Barks Lecture 1-2024 PDF

Pharmacognosy-II Fall Semestre 2024-2025 Shaza Hussiny Aly, PhD Lecturer of Pharmacognosy Faculty of Pharmacy Badr University in Cairo 2024 Lecture 5 28-10-2024 Barks ✓ Lectures outline: Barks I. Introduction to barks. II. Barks containi...

Pharmacognosy-II Fall Semestre 2024-2025 Shaza Hussiny Aly, PhD Lecturer of Pharmacognosy Faculty of Pharmacy Badr University in Cairo 2024 Lecture 5 28-10-2024 Barks ✓ Lectures outline: Barks I. Introduction to barks. II. Barks containing Alkaloids: Cinchona & Pomegranate III. Barks containing Volatile oil : Cinnamon & Cassia IV. Barks containing Anthraquinone glycosides: Cascara & Frangula V. Barks containing Saponin glycosides: Quillaia VI. Barks containing Phenolic glycosides: Salix VII. Barks containing Tannins: Hamamelis I. Introduction to barks Definition: All tissues outside cambium of woody plants Do u remember the layers of the stem?  Layers of Young stem: Activation of the cork 1. Epidermis cambium to protect the 2. Primary cortex internal tissues 3. Pericycle 4. 1ry phloem Activation of the Vascular cambium to 5. Cambium Give secondary thickening 6. 1ry xylem Appears first. 7. Pith  Where does the cork cambium start in the bark? 1.Epidermis Wherever it is activated, it 2. Primary cortex produces cork to the outside and secondary cortex to the 3. Pericycle inside. 4. 1ry phloem 5. Cambium 6. 1ry xylem 7. Pith  Formation of Barks Changes during barks formation  Types of Bark: If all layers of the bark are Complete bark present If any layer of the tissue of the Incomplete bark bark is removed Collection of Barks: When? Spring or early summer {when the cambium is active} & more easily torn. After a period of rain. High % active constituent. Removal of Barks: How? 1. Longitudinal incisions followed by horizontal ones. 2. With a knife [wood may be present]. Method of Drying: 1. Sun heat [Natural drying] 2. Artificial heat.  Decortication of Bark: Removal of cork, secondary cortex or whole tissues outside the 2ry phloem. Why? 1. It contains low % of or no active constituents. 2. It contains higher % of undesirable compounds e.g. tannins & coloring matter.  Shape 1. Flat. 2. Curved. 3. Channeled 4. Recurved !!!!!!!! 5. Quill (Single quill). 6. Double Quill. 7. Compound Quill. 2. Curved Slightly concave on inner side 3. Channeled Deeply concave on inner side 4. Recurved When the concave side is the outer side; Pomegranate 5. Single quill Deeply concave on inner side The edges nearly overlapped 6. Double quill Both edges are separately in rolled 7. Compound quill When single or double quills are packed inside one another  How to Differentiate between Stem & Root Bark ? Item Stem bark Root bark Position of Any where In the pericycle***** cambium 1. Darker than 1.Both inner & outer inner surfaces have Outer surface surface. the same color; Lighter. 2. Shows epiphytes. 2.No epiphytes. 3. Presence of 3.No lenticels. lenticels. Shape Thicker Thinner Some important features of the outer surface of the stem bark 1. Epiphytes 1. Epiphytes A-Lichens B- Liveworts and Mosses Type of fungus that They are foliaceous grows on the bark structure. surface. Consists of small stems to It exists as a grayish which small leaves are thalloid structure. attached in one plane.  Some important features of the outer surface of the stem bark 2. Lenticles They are breathing pores for gas exchange, larger in size and smaller in number than stomata. Placed transversely. Shape and number used to distinguish the bark type.  Some important features of the outer surface of the stem bark 3. Wrinkles and furrows The greater shrinkage of the softer tissues result in formation of wrinkles Because the shrinkage of the barks during drying occur chiefly transversely. 4. Cracks or fissures Owing to continued increase in growth and the lack of elasticity.  Histology ofthe Bark: 1. Rhytidoma (dead collapsed tissue). 2. Cork (Phellem). 3. Phellogen (cork cambium). 4. Phelloderm (secondary cortex). 5. Primary Cortex. 6. Pericycle. 7. Primary Phloem. 8. Secondary phloem. 1. Rhytidoma Outermost layer Dead cells. 2. Cork (Phellem). Secondary growth. Stratified layers with dark brown content Cork cells (S.V.) Cork cells (T.V.) 3. Cork cambium Meristematic cells. Produce cork to outside and secondary cortex to the inside. 4. Cortex ( 1°, 2°) Parenchyma cells. Contains CaOx crystals as Quillaia, Starch as Cinnamon. The main source of the active ingredients Alkaloids as Cinchona, Volatile oil as Cinnamon, Saponins as Quillaia, Anthraquinone as Cascara. 5. Pericycle Outer sheath of the vascular bundles. Formed of single layer to several layers. It may be: Parenchymatous. Isolated groups of fibres. Occasionally sclerenchyma (Cinnamon). 6. Phloem Sieve tubes + phloem parenchyma+ phloem fibres. ✓ Lectures outline: Barks I. Introduction to barks. II. Barks containing Alkaloids: Cinchona & Pomegranate III. Barks containing Volatile oil : Cinnamon & Cassia IV. Barks containing Anthraquinone glycosides: Cascara & Frangula V. Barks containing Saponin glycosides: Quillaia VI. Barks containing Phenolic glycosides: Salix VII. Barks containing Tannins: Hamamelis II. Barks containing Alkaloids: Cinchona Bark ◼ Syn.: Quina; Peruvian bark; Jesuit bark; Countess bark. ◼ Origin: Root & stem barks of Cinchona succirubra (Red cinchona); or Cinchona Ledgeriana & Cinchona calisaya (Yellow cinchona); or Cinchona officinalis (Pale cinchona) Family Rubiaceae. Shape: Flat, channeled & single quill.  Cinchona powder Ca. Ox. Crystals (Idioblast) Cork cells (S.V.) Phloem fiber Cork cells (T.V.) Starch granules  Active constituents: ✓ Quinoline alkaloids (30 alkaloids); total is known as Totaquine Quinine & Quinidine [stereoisomers]. Cinchonine & Cinchonidine [stereoisomers]. ✓ Present as salts with quinic acid & cinchotannic acid [condensed tannins that decompose to give cinchona red; RED fumes].  Chemical Tests 1. Test for Cinchona red (sublimation test): Heat Powder in dry test tube Reddish fumes 2. General test for Condensed Tannins: Powder + FeCl3 Greenish black color 3. General test for Alkaloids Powder + Mayer’s reagent Creamy white ppt  Chemical Tests 4. Special test for Quinine & Quinidine alkaloid [Thaleoquine test]. 5. Special test for Quinine alkaloid Blue Quinine alkaloid + Oxygenated acid (H2SO4) fluorescence Medicinal Uses 1. Bitter tonic & stomachic [Total extract in the form of tincture]. 2. Gargles in the form of decoction due to its tannin. 3. Antimalarial [Quinine]. 4. Stimulate hair growth [Quinine]. 5. Antiarrythmic & treatment of atrial fibrillation [Quinidine]. 6. Antirheumatic & antipyretic [Cinchonine & Cinchonidine] II. Barks containing Alkaloids: Pomegranate Bark ◼ Origin: Dried stem & root barks of Punica granatum, Family Punicaceae Active constituents: 1. Alkaloids (liquid): pelletierine, isopelletierine. 2. Tannins. Pomegranate Bark Action & uses: 1. Anthelmintic for tape worm. 2. Astringent. 3. Decrease cardiac risk factor. 4. Antioxidant. Chemical test: 1. Mayer’s test. 2. Ferric chloride test (tannins). ✓ Lectures outline: Barks I. Introduction to barks. II. Barks containing Alkaloids: Cinchona & Pomegranate III. Barks containing Volatile oil : Cinnamon & Cassia IV. Barks containing Anthraquinone glycosides: Cascara & Frangula V. Barks containing Saponin glycosides: Quillaia VI. Barks containing Phenolic glycosides: Salix VII. Barks containing Tannins: Hamamelis III. Barks containing Volatile Oil: Cinnamon and Cassia Cinnamon Cassia Synonym: Ceylon cinnamon ‫القرفه السيالني‬ Chinese Cinnamon ‫القرفه الصيني‬ Origin: Dried stem bark of the shoots of Dried stem bark of the coppiced trees of Cinnamomum cassia, Cinnamomum zeylanicum, Fam. Lauraceae Fam. Lauraceae Deprived of most of its cortex. Morphology: Single or double compound quill Channeled pieces or single quill  Cinnamon Cassia Single or double compound quill Channeled pieces or single quill Cinnamon Cassia Active constituents 1. Volatile oil Cinnamic 1. Volatile Oil Cinnamic aldehyde & aldehyde & Eugenol. No Eugenol 2. Condensed tannins 2. Higher %Condensed 3. Mucilage tannins. 3. Mucilage Chemical test: Test for volatile oil (Sudan III)---------Red color Test for Eugenol (KOH) ----------- Needles shape crystals Test for tannins (Fe Cl3 test) ---------Green color Test for mucilage (Ruthenium red) ---------Red color  Cinnamon Powder Starch granules Oil cell Phloem Calcium oxalate fibers Sclerides crystals Action & Uses of Cinnamon: Volatile oil 1. Antispasmodic in mild cramp GIT disorders. 2. Antiflatulent & carminative. 3. Flavoring agent. 4. Aromatic antiseptic [Eugenol in V.O.]. Total extract 1. Warming stimulant in cold conditions. 2. Emmenagogue i.e. stimulate the uterus & encourages menstrual bleeding. Tannins Mild astringent.