Post on 28-Nov-2014
Embed Size (px)
DESCRIPTION2nd yr sem 3 Pharmacognosy
The seed Definition: The Seed is a mature fertilized ovule containing an embryo (originated from fertilized ovules). The function of the seed is to ensure the propagation of the plant.
Structure of Mature ovulestigma style micropyle Ovary wall Ovum (zygot) Outer integument
1ry endosperm nucellus
Embryo sac [ 7-8 nuclei ] Inner integument Antipodal cells chalaza funicle
Outgrowths of testa 1- Arillus or Arili It arises from the funicle or from the tissue of the hilum and partly or completely enveloping the seed. It may be fleshy as in texture or dry and membranous as in Cardamom. 2- Arillode It arises from the tissue of the micropyle and partly or completely covering the seed, being usually fleshy as in Euonymus. N.B. The outgrowth of Nutmeg, named mace, arises from the tissues of both funicle and micropyle and thus it is considered as Arillus or Arillode. 3- Caruncle It is a localised fleshy outgrowth, formed from the tissue in the neighbourhood of the micropyle and covers it as in Ricinus and Croton seeds. 4- Strophiole It is a local, usually barrel-shaped enlargement along the line of the raph, due to an increase in the amount of parenchyma around the vascular strand of the raph as in Colchicum seed. 5- Wing It is an extension of the testa in the form of a membranous fold as in Pinus or in the form of plume of hairs at the summit as in Apocynaceae or at the base as in Salix or at both ends of the seed as in Alstonia. The plume is sessile and when borne on a stalk it is termed awn as in Strophanthus.
A- Cardamom (illuars). B- Nutmeg (mace). C- Castor seed (caruncle). D- Colchicum seed (strophiole). E- Salix seed (tuft of hairs). F- Argel seed (tuft of hairs). G- Pinus seed (with a wing) .H- Strophanthus seed (awn).a., awn; ca., caruncle.
A- Cardamom (arillus) .B- Nutmeg (mace) .C- Castor seed (caruncle). D- Colchicum seed (strophiole). E- Salix seed (tuft of hairs) .F- Argel seed (tuft of hairs). G- Pinus seed (with a wing) .H- Strophanthus seed (awn) .a., awn; ca., caruncle.
Structure of the Seed Testa: Developed from the integuments of the ovule. The Embryo: Developed from the fertilized ovum. The Endosperm: Surrounding the embryo and developed from the primary endosperm nucleus of the embryo sac. The Perisperm: Formed from nucellus. The Kernel Contain of all the tissues of the seed endosed within the testa. It may be formed of the embryo alone or of embryo surrounding by endosperm or persisperm or both.
Exalbuminous: In which the kernel consists of an embryo alone e.g. mustard. Albuminous: In which the kernel consists of an embryo and surrounding by endosperm (e.g. linseed, fenugreek, nuxvomica) or both perisperm and of endosperm (e.g. cardamom, nutmeg)
Funicle or hilum (h.) Chalaza (ch) Micropyle (m.) Embryo sac (es.)
Types of ovules
Forms of Embryo A- Incumbent, entire. F- Spiral B- Incumbent, in T.C. G- Coiled.C- Accumbent, entire. H- Orthoplocus D- Accumbent, in T.S. I- Orthoplocus, in T.S.E-Spiral embryo.Cots., cotyledons, En., endosperm, Rad., radicle; T., testa.
5 Forms of Embryo A-Incumbent,entire. B-Incumbent,inT.C.. C-Accumbent,entire. D-Accumbent,inT.S.. E-Spiral embryo. F- Spiral G- Coiled H- Orthoplocus I- Orthoplocus, in T.S Cots., cotyledons, En., endosperm, Rad., radicle; T., testa.
Funicle or hilum (h.) Chalaza (ch) Micropyle (m.) Embryo sac (es.)
Types of ovules
Linseed Origin: Linseed is the dried ripe seeds of Linum usitatissimum Linn Family: Linaceae.
Oval, flattened and shiny brown. Type of seed: Albuminous. Type of ovule: Anatropous. Type of embryo: Straight. Odor: Odorless when entire but characteristic when crushed. Taste: mucilaginous, bitter, oily.
Constituents: -30 to 40% of fixed oil. , 40% has high content of the unsaturated fatty acids and must be consumed as part of diet. - 25% of protein. 25% - 3-6% of mucilage -Small amount of a cyanogentic glycoside called linamarin.
hypodermis sclereids Nutritive layer
Characters of powder: Powdered Linseed has a characteristic odour and a mucilaginous oily taste. Microscopically, it is characterized by: Numerous oil globules, stained red with globules, alkana tincture and sudan III. III. Fragments with yellowish-brown yellowishsclerenchymatous cells, generally appearing cells, crossed by thin walled elongated cells on one side and by rounded somewhat thickened parenchyma on the other. This structure called mat like shape.
Characters of powder
Chemical test Linamarin + H2O 37C Glucose + Acetocyanohydrin Enzymatic hydrolysis Acetone + HCN HCN Na-Picrate Na-Picramate (Yellow) Reduction (Brick red)
1- Pigment layer
Uses and actions -In folk medicine, in acute or chronic gastritis. -Omega-3 fatty acids have demonstrated antiOmegaantiinflammatory effect used in patients with rheumatoid arthritis and psoriasis. anti-hypercholesterolaemia. As anti-hypercholesterolaemia. Also against angina and thrombosis since they reduce the whole blood viscosity. -Externally as an emollient in poultices for boils, carbuncles. -Linseed whole or crushed is used as a bulk forming laxative in habitual constipation, due to its mucilage constipation, which has a lubricant effect.
Black Mustard Origin Black mustard is the dried ripe seeds of Brassica nigra. Family Cruciferae Constituents - Mucilage; - Fixed oil and Protein. - Glycoside, sinigrin +myrosin enzyme in the presence of water yield glucose+ potassium sulphate + allylisothiocyanate (volatile oil).
Uses and actions: -spice, and as a rubefacient when applied externally.
Brassica AlbaWhite mustard and Yellow mustard
Origin White mustard is the dried ripe seeds of Brassica alba Family Cruciferae.
-Fixed oil and protein. -Mucilage. -Crystalline glycoside, sinalbin+ myrosin enzyme + water yield glucose + K-acid sinapine sulphate + acrinyl-iso-thiocyanate. acrinyl isothiocyanate with a pungent taste and powerful rubefacient action as it is not volatile.
Sclerieds of black mustard
Pigment layer of linseed
Origin: Foenugreek is the dried ripe seeds of Trigonella foenum-graecum Linne Family Leguminosae.
Embryo & endosperm
Constituents: Mucilage. -Alkaloids : trigonelline and choline -Flavonoids: apigenin, luteolin and quercetin. -Saponins Glycosides -coumarin, lipids (5-8 %), vitamins and minerals (a rich source of selenium).
Uses and actions - lactagogue. demulcent, and laxative. -. Foenugreek revealed hypocholesterolemic and hypoglycemic actions in normal and diabetic humans. --Selenium has cytotoxic effect. It is used to prevent colon, lung and prostate cancer.
Semen PsylliiPsyllium seed,
Origin Dried ripe seed of Plantago psyllium L. and P. albicans L. fam. Plantaginaceae.
Constituents : mucilage. fixed oil and protein. iridoid glycosides e.g. aucubin
Uses and actions: laxative (bulk laxative) especially in pregnant women Contraindication: Abnormal narrowing of the gastro intestinal tract (intestinal occlusion).
Origin: Dried ripe seeds of Strychnos nux vomica family: Loganiaceae.
Characters of powder 1- Sclereid epidermis with thick lignified walled (ten ribed lignified trichomes). 2- Numerous fragments of endosperm with hemicellulosic thick -walled polyhedral cells interconecting by a channels called plasmodesma. 3- Numerous lignified rod shaped fragments of ribs. Constituents: -Indole alkaloids: strychnine and brucine (1.8-5.3%). Strychnine is much more physiologically active than brucine. -The seeds also contain chlorogenic acid and an iridoid glycoside (loganin). This compounds are intermediates in the biogenesis of the strychnine type alkaloids
Constituents: -Indole alkaloids: strychnine and brucine
Uses and actions : It increases the blood pressure used as a circulatory stimulant in such cases as surgical shock Used as aphrodisiac strychnine used as antidote for barbiturates poisoning.
Toxicity In large doses, it causes violent convulsions and these involve the respiratory muscles and death ensues from asphyxiation.
Origin Colchicum seed is the dried ripe seeds of Colchicum autumnale. Family Liliaceae Constituents -Alkaloid: colchicine. - resin, fixed oil and glucose.
Uses and actions Colchicum is used as anti-gout. -Colchicine is a plant hormone.
Semen Strophanthi Origin Strophanthus is the dried ripe seeds of Strophanthus komb, of S . Hispidus. or of S. gratus Family: Apocynaceae deprived of their awns. One gm of Strophanthus corresponds in potency not less than 0.055 gm of the International Standard Ouabain
Constituents: cardiac glycoside K-Strophanthoside = Strophanthidin + Cymarose + - Glucose + - Glucose * K-Strophanthin-B = Strophanthidin + Cymarose + - Glucose * Cymarin = Strophanthidin + D- Cymarose * Ouabain (GStrophanthin) = Ouabigenin + L rhamnose -ouabain (Gstrophanthin. It is a potent cardiac glycoside, acts quickly, but wears off rapidly. and must be injected intravenously because it is poorly absorbed orally. Therefore, it has been used for emergency treatment in case of acute heart failure.
Uses and actions Strophanthus resembles that of digitalis leaves, being cardiac stimulant