Pharmacognosy

Organic Chemistry, Molecular and cellular biology, Biochemistry

Modules 1-2 capitalize fundamental knowledge about the main phytochemical bases for identifying and characterizing the main groups of naturally derived drugs and their respective medicinal plants, as well as naturally occurring substances used in Pharmacy as excipients and raw materials. This knowledge is consolidated with more complex tasks, involving the analysis of specialized scientific articles and the practical implementation (modules 3-4) of extraction methods and physicochemical analysis of bioactive substances and natural raw materials in accordance with the current good practices outlined in the Portuguese Pharmacopoeia. The teaching methodologies (ME) combine strategies of pedagogical innovation through moments of active learning, student-centered, aimed at promoting the trilogy of knowledge in its dimensions of knowing (knowledge), doing (skills), and being (competencies):

 ME1 – Interactive expository teaching through suitable audiovisual means, with active moments of individual learning focused on problem-solving in Pharmacognosy for knowledge application: Mentimeter Platform (Word cloud, Q&A, Multiple Choice, Ranking tools) [Modules 1-2]

ME2 – Interactive expository teaching through audiovisual means with active moments of group learning focused on the analysis and discussion of scientific articles in the field for knowledge application: Jigsaw Activities [Modules 2-3]

ME3 – Teaching based on planning and resolution: practice is geared towards action with the development of skills in extracting and analyzing bioactive compounds and natural raw materials according to current regulatory guidelines [Module 4]

 The outlined programmatic contents, combined with active and student-centered teaching methodologies, facilitate the acquisition of systemic thinking skills in Pharmacognosy, Phytotherapy and Dietary Supplements.

Upon completion of the course, students are expected to be able to:

 C1 – Identify the main groups of naturally derived drugs and their respective medicinal plants

C2 – Characterize the methodologies employed in the extraction and quantitative and qualitative analysis of bioactive compounds from medicinal plants

C3 – Understand the most commonly used natural raw materials in Pharmacy, as well as their analysis methodologies

C4 – Develop laboratory skills in the field of Pharmacognosy, as well as an understanding of its multidisciplinary nature in phytochemical, pharmacological, and phytotherapeutic aspects.

Theoretical Framework (T)

 Module 1. Pharmacognosy as a multidisciplinary science (2h T)

1.1. Definition of medicinal plant, drug, and active constituent

1.2. Primary and secondary biosynthetic pathways

1.3. Phytochemical principles and influences of chemotypes

1.4. Introduction to the Portuguese Pharmacopoeia

 Module 2. Phytochemical determinants, pharmacological effects, and monographic study of medicinal plants and/or raw materials (28h T)

 2.1. Drugs/Raw Materials with a high content of carbohydrates

2.1.1. Drugs predominantly containing holosides

2.1.1.1. Carbohydrates: chemical definition, epimers, and optical isomerism

2.1.1.2. Aldoses and ketoses series

2.1.1.3. Establishment of hemiacetals

2.1.2. Drugs predominantly containing poly-holosides

2.1.2.1. Starch: chemical composition, obtaining processes, physicochemical properties, and respective interest in Pharmacy

2.1.2.2. Cellulose: chemical composition, obtaining processes, physicochemical properties, and respective interest in Pharmacy

2.1.3. Drugs rich in polyuronides

2.1.3.1. Gums: chemical composition, obtaining processes, physicochemical properties, and respective interest in Pharmacy

2.1.3.2. Mucilages: chemical composition, obtaining processes, physicochemical properties, and respective interest in Pharmacy

2.1.3.3. Study of honey: chemical composition (sugar content, diastatic index, and hydroxymethylfurfural content), and classification according to i) production mode and ii) floral denomination. Sensory and pollen analysis of honey

2.1.3.4. Monographic study of Psyllium (seed) and Linum Usitatissimum

 2.2. Drugs/Raw Materials with a high content of lipids

2.2.1. Saturated and unsaturated fatty acids

2.2.2. Chemical composition of fatty drugs (homolipids and heterolipids)

2.2.3. Classification according to physical state and general properties

2.2.4. Saponification

2.2.5. Hydrolytic and oxidative alterations of fatty drugs

2.2.6. Monographic study of:

2.2.6.1. Castor oil

2.2.6.2. Almond oil

2.2.6.3. Cod liver oil

2.2.6.4. Cocoa butter

2.2.6.5. Spermaceti

2.2.6.6. Lanolin

 2.3. Aromatic drugs

2.3.1. Physicochemical properties

2.3.2. Terpenes – isoprenic unit and degree of polymerization

2.3.3. Classification and monographic study of aromatic drugs predominantly in:

 2.3.3.1. Hydrocarbons (e.g., turpentine essence)

2.3.3.2. Alcohols and esters (e.g., lavender, rosemary, and peppermint essences)

2.3.3.3. Carbonyl compounds (e.g., Ceylon cinnamon essence)

 2.4. Drugs predominantly containing alkaloids

2.4.1. Classification of alkaloids according to biogenesis: true, pseudo-alkaloids, and proto-alkaloids

2.4.2. Identification and chemical characterization of pyrrolidine, tropane, pyridine, piperidine, and indole nuclei

2.4.3. Monographic study of drugs extracted from medicinal plants:

2.4.3.1. Atropa belladonna L.

2.4.3.2. Erythroxylum coca L.

2.4.3.3. Conium maculatum L.

2.4.3.4. Strychnos nux-vomica L.

2.4.3.5. Ergot of Claviceps purpurea L.

2.4.4. Identification and chemical characterization of quinolic and isoquinolic nuclei

2.4.5. Quinine and the revolution in malaria treatment – obtaining processes

2.4.6. Curares and the revolution in anesthesia: obtaining processes

2.4.7. Monographic study of opium: main alkaloids extracted from Papaver somniferum L. and respective therapeutic indications

 2.5. Drugs predominantly containing cardiotonic heterosides

2.5.1. Chemical composition: lactonic ring, steroid nucleus, and osidic fraction

2.5.2. Distinction between bufadienolides and cardenolides

2.5.3. Mechanism of action, therapeutic properties, and potential drug interactions

2.5.4. Monographic study of the medicinal plant Digitalis purpurea L.

 2.6. Drugs predominantly containing polyphenols

2.6.1. Introduction to the study of phytoantioxidants

2.6.2. Definition of free radicals and oxidizing agents (examples)

2.6.3. Main oxidation reactions in lipids, proteins, carbohydrates, and nucleic acids and biological consequences

2.6.4. Endogenous antioxidant defenses (enzymatic and non-enzymatic systems)

2.6.5. Preventive, interception, and repair antioxidants

2.6.6. The international system of food additives – definition

2.6.7. Classification of phenolic compounds: simple phenols, phenolic acids, flavonoids, coumarins, lignans, tannins. Structure-activity relationship and occurrence in nature.

2.6.8. Phytoestrogens – definition and chemical characterization. Monographic study of the medicinal plant Glycine max L.

 2.7. Drugs predominantly containing anthracene heterosydes

2.7.1. Chemical equilibrium between anthrone and anthranol species and their toxic and therapeutic properties

2.7.2. Monographic study of drugs:

2.7.2.1. Rhubarb

2.7.2.2. Cascara Sagrada

2.7.2.3. Black alder

2.7.2.4. Senna

2.7.2.5. Aloes

 Theoretical-practical Framework (TP)

 Module 3. Processes of obtaining and physicochemical assays for qualitative and quantitative analysis of drugs and raw materials of natural origin (15h TP)

 3.1. Physicochemical analysis of honey

3.1.1. Phenylhydrazine derivatization reaction

3.1.2. Molisch’s test

3.1.3. Selivanoff’s test

3.1.4. Keller-Killiani test

3.1.5. Test for pentoses

3.1.6. Fehling’s reagent reduction reaction

3.1.7. DNS reagent reduction reaction

3.2. Characteristic indices of lipids

3.2.1. Acid value

3.2.2. Peroxide value

3.2.3. Iodine value

3.2.4. Unsaponifiable matter

3.3. Processes for obtaining volatile oils

3.3.1. Enfloration

3.3.2. Steam distillation

3.3.3. Extraction with organic solvents

3.3.4. Supercritical CO2 extraction

3.4. General reagents for alkaloids and extraction processes

3.5. Methods for determining antioxidant power

3.5.1. TRAP assay

3.5.2. MDA assay

3.5.3. Folin assay

3.5.4. ABTS assay

3.6. Methods for extraction and dosing of cardiotonic heterosides

3.6.1. Chromatic reactions characteristic of the lactonic ring, steroid nucleus, and osidic fraction

3.7. Identification and dosing of anthracene drug

3.7.1. Borntraeger reaction and search for O- and C-heterosides

 Practical Framework (P)

 Module 4. Extraction and qualitative/quantitative analysis of drugs and raw materials of natural origin – Portuguese Pharmacopoeia (30h P)

 4.1. Good practices and safety rules adapted to Experimental Pharmacognosy

4.2. Extraction and purification of photosynthetic pigments

4.3. Determination of reducing sugar content in a honey sample

4.4. Determination of Acid Index and Degree of Acidity in an olive oil sample

4.5. Determination of Iodine Index in samples of olive oil, peanut oil, and soybean oil

4.6. Determination of Peroxide Index in castor oil samples

4.7. Enzymatic processing of plant raw material rich in polyphenols and evaluation of structural and ultrastructural analysis

4.8. Folin assay: determination of total polyphenol content (TPC) in extracts (fruit/leaf) of Vaccinium spp

4.9. ABTS assay: determination of antioxidant activity of extracts (fruit/leaf) of Vaccinium spp 4.10. Extraction of alkaloids from the Quina drug

4.11. Regeneration reaction for dosing alkaloids from Quina extracts

4.12. Extraction and search for cardenolides from foxglove (Digitalis purpurea L.)

NAO

Primary bibliography:

COSTA, A. F., FARMACOGNOSIA, Vol. I, 5.ª edição, Fundação Calouste Gulbenkian, 2002

COSTA, A. F., FARMACOGNOSIA, Vol. II 5.ª edição, Fundação Calouste Gulbenkian, 2002

COSTA, A. F., FARMACOGNOSIA, Vol. III, 5.ª edição, Fundação Calouste Gulbenkian, 2002

Secondary bibliography:

Professor notes

Scientific articles indexed in international databases

Portuguese Pharmacopoeia