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All bark

  1. 1. - It is the first part of a tree that you see. - It's the stuff that's on the outside of the wood. - It is a very important part of the tree, and deserves to be discussed in this section.
  2. 2. • Bark management is important not only for securing 1 the supply of diverse raw materials bark provides (e.g., fibers, dyes, and medicines), but also for protecting the trees supplying these resources. • Bark does a number of important jobs for trees, but its main job is to 2 protect the wood underneath. It also 3 prevents the wood from being scorched if there is a forest fire.
  3. 3. Formation of bark: • meristematic zone • located between the bark and the wood, • the vascular cambium zone: "the cambium" . • Its cells divide inward and outward, laying down new wood cells on those already in place and new inner bark cells inside those already existing. • Definition: • Bark is all the tissues of the stem or the root of woody plants that are exterior to the cambium.
  4. 4. Bark consists of: a- Outer bark. b- Inner bark. A-Outer Bark • Outer bark (= rhytidome) • The surface of the outer bark of many species is perforated by corky lenticels that allow increased rates of gas exchange by living tissues inside the stem.
  5. 5. - The outer surface of the bark usually exhibits important features as: 1- Epiphytes: a- Lichens: - a type of fungus that grows on the surface of barks. - It exists as a grayish thalloid structure. - grow on trees using the bark as a medium for their nutrition and growth.
  6. 6. b-Liverworts: - are foliaceous structure, - consists of very small stems to which small leaves are attached in one plane.
  7. 7. c-Mosses: - are stem bearing spirally arranged leaves each possesses a midrib and lamina of one cell thick.
  8. 8. 2-Lenticles: - Lenticles, are breathing pores for exchange of gases, larger in size and smaller in number than stomata. - Placed transversely, - the shape and abundance of which may help in distinguishing the bark.
  9. 9. 3-Cracks and fissures: Arise due to continued increase in growth and the lack elasticity. 4-Wrinkles and furrows: The greater shrinkage of the softer tissues results in formation of wrinkles because the shrinkage of the barks during drying occurs chiefly transversely. 5-Smooth: When the cork is evenly developed. 6-Scaly: It may be rugged and scaly due to exfoliation of the outer tissues.
  10. 10. N.B.: A tree can often be identified by its bark because bark looks different on different trees.
  11. 11. B- Inner Bark: • Inner bark is produced by and adjacent to the vascular cambium. • It is composed of living secondary phloem. • Progressing towards the outside of the stem, inner bark is typically terminated by the innermost and most recent periderm, which is produced by the phellogen. The phellogen develops from parenchyma in the older phloem tissues or, in young stems, just beneath the epidermis.
  12. 12. Collection of Bark  Collection is usually in spring or early summer, when the cambium is active, and after a rainy season, the bark is most easily collected. Drying of Bark • Drying of barks is nearly always affected by the sun's heat in open air, or sometimes, after a preliminary drying in the open air, the operation is completed by some kind of artificial heat.
  13. 13. Different shapes of Bark (curvature) the bark is described as: 1-Flat: When quite flat and very thick, i.e. Quillaia. 2-Curved: When curved and slightly concave on the inner side, i.e. Wild cherry.
  14. 14. 3-Recurved: When the concave side is the outer one, i.e. Pomegranate. 4-Channelled: When deeply concave on the inner side, i.e. Cassia.
  15. 15. 5-Single quill: When deeply concave on the inner side that the edges of the bark nearly or quite overlap, i.e. Cinchona. 6-Double quill: When both edges are separately in rolled, i.e. Frangula.
  16. 16. 7-Compound quill: When single or double quills are packed inside one another, i.e. Cinnamon.
  17. 17. Fracture • It is the behavior of barks when broken across transversely and the appearance of the exposed surfaces. It is described as:  Short: When the fractured surface is smooth.  Granular: When the surfaces exhibit small rounded prominences.  Fibrous: When fibrous threads extend from the broken surfaces.  Laminated: When breaks into tangentially arranged layers.
  18. 18. Histology of Bark • The bark includes a number of different tissues. • From the outside to the inside of a mature woody stem, The layers include: (1) Cork (Phellem). (2) Cork cambium (Phellogen). (3) Phelloderm. (4) Cortex. (5) Phloem. (6) Vascular cambium. (7) Xylem.
  19. 19. BARK Outer Bark Inner Bark 2ry Phloem Transmits food made in the leaves down to the roots The Periderm 2ry Cortex Cork cambiumCork Phelloderm
  20. 20. Cork cambium (phellogen) Vascular cambium divides to the outside divides to the inside Cork (phellem) Phelloderm Secondary Phloem Secondary Xylem divides to the outside divides to the inside
  21. 21. Secretory Structures • Secretory structures could be: - External Secretory Structures (found on the surface of the plant) -Trichomes and Glands -Nectaries -Hydathodes - Internal Secretory Structures (embedded in various tissues) -Secretory cells -Secretory cavities and canals -Laticifers
  22. 22. Internal Secretory Tissues 1- Secretory Cells (Idioblasts): - are cells or groups of cells which produce a variety of secretions. - occur either isolated or rarely arranged in rows, - frequently found in all the tissues, - and differ from the other cells of the tissue mainly by their contents and size.
  23. 23. - Secretory cells may be elongated so called sacs or tubes and could be branched. - The secretory cells secretions may be volatile oil, resin, gum-resin, mucilage, enzyme or tannins.
  24. 24. Schizogenous cells Lysigenous cells Schizolysigenous sllec 2- Secretory Cavities or Sacs (Internal Glands)
  25. 25. 3- Secretory Ducts (Canals) • These are tube-like structures containing and producing secretion, • may extend through the whole length of the organ or even through the whole of the plant; • usually produce volatile oil or oleo-resin.
  26. 26. 4- Laticiferous Structures • These include cells and vessels which are, in most cases, in the form of tubes, the contents or secretion of these elements is called latex. • Latex is a colorless, milky white, yellowish or red slightly viscous emulsion or suspension of variable composition. • Laticiferous structures are most commonly found in the phloem.
  27. 27. Simple vessels Branched vessels Latex vessels
  28. 28. 1. The outer bark (cork). protects the tree from extreme temperatures, bad weather, insects and fungi. 2. The inner bark (2ry phloem) conveys the food-bearing sap developed in the leaves down to the various parts of the tree. 3. The cambium is a thin layer of cells, which produce phloem on one side and xylem (sapwood) on the other. 4. Sapwood is the living wood in the tree through which the raw sap rises from the roots to the leaves. 5. The heartwood consists of old cells. This is the dead part of the tree that nevertheless provides structural strength. 6. The pith is the central core of the tree (missing in many species). A transverse section in the trunk of an old stem
  29. 29. Cinchona Bark ‫الكـينــا‬ ‫قـشر‬ (Anti-malarial bark) • Botanical Origin: • It is the dried stem and root bark of Cinchona succirubra (Red Cinchona), C. ledgeriana, C. calisaya (Yellow Cinchona) and C. officinalis L. (Pale Cinchona), Family: Rubiaceae.
  30. 30. I- Stem Bark - Shape: quills, double quills, chips or curved pieces. - Size: up to 35 cm long, 1-4 cm wide and 2-9 mm thick. - The outer surface: grey or greyish-brown to reddish brown, bearing whitish or greyish lichens and mosses. It is rough with-corky longitudinal ridges and transverse fissures, exfoliation may occur. - Inner surface: pale yellowish-brown, longitudinally striated; fracture; short in the outer part, and shortly fibrous in the inner part. - Fracture: short in the outerpart and shortly fibrous in the inner part.
  31. 31. II-Root Bark - It is irregularly curved channeled, often twisted pieces, 2-7 cm long. - Lichens and other epiphytes are absent. -The outer surface is somewhat scaly while the inner surface is striated and is frequently fissured while the rest of other characters are similar to those of the stem bark.
  32. 32. Powder: - Powdered Cinchona is yellowish-brown, brown or reddish-brown in color. - It is characterized by: 1- Fragments of yellowish bright bast fibres, either entire or in broken pieces. 2- Fragments of brown parenchyma, occasionally with idioblasts. 3- Fragments of reddish brown cork. 4- Few small starch granules usually simple, rarely compound of 2 to 5 components and very minute microsphenoidal crystals of calcium oxalate.
  33. 33. Powdered Cinchona Bark starch granules Cork Cells Phloem fibres crystals of calcium oxalate
  34. 34. 1- Mainly alkaloids (Quinoline alkaloids): more than 30 alkaloids (6 -10 %). The four most important alkaloids are: - Quinine (20 %), - Cinchonidine (30 %), - Cinchonine (45 %), - Quindine (5 %) - and their methoxy derivatives. Active Constituents
  35. 35. 2- Tannins: Cinchotannic acid and Phlobatannin. 3- A glycoside Quinovin (up to 2%), which is yielding on hydrolysis quinovic acid and the sugar quinovose. 4- Calcium oxalate and starch. • The root bark is the richest in the alkaloidal contents and the stem bark is richer than the branch bark.
  36. 36. 1- Quinine is used as antimalarial and suitable for treatment of Plasmodium falciparum infection (falciparum malaria). 2- Quinine stimulates hair growth. 3- Quinidine is used for the prophylaxis from cardiac arrhythmias and for treatment of arterial fibrillation. 4- Cinchonine and Cinchonidine are used as antirheumatic. 5- A decoction and acid infusion are sometimes used as astringent gargles due to tannins. 6- Bitter tonic and stomachic. 7- Treatment of gastro-enteritis, gall-bladder problems and flatulence. Uses
  37. 37. 1- Test for Cinchona: • 0.5 g powder in dry test tube  heat  purplish red or carmine red fumes evolves  condense as purplish-red drops, soluble in alcohol (50 %)  a solution with blue fluorescence. Special Chemical Tests
  38. 38. 2- Test for alkaloids: • Shake 0.1 g powdered cinchona with 2 ml dil. HCl  filter  add to the filtrate a drop of potassium mercuric iodide (Mayer's reagent)  precipitate is formed immediately. 3- Test for Quinine and Quinidine: • + dil. oxygenated acids, i.e. dil. H2SO4  blue fluorescence. 4- Thalloquin test: • 2-3 ml of weakly acidic solution of Quinine or Quinidine salt + bromine water (few drops)  add 0.5-1 ml of strong ammonia solution  emerald green color is produced.
  39. 39. Cinnamon Bark ‫صيني‬ ‫دار‬ ‫قـشر‬ • Botanical Origin: • It is the dried shoot bark of Cinnamomum zeylanicum Nees., Family: Lauraceae, deprived of most of its cortex known as Ceylon Cinnamon.
  40. 40. Description: - Cinnamon bark - Odour a delicate, fragrant and aromatic - Taste it has sweet, agreeable and warm taste. Macroscopical Characters - Shape: quills (single, double and compound), compound quills are formed of 10-40 pieces. - Size: about 6-10 mm diameter (in good qualities it is not more than 0.5 mm).
  41. 41. - Outer surface: Yellowish-brown colored shows longitudinal shining wavy lines (pericyclic fibers) and shows scars and holes indicating the positions of leaves and twigs. - Inner surface: Dark brownish color shows fine longitudinal striations. -Fracture: short and splintery fracture, the drug is brittle. Powder - Powdered cinnamon colour: slight brown or yellowish-brown. - It is characterized by: 1- Fragments of bast fibres mostly isolated with thick walls. 2- Sclereids, numerous, unequally thickened and containing starch granules. 3- Fragments of parenchyma, containing either starch granules or minute acicular crystals of calcium oxalate and accompanied with occasional isolated oil cells.
  42. 42. 1- Volatile oil (0.5-1.0%): containing mainly Cinnammaldehyde (65%) Eugenol (4-10 %). 2- Tannins (1%). 3- Mucilage. 4- Traces of alkaloids. 5- Calcium oxalate and starch. Active Constituents
  43. 43. 1- Warming stimulant in cold conditions. 2- Antispasmodic in mild cramp-like GIT disorders, carminative in flatulence or distension and in mild digestive problem, i.e., nausea, vomiting and diarrhea. 3- Cinnammaldehyde is used as sedative and analgesic. 4- Flavoring agent. 5- It has also, aromatic antiseptic and mild astringent properties. Uses
  44. 44. 1- Powder + KOH (50%)  needle crystals of potassium eugenate (due to the presence of eugenol one of the volatile oil constituents). 2- Powder + Sudan III  examine under the microscope  orange red oil globules are seen indicating the presence of volatile oil. Special Chemical Tests
  45. 45. Cassia bark ‫صيني‬ ‫قرفة‬ ‫قـشر‬ Chinese Cinnamon • Botanical Origin • Dried stem bark of Cinnamomum cassia (Nees.& T.Nees.) J.Presl., Family: Lauraceae.
  46. 46. 1- Volatile oil containing about 85 % Cinnamaldehyde but Eugenol is absent. 2- Mucilage. 3- Tannins. 4- Flavonoid glycoside. 5- Series of diterpenes. Active Constituents
  47. 47. Differences between Cinnamon and Cassia Bark Cassia BarkCinnamon Bark Point of Comparison Dried stem bark of Cinnamomum cassia (Nees.& T.Nees.) J.Presl., Family: Lauraceae. It is the dried shoot bark of Cinnamomum zeylanicum Nees., Family: Lauraceae, deprived of most of its cortex known as Ceylon Cinnamon. Botanical Origin South of ChinaCeylonGeographical Origin Channeled piecesSingle, double, compound quillShape Dark brownYellowish brownColor Astringent & mucilaginousWarm, sweet, aromaticTaste PresentAbsentCork and cortex Up to 1.5%0.5-1.2 %Volatile oil Higher percent (80 %)Lower percent (65%)Cinnammaldehyde Absent (no eugenol)PresentEugenol Powder + KOH  No needle crystals formed. Powder + KOH  needle crystals of potassium eugenate. Chemical test
  48. 48. Cascara Bark ‫الكسكرة‬ ‫مقدس‬ ‫قـشر‬ (Laxative Bark) Botanical Origin: It is the dried stem bark of Rhamnus purshiana, Family: Rhamnaceae. Geographical Source: North America and Canada. • Cascara should be collected at least one year before being used medicinally and not to be after four years of collection.
  49. 49. Description: Cascara bark has a slight characteristic odor and bitter reseating taste. Macroscopical Characters: - Shape: single quills, curved, channeled or flatten pieces. - Outer Surface: smooth, dark purplish-brown in color, showing few lenticels. The bark more or less completely covered with silvery grey patches of lichens, bryophytes or mosses are often attached to the outer surface. - Inner Surface is yellowish to reddish-brown in color, showing longitudinal striations and faint transverse corrugations in some pieces. - Fracture: has short fracture in cork, cortex and shortly fibrous in the phloem.
  50. 50. Crystal sheath Cork cells (S.V) Prisms and cluster crystals of calcium oxalate Groups of sclerides Cork & cortex cells bearing clusters of ca.ox.
  51. 51. Anthraquinone derivatives (6-9%), which consists of the following: 1- Cascarosides A, B, C and D, they are O & C glycosides of aloin and chrysophanol. 2- Barbaloin and isobarbaloin are C-glycosides of aloin and chrysophanol. 3- O-glycosides of emodin, oxanthrone, aloe-emodin and chrysophanol. 4- Free aloe-emodin, emodin and chrysophanol. 5- Various dianthrones of emodin, aloe-emodin, chrysophanol. Active Constituents
  52. 52. 1- Purgative 2- Tonic and stomachic. 3- Emetic action. • The fresh bark is unsuitable for drug use, causing griping and nausea, and thus the bark is stored for at least a year before being processed. During this time, enzymatic hydrolysis and oxidation modify the anthraquinone-based constituents and thus the cathartic activity. Uses
  53. 53. 1- On microsublimation, powder Cascara gives a yellow crystalline sublimate, which produces a reddish-brown color with alkalie solutions. 2- Mount a section of corallin soda solution, wash with alcohol by irrigation. The callus plates acquire  red stain due to callose mucilage. Special Chemical Tests
  54. 54. 3- Borntrager’s test (test for anthraquinones): - In this test boil Cascara powder + 1ml of sluphuric acid in a test tube for 5min  filter while hot. - Cool the filterate and shake with equal volume of chloroform then separate the lower layer of chloroform and shake it with half volume of dilute ammonia  A ROSE PINK to RED colour is produced in the ammonical layer.
  55. 55. Frangula Bark ‫األسود‬ ‫العوسج‬ ‫قشر‬ Botanical Origin It is the dried stem bark of Rhamnus frangula L., Family: Rhamnaceae. - Frangula barks should be collected one year before being used medicinally. - The bark is obtained from the stem and branches. - It has an emetic effect and unpleasant odour when fresh, these properties disappears when the bark is dried and stored.
  56. 56. Frangula bark contains anthraquinone glycosides: 1- Glucofrangulins A and B which changes during drying process to glucose and frangulins A & B. Frangulin: crystallizes in lemon-yellow needles, slowly volatile at ordinary temperature and stains the paper in which it is kept. Active Constituents
  57. 57. 2- The fresh bark contains anthranols and anthrones which are unstable and readily oxidized to the corresponding anthraquinones. 3- Emodin-dianthrone, palmidin C, palmidin C monorhamnoside, emodin-dianthrone monorhamnoside and emodin -8-O-b- gentioside.
  58. 58. - It has been used as an agreeable laxative, preferable to Cascara on account of its less disagreeable taste. - Microsublimation (as Cascara). - Borntrager’s test as Cascara but gives cherry red colour. Uses Special Chemical Tests
  59. 59. Quillaia Bark ‫الكوياليا‬ ‫قشــر‬ Botanical Origin It is the dried inner part of the bark of Quillaia saponaria Molina, Family: Rosaceae. Active Constitutents 1- Two colorless amorphous, triterpenoid saponin glycosides named: • Quillajic acid. • Quillaia sapotoxin. 2- Sugars and uronic acids. 3- Starch and calcium oxalate.
  60. 60. 1- Treatment for various chest problems mainly as an expectorant. 2-As a substitute for soap, since it forms a lather with water. 3- In some skin creams to treat skin ulcers and eruptions. 4- In hair preparations and shampoos as anti- dandruff. 5- Also as foaming agent in fire extinguishers. Uses
  61. 61. 1- When powdered Quillaia is shaken with water  a copious persistent froth is produced. 2- Saponins are characterized by their haemolytic effect on RBCs. Special Chemical Tests
  62. 62. Pomegranate Bark ‫الـرمان‬ ‫قشـر‬ Botanical origin It is the dried stem and root bark of Punica granatum L., Family: Punicaceae. Active Constituents 1- Four liquid alkaloids; pelletierine (punicine), iso-pelletierine, methyl-pelletierine and methyl-isopelletierine. 2- One crystalline, alkaloid pseudo-pelletierine. 3- Tannins.
  63. 63. 1- Anthelmintic, expel tapeworms (not actually killed) due to irritant action. 2- Astringent. Macerate 0.5 g of powdered pomegranate bark with 25 ml of water and filter  the light yellow filtrate responds to the following tests; 1- 10 ml of the filtrate + a drop of ferric chloride  a BLUISH BLACK precipitate is formed. 2- 10 ml of the filtrate + a drop of calcium hydroxide  an ORANGE BROWN flocculent precipitate is formed. Uses Special Chemical Tests
  64. 64. Wild Cherry Bark ‫بـري‬ ‫كـرز‬ ‫قشــر‬ Botanical Origin Wild cherry bark is the dried stem bark of Prunus serotina, Family: Rosaceae. 1- The cyanogenic glycoside Prunasin and Prunase enzyme in bark. 2- Organic acids; benzoic acid, trimethyl-gallic acid and p-coumaric acid. 3- Tannins and traces of volatile oils. Active Constituents
  65. 65. 1- Antitussive; in cough preparations, for chronic, dry and whooping coughs, bronchitis, increases perspiration rate and mild sedative. 2- Nervous dyspepsia, poor digestion, gastritis and diarrhea. 3- Antibacterial and antiviral. Uses
  66. 66. - Test for hydrocyanic acid (Guignard's test): One gram of small pieces of the bark are put into a test tube + 1.0 ml of water and the tube is closed with a cork holding a strip of moistened sodium picrate paper (Guignard paper) between it and the tube  the HCN evolved over a period of 30 minutes  change to the yellow color of the picrate paper to BRICK RED colour. Special Chemical Test
  67. 67. Cascarilla Bark ‫العـنبــر‬ ‫قشــر‬ Botanical origin It is the dried stem bark of the trees of Corton elutaria L., Family: Euphorubiaceae. 1- Volatile oil (1-3 %), containing eugenol, limonene, an oxygenated principle, vanillin. 2- A crystalline bitter principle, cascarillin. 3- The alkaloid Cascarilline. 4- Tannins, lignins and resins. Active Constituents
  68. 68. 1- An aromatic, bitter stomachic, often mixed with rhubarb. 2- Fragrant component in soaps, creams and lotion. 3- On account of the aromatic odour which is emits on burning, it is used in fumigating mixtures. 4- It is largely used in flavouring liquors and in scenting tobacco. 5- Fumigant. Uses
  69. 69. Witch-hazel Bark ‫الهـمـاميـلـس‬ ‫قشــر‬ Botanical Origin It is the dried bark of Hamamelis virginiana L., Family: Hamamelidaceae. 1- Hamamelitannin (gallotannin 7%) and smaller amounts of condensed tannins. 2- Saponins, fixed oil (0.6%) and wax. 3- Volatile oil (0.5%) and resin. Active Constituents
  70. 70. 1- Treatment of diarrhea, in mucous colitis. 2- Treatment of varicose veins. 3- Treatment of prostate congestion and inflammation. Uses
  71. 71. • Boil 1 g powder in 10 ml of water for 2 minutes, filter, add to the filtrate few drops of ferric chloride (T.S.)  a BLACK BLUE ppt. is produced. Special Chemical Test

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