Alkaloids are basic nitrogen containing compounds obtained from plants, animals & microorganisms having a marked physiological action
📚They answer the following chemical tests:
📝 Mayer’s reagent- (potassium mercuric iodide)
cream coloured precipitate
📝Wagner’s reagent- (iodine in potassium iodide)
reddish brown precipitate
📝Hager’s reagent- (salt solution of picric acid)
yellow precipitate
📝Dragendorf’s reagent- (potassium bismuth iodide)
reddish brown precipitate
📌Caffeine is a pseudo alkaloid drug which does not answer this test.
📃TRUE ALKALOIDS
1. Pyrrole & pyrrolidine eg- coca
2. Pyridine & piperidine eg- coniine
3. Tropane eg- atropine
4. Quinoline eg- cinchona
5. Indole eg- rauwolfia
6. Purine eg- caffeine
7. Steroidal eg- kurchi
8. Isoquinoline eg- opium
🎯 PROTO ALKALOIDS
eg- ephedrine
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INDOLE ALKALOIDS
📕ERGOT / ARGOT / ST. ANTHONY’S FIRE
📝BIOLOGICAL SOURCE: schlerotium of fungus claviceps purpurea, at the ovary of rye plant secale cereale
Family: graminae (fungus belongs to family clavicipitaceae)
📝Chemistry: Derivatives of lysergic acid. Water soluble ones are ergometrine & ergometrinine
Water insoluble ones are ergotamine & ergotoxine
Only the levo isomer is active
📝Uses: Ergometrine is an oxytocic drug but its methyl derivative is preferred as it causes less hypertension. Ergotamine is analgesic in migraine
📝Chemical Test:
1⃣ Gives a blue colour with Van Curk’s reagent (para dimethyl amino benzaldehyde)
2⃣ Gives blue fluorescence in water
📑VINCA / PERIWINKLE
📝BIOLOGICAL SOURCE: aerial parts of catharanthus roseus
Family: apocynaceae
📝Chemistry: Indole alkaloids such as vinblastine, vincristine, ajamlicine & serpentine
📝Use: Potent anti cancer agent, hypotensive & anti diabetic
📑NUXVOMICA
📝BIOLOGICAL SOURCE: dried seeds of strychnos nuxvomica
Family: loganiaceae
📝Chemistry: Contains two main indole alkaloids strychnine & brucine
📝Use: Rarely used as a nerve tonic as it is poisonous in large doses
📝Chemical Test:
1⃣. Section when treated with concentrated HNO3 shows a yellow colour with brucine
2⃣ Section when treated with ammonium vanadate & H2SO4 shows a purple colour with strychnine
3⃣ Strychnine when treated with H2SO4 & K2Cr2O7 develops a violet to yellow colour
📑RAUWOLFIA / SARPAGANDHA
📝BIOLOGICAL SOURCE: dried roots of rauwolfia serpentina
Family: apocynaceae
📝Chemistry: Reserpine, ajamlicine, serpentine
📝Use: Antihypertensive by preventing uptake of adrenaline
📝Chemical Test:
1⃣Freshly fractured surface of the root when treated with concentrated HNO3 shows red coloured medullary rays
2⃣Reserpine gives a violet colour with vanillin in acetic acid
📕TROPANE ALKALOIDS
📑BELLADONA
📝BIOLOGICAL SOURCE: dried leaves of atropa belladonna
Family: solanaceae
📝Chemistry: Atropine, hyoscyanine, belladonine
📝Use: Atropine is a parasympatholytic, thus decreases secretion & spasms
📝Chemical Test:
1⃣Vitali morin test – to the drug fuming nitric acid is added & it is evaporated to dryness.
2⃣Methanolic KOH is added to the acetone solution of the nitrated residue. It develops a violet colour
📑STRAMONIUM
📝BIOLOGICAL SOURCE: dried leaves & flowering tops of datura stramonium
Family: solanaceae
📝Microscopic Characters:
Dorsiventral leaf Collenchyma above & below the mid rib
Unicellular covering & glandular trichomes Xylem surrounded by phloem Anisocytic stomata
📝Chemistry: Hyoscine, atropine, belladonine
📝Use: Hyoscine is an anti emetic
📝Chemical Test: Vitali morin test
📑COCA LEAVES
📝BIOLOGICAL SOURCE: dried leaves of erythroxylon coca (bolivian variety) Erythroxylon truxillense (Peruvian variety)
Family: erythroxylaceae
📝Microscopic Characters:
Dorsiventral leaf. Collenchyma above & below mid rib. Xylem surrounded by phloem & pericyclic fibres. Paracytic stomata
📝Chemistry: Cocaine, cinnamoyl cocaine, tropocaine, benzoylecgonine
📝Use: Local anaesthetic
📝Chemical Test: Drug powder when heated with concentrated H2SO4 gives a typical odour of methyl benzoate
📕QUINAZOLINE ALKALOIDS
📑VASAKA LEAF / ADULSA
📝BIOLOGICAL SOURCE: dried & fresh leaves of adhatoda vasica
Family: acanthaceae
📝Chemistry: Vasicine, vasicinone & adhatodic acid
📝Uses: Vasicine is an expectorant. It gets oxidized to vasicinone which in an abortifacient in large doses, otherwise a bronchodilator
📕PYRIDINE ALKALOIDS
📑LOBELIA HERB / INDIAN TOBACCO / ASTHMA WEED
📝BIOLOGICAL SOURCE: dried aerial parts of lobelia nicotianefolia
Family: campanulaceae
📝Chemistry: Lobeline, lobelidine & isolobanine
📝Use: Respiratory stimulant
📝Chemical Test:
1⃣ lobeline solution if heated gives typical odour of acetophenone
2⃣ lobeline in H2SO4 when treated with formaldehyde develops red colour
📕IMIDAZOLE ALKALOIDS
📑PILOCARPUS
📝BIOLOGICAL SOURCE: dried leaves of pilocarpus jaborandi Pilocarpus microphyllus
Family: rutaceae
📝Chemistry: Contains pilocarpine, pseudopilocarpine, pilosine & limonene
📝Uses: Antagonist to atropine, causes miosis, increases salivation & sweating
📕INDOLE ALKALOIDS
📑CALABAR BEANS
📝BIOLOGICAL SOURCE: dried type seeds of physostigma venenosum
Family: leguminosae
GEOGRAPHICAL SOURCE: Africa
📝Chemistry: Contains physostigmine, starch & proteins
📝Use: Helps in contraction of pupil, retards respiration & causes bradycardia
📑OPIUM / POPPY PLANT
📝BIOLOGICAL SOURCE: dried latex obtained from capsules of papaver somniferum
Family: papaveraceae
📝Chemistry: Contains phenanthrene type of alkaloids such as morphine & codeine & benzyl isoquinoline type of alkaloids such as papaverine & noscapine. These occur as salts of meconic acid
📝Use: Morphine is a narcotic analgesic & stimulant. Codeine is an anti tussive. Papverine is a smooth muscle relaxant
📑CINCHONA BARK / JESUIT’S BARK / PERUVIAN BARK
📝BIOLOGICAL SOURCE: dried bark of cultivated trees of cinchona calisaya ,Cinchona officinalis, Cinchona ledgeriana, Cinchona succirubra
Family: rubiaceae
📝Microscopic Characters: Cork cells are thin walled. Cortex has phloem fibres. Medullary rays with radially arranged cells. Idioblast of calcium oxalate is a specific characteristic. Starch grains in parenchymatous tissues
Stone cells rarely present
📝Chemistry: Contains quinine, quinidine, cinchonine & cinchonidine. Also contains quinic acid & cinchotannic acid
📝Chemical Test:
1⃣n heating the drug in a dry test tube with glacial acetic acid, purple vapours are produced
2⃣ Thalleoquin test: drug + bromine water + dilute ammonia gives an emerald green colour
3⃣Drug when treated with quinidine solution gives a white precipitate with silver nitrate which is soluble in nitric acid
📝Uses: Anti malarial, anti pyretic, quinine is used in arrythmias against atrial fibrillation
📕ISOQUINOLINE ALKALOIDS
📑IPECAC
📝BIOLOGICAL SOURCE: dried roots of cephalis ipecacuanha (brazilian / rio) Cephalis acuminata (panama / cartagena)
Family: rubiaceae
📝Chemistry: Brazilian – emetine:cephalin ratio is 4:1
Panama – emetine:cephalin ratio is 1:1
📝Uses: Expectorant in mild doses & as an emetic in large doses
Emetine also possesses anti protozoal activity
📕PYRIDINE- PIPERIDINE ALKALOIDS
📑TOBACCO
📝BIOLOGICAL SOURCE: dried leaves of nicotiana tabacum
Family: solanaceae
📝Chemistry: Nicotine, nornicotine & anabasine
📝Use: Stimulant
📕PROTO ALKALOIDS
📑EPHEDRA / MA HUANG
📝BIOLOGICAL SOURCE: dried stem of ephedra gerardiana
Family: ephedreaceae / gnetaceae
📝Chemistry: Contains amino alkaloids like ephedrine, norephedrine & pseudo ephedrine
Uses: Sympathomimetic & bronchodilator
📑COLCHICUM / AUTUMN CROCUS
📝BIOLOGICAL SOURCE: dried seeds & corms of colchicum luteum. Family: liliaceae
📝Chemistry: Contains amino alkaloid colchicine & demecolchicine
📝Uses: Rheumatism, treatment of gout, anti tumour activity & polyploidy
📑ACONITE / BACHNAG
📝BIOLOGICAL SOURCE: dried roots of aconitum napellus
Family: ranunculaceae
📝Chemistry: Diterpene alkaloids such as aconitine, neopelline, neoline & small amount of ephedrine. Aconitine is an active constituent but if hydrolysed forms benzoyl aconine & aconine which are less active
📝Uses: Externally in neuralgia & sciatica
📕PSEUDO ALKALOIDS
📑COFFEE
📝BIOLOGICAL SOURCE: dried seeds of coffee Arabica
Family: rubiaceae
📝Chemistry: Contains caffeine which is a salt of chlorogenic acid, volatile oil known as caffeol, enzymes & other phenolic compounds
📝Uses: Stimulant, diuretic (due to theophylline), & source of caffeine
📝Chemical Test:
1⃣ Murexide test: caffeine when heated with HCl & potassium chlorate gives a residue which turns purple when exposed to ammonia vapours
2⃣ Caffeine forms a white precipitate with tannin solution
📑TEA
📝BIOLOGICAL SOURCE: prepared leaves of thea sinensis
Family: theaceae
📝Chemistry: Contains caffeine, theophylline, theobromine, oxidase enzyme & tannins
📝Use: Stimulant, diuretic, source of caffeine
📝Chemical Test: Murexide test
📑KOLA NUTS / BISSY SEEDS
📝BIOLOGICAL SOURCE: seeds of cola nitida
Family: sterculiaceae
📝Chemistry: Contains caffeine, theobromine & a red pigment known as kola catechin
📝Use: Stimulant
📑COCOA SEEDS
📝BIOLOGICAL SOURCE: seeds of theobroma cacao
Family: sterculiaceae
📝Chemistry: Caffeine. Theobromine, other phenolic compounds
📝Use: Stimulant
📕STEROIDAL ALKALOIDS
📑KURCHI
📝BIOLOGICAL SOURCE: dried bark of holarrhena antidysenterica
Family: apocynaceae
📝Chemistry: Steroidal alkaloid conessine & norconessine
📝Use: Amoebic dysentery
📑ASHWAGANDHA
📝BIOLOGICAL SOURCE: dried roots of withania somnifera
Family: solanaceae
📝Chemistry:
2 types of chemical constituents
1⃣ steroidal lactones called withanolides like withaferine
2⃣ alkaloids like withanine, somniferine, anaferine. Also contains alcohols known as somnitol & somnirol
📝Uses:
Sedative, hypnotic, hypotensive & immunomodulatory
📕PYRAZOLINE ALKALOIDS
📑PEPPER
📝BIOLOGICAL SOURCE: dried fruits of piper nigrum
Family: piperaceae
📝Chemistry: Alkaloid piperine is responsible for pungent taste aong with piperetine, resins, volatile oils containing limonene & pinen responsible for the odour
📝Uses: Bronchitis & gonorrhoea