquinone glycosides are generally used as cathartics or laxatives STEP 8: Evaluation (5 minutes) • What are the therapeutic uses of Rhubarb? • What are the constituents of Senna leaf? • Mention the uses of aloe vera? References Trease, G. E., Evans, W. C., & Evans, D. (2009). Trease and Evans pharmacognosy. London: Saunders. Joanne Barnes et al (2002), Herbal medicines 3rd Edition: Pharmaceutical Press Wallis, T. E. (2005). Textbook of pharmacognosy. New Delhi: CBS. Robbers, J. E., Speedie, M. K., Tyler, V. E., & Tyler, V. E. (1996). Pharmacognosy and pharmacobiotechnology. Baltimore: Williams & Wilkins. Heinrich, M., Kinghorn, A. D., Maizels, D., Gibbons, S., & Phillipson, J. D. (2012). Fundamentals of pharmacognosy and phytotherapy. Edinburgh: Churchill Livingstone/Elsevier. ← Previous TopicNext Topic →View all Basic Pharmacognosy topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260

NTA Level 5 • Semester 2 • PST05210 Cardiac Glycosides Basic Pharmacognosy • Source Session/Topic 28 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 28: Cardiac Glycosides Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define cardiac glycosides • List properties of cardiac glycosides • Mention natural sources of cardiac glycosides • Explain mechanisms of action • Differentiate types of cardiac glycosides • Explain chemical tests for cardiac glycosides • Mention general uses of cardiac glycoside Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • LCD Projector and Lapatop SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Objectives | |2 |30 minutes |Presentation |Properties of Cardiac Glycosides | |3 |60 minutes |Presentation |Sources, Constituents and Uses of | | | | |Selected Cardiac Glycosides | |4 |15 minutes |Presentation |Mechanism of Action for Cardiac | | | | |Glycosides | |5 |5 minutes |Presentation |Key Points | |6 |5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Properties of Cardiac Glycosides (30 minutes) • Cardiac glycosides are a group of glycosides with powerful action on cardiac muscles (positive ionotropic effect on the heart) • Cardiac glycosides are also made up of aglycone and glycone moities • The Glycone part o consists of one or more monosaccharide units o contains a steroid nucleus and a lactone ring • The Aglycone part o has steroidal nucleus o is always attached at C-3 position of aglycone part • There are two groups of cardiac glycosides; o Cardenolides ▪ The cardenolides have an unsaturated butyrolactone ring –a five membered-ring e.g. strophanthus o Bufadienolides ▪ In this group the lactone ring is a 6 membered (pyrrone) ring ▪ These are obtained from animal sources e.g. Bufadieonolides from toads • Characteristics of Cardiac Glycosides; o Amorphous o Odorless o Bitter tasting o Soluble in water o Insoluble in organic solvents o Very toxic compounds • Chemical tests for cardiac glycosides o Keller Kilian test ▪ Cardiac glycoside + CH3COOH + H2SO4 + FeCl3, produces brown colour o Legal test ▪ Cardiac glycoside + pyridine Sodium Nitroprusside, produces red to pink colour STEP 3: Sources, Constituents and Uses of Selected Cardiac Glycosides (60 minutes) • Digitalis o Definition ▪ Digitalis consists of dried leaves of Digitalis lanata or Digitalis purpurea (common name purple fox glove), family Scrophulariaceae ▪ Digitalis – finger-like corolla ▪ Purpurea – purple colour o Constituents ▪ D. purpurea produces primary glycosides • Purpurea glycoside A • Purpurea glycoside B • Glucogitaloxin ▪ On drying, enzyme degradation taken place with the loss of the terminal glucose to produce; • Digitoxin from purpurea glycoside A • Gitoxin from purpurea glycoside B • Gitaloxin o D. lanata produces ▪ Digoxin ▪ Lanatosides A, B and C • During drying: acetyl terminal sugar can be lost • Deacetylation produces primary glycosides as those produced by Digitalis purpurea • Lanatoside A produces Purpurea glycoside A • Lanatoside B produces Purpurea glycoside B • Lanatoside C produces Deslanoside C/ Deacetyllanatoside o Uses of digitalis ▪ Digitalis glycosides are used for the treatment of; • Congestive Heart Failure (CHF) • Arrhythmias • Atrial fibrillations • Squill o Definition ▪ Squill consists of the dried sliced bulbs of Urgenea maritima, from which the membrenous outer scales have been removed (family Liliaceae) ▪ The common name for squill is “sea onion” ▪ There are two types of squill; red squill and white squill o Constituents ▪ Squill contains the glycosides; • Scillaren A o Which is crystalline in form • Scillaren B o An amorphous mixture of glycosides • The red squill contains Scillirosides in addition to the other glycosides o Uses ▪ White squill • As cardiotonic drugs • As diuretics agents • In small dose –as expectorant agents • In large dose –as emetic agents ▪ Red squill • Used as a rodenticide (due to Scillirosides) • Strophanthus o Definition ▪ Consist of the dried ripe seed of Strophanthus kombe/strophanthus hispidus, family apocynaceae o Constituents ▪ Mixture of glycosides • K-strophanithin, erysimoside, K strophanthoside and cymarin • Fixed oils, resins and mucilage are also present • K-strophanthosides; o Composed of the genin strophanthidin o Coupled to a trissaccharide with cymarose, β-glucose and α-glucose o Are short-acting cardiac glycosides STEP 4: Mechanism of Action for Cardiac Glycosides (15 minutes) • Cardiac glycosides act by; o Inhibition of Na+/K+ ATPase of the cardiac cells, which increases the intracellular Na+ ions levels o The increased Na+ ion levels within the cardiac cells inhibits the Na+/Ca2+ exchanger, this in turn, results in increased concentrations of Ca2+ within the cardiac cells o The increased intracellular Ca2+ increases contractile force of the cardiac muscles [pic] STEP 5: Key Points (5 minutes) • Cardiac glycosides are glycosides with powerful positive inotropic action on cardiac muscles • Digitalis consists of dried leaves of Digitalis lanata or Digitalis purpurea • Digoxin is obtained from Digitalis lanata • Digitalis glycosides are used for the treatment of heart conditions including congestive heart failure (CHF), arrhythmias and atrial fibrillations STEP 10: Evaluation (5 minutes) • What is the source of digoxin? • What is the main use of digoxin? • What is strophanthus? References Trease, G. E., Evans, W. C., & Evans, D. (2009). Trease and Evans pharmacognosy. London: Saunders. Joanne Barnes et al (2002), Herbal medicines 3rd Edition: Pharmaceutical Press Wallis, T. E. (2005). Textbook of pharmacognosy. New Delhi: CBS. Robbers, J. E., Speedie, M. K., Tyler, V. E., & Tyler, V. E. (1996). Pharmacognosy and pharmacobiotechnology. Baltimore: Williams & Wilkins. Heinrich, M., Kinghorn, A.

NTA Level 5 • Semester 2 • PST05210 Introduction of Glycosides Basic Pharmacognosy • Source Session/Topic 27 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 27: Introduction of Glycosides Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Explain the meaning of glycosides • List the characteristics of glycosides • Classify glycosides • List functions of glycosides in the plants Resources Needed • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • LCD projector and Laptop SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 Minutes |Presentation |Introduction, Learning Tasks | |2 |15 Minutes |Presentation |Meaning and Characteristics of | | | | |Glycosides | |3 |30 Minutes |Presentation |Classification of Glycosides | |4 |05 Minutes |Presentation |Key Points | | 5|05 Minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Meaning and Characteristics of Glycosides (15 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is a glycoside? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARIZE by using the content below | ← Glycosides are molecules in which a sugar part (sugar moiety called the glycone) is bound to a non-sugar part (non-sugar moiety called the aglycone) joined together by glycosidic bond ← Glycosides play numerous important roles in living organisms ← Many plants store important chemicals in the form of inactive glycosides ← Many such plant glycosides are used as medications ← Characteristics of glycosides include; o Glycosides are soluble in water but insoluble in organic solvents ▪ The glycone part is water soluble but insoluble in the organic solvents ▪ The aglycone part is water insoluble but soluble in the organic solvents ▪ Some glycosides are soluble in alcohol o Glycosides are ccolorless (except flavonoid- yellow, anthraquinone-red or orange) o They are solid, amorphous and nonvolatile o They give a positive reaction with Molisch's and Fehling's solution test (after hydrolysis). o Most glycosides have bitter taste o They are oodorless except saponin (glycyrrhizin). o Glycosides with lots of sugars have increased solubility in water o Glycosides hydrolyzed by using mineral acids and temperature or by using enzymes STEP 3: Classification of Glycosides (30 minutes) ← Glycosides can be classified base on the following basis: o Based on therapeutic effects ▪ Cardiac glycosides, Laxative glycosides etc. o Based on glycone moiety ▪ Rhamnosides, glucorhamnosides, rhamnoglucosides etc. o Based on glycosidic linkage/bond ▪ O-glycosides, s-glycosides, N-glycosides, C-glycosides o Based on chemical nature of the aglycone ▪ Alcoholic and phenolic glycosides ▪ Anthraquinone glycosides ▪ Coumarin glycosides ▪ Cyanogenic glycosides ▪ Flavanoidal glycosides ▪ Steroidal glycosides ▪ Thioglycosides STEP 4: Key Points (5 minutes) ← Glycosides are made up of a glycone and aglycone moieties ← Glycosides are water soluble ← Glycosides are hydrolysed by acids, bases and acids into their components STEP 5: Evaluation (5 minutes) ← What is a glycoside? ← What are characteristics of glycosides ← What are the classes of glycosides References: Gleadow, RM; Møller, BL (2014). "Cyanogenic glycosides: synthesis, physiology, and phenotypic plasticity". Annual Review of Plant Biology. 65: 155–85. doi:10.1146/annurev-arplant-050213- 040027. PMID 24579992. Sun, Hong-Xiang; Xie, Yong; Ye, Yi-Ping (2009). "Advances in saponin-based adjuvants". Vaccine. 27 (12): 1787–1796. doi:10.1016/j.vaccine.01.091. Trease, G. E., Evans, W. C., & Evans, D. (2009). Trease and Evans pharmacognosy. London: Saunders. Joanne Barnes et al (2002), Herbal medicines 3rd Edition: Pharmaceutical Press Wallis, T. E. (2005). Textbook of pharmacognosy. New Delhi: CBS. Robbers, J. E., Speedie, M. K., Tyler, V. E., & Tyler, V. E. (1996). Pharmacognosy and pharmacobiotechnology. Baltimore: Williams & Wilkins. Heinrich, M., Kinghorn, A. D., Maizels, D., Gibbons, S., & Phillipson, J. D. (2012). Fundamentals of pharmacognosy and phytotherapy. Edinburgh: Churchill Livingstone/Elsevier. ← Previous TopicNext Topic →View all Basic Pharmacognosy topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260

NTA Level 5 • Semester 2 • PST05210 Proto alkaloids Basic Pharmacognosy • Source Session/Topic 26 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 26: Proto alkaloids Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define proto-alkaloids • Explain natural source and uses of proto-alkaloids Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • LCD Projector and Laptop SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Objectives | |2 |10 minutes |Brainstorming |Introduction to Proto-alkaloids | | | |Presentation | | |3 |35 minutes |Presentation |Natural Sources of Proto-alkaloids| |4 |05 minutes |Presentation |Key Points | |5 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Introduction to Proto-alkaloids (10 minutes) |Activity: Brainstorming (3 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the characteristics of proto-alkaloids? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARIZE by using the content below | • Proto-alkaloids do not have nitrogen as part of the heterocyclic ring • Proto-alkaloids include ephedrine adrenaline, • Both cause dilation of the bronchi, increase heart rate and peripheral vasoconstriction STEP 3: Natural Sources of Proto-alkaloids (35 minutes) • Ephedra o Ephedra is a protoalkaloid obtained from dried young stems of Ephedra gerardiana and Ephedra nebrodensis, family Ephedraceeae o Its synonym is Ma-Huang o Constituents ▪ Ephedrine ▪ Nor-ephedrine ▪ Pseudoephidrine ▪ N-methylephedrine o Uses ▪ Included in asthma, colds, flu and Hayfever medications • It is a bronchodilator • Action is more prolonged than adrenaline • Need not be given by injection, but can be administered orally • Allopathic: Sinumed (dries a runny nose) • Used as an anti-inflammatory. • Used for weight loss • Increases metabolism • Decreases appetite • CNS stimulant – acts on adrenergic receptors • Colchicum o Colchicum is the dried ripe seeds of Colchicum luteum and Colchicum autumnale. o Family: Liliaceae o Constituents ▪ Colchicine (main constituent) ▪ Demecolcine o Uses ▪ Relieves gout (used with caution – professional supervision) ▪ Also used in biological experiments to produce polyploidy (multiplication of the chromosomes in a cell nucleus) in horticulture and cultivation of medicinal plants STEP 4: Key Points (5 minutes) • Proto-alkaloids do not have nitrogen as part of the heterocyclic ring • Ephedra is a protoalkaloid obtained from dried young stems of Ephedra gerardiana and Ephedra nebrodensis • Ephedrine is a bronchodilator which is included in asthma, colds, flu and hay fever medications STEP 5: Evaluation (5 minutes) • What is the natural source of Ephedra? • What are the uses of ephedrine? References Trease, G. E., Evans, W. C., & Evans, D. (2009). Trease and Evans pharmacognosy. London: Saunders. Joanne Barnes et al (2002), Herbal medicines 3rd Edition: Pharmaceutical Press Wallis, T. E. (2005). Textbook of pharmacognosy. New Delhi: CBS. Robbers, J. E., Speedie, M. K., Tyler, V. E., & Tyler, V. E. (1996). Pharmacognosy and pharmacobiotechnology. Baltimore: Williams & Wilkins. Heinrich, M., Kinghorn, A. D., Maizels, D., Gibbons, S., & Phillipson, J. D. (2012). Fundamentals of pharmacognosy and phytotherapy. Edinburgh: Churchill Livingstone/Elsevier. ← Previous TopicNext Topic →View all Basic Pharmacognosy topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260

NTA Level 5 • Semester 2 • PST05210 Purine Alkaloids Basic Pharmacognosy • Source Session/Topic 25 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 25: Purine Alkaloids Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define purine alkaloids • Explain natural sources and uses of alkaloids Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • LCD Projector and laptop SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |15 minutes |Presentation |Introduction to Purine Alkaloids | |3 |30 minutes |Presentation/ |Natural Sources and Uses of | | | |Brainstorming |Alkaloids | |4 |05 minutes |Presentation |Key Points | |5 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Introduction to Purine Alkaloids (15 minutes) • Purine alkaloids are derivatives of Xanthines • They have amphoteric character • They exhibit peculiar solubility in warm water and in chlorinated solvents • These alkaloids include caffeine (seeds of coffee plants, kola plants, tea leaves and guarana seeds), theobromine (Theobroma cocao) and theophylline (tea leaves and cola nuts) • The stimulant action in beverages such as tea and coffee is due to the purine alkaloids • Caffeine (1, 3, 7-trimethylxanthine) stimulates CNS and has a weak diuretic action. • Theobromine (3,7-dimetylxanthine) produce opposite action to that of Caffeine • Theophylline (1,3-dimetylxanthine) relaxes involuntary muscles more effectively than caffeine or theobromine STEP 3: Natural Sources and Uses of Alkaloids (30 minutes) • Cocoa o Cocoa consists of seeds of Theobroma cacao, family sterculiaceae o Cocoa is produced in South America (Ecuador, Columbia, Venezuela), West Indies and West Africa (Nigeria, Ghana and Java) o Cocoa kernels contain 0.9 – 3% theobromine and the husk 0.19- 2.98% of this alkaloid o The seed also contains 0.05 – 0.36% caffeine, cocoa fat/butter, condensed tannins and volatile compounds o Main constituents are Theobromine and Theophyllline o Uses ▪ Theobromine is used • As base for suppositories (cocoa butter) • For heart and kidney tonic • As a drink e.g. cocoa • As flavouring agent e.g. chocolate ▪ Theophylline • Relaxes bronchial smooth muscles • Stimulates respiratory centre in the brain stem by increasing sensitivity to CO2 • Stimulates the CNS • Slightly inotropic • Diuretic activity is stronger than that of caffeine • Used for relief of cough (bronchodilator) • Smooth muscle relaxant for symptomatic relief/prevention of bronchial asthma • Treatment of reversible bronchospasm associated with chronic bronchitis and emphysema • Coffee o Coffee consists of seeds of coffea arabica and other species of coffee, family rubiaceae o Constituents: ▪ Caffeine, tannins, Nicotinic acid, fixed oils and chlorogenic acid ▪ Caffeine eenhances alertness, ffacilitates thought formation and decreases the sensation of fatigue. At high doses caffeine induces nervousness, insomnia and tremors. o Another source of caffeine is Tea, which consists of prepared leaves of Thea sinensis/Camellia sinensis |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the uses of Caffeine? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | o Uses ▪ Coffee produce caffeine which is used in combinations with antipyretics and analgesics, cold and flu medication (increases the intestinal absorption of some of these drugs or to counteract drowsiness) ▪ Caffeine is also used as an ingredient in non-alcoholic beverages and “energizing” beverages STEP 4: Key Points (5 minutes) • Purine alkaloids are derivatives of xanthines • Purine alkaloids exhibit peculiar solubility in warm water • Main constituents of cocoa are Theobromine and Theophyllline • Cocoa butter is used a suppository base STEP 5: Evaluation (5 minutes) • Mention the cardiovascular use of caffeine • What are the pharmacological uses of Theophylline? • What are the uses of Theobromine? References Trease, G. E., Evans, W. C., & Evans, D. (2009). Trease and Evans pharmacognosy. London: Saunders. Joanne Barnes et al (2002), Herbal medicines 3rd Edition: Pharmaceutical Press Wallis, T. E. (2005). Textbook of pharmacognosy. New Delhi: CBS. Robbers, J. E., Speedie, M. K., Tyler, V. E., & Tyler, V. E. (1996). Pharmacognosy and pharmacobiotechnology. Baltimore: Williams & Wilkins. Heinrich, M., Kinghorn, A. D., Maizels, D., Gibbons, S., & Phillipson, J. D. (2012). Fundamentals of pharmacognosy and phytotherapy. Edinburgh: Churchill Livingstone/Elsevier. ← Previous TopicNext Topic →View all Basic Pharmacognosy topicsOpen Complete Full Notes PDF / OFFLINE NOTES Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP WhatsApp: 255620339260