bark 5

Bark, Wood And Galls

Lecture-5 By

Dr. Ahmed Metwaly

Willow bark 1. Origin. 2. Macroscopical properties. 3. Active constituents. 4. Uses. 5. Pharmacokinetics and action. 6. Side effects

Galls 1. Origin. 2. Macroscopical properties. 3. Microscopical properties 4. Active constituents. 5. Uses. 6. Chemical test.

Origin: Cortex Salicis consists of the whole or fragmented dried bark from young branches of Salix alba, S. fragilis and other Salix species (Salicaceae).

The shape and diameters: The bark is gray, rough and deeply furrowed. Pices The bark is 1–2 cm wide and 1–2 mm thick and occurs

in flexible, elongated, quilled or curved pieces. The outer surface: smooth or slightly wrinkled longitudinally and

greenish-yellow in the younger bark to brownish grey in the older bark.

The inner surface: The inner surface is smooth or finely striated

longitudinally and white, pale yellow or reddish-brown, depending on thespecies.

The fracture: The fracture is short in the outer part and coarsely

fibrous in the inner region, and is easily split longitudinally.

1. Phenolic Glycosides (Salicylates) Various phenolic glycosides including salicin, salicortin and fragilin Salicylates (calculated as salicin) Vary between species, 0.5% in S. alba, 1–10% in S. fragilis

Oxidation

salicin is a pro-drug that is gradually transported to the lower part of the intestine, hydrolysed to saligenin by intestinal bacteria, and converted to salicylic acid after absorption.

It thus produces an antipyretic action without causing gastric injury

Flavonoids: Flavanones, eriodictoyl-7-glucoside and

naringenin-5-glucoside; chalcone; isosalipurposide; catechin. Tannins: Condensed.

Analgesic Antipyretic Anti-inflammatory Anticoagulant

hypersensitivity to aspirin, asthma, active peptic ulceration, diabetes, gout, haemophilia, hypoprothrombinaemia, kidney or liver disease

Pregnancy and lactation: The use of willow during pregnancy and lactation

should be avoided. Should be avoided with children under the age

of 12 years due to the possibility of Reye’s syndrome.

is a potentially fatal syndrome that has numerous

detrimental effects to many organs, especially the brain and liver causing fatty liver with minimal inflammation and cerebral edema.

Reye syndrome appear to result from damage to cellular mitochondria.

The precise mechanism by which Reye syndrome occurs is unknown.

There is an association between taking aspirin for viral illnesses and the development of Reye syndrome.

Origin: Galls is a pathological outgrowth, formed on the young twigs of oak tree (Quercus infectoria Family Fagaceae), as a result of the deposition of the eggs of female insect (Cynips gallae tinctoria Family Cynipidae).

Syn. Aleppo Galls, blue galls, nut galls

Should be collected before insect escape!!!

Odor Odorless

Taste Astringent

Shape Nearly spherical or sub-spherical, hard

and sink in water.

Color Dark bluish-green olive to yellowish-

brown

Surface Lower half nearly smooth and upper

one is rough with short pointed

projections.

Powder; Odorless, dirty green to pale buff in color with astringent taste followed by sweetness , the powder is characterized by the following elements : 1) Numerous sclereidal cells with thick pitted walls and narrow lumen (fibrous sclereids). 2) Tannin plates. 3) Few fragments of starch granules. 4) Lignin Bodies.

50-70% tannins (Gallotannin) , which yields gallotannic acid, gallic acid and ellagic acid.

Tannic acid

Ellagic acid

Gallic acid

Blue galls White galls Time of collection Before insect escape After Shape ? ? Weight ? ? Color ? ? A. C. ? ?

Medically; as a local astringent. Technically; in tanning, dying in the manufacture of ink and

in the manufacture of leather.

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Willow bark 1. Origin. 2. Macroscopical properties. 3. Active constituents. 4. Uses. 5. Pharmacokinetics and action. 6. Side effects

Galls 1. Origin. 2. Macroscopical properties. 3. Microscopical properties 4. Active constituents. 5. Uses. 6. Chemical test.