T Y B Sc Semester V Botany Paper

T. Y. B. Sc Semester V Botany Paper IV Unit IV : Pharmacognosy Nux-vomica, Clove, Senna By Mrs. Mandakini R Ingle Department of Botany Satish Pradhan Dnyanasadhana College, Thane (w)

Nux-vomica Botanical name: Strychnos nux-vomica Family : Loganiaceae Part used: dried seeds Collection: Fruit -berry about the size of a small orange. When ripe it has a rather hard orange-yellow epicarp and a white, pulpy, interior in which 1– 5 seeds are embedded. The seeds are washed free from pulp and dried. They are exported in small sacks, known as ‘pockets’, holding about 18– 25 kg.

Seed Macroscopy • Seeds are extremely hard, greenish-grey, disc -shaped, 10– 30 mm diameter and 4– 6 mm thick. • Most of the seeds are nearly flat and regular in shape, but a few are irregularly bent and somewhat oval in outline. • The edge is rounded or acute. • The testa is covered with silky, closely appressed, radiating hairs. • In the centre of one of the flattened sides is a distinct hilum, and a small prominence on the circumference marks the position of the micropyle, which is joined to the hilum by a radial ridge.

• Within the seed, is a slit-like cavity. • Endosperm – horny greyish followed by a lens shaped cavity enclosing the embryo • Embryo - small and white, present at the micropyle, with two cordate cotyledons and a cylindrical radicle, the latter directed towards the micropyle, will be seen embedded in a grey, horny endosperm. • The seeds are odourless when dry; but if soaked in water and left for a day or two, they develop a very unpleasant odour. They have a very bitter taste.

Seed Microscopy

Chemical constituents • 1. 8– 5. 3% of the indole alkaloids strychnine (1. 23% ) and brucine (1. 55% ). • Strychnine is physiologically much more active than brucine • Minor related alkaloids: α-colubrine, β-colubrine, icajine, 3 methoxyicajine, protostrychnine, vomicine, novacine, N- oxystrychnine, pseudostrychnine and isostrychnine. • Iridoids of the seeds include the glycoside loganin, loganic acid and 7 -O- acetyl loganic acid together with three new iridoids, 6′-O-acetyl loganic acid, 4′-O-acetyl loganic acid and 3′-Oacetyl loganic. • Chlorogenic acid and about 3% of fixed oil. • Loganin, although present only in small amounts in the seed.

Uses • The action of the whole drug closely resembles that of strychnine. • Formerly used as a circulatory stimulant in such cases as surgical shock, but its use is now more limited to that of a respiratory stimulant in certain cases of poisoning. • Strychnine improves the appetite and digestion, but it has been considerably misused as a ‘general tonic’. • used in Chinese medicine and the seeds are usually processed to reduce their toxicity. • Heat-treatment of the seeds reduces the normal levels of the principal alkaloids and the amounts of isostrychnine, isobrucine, strychnine N-oxide and brucine N-oxide are increased.

Allied drugs • Ignatius beans are the seeds of Strychnos ignatii, a plant occurring in the Philippines, Vietnam and elsewhere. The fruits are larger than those of nux vomica and may contain as many as 30 seeds. • The structure closely resembles that of nux vomica, but the testa, which bears irregularly arranged greyish hairs, is easily rubbed off and is almost entirely absent in the commercial drug. The seeds contain about 2. 5– 3. 0% of total alkaloids, of which about 46– 62% is strychnine. • The seeds of S. ignatii from Java contain 1. 5% strychnine and no brucine and from Hainen (S. hainanensis) mainly brucine with little strychnine. In addition to the seeds, other parts of the plants of Strychnos spp. may contain alkaloids including strychnine. • S. potatorum, from India, and S. nux-blanda, from Burma, have been substituted for nux vomica; although they contain no strychnine or brucine. • The seeds of S. potatorum are used in India for clearing water, whence the specific name.

Clove Botanical name: Syzygium aromaticum / Eugenia caryophyllus Family : Myrtaceae Part used: Dried unripe flower buds A tree 10– 20 m high, indigenous to the Molucca and cultivated in Zanzibar and in the neighboring island of Pemba and now the principal producers are Madagascar, Indonesia and Brazil. Smaller quantities are grown in Sri Lanka and Tanzania.

Collection and preparation. • The flower buds are collected when their lower part turns from green to crimson. • In Zanzibar and Pemba collection takes place twice yearly, between August and December. • The cloves are dried in the open air on mats and separated from their peduncles, the latter forming a separate article of commerce known as ‘clove stalks’. • If left too long on the tree, the buds open and the petals fall, leaving ‘blown cloves’; later the fruits known as ‘mother cloves’ are produced. • Cloves are imported in bales covered with matting made from strips of coconut leaves.

Macroscopy: • About 12 -21 mm long, • Penang and Amboyna varieties largest, plumpest and reddish-brown colour • Zanzibar variety, however, smaller and leaner than the Penang and blackish- brown. • The lower stalk like portion terminating in 4 triangular slightly projecting calyx teeth and a dome shaped head of 4 unexpanded imbricated petals that encloses the other whorls. Androecium: numerous stamens, curved inwards, tetradelphous Gynoecium: inferior bicarpellary bilocular ovary with axile placentation Hypanthium: The ‘stalk’ of the clove consists of a solid cylindrical hypanthium or swelling of the torus, about 10 -13 mm long , above which is a inferior bilocular ovary containing numerous ovules attached to axile placenta. large oil glands near periphery.

Epidermis: small polygonal thickwalled isodiametric cells with very thick cuticle Cortex: parenchyma cells containing large oval radially elongated schizolysigenous oil glands followed by a layer of parenchyma and collenchyma cluster crystals of calcium oxalate and traversed by small irregularly arranged vascular bundles accompanied by usually isolated fusiform pericycle fibres having strongly thickened lignified walls Lacunous layer: thin walled parenchyma cells Columella layer: thin walled parenchyma with numerous cluster crystals of calcium oxalate surrounded by many closely arranged vascular bundles. Ovary: no lacunous or columella layer, bilocular ovary with cluster crystals of calcium oxalate. -Starch, trichomes, long fibres absent

Constituents • About 14– 21% of volatile oil , contains eugenol (81%) that gives strong burning flavour; eugenyl acetate (7%), β-caryophyllene (9%), α and β humulene. • It also 10– 13% of tannin; triterpene acids and esters, and glycosides of the following: aliphatic and monoterpenoid alcohols, eugenol, isoeugenol, farnesol, nerolidol, sitosterol, stigmasterol and campestrol. • Clove oil contains 84– 95% of phenols (eugenol with about 3% of acetyleugenol), sesquiterpenes (α- and β-caryophyllenes) and small quantities of esters, ketones and alcohols. Oil of clove, like other essential oils, should be stored in well-filled, airtight containers, protected from light and heat.

Uses • Cloves are used as a stimulant, aromatic, flavouring agent, as a spice, antiseptic and for the preparation of the volatile oil. • The sesquiterpenes of clove have been cited as potential anticarcinogenic compounds. • Clove oil used in perfumery industries. It is a a pain reliever and a mild anaesthetic for tooth aches. • It causes the blood vessels near the skin to dilate, thus giving a warm feeling to the skin. • It helps to get rid or intestinal gas and fights nausea. • It has antibacterial and antifungal properties due to eugenol.

Senna Botanical name: Cassia angustifolia Vahl. (Indian senna), Cassia acutifolia (Alexandrian Senna) Family : Leguminosae Sub- family : Caesalpineae Part used: dried leaflets Alexandrian senna is indigenous to tropical Africa and is cultivated in the Sudan (Kordofan, Sennar). C. angustifolia is indigenous to Somaliland, Arabia, Sind and the Punjab, and is cultivated in South India (Tinnevelly). Indian senna is cultivated in Tinnevelly, Madurai and Ramnathpuram districts of Tamil Nadu. It is also attempted in cudappa district of Andhra Pradesh and to some extent in Kutch (Gujarat) and Rajasthan

Macroscopy • • Alexandrian senna is 2 -4 cm long and 7 -12 mm wide ovate- lanceolate shape, pale greyish- green colour Margin entire, curled Leaf base asymmetrical More pubescent and has a thin brittle texture Differentiation between two species: stomatal index, palisade ratio and vein-islet number

Comparison between Alexandrian and Tinnevelly senna Macroscopical characters Alexandrian senna Seldom exceed 40 mm in length Greyish-green More asymmetric at base Rather more broken and curled at the edges Tinnevelly senna Seldom exceed 50 mm in length Yellowish-green Less asymmetric at base Seldom broken and usually flat Few press markings owing to compression Often shows impressions due to the midvein of other leaflets Microscopical characters Hairs more numerous, the average distance Hairs less numerous, the average between each being about three epidermal cells distance between each being about six epidermal cells Most of the stomata have two subsidiary cells The stomata having two or three only subsidiary cells respectively are in the ratio of about 7: 3 Vein-islet number 25– 29. 5 Vein-islet number 19. 5– 22. 5 Stomatal index 10. 0– 15. 0, usually 12. 5 Stomatal index 14. 0– 20. 0, usually 17. 5

Chemical tests Alexandrian senna Tinnevelly senna Ether extract of hydrolysed acid solution of drug gives with methanolic magnesium acetate solution: a pink colour in daylight An orange colour in daylight a pale greenish-orange in a yellowish-green in filtered ultraviolet light TLC test for distinctive naphthalene derivatives 6 -Hydroxymusizin glycoside Tinnevellin glycoside present

• Leaflets are isobilateral. • The epidermal cells have straight walls, and many contain mucilage. • Both surfaces bear scattered, unicellular, nonlignified warty hairs up to 260 mm long. • The stomata have two cells with their long axes parallel to the pore and sometimes a third or fourth subsidiary cell. • The mesophyll, consisting of upper and lower palisade layers and median spongy mesophyll, contains cluster crystals about 15– 20 μm in diameter. • The midrib is biconvex. • Below the midrib bundle is a zone of collenchyma. • The midrib bundle and larger veins are almost surrounded by a zone of lignified pericyclic fibres and a sheath of parenchymatous cells containing prisms of calcium oxalate 10– 20 μm long.

Constituents • Tutin first isolated aloe-emodin and rhein in 1913. • Stoll et al. (1941) isolated two active crystalline glycosides, sennoside A and sennoside B. They both hydrolyse to give two molecules of glucose and the aglycones sennidin A and B. • Sennidin A is dextrorotatory and B is its mesoformed by intramolecular compensation. • Later other researchers demonstrated the presence of many other components : sennosides C and D, which are the glycosides of heterodianthrones; palmidin A; aloe-emodin dianthrone-diglycoside, rhein-anthrone- 8 -glycoside, rhein-8 -diglucoside, aloe-emodin-8 -glucoside, aloeemodin-anthrone-diglucoside, • A new anthraquinone glycoside, emodin-8 -O-sophoroside (a diglucoside), has been isolated from dried Indian senna leaves

Two naphthalene glycosides isolated from senna leaves and pods are 6 hydroxymusizin glucoside and tinnevellin glucoside. The former is found in Alexandrian senna and the latter in Indian senna. • • Senna also contains the yellow flavonol colouring matters kaempferol (3, 4′, 5, 7 tetrahydroxyflavone), its glucoside (kaempferin) and isorhamnetin; also a sterol and its glucoside, mucilage, calcium oxalate and resin. • The structures of water-soluble polysaccharides and a lignan have been reported. • Although senna is noted for its volatile components, few researchers have identified presence of volatile oils in Senna which includes monoterpenes, phenylpropanes, fatty acids and esters, etc. Hexadecanoic acid was a significant component in addition to many of the more common constituents of volatile oils

Uses • The use of laxatives is increasing and senna constitutes a useful purgative for either habitual constipation or occasional use. • It lacks the astringent after-effect of rhubarb. • Despite the availability of a number of synthetics, sennoside preparations remain among the most important pharmaceutical laxatives. • In Ayurvedic medicine the plant is used to treat a variety of ailments. • Its antifungal, antibacterial and laxative properties have been established and more recently

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