ECU Medicinal Plant Intro PDF

Part 2 Medicinal Plant PG 101 1  Primary metabolites e.g. Starch, lipids, protein Water ✓ Essential for living of the plant...

Part 2 Medicinal Plant PG 101 1  Primary metabolites e.g. Starch, lipids, protein Water ✓ Essential for living of the plant supply ✓ Used for growth and energy for light viable processes. Photosynthesis ✓ present in all plant cells ❑ Important for basic human nutrition Biosynthesis Soil Sugars, Secondary metabolites Fatty acids, e.g. Aroma, colorants, nutrients Amino acids ❑ Not essential for living of the plant, however, important for adaption to the environment.e.g. Attraction of insects, birds for seeds dispersal and pollination. Defending against bacteria, Most medicines belong to this group fungi, and animals ❑ not present in all plant cells ❑ Important for healthy human nutrition or important as a medicine  V-Secondary plant metabolites (Active constituents) These act as protective agents. Some are the waste products of metabolism (detoxification). They are not nutrients but biosynthesized to aid producers to adapt to the surrounding environment. Usually, they are produced by special cells or organs and stored in cell vacuole or specialized structure. Plants control their rate of production, storage and release according to its needs. Calssified according to its chemical structure Classification of PLANT SECONDARY METABOLITES 1. Alkaloids 2. Glycosides A) Phenolic glycosides i) Simple phenolic glycosides ii) Flavonoid glycosides iii) Anthocyanin glycosides iv) Anthraquinone glycosides B) Cyanophoric (cyanogenic) glycosides C) Thioglycosides (thiocyanate or sulphated glycosides D) Steroidal cardioactive glycosides (cardiac glycosides) E) Saponins 3. Carbohydrates 4. Tannins 5. Oil  1. Alkaloids 1 - (Alkali-like) 2 -They are basic nitrogenous compounds of natural origin and has a physiological activity. 3 -To be an alkaloid, compounds should have the previous 3 characters. The ones have charachter 1 and 2 only are called biological amines. - For plants: protect against insects and animals as they have a bitter taste. - For humans: Most of them act on central nervous system e.g. Caffeine, Nicotine, Cocaine. -All names end with the suffix (ine) - Most alkloids are detected by precipitating with Mayer`s reagent caffeine cocaine  2-Glycosides - Glycosides are Compounds consist of two parts: i) Sugar part (glycone), ii) Non sugar part (aglycone, genin) Aglycone salicin Non sugar part X Site of linking Glycone Sugar part Aglycone One - Water soluble atom - lipid soluble - make the glycoside water O, S, C - responsible for the soluble and deliver it to site of atoms pharmacological action action Condensation - so versatile in structure - could be hexose or pentose (loss of water) sugar X Aglycone sugar OH HX Aglycone + Glycoside X = O, S, C + H2O  2-Glycosides (cont.) Non-reducing organic compounds hydrolyzed by acids, alkalies or enzymes The glycosides are soluble in water and hydroalcoholic Salicin solvents and the aglycones are Parent of aspirin soluble in organic solvents. The name ends with suffix -in H2O X sugar OH HX aglycone + H2O + acid Glycoside or Alklai or enzyme  Glycoside It is soluble in water, so make a tea from it. Go to the patient Glycoside is hydrolysed in intestine. intestine Aglycone is absorbed and go to blood where it go its site of action (heart, joints, kidney, liver). Sugar remain in intestine or absorbed. (Sugar acts as a carrier which deliver the aglycone to its site of action) Classification of Glycosides: According to the nature of the aglycone (genin): A. Phenolic glycosides: i. Simple phenolic glycosides: e.g. Salicin in Salix phenol (aromatic ring + -OH group) C6 Salicin ii. Flavonoid glycosides: - They are also phenolic but consist of three rings with arrangement C6-C3-C6 Kaempferol - For plants: they give the showy yellow-orange color of flowers which attract insects. Protect against UV rays. - For humans: most have antioxidant activity and strength the blood vessel walls. e.g. Diosmin in Buchu. Chemical Test: their solution gives yellow color with KOH iii-Anthocyanin glycosides: They are also phenolic and related to flavonoids (C6-C3-C6),but the oxygen atom is positively charged. Their color depend on the pH (red in acidic pH, violet in neutral, blue in alkaline medium). For plants: They are the colour pigments of flowers e.g. Karkadeh. For humans: used as natural colouring matter and antioxidant. Cyanidin iv- Anthraquinone glycosides: For plants: presumed to help in oxidation-reduction reactions, main value is not yet known. For humans: laxative used in treatment of constipation. The aglycones are di, tri or tetrahydroxy methyl anthraquinone anthraquinone B. Cyanophoric (cyanogenic) glycosides: They yield HCN on hydrolysis. Hence the name (-phore : carrier, -genic: source precursor) For plants: defense because it releases HCN on hydrolysis which is extremely toxic. For humans: They don’t have many applications due to the poisonous properties of HCN. e.g. linamarin in Linseed. Cyano group sugar linamarin C- Thioglycosides (thiocyanate or sulphated glycosides The aglycone part contains sulphur, which on hydrolysis produce SCN (thiocyanate). For plants: defense against insects. For humans: antioxidant and some of them are antirheumatic. e.g. Sinigrin from black mustard used as antirheumatic. Sinigrin broccoli cauliflower  D-Steroidal cardioactive glycosides (cardiac glycosides): They exert a special powerful action on cardiac muscles. A v. small amount stimulate the diseased heart, but excessive dose may cause death. They increase tone, excitability and contractibility of the cardiac muscle, also increase renal circulation so have diuretic effect. For plants: defense against animals For humans: treatment of heart failure Cardiac glycoside  For the activity of cardiac glycosides, they should have: 1. Steroidal nucleus. 2. Lactone ring, either ✓ 5-membered ring (cardenolides in digitalis) or ✓ 6-membered ring (Bufadienolides as in squill) 3. Deoxy sugar.  E-Saponins It foams in aqueous solutions. It causes haemolysis of RBCs. Highly toxic if injected to blood (cause haemolysis). Possess several pharmacological activities e.g. Liquorice Haemolysis of RBCs 3-Carbohydrates and related compounds Carbohydates: hydrates of carbon Cn (H2O)n example: glucose (C6H12O6) They are compounds composed of C,H & O [polyhydroxy ketones or aldehydes]. e.g. lactose, sucrose, starch, gums, mucilage and pectin.  Polysaccharides: Gums, mucilage and pectins Gums: Produced in higher plants as protective after injury. e.g. G. acacia and G. tragacanth. Mucilage: Produced normally by plants to help them in water storage. ✓ Pectose type (red colour with ruthenium red e.g. senna, buchu and henna leaves) ✓ Callose type (red colour with corallin soda, e.g. squill), ✓ Neutral (blue with methylene blue e.g. foenugreek). Pectin: Purified CHO obtained from of the inner part of the rind of Citrus fruit. An ingredient in anti-diarrheal preparation.  4-Tannins Complex substances, their solutions have astringent taste, drugs containing tannins can be used as: Astringent in G.I.T. and haemostatic. Tanning of leather. Astringent taste Treatment of burns (form protective coat). Antioxidants  Types of Tannins Hydrolysable tannins: (pyrogallol tannins) e.g. Galls and Cinchona. ✓ give blue colour with FeCl3 and ✓ no ppt. with bromine water. Condensed tannins: (catechol tannins) e.g. Cinnamon, Tea and Henna leaves. ✓ give green colour with FeCl3, and ✓ give ppt. with bromine water.  Oils What is the difference between essential oil and fixed oil? (volatile oil)  5-Oils Volatile oils (essential oil) Fixed oils Volatilize with steam and at R.T. Non-volatile Don’t leave permanent stain on Leave a permanent stain on filter filter paper paper Mixtures of hydrocarbons (mostly Triglyceryl esters of fatty acids terpenes) and their oxygenated compounds Non saponifiable Saponifiable On standing they resenify On standing they rancid Present in oil cells, secreting canals, Endosperm or embryo of seeds cavities or glandular hairs Uses : flavoring, in perfumery, spices, Food or paint industry antiseptic, antispasmodic and carminative e.g. lavender flowers Linseed Both give red color with Sudan III  5-Oils Volatile oils (essential oil) Fixed oils Triglyceryl esters of fatty acids Limonene + KOH + Carvone Glycerol Soap: K salt of fatty acids  A New compound have a pharmacological action Contain Nitrogen?? Yes NO Alkaloid Hydrocarbon Fixed or volatile oil Contain sugar part and non sugar part? Glycoside Ploymer of sugars only Atom of polysacharide linkage Sulphur thioglycoside oxygen C6 C6-C3-C6 C6-C3-C6 Anthraquinone Sterol Phenolic flavonoid + positive oxygen Anthocyanins + lactone ring No lactone ring Cardiac glycoside Saponins