Pharmacognosy 2

Pharmacognosy 2

اسلاید 1: www.tabaye.ir

اسلاید 2: Pharmacognosy

اسلاید 3: Introduction to PharmacognosyA brief history of natural products in medicineValue of natural drug productsProduction of natural drug productsThe role of natural products in drug discoveryGeneral principles of botany: morphology and systematics

اسلاید 4: I. The history of natural products in medicineA great proportion of the natural products used as drugsThe study of drugs used by traditional healers is an important object of pharmacognostical researchSumerians and Akkadians (3rd millennium BC)

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اسلاید 6: Egyptians (Ebers papyrus, 1550 BC)

اسلاید 7: Authors of antiquity Hippocrates (460-377 BC) “The Father of Medicine”

اسلاید 8: Dioscorides (40-80 AD) “De Materia Medica” (600 medicinal plants)

اسلاید 9: The Islamic era Ibn Altabari (770850) ” فردوس الحكمه“

اسلاید 10: Ibn Sina (980-1037) ”القانون في الطب“

اسلاید 11: Ibn Albitar (1148-1197) ”الجامع لمفردات الأدوية والأغذية“

اسلاید 12: The era of European exploration overseas (16th and 17th century)

اسلاید 13: The 18th century, PharmacognosyJohann Adam (1759-1809)Linnaeus (naming and classifying plants)At the end of the 18th century, crude drugs were still being used as powders, simple extracts, or tinctures

اسلاید 14: The era of pure compounds (In 1803, a new era in the history of medicine)Isolation of morphine from opiumStrychnine (1817)Quinine and caffeine (1820)Nicotine (1828)Atropine (1833)Cocaine (1855)

اسلاید 15: In the 19th century, the chemical structures of many of the isolated compounds were determinedIn the 20th century, the discovery of important drugs from the animal kingdom, particularly hormones and vitamins. microorganisms have become a very important source of drugs

اسلاید 16: Definitions Pharmacognosy: It is the science of biogenic or nature-derived pharmaceuticals and poisonsCrude drugs: It is used for those natural products such as plants or part of plants, extracts and exudates which are not pure compounds

اسلاید 17: Ethnobotany: It is a broad term referring to the study of plants by humansEthnomedicine: It refers to the use of plants by humans as medicine Traditional medicine: It is the sum total of all non-mainstream medical practices, usually excluding so called “western” medicine

اسلاید 18: Natural products: they can beEntire organism (plant, animal, organism)Part of an organism (a leaf or flower of a plant, an isolated gland or other organ of an animal)An extract or an exudate of an organismIsolated pure compounds

اسلاید 19: Types of drugs derived from plantsHerbal drugs, derived from specific parts of a medicinal plantCompounds isolated from natureNutraceuticals, or “functional foods”

اسلاید 20: II. Value of natural productsCompounds from natural sources play four significant roles in modern medicine:They provide a number of extremely useful drugs that are difficult, if not impossible, to produce commercially by synthetic meansNatural sources also supply basic compounds that may be modified slightly to render them more effective or less toxic

اسلاید 21: 3. Their utility as prototypes or models for synthetic drugs possessing physiologic activities similar to the originals

اسلاید 22: 4. Some natural products contain compounds that demonstrate little or no activity themselves but which can be modified by chemical or biological methods to produce potent drugs not easily obtained by other methodsBaccatin III  Taxol

اسلاید 23: III. Production of natural drug productsCollection (wild)Cultivation (commercial), collection, harvesting, drying, garbling, packaging, storage and preservation e.g. ginseng, ginkgo, peppermintFermentation (Recombinant DNA technology or Genetically engineered drugs) Cell-culture techniquesMicrobial transformationBiologics (prepared from the blood of animals)

اسلاید 24: IV. The role of natural products in drug discoveryCombinatorial chemistryHigh-throughput screening of natural productsCombinatorial biosynthesisEthnopharmacology

اسلاید 25: V. General principles of botany: morphology and systematicsHow to define a pharmaceutical plant-derived drug from the botanical point of view ?a botanical drug is a product that is either:Derived from a plant and transformed into a drug by drying certain plant parts, or sometimes the whole plant, orObtained from a plant, but no longer retains the structure of the plant or its organs and contains a complex mixture of biogenic compounds (e.g. fatty and essential oils, gums, resins, balms)

اسلاید 26: isolated pure natural products are thus not “botanical drugs”, but rather chemically defined drugs derived from nature. the following plant organs are the most important, with the Latin name that is used, for example in international trade, in parentheses:Aerial parts or herb (herba)Leaf (folia)Flower (flos)Fruit (fructus)Bark (cortex)Root (radix)Rhizome (rhizoma)Bulb (bulbus)

اسلاید 27: The large majority of botanical drugs in current use are derived from leaves or aerial parts.A plant-derived drug should be defined not only in terms of the species from which it is obtained but also the plant part that is used to produce the dried product. Thus, a drug is considered to be adulterated if the wrong plant parts are included (e.g. aerial parts instead of leaves)

اسلاید 28: Taxonomy It is the science of naming organisms and their correct integration into the existing system of nomenclatureThe names of species are given in binomial form: the first part of the name indicates the wider taxonomic group, the genus; the second part of the name is the species.

اسلاید 29: Papaver somniferum L.Species: somniferum, here meaning ‘sleep- producing’Genus: Papaver (a group of species, in this case poppies, which are closely related)Family: Papaveraceae (a group of genera sharing certain traits)L.: indicates the botanist who provided the first scientific description of the species and who assigned the botanical name

اسلاید 30: Morphology of higher plants1. FlowerIt is the essential reproductive organ of a plant.For an inexperienced observer, two characteristics of a flower are particularly noteworthy: the size and the colorAlthough the flowers are of great botanical importance, they are only a minor source of drugs used in phytotherapy or pharmacy e.g. chamomile, Matricaria recutita L. (Asteraceae )

اسلاید 31: 2. Fruit and seedThe lower plants, such as algae, mosses and ferns, do not produce seedsGymnosperm and AngiospermGymnosperm: they are characterized by seeds that are not covered by a secondary outer protective layer, but only by the testa – the seed’s outer layer Angiosperm: the seeds are covered with a specialized organ (the carpels) which in turn develop into the pericarp.

اسلاید 32: Drugs from the fruit thus have to be derived from an angiosperm speciesFruits and seeds have yielded important phytotherapeutic products, including:Fruit Caraway, Carum carvi L. (Umbelliferae)Seed (white) mustard, Sinapis alba L. (Brassicaceae)

اسلاید 33: 3. Leaves The function of the leaves, as collectors of the sun’s energy and its assimilation, results in their typical general anatomy with a petiole (stem) and a lamina (blade)A key characteristic of a species is the way in which the leaves are arranged on the stem, they may be:AlternateDistichousOppositeDecussateWhorled

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اسلاید 35: The form and size of leaves are essential characteristics e.g. oval, oblong, obovate, rounded, linear, lanceolate, elliptic, spatulate, cordate, hastate or tendrilThe margin of the leaf is another characteristic feature e.g. entire, serrate, dentate, sinuate, ciliate or spinose

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اسلاید 37: Numerous drugs contain leaf material as the main component. e.g. Deadly nightshade, Atropa belladonna L. (Solanaceae)

اسلاید 38: 4. BarkThe bark as an outer protective layer frequently accumulates biologically active substances e.g.Red cinchona, Cinchona succirubra L. (Rubiaceae)No stem-derived drug is currently of major importance

اسلاید 39: 5. Rhizome and root drugsUnderground organs of only a few species have yielded pharmaceutically important drugs e.g.Sarsaparilla, Smilax regelii (Smilacaceae)Korean ginseng, Panax ginseng (Araliaceae) 6. The bulbs and exudatesGarlic, Allium sativum L. (Liliaceae)Aloe vera L. (Asphodelaceae)