LECTURE
Herbs and raw stuff that contain anthracene derivatives.
Anthracene derivatives are the group of natural compounds and anthracene is in their basis.
Anthracene
The oxidation level of the medium ring can be different- to anthranol, anthrone, oxanthrone and anthraquinone. Anthranols, anthrones and oxanthrone are easily oxydate even by oxygen in the air thus the most spreaded and studied are anthraquinone derivatives.
Anthrone
Anthranol
Anthraquinone
Anthraquinones are yellow-brown pigments, most commonly occurring as O-glycosides or C-glycosides. Hydroxyl groups always occur at position 1 and 8, that is 1,8-dihydroxyanthraquinones or emodines (chryzacines) and in position 1 and 2, that is 1,2-dihydroxyanthraquinones or alizarins:
Emodine
Alizarine
Sometimes anthraquinones form dimmers (sennosides) and condensed compounds (hypericin):
Sennoside
Spreading. Anthraquinones occur in Rubiaceae, Polygonaceae, Rhamnaceae, Ericaceae, Euphorbiaceae, Scrophulariaceae, Liliaceae etc.
In MRM anthraquinones occur as simple free compounds (aglycones) or as glycosides. Most commonly they are connected with glucose, rhamnose, xylose or arabinose. Anthraglycosides occur in cells juice and can be easily determined microchemically or can be visible without reactions by orange colour of roots and bark, in green parts of the plants they are masked by chlorophyl. While dry raw material is heated we can see sublimate- orange crystals, which are soluble in alkaline solution with red colour.
Physicochemical properties. Anthraquinone derivatives are usually soluble in hot water or dilute alcohol, insoluble in organic solvents. Aglycones are very good soluble in benzole, chlorophorm, ether and other organic solvents. Borntrager’s test is often used for their detection. The powdered drud is macerated with an organic solvent, ether is recommended, and after filtration aqueous ammonia or caustic soda is added, when a pink, red or violet colour in the aqueous layer after shaking indicates the presence of free anthraquinone derivatives. If glycosides only are present, the test should be modified by first hydrolysing with alcoholic potassium hydroxide solution or 2M acid. When alkali is added to powdered drugs or to sections, the red colour produced serves to locate the anthraquinone derivatives in the tissue. If the drug being tested contains either very stable anthraquinone glycosides or reduced derivatives of the anthranol type, Borntrager’s test will be negative.
Anthraquinones (A) containing free carboxylic acid group (e.g. rhein) can be separated from other A. by extraction from an organic solution with sodium bicarbonate solution.
Therapeutic actions. Anthraquinone derivatives have different actions.
Derivatives of emodine have purgative action. This action appears in 8-12 hours after taking medicines.
Alizarines have spasmolitic and nephrolitic action.
Condenced derivatives have antibacterial action.
MP and MRM which contain emodines (chryzacines)
Cortex Frangulae- Frangula bark
Frangula alnus- Alder Buckthorn, Alder Dogwood
Rhamnaceae- Buckthorn family
Geographical distribution. Alder Buckthrn grows in Central, East and North Europe, West Asia and
Description of the bark. The bark occurs in single or double quills which are 0,5-4mm thick. It has a purplish cork and transversely elongated, whitish lenticels. On removing the outer cork cells by scrapping, a dark crimson inner cork is exposed. Smell is specific, taste bitter, slightly spicy. While chewing the saliva becomes yellow.
Constituents. Frangula contains anthraquinone derivatives present mainly in the form of glycosides. The rhamnoside (frangulin) was isolated in 1857. This is now known to consist of two isomers- frangulosides A and B. The fresh bark also contains anthranols and anthrones, frangula-emodine and glycoside.
Usses. Decoction has purgative action. In pharmaceutical industry liquid extract, dry extract in tablets and “Rhamnil” are produced.
Bark can be used only in 1 year after collection.
Folia Sennae
Fructus Sennae
Cassia acutifolia- Alexandrian senna
Cassia angustifolia- Tinnevelly senna or Indian senna
Fabaceae
Description and geographical distribution. The senna plants are small schrubs about 1m high, with peripinnate compound leaves, having 3-7 pairs of leaflets. C. acutifolia is indigenous to tropical Africa and is cultivated in the
Senna is collected mainly in September.
Constituents. Leaves contain a family of hydroxyanthracene glycosides, the most plentiful of which are sennosides A and B. There are also small amounts of aloe-emodine and rhein 8-glucosides; mucilage; flavonoids and naphthalene precursors.
Usses. Infusion is used as a laxative drug. To reduce the level of resinous substances the infusion should be filtrated. Medicines- laxative and antihaemorrhoidal mixes, “Senadexin”, “Cafiol”, “Senade”, “Regulax”.
Radices Rhei
Rheum palmaticum L. var. tanguticum- Rhubarb, Chinese Rhubarb
Polygonaceae
Geographical distribution.
Plant description. Rheum species are perennial herbs resembling the common garden rhubarb
except for their lower growth and shape of their leaf blades; the underground
portion consists of a strong vertical rhizome with fleshy, spreading roots; the
portion above ground consists of a number of long petioled leaves that arise
from the rhizome in the spring, and flower shoots bearing elongated leafy
panicles that are crowded with greenish white, white, to dark purple flowers;
the lamina is cordate to somewhat orbicular, palmately lobed. The fruit is an ovoid-oblong or orbicular achene bearing 3 broad membranous wings and the remains of the perianth at the base.
Constituents. 3,5-6% of anthraglycosides- rheum-emodine, chrysophanol, aloe-emodin, physcione, franguloemodin; 7-10% of tannins.
Usses. Is used as a powder or composed powders, tablets (0.5g) and dry extract for treatment of constipation.
In low doses (0.05-0.2g) powder has astringent effect.
Folia Aloes
Aloe arborescens- Krantz Aloe
Liliaceae
Geographical distribution. South and
Plant description. The Krantz Aloe is succulent and develops into a multiheaded schrub 2-3m high with striking grey-green leaves arranged in attractive rosettes. The leaf margins are armed with conspicuous pale teeth. The large colourfull flower spikes are usually deep orange. The inflorescence is usually unbranched with two to several arising from a single rosette.
Leaves description. Leaves are greyish-green and slightly concave, the margins are armed with teeth. The length is up to 70cm. Odour is sour, taste bitter and nauseous.
Sabur is a thick juice from leaves and it is in the shape of unformed black-brown pieces. It soluble in hot water and alcohol, has a specific smell and sour, bitter taste.
Constituents. Aloe-emodin and its glycoside, chrysophanol, rheum-emodin; up to 20% of resinous substances, polysaccharides, amino acids, steroid compounds, enzymes.
Usses. Sabur is a purgative drug. Small doses increase appetite, big- used in abortion. Juice is used in treatment of tuberculosis, gastrointestinal diseases, bronchial asthma. Externally- seborrheic dermatitis and different inflammatory diseases of skin. Liquid Aloe extract is biogenic stimulator in eye diseases.
Clinical trials show the anti-cancer action of alcohol extract of Aloe.
Also Aloe is widely used in cosmetic industry.
MP and MRM containing alizarines
Rhizomata cum radicibus Rubiae
Rubia tinctorum- Common Madder, Rubia
Rubiaceae
Geographical distribution.
Plant description. The Common Madder can grow up to 1.5m high. The evergreen leaves are 5-10 cm long and 2-3cm broad, produced in whorls of 4-7 starlike around the central stem. It climbs with tiny hooks at the leaves and stems. The flowers are small (3-5mm across), with 5 pale yellow petals in dense racemes, followed by small (4-6mm) red to black berries.
Rhizomes and roots can be collected from 3-year-old plants in autumn.
Constituents. Anthraquinone derivatives (alizarins) – rubiadin-glycoside, rubiadin, rubierythrinic acid; flavonoids, iridoids.
Uses. Medicines are used in treatment of cholelithiasis and nephrolithiasis and gout (podagra), because it dissolves and excretes phosphates, oxalates and urates.
Dry extract is the main constituent of Cystenal and Marelin.
Prepared by assist. Dakhym I.S.
