I- Drugs Containing Alkaloids

1- Solanaceous Leaves a- Belladonna leaf (Folium Belladonnae) "Deadly nightshade" Origin: the dried leaf and flowering top of Atropa belladonna F. Solanaceae Morphology: leaves are ovate, yellowish green in colour, petiolate, the lamina is simple, with entire margin, acuminate apex and decurrent base, lateral veins are anastomosing near the margin by a series of arches.

Powder: green to brownish green, showing fragments of: epidermis with wavy walls, striated cuticle, stomata are anisocytic. Non-glandular hairs, multicellular, uniseriate. Clavate hair, glandular with unicellular curved stalk and multicellular club-shaped head. Idioblasts: parenchyma cells contain microsphenoidal crystals of Ca oxalate.

Active constituents: Mydriatic alkaloids: hyoscyamine, atropine, hyoscine (scopolamine) and belladonnine. N.B. hyoscyamine (levorotatory) and atropine (racemic) are isomers, atropine is absent in fresh plant but produced during drying by racemization of hyoscyamine. Uses: "Parasympatholytic" Mydriatic Antispasmodic (for colic) and reduces hyperacidity, so used in peptic ulcer. Local anaesthetic. Sedative to the respiratory nerves to relieve spasmodic cough.

Chemical tests: Mayer's test: powder + dil. HCl, boil, filter, add Mayer's reagent → white ppt. Vitali's test: boil the powder with dil. HCl, filter, evaporate to dryness, cool add 10 dps. of conc. nitric acid → yellow solution, evaporate to dryness, add 2 drops of alcoholic KOH → violet colour.

b- Stramonium Leaf (Folium Stramonii) "Thorn Apple Leaf" Origin: the dried leaves and flowering tops of Datura stramonium" F. Solanaceae Morphology: Leaves are petiolate showing long petiole hooked when dried, lamina is ovate coarsely dentate with acuminate apex and asymmetric base.

Powder: grayish green to brownish green in colour, showing fragments of: Epidermis with wavy walls, smooth cuticle and anisocytic stomata. Clavate hair. Non-glandular hair, multicellular uniseriate with enlarged basal cell covered with warty cuticle. Cluster crystals of calcium oxalate arranged in crystal layer.

Active constituents: Mydriatic alkaloids: hyoscyamine, atropine, apoatropine, belladonnine and scopolamine (hyoscine). Uses: relax bronchial muscle in the bronchial spasms of asthma. Scopolamine is effective in the prevention of nausea and vomiting associated with motion sickness. Scopolamine is used for preanaesthetic sedation. Chemical tests: as belladonna.

c- Hyoscyamus Leaves (Folium Hyoscyami) "Egyptian Henbane" Origin: the dried leaves, smaller stems and flowering tops of "Hyoscyamus muticus" F. Solanaceae Morphology: Leaves are pale green, fleshy, ovate lanceolate , broadly dentate margin, acuminate apex and asymmetric base.

Powder: yellowish brown with salty taste, showing fragments of: epidermis with more or less straight walls, smooth cuticle except at the base of the hairs it's striated, anisocytic stomata. Branched glandular hair. Prisms and twin prisms of calcium oxalate.

Active constituents: 0.7-1.5% of total alkaloids, most of which are hyoscyamine, scopolamine. Uses: scopolamine is a sedative to the central nervous system and used as hydrobromide as a sedative in acute maniacal excitement. Combined with purgatives to obviate their griping action. Mydriatic. Chemical tests: as belladonna.

2- Jaborandi Leaf (Folium Jaborandi) Origin: the dried leaflets of various Pilocarpus species, mainly Pilocarpus jaborandi known as Pernambuco Jaborandi and Pilocarpus microphyllus known as Maranham Jaborandi F. Rutaceae Active constituents: 1- Myotic alkaloids: pilocarpine, isopilocarpine, pilocarpidine and pilosine. 2- Volatile oil

Uses: "Parasympathomimetic" 1- Diaphoretic and sialagogue. 2- Myotic to hasten the contraction of eye pupil after mydriatics and for treatment of glaucoma. 3- in congestion of the middle and inner ear and in alopecia. 4- antidote for atropine poisoning. Chemical test: Mayer's test: powder + dil. HCl, boil, filter, add Mayer's reagent → white ppt. Helch's test: extract the powder with dil. H2SO4, filter, add H2O2 + K2Cr2O7, shake with benzene → violet colour in benzene.

3- Cinchona Bark Origin: the dried stem and root bark of Cinchona succirubra and its hybrids known as red Cinchona, C. Ledgeriana and C. calisaya and their hybrids known as yellow Cinchona, C. officinalis and its hybrids known as pale Cinchona F. Rubiaceae. Morphology: flat, curved and quill, with rough grayish outer surface and longitudinally striated inner surface.

Powder: reddish brown, showing fragments of: cork cells thin walled suberized with brown content. Phloem fibre, long, fusiform, thick wall, lignified with narrow lumen, pointed apex and showing funnel-shaped pits. parenchyma with starch granules. Idioblasts contain microprisms of calcium oxalate.

Active constituents: Alkaloids: quinine, quinidine, cinchonine and cinchonidine in combination with cinchotannic acid. Uses: Quinine is antimalyrial. Quinine is used externally as hair tonic. Quinidine is antiarrythmic. Cinchonine and cinchonidine are antirhumatic. Total alcohol extract is bitter stomachic and tonic. Chemical test: Mayer's test: +ve. Extract gives blue fluorescence with oxygenated acids due to quinine. Dry heat test: gives purple fumes due to cinchona red colouring matter.

4- Nux vomica Seed (Semen Strychni) Origin: dried seeds of Strychnos nux-vomica F. Loganiaceae. Morphology: the seeds are disc-shaped, about 20-25 mm in diameter and 4 mm thick, ash-grey to greenish-grey in colour usually not quite flat being a little depressed on one side.

Powder: yellowish grey to brownish grey with bitter persistent taste, showing fragments of: epidermal cells strongly thickened, lignified extended to form a trichome, each trichome has ten lignified rods. Lignified rods of the trichomes. Cells of endosperm.

Active constituents: Alkaloids: mainly strychnine and brucine. Uses: bitter stomachic and tonic. Increase peristalsis and so used in constipation. CNS stimulant. In high doses leads to convulsions involves respiratory muscles and death may occur due to asphyxia. Chemical test: Powder + nitric acid → orange red colour in the endosperm cells. Powder + sulfovanadic acid → pink to violet colour especially in endosperm cells.

5- Pomegranate Bark (Cortex Grantii) Origin: dried stem and root bark of Punica granatum F. Punicaceae.

Active constituents: 1- five alkaloids, four liquid alkaloids: pelletierine, isopelletierine, methylpelletierine and methylisopelletierine and one solid alkaloid pseudopelletierine. 2- about 22% gallotannic acid. Uses: anthelmintic for tapeworm. Chemical test: +ve Mayer's test.