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NTA Level 5 • Semester 2 • PST05210 Isoquinoline Alkaloids Basic Pharmacognosy • Source Session/Topic 23 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 23: Isoquinoline Alkaloids Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define isoquinoline alkaloids • Explain natural sources and uses of isoquinoline 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 |10 minutes |Presentation |Definition of Isoquinoline | | | | |Alkaloids | |3 |15 minutes |Buzzing |Natural Sources and Uses of Opium | | | |Presentation | | |4 |10 minutes |Presentation |Natural Sources and Uses of Curare| |5 |10 minutes |Presentation |Natural Sources and Uses of | | | | |Ipecacuanha | |6 |05 minutes |Presentation |Key Points | |7 |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: Definition of Isoquinoline Alkaloids (10 minutes) • Isoquinoline consist of alkaloids and alkaloid salts obtained from opium and ipecacuanha • Both of these alkaloids are in the same group but differ chemically and in their pharmacological actions • The amount of alkaloids present depends on the species, environment age, and method of bark collection STEP 3: Natural Sources Uses of Opium (15 minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What is opium? | | | |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 Opium (raw opium) is the latex obtained by incision from the unripe capsules of Papaver somniferum, family papaveraceae o It is dried partially by spontaneous evaporation and partly by artificial heat o It is commercially known as Indian opium. o According to the BP, opium is intended only as a starting point for the manufacture of galenicals, and should not be dispensed as such. • Constituents o There are 6 main alkaloids produced by opium; ▪ Morphine ▪ Codeine ▪ Thebaine ▪ Noscapine ▪ Narceine ▪ Papaverine • Uses o Opium and Morphine are used to relieve pain, as hypnotic, and for decreasing metabolism ▪ Morphine is a potent analgesic o Opium ▪ Closely resembles morphine – exerts action more slowly – preferred to morphine (e.g. in diarrhoea). ▪ Opium is a diaphoretic agent o Codeine ▪ Milder sedative ▪ Relieve cough ▪ Habitual use may cause constipation STEP 4: Natural Sources and Uses of Curare (10 minutes) • Definition o Curare refers to various South America arrow poisons extracts obtained from members of Menispermaceae (Stephania) and Loganiaceae (Chondrodendron tomentosum) o There are three kinds of curare depending on their containers and chemical characteristics; ▪ Tube-curare ▪ Packed in bamboo tubes (Brazil and Peru) ▪ The alkaloid was then named “tubocurarine” ▪ Calabash-curare • Packed in gourds (Guiana, Venezuela and Columbia) o Pot-curare • Packed in earthenware pots • Constituents o Tubocurarine o Curarine • Uses o Tubocurarine chloride is used to produce muscular relaxation in surgical operations and neurological conditions STEP 5: Natural Sources and Uses of Ipecacuahnha (10 minutes) • Ipecacuanha consists of dried rhizome and roots of Cephalis ipecacuanha (Brazilian ipec) or Cèphalis acuminata (Costa Rica ipecac), family Rubiaceae • Constituents o Emetine (60-75%) o Cephaeline, o Psychotrine o Psychotrine methyl ether o Ipecacuanhin • Other constituents; o Emetamine o Psychotrine methylether o Ipecoside (glycoside) • The drug also contains crystalline glucosidal tannin (ipecacuanhin, ipecacuanhic acid) ipecoside, starch and calcium oxalate • Uses of ipecacuanha o Expectorant o Emetic o Amoebic Dysentry o Emetine is more expectorant and less emetic in action than cephaeline o Psychotrine: o Selective HIV inhibitors (study could lead to therapeutically useful agents) STEP 6: Key Points (5 minutes) • Isoquinoline alkaloids consist of alkaloids and alkaloid salts obtained from opium and ipecacuanha • Opium (raw Opium) is the latex obtained by incision from the unripe capsules of Papaver somniferum, family papaveraceae • Curare refers to various South America arrow poisons made from different plants STEP 7: Evaluation (5 minutes) • What is the source of ipecacuanha? • What are the uses of opium? • What is the natural source of Opium? 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 Quinoline Alkaloids Basic Pharmacognosy • Source Session/Topic 22 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 22: Quinoline Alkaloids Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define quinoline 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 |10 minutes |Presentation |Definition of Quinoline | | | | |Alkaloids | |3 |25 minutes |Presentation |Natural Sources and Uses of | | | | |Cinchona | |4 |05 minutes |Presentation |Key Points | |5 |05 minutes |Presentation |Evaluation | |6 |10minutes |Presentation |Assignment | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning objectives and clarify ASK students if they have any questions before continuing. STEP 2: Definition of Quinoline Alkaloids (10 minutes) • Quinoline consist of alkaloids and alkaloid salts obtained from the bark of Cinchona species • Quinolone alkaloids include quinine, quinidine, cinchonine and cinchonidine • The amount of alkaloids present depends on the species, environment of the tree, age, and method of bark collection. STEP 3: Natural Sources and Uses of Cinchona (25 minutes) • Definition o Cinchona bark consist of dried bark of the stem or root of Cinchona succirubra, Cinchona ledgeriana, Cinchona officinalis and Cinchona calisaya o Chinchona belongs to the family Rubiaceae o The plants are trees indigenous to Colombia Equador, Peru and Bolivia and are cultivated in Indonesia, India and Tanzania o There are over 36 known species and hybrids of cinchona • Constituents o Contains quinoline alkaloids, the principal quinoline alkaloid are quinine and quinidine o Other quinoline alkaloids are quinicine, cinchonicine, cinchotannic acid and anthraquinones |Activity: Small Group Discussion (15 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | | | |What are the uses of Quinine and Quinidine? | | | |ALLOW students to discuss for 10 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • Uses o Bitter tonic and stomachic (cinchona extract) o Used as gargles (tannins in bark – astringent) o Treatment of malaria o Prophylaxis of cardiac arrhythmias o Treatment of atrial fibrillation (quinidine) STEP 4: Key Points (5 minutes) • Quinolone alkaloids consist of alkaloids and alkaloid salts obtained from the bark of Cinchona species • Cinchona bark consist of dried bark of the stem or root of Cinchona succirubra, Cinchona ledgeriana, Cinchona officinalis and Cinchona calisaya • Important quinolone alkaloids include quinine which is used for treatment of malaria STEP 5: Evaluation (5 minutes) • What is cinchona bark? • What are the constituents of cinchona? • Mention the medicinal uses of cinchona STEP 6: Assignment (10 minutes) |Activity: Take home Assignment (10 minutes) | | | |DIVIDE students in groups or individual. | | | |ASK the students to work on the following assignment | | | |What is cinchonism? | |List the sign and symptoms of cinchonism | | | |ALLOCATE time for students to do the assignment and submit | | | |REFER students to recommended references | 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 Lobelia and Tobacco Basic Pharmacognosy • Source Session/Topic 21 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 21: Lobelia and Tobacco Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define lobelia • Define Tobacco • Explain natural sources and uses of lobelia and Tobacco 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 |45 minutes |Buzzing |Natural Sources and Uses of | | | |Presentation |lobelia and Tobacco | |3 |05 minutes |Presentation |Key Points | |4 |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 objectives and clarify ASK students if they have any questions before continuing. STEP 2: Natural Sources and Uses of Lobelia and Tobacco (45 minutes) • Lobelia o Lobelia consists of the dried aerial parts of Lobelia inflata o Common Names: Lobelia, Indian Tobacco o The plant was traditionally used by the Native Americans for asthma o Constituents ▪ Lobelia contains about 0.24 – 0.4% of pyrrolizidine alkaloids (BP 1988, not less than 0.25%), the most important of which is lobeline ▪ Other constituents are lobelidine, lobelanine and isolobelanine o Uses ▪ Treatment of asthma ▪ Chronic bronchitis ▪ In anti-smoking preparations ▪ Injection of lobeline hydrochloride is used in the resuscitation of new-born infants |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What is tobacco? | | | |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 | • Tobacco o Tobacco consists of dried leaves of Nicotiana tobacum, family Solanaceae o Tobacco is also known as Tumbakhu o Constituents ▪ Nicotine ▪ Narcotine ▪ Anabasine o Uses ▪ Pesticide ▪ Insecticide STEP 3: Key Points (5 minutes) • Lobelia herb consists of the dried aerial parts of Lobelia inflate • Lobelia is used in anti-smoking preparations • Tobacco is used as insecticide and pesticide STEP 4: Evaluation (5 minutes) • What are the uses of Lobelia? • What are the main constituents of Lobelia? • What is tobacco? 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 Tropane Alkaloids Basic Pharmacognosy • Source Session/Topic 20 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 20: Tropane Alkaloids Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define tropane alkaloids • Explain natural sources and uses of tropane 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 |20 minutes |Presentation |Introduction to Tropane Alkaloids | | | |Buzzing | | |3 |20 minutes |Presentation |Natural Sources and Uses of | | | |Brainstorming |Stramonium | |4 |25 minutes |Presentation |Natural Sources and Uses of | | | | |Belladonna | |5 |20 minutes |Presentation |Natural Sources and Uses of | | | | |Hyocyamus | |6 |20 minutes |Presentation |Natural Sources and Uses of Coca | |7 |05 minutes |Presentation |Key Points | |8 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Objectives (5 minutes) READ or ASK students to read the learning objectives and clarify ASK students if they have any questions before continuing. STEP 2: Introduction to Tropane Alkaloids (20 minutes) • Tropane alkaloids are derived from tropine and consist of mandelic, tropic or benzoic acid esters of tropine • Chemically they are formed by fusion of pyrrolidine and piperidine ring with a common methylated nitrogen o Tropane alkaloids are very closely related to each other • All tropane alkaloids have pronounced physiological actions • Tropane alkaloids include: o Hyoscyamine o Hyoscine o Atropine o Cocaine • They all occur within the Solanaceae family (except cocaine which occurs in Erythroxylaceae family) STEP 3: Natural Sources and Uses of Stramonium (20 minutes) • Definition o Stramonium is defined as dried leaves and flowering tops of Datura stramonium and its varieties, family Solanaceae o Its synonyms are thornapple, jimson or Jamestown weed o Drug is required to contain not less than 0.25% of alkaloid calculated as hyocyamine o Drug is widely distributed in Africa, Germany, France, Hungary o Adulterant: Solanum nigrum o Allied Drugs are Datura inoxia, Datura metel and Datura sanguinea • Constituents o Contain 0.2 – 0.45% alkaloids, the major alkaloids are; ▪ Hyoscyamine ▪ Hyoscine ▪ Small quantities of atropine o Hyoscyamine and hyoscine are found in the ration 2:1 (hyoscyamine: hyoscine) o Younger plants contain hyoscine, atropine is little and is formed from racemization of hyoscyamine o These alkaloids test positive for Vitali-Morin test • Uses of Stramonium; o Hyoscyamine is used to treat urinary tract disorders o It is used to treat spasms of the bladder o Hyoscyamine preparations are also used as antispasmodics in the therapy of peptic ulcers o Hyoscine hydrobromide is used in pre-operative medication 30 – 60 minutes before induction of anaesthesia o Hyoscine butylbromide used in irritable bowel syndrome to relief pain due to abdominal cramps o It is also used in dysmenorrhea STEP 4: Natural Sources and Uses of Belladonna (25 minutes) • Definition o Consist of the dried leaves and flowering tops of Atropa belladonna ▪ Its synonym is deadly night shade ▪ Family: Solanaceae ▪ Contains not less than 0.3% of total alkaloids calculated as hyoscyamine o Adulterant: Phytolacca dodecandra o Allied drugs are Indian belladonna and Atropa acuminata • Constituents o Contains 0.3 – 0.6% of Tropane alkaloids, the chief of which is hyoscyamine o Belladonin o Small quantities of volatile bases e.g. pyridine and N- methylpyrroline are present • Pharmacological Actions o Atropine ▪ Stimulant on CNS ▪ Dilates eye pupils ▪ Decreases sweating ▪ Produces stomach acid and saliva and relaxes smooth muscle (asthma and colic) o Hyoscine ▪ lacks CNS stimulant action of atropine ▪ Sedative – motion sickness o Atropine and Hyoscine ▪ Used in ophthalmic practice to dilate pupil • Uses of Belladonna o Belladonna leaves are used for internal preparations o Used as sedative, antispasmodic and to check secretions o Roots are used for external preparations o Atropine is indicated in organophosphates and carbamate insecticides poisoning o It produces mydriatic effect by paralyzing the iris and the ciliary muscles o Is it used as an antispasmodic to lessen smooth muscle spasm/griping o Used to treat some types of arrhythmias STEP 5: Natural Sources and Uses of Hyocyamus (20 minutes) • Definition o Hyoscyamus leaf consists of the dried leaves or dried leaves and flowering tops of Hyoscyamus niger, family Solanaceae o Common name: Henbane • Constituents: o Tropane alkaloids mainly: ▪ Hyoscyamine in small amount ▪ Hyoscine (main constituent) o Allied Drugs are Hyoscyamus albus, Hyosycamus muticus, Hyoscyamus pusillus, Hyoscyamus aureus • Uses of Hyocyamus o Resembles belladonna and stramonium in action but weaker ▪ Higher hyoscine content hence less likely to cause cerebral stimulation o Used to relieve spasm of the urinary tract o Used as a sedative o Used as an expectorant o Anti-asthmatic STEP 6: Natural Sources and Uses of Coca (20 minutes) • Definition o Coca is derived from dried leaves of Erythroxylum coca (Bolivian or Huanuco) and E. truxillense (Peruvian or Truxillo), cultivated in Peru, Bolivia, Colombia and Indonesia, family Erythroxylaceae ▪ Coca leaves have been used in South America as a masticatory from very early times ▪ The leaves are artificially or sun-dried and packed in bags. o Constituents ▪ Coca leaves contain about 0.7 to 1.5% of total alkaloids, of which cocaine, cinnamylcocaine and α-truxilline are the most important. ▪ These alkaloids occur in different proportions in different commercial varieties ▪ Other substances are hygrine, hygroline, tropacocaine o Uses ▪ Local anaesthetic agent ▪ Stimulan STEP 6: Key Points (5 minutes) • Tropane alkaloids are very closely related to each other • Belladonna consists of dried leaves

NTA Level 5 • Semester 2 • PST05210 Classification, Uses and Extraction of Alkaloids Basic Pharmacognosy • Source Session/Topic 19 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 19: Classification, Uses and Extraction of Alkaloids Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Classify alkaloids • List pharmacological actions and uses of alkaloids • Explain extraction, purification and isolation of alkaloids from powdered plants • Explain chemical tests for 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 |35 minutes |Presentation |Classification of Alkaloids | |3 |15 minutes |Brainstorming |Pharmacological Actions and Uses | | | |Presentation |of Alkaloids | |4 |30 minutes |Presentation |Extraction, Purification and | | | | |Isolation of Alkaloids | |5 |20 minutes |Presentation |Chemical Tests for Alkaloids | |6 |10 minutes |Presentation |Key Points | |7 |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 objectives and clarify ASK students if they have any questions before continuing. STEP 2: Classification of Alkaloids (40 minutes) • Alkaloids differ widely in their botanical and biochemical origin, in chemical structure and their pharmaceutical action • Therefore, there many different systems for classification of alkaloids • Major classification systems include o On the basis of basicity ▪ Alkaloids may be classified into weak bases e.g. caffeine, strong bases e.g. atropine, amphoteric alkaloids e.g. phenolic alkaloids like morphine and neutral alkaloids e.g. colchicine o Biological origin o Chemical structure o Biosynthetic pathway • Classification based on chemical structures (the Hegnauer’s classification) is more useful and practical • By the Hegnauer’s Classification, alkaloids are grouped into: o Typical/True Alkaloids ▪ They are derived from amino acids and contain a nitrogen in a heterocyclic ring e.g. Atropine ▪ They are toxic ▪ Show a wide range of physiological activity ▪ They are almost invariably basic ▪ They are biosynthesized from amino acids ▪ They normally occur in the plant as salt of an organic acid ▪ Colchicine and quaternary alkaloids are not basic in nature and do not have heterocyclic ring in their structures ▪ They are divided into the following groups based on their ring structures • Pyrrole and Pyrolidine e.g. hygrine, strychnine • Pyrrolizidine e.g. symphitine, echimidine etc. • Pyridine and Piperidine e.g. Nicotine etc. • Tropane (Piperidine/N-methyl-pyrrolidine) e.g. hyoscyamine, atropine, etc. • Quinoline e.g. quinine etc. • Isoquinoline e.g. emetine, morphine, codeine, etc. • Aporphine (reduced isoquinine/ naphthalene) e.g. boldine • Quinolizidine e.g. cytisine etc • Indole or Benzopyrrole e.g. Ergometrine, ergotamine etc. • Indolizidine e.g. Castanospermine etc. • Imidazole or Glyoxaline e.g. pilocarpine • Terpenoid e.g. Aconitine o Proto-alkaloids/Atypical Alkaloids ▪ Derived from amino acids but do not contain nitrogen in the heterocyclic ring ▪ They are also called biogenic amines ▪ They are simple amines biosynthesized from amino acids and are basic ▪ Examples of proto-alkaloids include mescaline, ephedrine, erythromycin, taxol o Pseudoalkaloids ▪ They are not derived from amino acids ▪ There are two major series in this class: • The steroidal alkaloids e.g. Conessine • The terpenoid alkaloids e.g. Purines, Caffeine, Theophylline and Theobromine [pic] STEP 3: Pharmacological Actions and Uses of Alkaloids (15 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the uses of alkaloids? | | | |ALLOW few students to respond? | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARIZE by using the content below | • Alkaloids have marked pharmacological activities o Analgesics and narcotics e.g. morphine and codeine o CNS stimulants e.g. caffeine and strychnine o Anticancer activity e.g. vincristine, vinblastine and taxol o Mydriatics e.g. atropine o Anti-asthmatic activity e.g. ephedrine o Antitussive e.g. codeine o Expectorant effect e.g. lobeline o Anti-hypertensive e.g. reserpine o Smooth muscle relaxants e.g. atropine and papaverine o Skeletal muscle relaxants e.g. d-tubocurarine o Anthelmintic activity e.g. pelletierine and arecoline o Antiparasitic action e.g. quinine and emetine o Antibacterial activity e.g. berberine STEP 4: Extraction, Purification and Isolation of Alkaloids (25 minutes) • Stas-Otto Method o This technique involves the distribution of alkaloid bases between acid or aqueous solution and immiscible organic solvent o First Stage ▪ Powdered plant material is moistened with water and mixed with alkali like sodium and potassium carbonate, ammonia, calcium hydroxide. A paste is made with water, dried and re-powdered • The lime combines with acid, tannins and other phenolic substances and sets free the alkaloids o Second Stage ▪ The free alkaloids are extracted by hot continuous percolation with chloroform or other organic solvent • The free alkaloids dissolve together with other substances soluble in solvent o Third stage ▪ Chloroform solution is agitated with successive portions of dilute sulphuric acid separating the aqueous layer before adding the next portion ▪ The alkaloids are converted into alkaloidal sulphates, which being soluble in water, pass into the aqueous layer o Fourth Stage ▪ The mixed aqueous liquid is made alkaline with ammonia, and precipitates that form are collected, washed with water and dried • Ammonia decomposes the alkaloidal sulphates forming ammonium sulphates, soluble in water and the free alkaloid which being practically insoluble in water is precipitated • Volatile alkaloids are extracted by steam distillation i.e. Plant material + water + Fixed alkali [pic] steam containing alkaloids Heat received in acidic solution • Alkaloids are purified by; o Direct crystallization from solvent o Steam distillation o Chromatography techniques o Gradient pH techniques STEP 5: Chemical Tests for Alkaloids (20 minutes) • Alkaloids can be identified by chemical tests •

NTA Level 5 • Semester 2 • PST05210 Introduction to Alkaloids Basic Pharmacognosy • Source Session/Topic 18 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 18: Introduction to Alkaloids Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Explain the occurrence and distribution of alkaloids • Explain naming of alkaloids • Explain properties of alkaloids Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |35 minutes |Presentation |Occurrence and Distribution of | | | | |Alkaloid | |3 |35 minutes |Presentation |Naming of Alkaloids | |4 |35 minutes |Presentation |Properties of Alkaloids | |5 |05 minutes |Presentation |Key Points | |6 |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 objectives and clarify ASK students if they have any questions before continuing. STEP 2: Occurrence and Distribution of Alkaloids (35 minutes) • Alkaloids are basic naturally occurring compounds containing one or more nitrogen atoms usually in a heterocyclic ring and have a marked physiological action on man or other animals • Some alkaloids occur in certain families while others only occur in specific species • Alkaloids are highly found in apocynaceae, rubiaceae, solanaceae and papaveracea • Alkaloids are not found in rosaceae and labiatae families • Alkaloids are produced by a large variety of organisms, including bacteria, fungi, plants, and animals • Most alkaloids are basic (form salts with acids) • Some alkaloids are not basic e.g. colchicine, piperine, quaternary alkaloids. • The nitrogen in some alkaloids is not in a heterocyclic ring e.g. Ephedrine, Colchicine, Mescaline. • Alkaloids are rare in lower plants and richer in dicots than in monocots • Alkaloids may occur in free state (e.g. as free bases), as salts (e.g. with organic acids), as glycosides, and as alkaloid N-oxides • Alkaloids may be found in all parts of the plant, in barks, seeds, roots, fruits, leaves and in latex • Functions of alkaloids in the plant; o Protect against insects and herbivores due to their bitterness and toxicity o Are final products of detoxification in some cases. o Source of nitrogen in case of nitrogen deficiency o Act as growth regulators in certain metabolic systems. STEP 3: Properties of Alkaloids (35 minutes) • Physical properties o Most alkaloids are crystalline solids, a few are amorphous solids e.g. emetine. o Some are liquids that are either volatile or non-volatile o Majority of the alkaloids are colorless but some are colored; o Alkaloidal bases are soluble in organic solvents and insoluble in water o Salts of alkaloids are usually soluble in water and, insoluble or sparingly soluble in organic solvents. o Alkaloids are bitter tasting o Many alkaloids are extremely toxic to other organisms. o Alkaloids exhibit isomerism e.g. optical isomerism i.e L-ephedrine is 3.5 times more active than d-ephedrine • Chemical properties o Alkaloids are amines (may be primary, secondary, tertiary and quaternary) o Most alkaloids contain oxygen and are solid in nature e.g. Atropine. o Alkaloids are decomposed by heat, except Strychnine and Caffeine o Alkaloids react with acids to form salts o Dilute alkalis liberate most alkaloids from their salts e.g. NH3 o Some alkaloids are unstable when exposed to light and oxygen while others are not STEP 5: Naming of Alkaloids (35 minutes) • Alkaloids are named by various methods • Names of alkaloids end by "ine". These names may be derived from: o Generic plant name – Atropine from Atropa belladonna o Specific name of the plant – Cocaine from Erythroxylum coca o Names of loved ones e.g. Cathelenine o Common name of the plant – Ergotamine from ergot (rye) o Physiological action of the plant – Emetine producing emesis • Prefixes and Suffixes used in naming of alkaloids • Prefixes: o "Nor-" designates N-demethylation or N-demethoxylation, e.g. Norpseudoephedrine and Nornicotine. o "Apo-" designates dehydration e.g. Apomorphine. o "Iso-, pseudo-, neo-, and epi-" indicate different types of isomers • Suffixes: o "-dine" designates isomerism as Quinidine and Cinchonidine. o "-ine" indicates, in case of ergot alkaloids, a lower pharmacological activity e.g. Ergotaminine which is less potent than ergotamine STEP 7: Key Points (5 minutes) • Alkaloids are basic naturally occurring compounds containing one or more nitrogen atoms usually in a heterocyclic ring and have a marked physiological action on man or other animals • Alkaloids are produced by a large variety of organisms, including bacteria, fungi, plants, and animals and are part of the group of natural products • Alkaloids may occur in free state (e.g. as free bases), as salts (e.g. with organic acids), STEP 8: Evaluation (5 minutes) • What are alkaloids? • What are the functions of alkaloids in plants? • Mention physical properties of alkaloids? 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 Gum, Mucilage and Pectins Basic Pharmacognosy • Source Session/Topic 17 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 17: Gum, Mucilage and Pectins Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define gum, mucilage and pectins • Explain natural source, constituents and uses of Tragacanth gum • Explain natural source, constituents and uses of Acacia gum • Explain natural source, constituents and uses of Sterculia gum • Explain natural source, constituents and uses of Psyllium Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |15 minutes |Presentation |Introduction to Gum, Mucilage and | | | | |Pectins | |3 |25 minutes |Presentation |Natural Source, Constituents and | | | | |Uses of Tragacanth Gum | |4 |25 minutes |Presentation |Natural Source, Constituents and | | | |Buzzing |Uses of Acacia Gum | |5 |20 minutes |Presentation |Natural Source, Constituents and | | | | |Uses of Sterculia Gum | |6 |20 minutes |Presentation |Natural Source, Constituents and | | | |Brainstorming |Uses of Psyllium | |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 objectives and clarify ASK students if they have any questions before continuing. STEP 2: Introduction to Gums, Mucilage and Pectins (15 minutes) • Gums and mucilage have similar constitutuons and on hydrolysis yield a mixture of sugar and uronic acids. • Gums are considered to be pathological products formed upon injury of the plant or owing to unfavourable conditions such as draught, by a breakdown of cell walls e.g. tragacanth (extracellular formation gummosis) • They are insoluble in alcohol but dissolve or swell in water • Conversely, mucilage are generally normal products of metabolism formed within the cell (intracellular formation) and may represent storage material, a water storage reservoir or a protection for germinating seeds. • They are often found in quantity in the epidermal cells of leaves, e.g senna, in seed coats (linseed, psyllium etc.) roots (marshmallow) and barks (slippery elm) STEP 3: Natural Source, Constituents and Uses of Tragacanth Gum (25 minutes) • Definition o Tragacanth is the “air hardened gummy exudate flowing naturally or obtained by incision, from the trunk & branches of Astragalus gummifer (Labillardiere) and certain other spp. of Astragalus o Tragacanth is the gum that exudes immediately after injury of the plant occurs and is therefore pre-formed in the plant • Constituents o Tragacanthin o Bassorin o Sugar o Uronic acids • Uses o Used as a suspending agent for insoluble powders o Binding agent in pills and tablets o Emulgent o A binding agent in food industry STEP 4: Natural Source, Constituents and Uses of Acacia Gum (25 minutes) • Definition o Acacia gum is a dried gum obtained from the stem and branches of Acacia senegal and some other spp of Acacia (Leguminoseae). • Constituents o Arabin (Arabic acid) o Galactose o Arabinose o Rhamnose o Uronic acids o Oxidase enzyme |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are the uses of acacia gum in pharmacy? | | | |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 | • Uses o Used as a general stabilizer in emulsions o Used in lozenges o As demulcent o Used for treatment of diarrhoea, cough and sore throat o It is also widely used in food and drink industries STEP 5: Natural Source, Constituents and Uses of Sterculia Gum (20 minutes) • Definition o Sterculia gum is the gummy exudate obtained from the tree, Sterculia urens (Sterculiaceae). • Constituents o Uronic acids o Partial hydrolysis yields ▪ D-galactose ▪ L-rhamnose ▪ D-galacturonic acid ▪ Acetic acid • Uses o Granular grades are used as a bulk laxative (second only to psyllium seed in use as a bulk laxative). o Powdered gum is used in lozenges, pastes and denture fixture powders. STEP 6: Natural Source, Constituents and Uses of Psyllium (20 minutes) • Definition o Psyllium consists of the dried, ripe seeds of Plantago afra (Plantago psyllium), P. indica (P. arenaria) and P. ovata (Plantaginaceae) • Constituents o Mucilage o Fixed oil o Sugars o Sterols o Protein |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are the uses of psyllium? | | | |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 | • Uses of Psyllium o Psyllium is mainly used as a ▪ Dietary fibre to relieve symptoms of both constipation ▪ Mild diarrhea ▪ Occasionally as a food thickener. ▪ Research has shown lowering of blood cholesterol levels in people with elevated cholesterol, ▪ Lowering of blood glucose levels in people with type 2 diabetes. STEP 7: Key Points (5 minutes) • Gums, mucilage and pectins have similar constitutuons and on hydrolysis yield a mixture of sugar and uronic acids. • Gums are pathological products formed upon injury of the plant or owing to unfavourable conditions such as draught, by a breakdown of cell walls e.g. tragacanth • Acacia gum is a dried gum obtained from

NTA Level 5 • Semester 2 • PST05210 Introduction to Ergastic Substances Basic Pharmacognosy • Source Session/Topic 16 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 16: Introduction to Ergastic Substances Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define ergastic substances • Classify ergastic substances • Describe carbohydrates • Describe proteins • Gums, mucillages and Pectins • Describe tannins • Describe ergastic crystals 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 |10 minutes |Presentation |Meaning and Classification| | | | |of Ergastic Substances | |3 | |Presentation |Carbohydrates | | |15 minutes |Buzzing | | |4 | |Small group discussion|Proteins | | |25 minutes |Presentation | | |5 |15 minutes |Presentation |Gums, Mucillages and | | | | |Pectins | |6 |15 minutes |Presentation |Tannins | |7 |25 minutes |Presentation |Ergastic Crystals | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Objectives (5 minutes) READ or ASK students to read the learning objectives and clarify ASK students if they have any questions before continuing. STEP 2: Meaning and Classification of Ergastic Substances (10 minutes) • Ergastic substances are non-living cell contents which can be identified by microscopical examination or by chemical and physical tests • Ergastic substances are food reserve (storage products) or by-products of metabolism (excretory/secretory products) • Classes of ergastic substances are; o Carbohydrates o Proteins o Fixed oils and fats (Elaioplasts/spherosomes) o Alkaloids (and purines) o Glycosides o Gums, mucilages and Pectins o Volatile oils and Resins o Tannins o Crystals (Calcium oxalate, calcium carbonate and silica) STEP 3: Carbohydrates (15 minutes) |Activity: Buzzing (10 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | | | |What are the characteristics and chemicals tests of cellulose and | |starch? | | | |ALLOW students to discuss for 10 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned| | | | | |CLARIFY and SUMMARIZE by using the contents below | • Cellulose and starch are the main ergastic substances of plant cells • Cellulose is the chief component of cell wall • Starch occurs as a reserve material in the protoplasm o Found in plastids (leucoplasts and amyloplasts) o Occurs in granules (starch grains) of different sizes in almost all organs of plants o Occurs abundantly in roots, rhizomes, fruits and seeds o Physical tests: ▪ Pure starch is a white, tasteless and odourless powder insoluble in cold water or alcohol o Chemical tests for starch granules ▪ Starch are unique in shape of starch granules in granular size, shape and crystallization pattern ▪ Starch grains are observed under the microscope e.g. when stained with iodine STEP 4: Proteins (25 minutes) |Activity: Small Group Discussion (10 minutes) | | | |DIVIDE students into small manageable groups | |ASK students to discuss on the following question | | | |What are the characteristics and chemicals tests of proteins? | | | |ALLOW students to discuss for 10 minutes | |ALLOW few groups to present and the rest to add points not | |mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • Proteins are large macromolecules made up of long chains of amino acids joined by peptide bond • Proteins are the main component of living protoplasm • Proteins also occur as inactive ergastic bodies in amorphous or crystalline forms • They occur in form of aleurone grains which are well seen in oily seeds (e.g. castor seeds) • Simplest aleurone grain consists of a mass of proteins surrounded by a thin membrane • Ground mass of protein encloses one or more rounded bodies or globoids and an angular body known as crystalloids • So, microscopically, they are observed as mass of protein surrounded by thin membrane (globoidal in shape) • Aleurone grain are best seen after deflating and removal of starch (if starch is present in large amounts) • Chemical tests o Millon’s reagent, which stains the protein red on warming o Iodine solution, which stain the ground substance and crystalloid yellowish-brown but leaves the globoids unstained o Picric acid which stain stains the ground substance and crystalloid yellow STEP 5: Gums, Mucillages and Pectins (15 minutes) • These are polysaccharides complexes formed from sugar and uronic acid units • They are insoluble in alcohol but dissolve or swell in water • They are usually formed from the cell wall e.g. tragacanth or they are deposited on the cell wall in successive layers • When cells containing these substances are mounted in alcohol and irrigated with water, stratifications (of the successive layers of these ergastic substances) may often be seen e.g. Mustard and linseed • Tests o There are no specific tests for these substances o The official solution of Ruthenium red • Stains the mucilage of Senna and Buchu leaves, Althea, Linseed and Mustard o Alkaline solution of Corallin • Stains some forms of mucilage e.g. mucilage from Squill o Chlor-zinc-iodine or Methylene blue dissolved in alcohol and glycerine ▪ Stain some mucilage STEP 6: Tannins (15 minutes) • Tannins are phenolic compounds obtained from various parts of different plants • Tannins are widely distributed in plants • Occur in solution in cell sap, often in distinct vacuole • Are abundant in the tree bark, wood, fruit, fruit pod, leaves, and roots • Tannins are obtained from plants like wattle (Acacia sp.), oak (Quercus sp.), eucalyptus (Eucalyptus sp.), willow (Salix caprea),

NTA Level 5 • Semester 2 • PST05210 Adulteration of Medicinal Plants Basic Pharmacognosy • Source Session/Topic 15 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 15: Adulteration of Medicinal Plants Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define adulteration • List methods of adulteration • Explain the effects of adulteration 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 |10 minutes |Presentation |Meaning of Adulteration | |3 | 25 |Presentation |Methods and Effects of | | |minutes | |Adulteration | |4 |05 minutes |Presentation |Key Points | |5 |05 minutes |Presentation |Evaluation | |6 | 10minutes |Presentation |Assignment | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning objectives and clarify ASK students if they have any questions before continuing. STEP 2: Meaning of Adulteration (10 minutes) • Adulteration is defined as anything causing debasement of a drug • An adulterant is a medicinal plant which does not conform to official standards or which does not comply with the requirement of the pharmacopoeia cheap and easily available in large quantities o An adulterant must be • Adulteration or debasement of medicinal plants are of two major types; o Deliberate adulteration ▪ This is intentional and normally commercial mainly for enhancement of profits o Accidental adulteration • Deliberate adulteration is usually practised when certain medicinal plants are scarce or expensive • Adulteration of crude drugs usually involves practices such as substitution of the original crude drugs partially or fully with other substances which are either free from or inferior in therapeutic and chemical properties • Adulteration can occur through; o Faulty collection of the drug o Improper preparation of the drug o Poor storage condition o Deliberate practices • Reasons for adulteration of crude drugs include; o Scarcity of the drug o High price of the drug in the market e.g. clove, cardamom o Contraband drug e.g. opium STEP 3: Methods and Effects of Adulteration (25 minutes) • Inferior medicinal plant quality o Which leads to a sub-standard drug o This may result from; ▪ Ignorance/carelessness e.g. collection of genuine material regardless of the time factor –collecting herbs prior/after ideal time ▪ Collection at incorrect stage of development e.g. coriander – fully ripe fruits (should be nearly ripe), clove (flowers in bud stage) ▪ Collection of parts which are not medicinally valuable e.g. Chamomile leaves ▪ Collection of incorrect herb (close resemblance to intended herb) ▪ Imperfect preparation e.g. not removing undesired parts e.g. cork from ginger rhizome/incorrect drying conditions ▪ Incorrect storage: e.g. volatile oils: cool, dry place in air tight containers ▪ Inferiority may be avoided by careful selection of the plant material • Spoilage of Drug o When the quality or medicinal value/ usefulness of herb is impaired or destroyed by bacterial/ fungal action, insects, rodents or other pests o Normally results from incorrect storage (effects of water/temperature) o Avoided by careful attention to the drying and storage conditions • Deterioration o Occurs when value or quality of the drug has been impaired • Admixture o Admixture occurs when another species is added to the medicinally valuable drug; intentional or accidentally o This may result from; ▪ Poor collection due to unskilled labour ▪ Presence of plant parts other than those allowed by the definition ▪ Collection of foreign material (stones, dirt) • Sophistication with inferior varieties o This is the deliberate addition of inferior material with the intention of decreasing medicinal action of the desired drug e.g. ▪ Candle wax coloured yellow and being offered as Beeswax ▪ Addition of flour to powdered ginger with chillies for potency • Substitution o Substitution is the addition of an allied drug, or one which is botanically different e.g. Digitalis thaspi for Digitalis purpurea • Addition of worthless heavy materials o Large mass of stomes mixed with liquorice root, pieces of limestone are added in asafoedita • Adulteration causes problems in natural drugs STEP 4: Key Points (5 minutes) • Adulteration addition of anything into the crude drugs that causes debasement of that drug • An adulterant is a medicinal plant which does not conform to official standards or which does not comply with the requirement of the pharmacopoeia. • Deliberate adulteration is usually practiced when the drug in question is scarce or expensive STEP 5: Evaluation (5 minutes) • What is adulteration of crude drugs? • What is sophistication? • What are effects of adulteration? STEP 6: Take Home Assignment (10 minutes) |Activity: Take Home Assignment (10 minutes) | | | |DIVIDE students in groups or individuals | | | |ASK the students to work on the following Assignment | |List monographs of medicinal plants | |List the effects of adulteration | |List classes of plants containing toxic substances | |List toxic substances from plants | |List common misuses of medicinal plants | | | |ALLOCATE time for students to do the assignments and submit | | | |REFER students to recommended reference | 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

NTA Level 5 • Semester 2 • PST05210 Extraction of Active Medicinal Principles from Natural Sources Basic Pharmacognosy • Source Session/Topic 14 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 14: Extraction of Active Medicinal Principles from Natural Sources Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Definition of terms • List types of extracts • Explain factors affecting extraction process • Explain Mechanism of solvent extraction • Outline properties and types solvents • Explain methods for extraction of active drugs 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 |10 minutes |presentation |Definition of terms | |3 |05 minutes |Presentation |Types of extracts | |4 |30 minutes |Presentation |Properties and types of | | | |buzzing |solvents | |5 |15 minutes |Presentation |Mechanism of Solvent | | | | |Extraction | |6 |05 minutes |Presentation |Factors affecting | | | | |extraction | |7 |40 minutes |Presentation |Methods of extraction | | | |Small group Discussion| | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Objectives (05 minutes) READ or ASK students to read the learning objectives and clarify ASK students if they have any questions before continuing. STEP 2: Definition of terms (10 Minutes) • Extraction is the method of removing active constituents from a solid or liquid by means of liquid solvent. o The separation of medicinally active portions of plant or animal tissues from the inactive or inert components by using selective solvents. o In this method the wanted components are dissolved by the use of selective solvents known as menstrum & undissolved part is a marc, after the extraction unwanted matter is removed. • Extract: Extracts can be defined as preparations of crude drugs which contain all the constituents which are soluble in the solvent. • Marc: Solid residue obtain after extraction Menstruum • Solvent is a liquid substance capable to dissolve other substances (solutes) without chemical changes. o (The term “Solvents” refers to a class of chemical compounds described by function – the term derives from Latin, meaning roughly to “loosen.” In chemistry, solvents – which are generally in liquid form – are used to dissolve, suspend or extract other materials, usually without chemically changing either the solvents or the other materials Step 3: Types of Extracts (05 minutes) • Type of extracts o Dry extract (Tab, cap.) E.g. belladonna extract o Soft (Ointment, suppository) E.g. glycerrhiza extract. o Liquid: As tincture. STEP 4: Properties and Types of Solvents (30 minutes) |Activity: Buzzing (10 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | | | |What are types of solvents? | | | |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 | • Types of Solvent o Molecular structure of solvents o Inorganic solvents o Organic solvents • Molecular structure of solvents o Molecular structure of solvents, Ability of a substance to dissolve another substance is determined by compatibility of their molecular structures (like dissolves like). ▪ Types of molecular structures of the solvents are as follows: • Polar protic solvents o A polar protic molecule consists of a polar group OH and a non- polar tail. The structure may be represented by a formula R-OH. Polar protic solvents dissolve other substances with polar protic molecular structure. Polar protic solvents are miscible with water (hydrophilic). Examples of polar protic solvents: ▪ Water (H-OH), ▪ Acetic acid (CH3CO-OH) ▪ Methanol (CH3-OH), ▪ Ethanol (CH3CH2-OH), ▪ n-propanol (CH3CH2CH2-OH), ▪ n-butanol (CH3CH2CH2CH2-OH). • Dipolar aprotic solvent o Dipolar aprotic molecules possess a large bond dipole moment (a measure of polarity of a molecule chemical bond). They do not contain OH group. Examples of dipolar aprotic solvents:\ ▪ Acetone ((CH3)2C=O), ▪ Ehyl acetate (CH3CO2CH2CH3), ▪ Dimethyl sulfoxide ( (CH3)2SO ), ▪ Acetonitrile (CH3CN), ▪ Dimethylformamide ( (CH3)2NC(O)H ). • Non-polar solvents o Electric charge in the molecules of non-polar solvents is evenly distributed, therefore the molecules have low dielectric constant. Non-polar solvents are hydrophobic (immiscible with water). Non-polar solvents are liphophilic as they dissolve non- polar substances such as oils, fats, greases. Examples of non-polar solvents: ▪ carbon tetrachloride (CCl4), ▪ benzene (C6H6), ▪ and diethyl ether ( CH3CH2OCH2CH3), ▪ hexane (CH3(CH2)4CH3), ▪ methylene chloride (CH2Cl2). • Inorganic solvents o The most popular inorganic (not containing carbon) solvents are o water (H2O) and aqueous solutions containing special additives (surfacants, detergents, PH buffers, inhibitors). o Other inorganic solvents are liquid anhydrous ▪ Ammonia (NH3), ▪ concentrated sulfuric acid (H2SO4), ▪ sulfuryl chloride fluoride (SO2ClF). • Organic solvents o Oxygenated solvent is an organic solvent, molecules of which contain oxygen. Oxygenated solvents are widely used in the paints, inks, pharmaceuticals, fragrance sectors, adhesives, cosmetics, detergents, food industries. Examples of oxygenated solvents: ▪ Alcohols, ▪ Glycol ethers, ▪ Methyl acetate, ▪ Ethyl acetate, ▪ Ketones, ▪ Esters, ▪ Glycol ether/esters STEP 5: Mechanism of Solvent Extraction (15 minutes) • Mechanism of solvent extraction o Dissolution of extractive substances out of disintegrated cells. o Dissolution of extractive substances out of intact plant cell by diffusion (requires steeping and swelling) o Penetration of the solvent into the plant cells and swelling of the cells. o Diffusion of the dissolved extractive substances out of the cell. o Plant constituents are usually contained inside the cells. o Therefore, the solvent used for extraction must diffuse into