5. BIOLOGICAL SOURCE, CHEMICAL CONSTITUENTS AND THERAPEUTIC EFFICACY OF CRUDE DRUGS

BIOLOGICAL SOURCE, CHEMICAL CONSTITUENTS AND THERAPEUTIC EFFICACY OF CRUDE DRUGS: A TEACHER’S COMPREHENSIVE GUIDE

Welcome, future pharmacognosists and pharmaceutical scientists!

The study of crude drugs from natural sources is one of the most fascinating and essential areas of pharmacognosy. Understanding the biological source, chemical constituents, and therapeutic efficacy of medicinal plants is fundamental to the rational use of herbal medicines. As a pharmacognosy educator with years of experience teaching natural products, I have observed that students often find it challenging to remember the vast array of drugs and their properties. Let me tell you: Mastering the sources and constituents of crude drugs is the key to understanding how natural products heal.

In this comprehensive guide, I will walk you through the biological sources, chemical constituents, and therapeutic efficacy of a wide range of crude drugs—including laxatives, cardiotonics, carminatives, astringents, drugs acting on the nervous system, antihypertensives, antitussives, antirheumatics, antitumour agents, antidiabetics, diuretics, antidysenterics, antiseptics, antimalarials, oxytocics, vitamins, enzymes, and pharmaceutical aids. Let us begin!

Dpharmguru’s exam insights:

Biological sources and chemical constituents are frequently tested in pharmacognosy exams. Remember: Aloe contains barbaloin (C-glycoside). Castor oil contains ricinoleic acid. Senna contains sennosides A and B. Digitalis contains cardiac glycosides. Rauwolfia contains reserpine. Vinca contains vincristine and vinblastine. Cinchona contains quinine. These are classic exam questions! Pay special attention to the therapeutic uses and chemical constituents—they are almost always asked.

5.1. LAXATIVES

Laxatives are substances that encourage the evacuation of the bowels while treating constipation. They work through various methods—saline purgatives, faecal softeners, contact purgatives, and bulk laxatives.

5.1.1. Aloe

Synonyms: Mussabar, Ghritkumari, Aloe

Biological Source: Dried juice from leaves of Aloe perryi (Scotorine aloe), Aloe vera (Curacao aloe), and Aloe africana (Cape aloe). Family: Liliaceae.

Chemical Constituents: Contains 30% aloin (barbaloin, β-barbaloin, isobarbaloin). Barbaloin is a C-glycoside. Also contains aloinsides A and B, aloe-emodin anthrone, and resin.

Therapeutic Efficacy: Used in stomach and mouth ulcers, burns, wound healing, skin irritations. Shows antibacterial, anti-inflammatory, emollient, and antioxidant properties.

5.1.2. Castor Oil

Synonyms: Castor bean oil, Ricinus oil, Oleum ricini

Biological Source: Cold expression from seeds of Ricinus communis. Family: Euphorbiaceae.

Chemical Constituents: Contains 80% triglyceride of ricinoleic acid. Also contains isoricinoleic, linoleic, stearic, and isostearic acids. Contains toxic protein ricin (3% of whole seeds).

Therapeutic Efficacy: Acts as a cathartic due to ricinoleic acid. Used in contraceptive creams, fungicides (undecylenic acid), and as a lubricant.

5.1.3. Ispaghula

Synonyms: Isabgul, Spongeal seeds, Indian psyllium, Flea seed

Biological Source: Dried ripe seeds of Plantago ovata, P. psyllium, P. arenaria. Family: Plantaginaceae.

Chemical Constituents: Contains 10% mucilage in epidermis. Principle constituents: pentosan (xylose, arabinose) and aldobionic acid (galacturonic acid, rhamnose). Contains fixed oil (linolenic, linoleic, oleic, palmitic, stearic acids).

Therapeutic Efficacy: Used as demulcent, laxative, and emollient. Effective in chronic constipation, amoebic and bacillary dysentery, duodenal ulcers, and piles.

5.1.4. Senna

Synonyms: Cassia senna, Folia senna, Tinnevelles senna

Biological Source: Dried leaflets of Cassia angustifolia. Family: Leguminosae.

Chemical Constituents: Contains sennoside A and sennoside B (not less than 2.5%)—dimeric glycosides with rhein dianthrone as aglycone. Also contains sennosides C and D, rhein 8-glucoside, aloe-emodin, kaempferol, and isorhamnetin.

Therapeutic Efficacy: Used as a purgative and stimulant cathartic. Often dispensed with carminatives to counteract griping.

5.2. CARDIOTONICS

Cardiotonics are drugs used to increase the heart muscle’s contraction and efficiency, enhancing blood flow. They have a positive inotropic action.

5.2.1. Digitalis

Synonyms: Digitalis leaves, Foxglove leaves

Biological Source: Dried leaves of Digitalis purpurea. Family: Scrophulariaceae. Dried below 60°C; moisture not more than 5%.

Chemical Constituents: Contains 0.2-0.45% cardiac glycosides (cardenolides). Purpurea glycosides A and B, glucogitaloxin, digitonin, and gitonin (saponin glycosides). About 30 glycosides reported.

Therapeutic Efficacy: Enhances contraction force of heart muscles, increases cardiac output, decreases heart size, venous pressure, and blood volume. Exerts cumulative effect in the body.

5.2.2. Arjuna

Synonyms: Arjun bark, Arjun

Biological Source: Dried stem bark of Terminalia arjuna. Family: Combretaceae.

Chemical Constituents: Contains hydrolysable tannins (15%), triterpenoid saponin, arjunolic acid, arjunic acid, arjunogenin, β-sitosterol, ellagic acid, arjunetin, arjunolone, and arjunone.

Therapeutic Efficacy: Maintains normal cholesterol levels, strengthens heart muscles, improves cardiac functioning. Used in coronary artery disease, heart failure, oedema, angina, and hypercholesterolemia.

5.3. CARMINATIVES AND G.I. REGULATORS

Carminatives are soothing drugs that relieve stomach and intestinal pain and expel gas from GIT by peristalsis. Examples: Fennel, Ginger, Coriander, Cinnamon, Nutmeg, Asafoetida, Clove.

5.3.1. Coriander

Synonyms: Coriander fruits, Chinese parsley, Indian parsley

Biological Source: Dried ripe fruits of Coriandrum sativum. Family: Umbelliferae.

Chemical Constituents: Volatile oil (0.3-1%)—90% D-linalool (coriandrol), coriandryl acetate, L-borneol, geraniol. Fixed oil (13%), proteins (20%), Vitamin A.

Therapeutic Efficacy: Lowers blood sugar by stimulating insulin secretion. Acts as carminative, antispasmodic, decreases blood pressure, improves cholesterol levels.

5.3.2. Fennel

Synonyms: Sweet fennel, Fennel fruit, Saunf

Biological Source: Dried ripe fruits of Foeniculum vulgare. Family: Umbelliferae.

Chemical Constituents: Volatile oil (2-6.5%)—50-60% phenolic ether, 18-20% fenchone, methyl chavicol, anisic aldehyde, anisic acid, α-pinene, dipentene, limonene. Fixed oil (12%).

Therapeutic Efficacy: Used as stimulant, aromatic, stomachic, carminative, emmenagogue, and expectorant. Common ingredient in cough and stomach mixtures.

5.3.3. Cardamom

Synonyms: Cardamom fruit, Elaichi, Cardamom seeds

Biological Source: Dried ripe fruits of Elettaria cardamomum. Family: Zingiberaceae.

Chemical Constituents: Volatile oil (2.8-6.2%), starch (50%), fixed oil (1-10%), calcium oxalate. Oil contains α-pinene, β-pinene, limonene, α-terpineol, geraniol, methyl eugenol, linalool, linalyl acetate.

Therapeutic Efficacy: Used as stimulant and carminative. Treats indigestion, constipation, flatulence. Used as breath-freshener, antiseptic, antispasmodic, diuretic, expectorant.

5.3.4. Ginger

Synonyms: Zingiber, Zingiberis

Biological Source: Rhizomes of Zingiber officinale. Family: Zingiberaceae.

Chemical Constituents: Volatile oil (1-4%)—α-zingiberene, β-bisabolene, α-farnesene, β-sesquiphellandrene. Starch (40-60%), fat (10%), acrid resinous matter (5-8%). Contains zingerone, shogaols, and gingerols.

Therapeutic Efficacy: Used as stomachic, aromatic, carminative, stimulant, flavouring agent. Effective in motion sickness, nausea, and GI disorders.

5.3.5. Clove

Synonyms: Caryophyllum, Clove flower, Clove buds

Biological Source: Dried flower buds of Eugenia caryophyllus. Family: Myrtaceae. Should contain 15% or more of clove oil.

Chemical Constituents: Volatile oil (15-20%)—70-90% eugenol, eugenol acetate, caryophyllenes. Tannins (10-13%) as gallotannic acid, resin, chromone, eugenin.

Therapeutic Efficacy: Used in dental applications (pain reliever, anaesthetic, antiseptic). Acts as carminative, anti-diarrhoeal, expectorant, anti-inflammatory. Used as flavouring agent.

5.3.6. Black Pepper

Synonyms: Pepper, Piper nigrum, Maricha

Biological Source: Dried unripe fruit of Piper nigrum. Family: Piperaceae. Contains not less than 2.5% dried piperine.

Chemical Constituents: Piperine (5-9%), volatile oil (1-2.5%), pungent resin (6%), piperidine, starch (30%). Volatile oil contains phellandrene and caryophyllene.

Therapeutic Efficacy: Aromatic, stimulant, stomachic, carminative. Enhances bioavailability of some drugs. Stimulates taste buds and gastric juice production.

5.3.7. Asafoetida

Synonyms: Gum Asafoetida, Devil’s dung

Biological Source: Oleo-gum resin from rhizomes and roots of Ferula foetida. Family: Umbelliferae.

Chemical Constituents: Resin (40-65%), gum (20-25%), volatile oil (4-20%). Chief resin is asaresinotannol. Sulphur compounds (C₇H₁₄S₂, C₁₆H₂₀S₂, C₁₀H₁₆S₂) impart odour.

Therapeutic Efficacy: Used as antispasmodic, carminative, expectorant, and laxative. Powerful nerving stimulant in nervous disorders like hysteria.

5.3.8. Nutmeg

Synonyms: Semen myristicae, Myristica, Jayfal

Biological Source: Kernel of dried ripe seeds of Myristica fragrans. Family: Myristicaceae.

Chemical Constituents: Volatile oil (5-15%)—myristicin (4-8%), elemicine, terpene alcohols (borneol, geraniol), pinene, camphene, dipentene. Also contains safrol, eugenol, isoeugenol.

Therapeutic Efficacy: Aromatic, carminative, flavouring agent. Shows narcotic and anaesthetic action on CNS. Myristicin and elemicin have hallucinogenic properties.

5.3.9. Cinnamon

Synonyms: Cinnamon bark, Kalmi-Dalchini, Ceylon cinnamon

Biological Source: Dried inner bark of shoots of Cinnamomum zeylanicum. Family: Lauraceae. Should contain 1.0% or more volatile oil.

Chemical Constituents: Volatile oil (0.5-1.0%)—cinnamaldehyde (60-70%), eugenol (5-10%), benzaldehyde, cuminaldehyde, terpenes. Contains phlobatannins (1.2%), mucilage, calcium oxalate, starch, mannitol.

Therapeutic Efficacy: Carminative, stomachic, mild astringent. Used as flavouring agent, stimulant, aromatic, antiseptic. Used in type-2 diabetes, chronic wound healing, and Alzheimer’s disease.

5.4. ASTRINGENTS

Astringents cause contraction or shrinkage of body tissues and dry body secretions. The term comes from Latin adstringere—to bind fast.

5.4.1. Myrobalan

Synonyms: Emblic, Indian Gooseberry, Amla

Biological Source: Dried and fresh fruits of Emblica officinalis. Family: Euphorbiaceae.

Chemical Constituents: Rich source of Vitamin C, fat (0.5%), phyllemblin, tannin (5%), pectin, phosphorus, iron, calcium. Fresh fruits contain ~75% moisture.

Therapeutic Efficacy: Beneficial in skin diseases, delays wrinkles, facilitates hair growth, improves liver functioning.

5.4.2. Black Catechu

Synonyms: Catechu, Cutch, Katha

Biological Source: Dried aqueous extract from heartwood of Acacia catechu. Family: Leguminosae.

Chemical Constituents: Tannic acid (7.5-35%), catechin (10-15%), acacatechin (2-12%), phlobatannin (25-35%), gum (20-30%), quercitrin.

Therapeutic Efficacy: Used as astringent in GIT disturbance, relaxed conditions of throat, mouth, gums, cough, diarrhoea. Applied to ulcers, boils, skin eruptions.

5.4.3. Pale Catechu

Synonyms: Gambier, Terra Japonica

Biological Source: Extract from leaves and young shoots of Uncaria gambier. Family: Rubiaceae.

Chemical Constituents: Contains 7.33% (+) catechin and 22-50% catechutannic acid. Also contains catechu-red, quercetin, gambier fluorescin.

Therapeutic Efficacy: Used as astringent, skin lotions, treatment of burns, diarrhoea, dysentery, and sore throat.

5.5. DRUGS ACTING ON NERVOUS SYSTEM

5.5.1. Hyoscyamus

Synonyms: Henbane, Hyoscyamus herb

Biological Source: Dried leaves and flowering tops of Hyoscyamus niger. Family: Solanaceae. Contains not less than 0.05% l-hyoscyamine.

Chemical Constituents: Chief alkaloid—hyoscyamine. Also contains atropine, hyoscine (scopolamine), choline, mucilage, albumin, calcium oxalate, potassium nitrate.

Therapeutic Efficacy: Used as sedative, hypnotic, expectorant, antispasmodic, anti-asthmatic, mild diuretic. Used to counter gripping action of purgatives.

5.5.2. Belladonna

Synonyms: Poison black cherry, Deadly nightshade leaf

Biological Source: Dried leaves and flowering tops of Atropa belladonna. Family: Solanaceae. Should contain 0.30% or more total alkaloids as hyoscyamine.

Chemical Constituents: Hyoscyamine (main component). Also contains scopoletin, calcium oxalate crystals.

Therapeutic Efficacy: Anticholinergic and parasympathetic. Used as antidote in opium and chloral hydrate poisoning. Reduces sweat and secretions.

5.5.3. Ephedra

Synonym: Ma Huang

Biological Source: Dried young stems of Ephedra sinica, E. gerardiana, E. equisetina. Family: Ephedraceae.

Chemical Constituents: Primary amino alkaloids—ephedrine, N-methyl ephedrine, nor-ephedrine, pseudo-ephedrine. Also contains ephedradines (macrocyclic alkaloids).

Therapeutic Efficacy: Used for relief from asthma and hay fever. Causes mydriasis. Shows sympathomimetic actions by stimulating α-, β₁-, and β₂-adrenergic receptors.

5.5.4. Opium

Synonyms: Raw Opium, Gum Opium, Afeem

Biological Source: Dried latex from unripe capsules of Papaver somniferum. Family: Papaveraceae.

Chemical Constituents: Alkaloids derived from phenylalanine and tyrosine—Morphine, Codeine, Narcotine, Papaverine, Thebaine. Also contains sugar, wax, mucilage, calcium, potassium, magnesium salts.

Therapeutic Efficacy: Hypnotic, sedative, and analgesic (morphine). Antitussive (codeine). Muscle relaxant (papaverine). Causes addiction, used only in severe pain.

5.5.5. Tea Leaves

Synonym: Folia thea

Biological Source: Leaf buds and leaves of Thea sinensis. Family: Theaceae.

Chemical Constituents: Caffeine (1-5%), tannin (10-24%), adenine, theophylline, theobromine, xanthine, volatile oil.

Therapeutic Efficacy: CNS stimulant and diuretic. Shows antioxidant properties. Helps in treating genetic haemochromatosis, diabetes-induced blindness, and ischemic heart disease.

5.5.6. Coffee Seeds

Synonyms: Coffee seed, Coffee bean

Biological Source: Dried ripe seeds of Coffea arabica or C. liberica. Family: Rubiaceae.

Chemical Constituents: Caffeine (2-3%), tannins (3-5%), proteins (13%), fixed oils (10-15%), chlorogenic acid, dextrin, glucose.

Therapeutic Efficacy: Used as source of caffeine—stimulant and diuretic. Used to counteract toxic effects of CNS depressant drugs.

5.5.7. Coca

Synonyms: Coca, Huanaco coca, Truxillo coca

Biological Source: Dried leaves of Erythroxylum coca or E. truxillense. Family: Erythroxylaceae.

Chemical Constituents: Total alkaloids (0.7-1.5%)—cocaine (methyl benzoyl ecgonine), cinnamyl cocaine, α-truxilline, tropocaine, benzoyltropine.

Therapeutic Efficacy: Local anaesthetic (first known). Used in ophthalmic surgery and surgery of ear, nose, and throat. Causes hallucinogenic and addictive effects.

5.6. ANTIHYPERTENSIVES

5.6.1. Rauwolfia

Synonyms: Rauwolfia root, Sarpagandha, Indian snake root

Biological Source: Dried roots of Rauwolfia serpentina. Family: Apocynaceae.

Chemical Constituents: Total alkaloids (0.7-2.4%). Over 80 alkaloids isolated—reserpine, rescinnamine, ajmaline, ajmalicine, serpentine, serpentinine. Reserpine is the most important.

Therapeutic Efficacy: Hypotensive drug with strong sedative activity. Mild tranquiliser. Root decoction useful for snake poison treatment. Decreases pain during menstruation.

5.7. ANTITUSSIVES

5.7.1. Vasaka

Synonyms: Adhatoda, Adulsa, Malabar nut

Biological Source: Dried and fresh leaves of Adhatoda vasica. Family: Acanthaceae.

Chemical Constituents: Vasicine, vasicinone, 6-hydroxy vasicine (quinazoline derivatives). Also contains volatile oil, betain, vasakin, adhatodic acid.

Therapeutic Efficacy: Used as expectorant and bronchodilator. Vasicine shows oxytocic property. Synthetic derivative bromhexine HCl reduces sputum viscosity.

5.7.2. Tolu Balsam

Synonyms: Balsam of tolu, Resin tolu

Biological Source: Solid or semi-solid balsam from trunk of Myroxylon balsamum. Family: Leguminosae.

Chemical Constituents: Cinnamic acid (10-15%), benzoic acid (6-8%), resin esters (75-80%), vanillin (1-2%).

Therapeutic Efficacy: Used as flavouring agent in syrups, confectionery, chewing gums. Used for coughs, lung congestion, skin rashes, colds, flu.

5.8. ANTIRHEUMATIC

5.8.1. Colchicum Seed

Synonyms: Wild Saffron, Meadow Crocus

Biological Source: Dried ripe seeds and corm of Colchicum autumnale. Family: Liliaceae.

Chemical Constituents: Colchicine (0.2-1%)—chief alkaloid. Also contains demecolcine. Colchicine contains tropolone ring structure.

Therapeutic Efficacy: Drug of choice for rheumatism and gout. Also possesses anti-tumour activity and anti-arthritic activity.

5.9. ANTITUMOUR

5.9.1. Vinca

Synonyms: Catharanthus, Periwinkle, Sadabahar

Biological Source: Dried whole plant of Catharanthus roseus (Vinca rosea). Family: Apocynaceae.

Chemical Constituents: Large number of indole alkaloids. Vincristine and vinblastine are most significant dimeric indole dihydroindole alkaloids with oncolytic activity.

Therapeutic Efficacy: Antitumour and anticancer properties. Leaves used for controlling diabetes and high blood pressure. Alkaloids are sedative and tranquiliser.

5.9.2. Podophyllum

Synonyms: Indian Podophyllum, Himalayan Mayapple

Biological Source: Dried rhizomes and roots of Podophyllum hexandrum. Family: Berberidaceae.

Chemical Constituents: Contains 7-15% resin (podophyllin). Active principle—podophyllotoxin (at least 40% in Indian variety).

Therapeutic Efficacy: Cytotoxic—used in treatment of venereal and other warts. Purgative, cholagogue, bitter tonic. Used in semi-synthetic production of etoposide.

5.10. ANTIDIABETICS

5.10.1. Pterocarpus

Synonyms: Bijasal, Indian kino tree, Malabar kino

Biological Source: Dried juice of Pterocarpus marsupium. Family: Leguminosae.

Chemical Constituents: Kinotannic acid (70-80%), kino-red, pyrocatechin (catechol), resin, gallic acid.

Therapeutic Efficacy: Powerful astringent. Used for diarrhoea, dysentery. Aqueous infusion shows hypoglycaemic action in diabetes.

5.10.2. Gymnema

Synonyms: Gurmar, Madhunashini

Biological Source: Leaves of Gymnema sylvestre. Family: Asclepiadaceae. Should contain not less than 1.0% gymnemic acids.

Chemical Constituents: Gymnemic acids (anti-sweet compounds), triterpene saponins, anthraquinone derivatives, alkaloids, betain, choline, lupeol, β-amyrin, stigmasterol.

Therapeutic Efficacy: Antidiabetic—hypoglycaemic effect by stimulating insulin secretion. Stomachic, stimulant, laxative, diuretic. Prevents dental plaque and caries.

5.11. DIURETICS

5.11.1. Gokhru

Synonyms: Gokshur, puncture vine, land caltrops

Biological Source: Dried ripe fruits of Tribulus terrestris. Family: Zygophyllaceae.

Chemical Constituents: Steroidal saponins—terestrosins (A, B, C, D, E), desgalactotigonin, F-gitonin. Hydrolysis yields diosgenin, chlorogenin, hecogenin. Flavonoid derivatives—tribuloside, quercetin, kaempferol.

Therapeutic Efficacy: Diuretic due to nitrates and essential oils. Used in diarrhoea, dysentery, psoriasis, eczema, urinary tract disorders.

5.11.2. Punarnava

Synonyms: Hogweed, Vishkhapara, Khatan

Biological Source: Dried whole plant of Boerhaavia diffusa. Family: Nyctaginaceae.

Chemical Constituents: Punarnavine (0.04-0.1%), punernavoside, potassium nitrate (6%), ursolic acid, β-sitosterol, fatty acids.

Therapeutic Efficacy: Immunomodulatory, antidiabetic, antioxidant, analgesic, anti-inflammatory, hepatoprotective, antibacterial activities.

5.12. ANTIDYSENTERIC

5.12.1. Ipecacuanha

Synonyms: Ipecacuanha root, Radix ipecacuanha

Biological Source: Dried rhizomes and roots of Cephaelis ipecacuanha. Family: Rubiaceae. Should contain 2% or more of ether soluble alkaloids.

Chemical Constituents: Alkaloids (2-2.5%)—emetine (30-75%), cephaline, psychotrine, dimethyl psychotrine. Also contains calcium oxalate, starch, glucosidal tannin.

Therapeutic Efficacy: Expectorant for coughs. Emesis inducer. Amoebicidal. Emetine hydrochloride used parenterally for amoebic dysentery.

5.13. ANTISEPTICS AND DISINFECTANTS

5.13.1. Benzoin

Synonyms: Sumatra Benzoin, Loban

Biological Source: Balsamic resin from Styrax benzoin (Sumatra Benzoin) or Styrax tonkinensis (Siam Benzoin). Family: Styracaceae.

Chemical Constituents: Sumatra: Benzoic acid (18%+), cinnamic acid (20%), vanillin (1%). Siam: Benzoic acid (38%). Should contain not less than 25% total balsamic acids.

Therapeutic Efficacy: Irritating expectorant, carminative, diuretic. Externally used as antiseptic. Used in compound tincture for upper respiratory tract infection.

5.13.2. Myrrh

Synonyms: Gum, Bol, Myrrha

Biological Source: Oleo-gum-resin from Commiphora molmol. Family: Burseraceae.

Chemical Constituents: Volatile oil (10%), gum (60%), resin (25-40%), bitter principle (3-4%). Resin contains α, β, γ commiphora acids.

Therapeutic Efficacy: Used as stimulant and antiseptic. Astringent to mucous membrane. Tincture used in mouthwashes and gargles.

5.13.3. Neem

Synonyms: Margosa, Nimba

Biological Source: All aerial parts of Azadirachta indica. Family: Meliaceae.

Chemical Constituents: Nimbidin (bitter constituent), azadirachtin (complex liminoid compound from seeds). Seeds contain 45% oil.

Therapeutic Efficacy: Bark used as bitter tonic, astringent, antiperiodic. Used in malarial fever, skin diseases. Oil has anthelmintic and insecticidal property.

5.13.4. Turmeric

Synonyms: Indian saffron, Turmeric

Biological Source: Dried and fresh rhizomes of Curcuma longa. Family: Zingiberaceae. Should contain not less than 4% volatile oil.

Chemical Constituents: Volatile oil (1-6.5%), curcuminoids—curcumin (50-60%). Volatile oil contains α and β pinene, α-phellandrene, camphor, camphene, zingiberene.

Therapeutic Efficacy: Used as colouring agent, anti-inflammatory, antiarthritic agent. Used for cervical cancer and detection of boric acid.

5.14. ANTIMALARIALS

5.14.1. Cinchona

Synonyms: Jesuit’s bark, Peruvian bark, Calisaya bark

Biological Source: Dried bark of stem or root of Cinchona succirubra, C. ledgeriana, C. calisaya. Family: Rubiaceae.

Chemical Constituents: Quinoline alkaloids—quinine, quinidine, cinchonidine, cinchonine. Also contains quinic acid (5-8%), cinchotannic acid, glycoside quinovin (2%).

Therapeutic Efficacy: Antimalarial, antipyretic, analgesic. Used as antiseptic in abscesses, ulcers, mouthwash, sore-throat. Good ingredient in dentifrice.

5.14.2. Artemisia

Synonyms: Santonica, Worm seeds

Biological Source: Unexpanded flower-head of Artemisia cina, A. brevifolia, A. maritima. Family: Asteraceae.

Chemical Constituents: Essential oil (1-2%), santonin (2%)—a sesquiterpene lactone. Oil contains cineole, pinene, resin.

Therapeutic Efficacy: Strong anthelmintic against roundworm infections. Used for fever, chills, malaria, cough, stomach upset, common cold.

5.15. OXYTOCIC

5.15.1. Ergot

Synonyms: Ergot of Rye, Ergota

Biological Source: Dried sclerotium of fungus Claviceps purpurea on rye (Secale cereal). Family: Clavicipitaceae.

Chemical Constituents: Indole alkaloids (0.1-0.25%)—peptide derivatives of lysergic acid. Contains ergotamine, ergometrine, ergotoxine. Also contains histamine, amino acids, ergosterol, chitin.

Therapeutic Efficacy: Oxytocic—enhances labour pain and prevents postpartum haemorrhage. Ergotamine tartrate—analgesic for migraine. LSD has psychomimetic action.

5.16. VITAMINS

5.16.1. Cod Liver Oil

Synonym: Oleum morrhi

Biological Source: Fresh liver of cod fish Gadus morrhua. Family: Gadidae.

Chemical Constituents: Vitamin A (≥255 mcg/g) and Vitamin D (≥2.125 mcg/g). Glyceryl esters of oleic, linoleic, gadoleic, myristic, palmitic acids. Contains 7% eicosapentaenoic acid and 7% docosahexaenoic acid.

Therapeutic Efficacy: Used as dietary supplement. Beneficial in rickets and TB. Relieves arthritis pain. Effective in treatment of domestic burns.

5.16.2. Shark Liver Oil

Synonym: Oleum Selachoids

Biological Source: Fixed oil from livers of sharks (Hypoprion brevirostris, Galeorhinus zyopterus). Family: Carcharhinidae.

Chemical Constituents: Vitamin A (15,000-30,000 IU/g). Glycerides of saturated and unsaturated fatty acids.

Therapeutic Efficacy: Used in vitamin A deficiency. Used as nutritive oil. Ingredient in sunburn ointments.

5.17. ENZYMES

5.17.1. Papaya

Synonyms: Papayotin, Vegetable pepsin, Caroid

Biological Source: Dried and purified latex of green fruits and leaves of Carica papaya. Family: Caricaceae.

Chemical Constituents: Papain (proteolytic enzyme), chymopapain, papaya proteinase. Contains nitrogen (15.5%) and sulphur (1.2%). Leaves contain dehydrocarpaines I and II, carpaine, pseudocarpaine.

Therapeutic Efficacy: Used as protein digestant, anthelmintic, anti-inflammatory. Used in treating dyspepsia, intestinal disorders. Used as additive in digestive mixtures.

5.17.2. Diastase

Synonyms: Maltin, Amylase, Malt extract

Biological Source: Malt extract from dried barley grains of Hordeum vulgare. Family: Poaceae.

Chemical Constituents: Dextrin, maltose, glucose (traces), diastase (8%)—amylolytic enzyme.

Therapeutic Efficacy: Used as amylolytic enzyme. Aids in digestion of starch. Used as bulk producing laxatives.

5.17.3. Pancreatin

Synonyms: Diastase vera, Pancreatic acid

Biological Source: Obtained from animal (cattle or pigs) or plant sources. Contains amylase, lipase, and protease.

Therapeutic Efficacy: Promotes healthy weight gain. Promotes absorption of vitamins and minerals. Helps breakdown proteins, fats, and carbohydrates.

5.17.4. Yeast

Synonyms: Brewer’s yeast, Baker’s yeast

Biological Source: Unicellular fungus Saccharomyces cerevisiae. Family: Saccharomycetaceae.

Chemical Constituents: Moisture (65-85%), nitrogenous compounds (proteins), glycogen, fat, vitamins (thiamine, riboflavin, nicotinic acid, pantothenic acid), ash, enzymes (invertase, diastase, zymase, maltase).

Therapeutic Efficacy: Used for manufacturing alcohol, beer, wines, bread. Irradiated form—source of vitamin D. Good source of protein.

5.18. PHARMACEUTICAL AIDS

5.18.1. Kaolin

Synonyms: China clay, White clay

Biological Source: Hydrous aluminium silicate—kaolinite. Formula: Al₂O₃·2SiO₂·2H₂O.

Therapeutic Efficacy: Used in diarrhoea, dysentery, cholera. Applied on skin as poultice or dusting powder. Used in tablet preparation.

5.18.2. Lanolin

Synonyms: Wool fat, Wool wax, Adeps Lanae

Biological Source: Fat-like substance from sebaceous glands of sheep Ovis aries. Family: Bovidae.

Chemical Constituents: Esters of cholesterol and isocholesterol with carnaubic, oleic, myristic, palmitic, lignoceric acids. Contains 50% water.

Therapeutic Efficacy: Applied topically for dry skin, itching, diaper rash, radiation therapy burns. Used for sore and cracked nipples.

5.18.3. Beeswax

Synonyms: Cera flava, Cera alba, White bees wax, Yellow bees wax

Biological Source: Purified wax from honey comb of Apis mellifera. Family: Apidae.

Chemical Constituents: Myricin (80%)—myricyl palmitate, free cerotic acid (15%), melissic acid, cerolein.

Therapeutic Efficacy: Used in plasters, polishes, ointments. Ingredient of paraffin ointment.

5.18.4. Acacia

Synonyms: Gum acacia, Gum arabic

Biological Source: Dried gummy exudation from stems and branches of Acacia senegal. Family: Leguminosae.

Chemical Constituents: Arabin—complex mixture of calcium, magnesium, potassium salts of Arabic acid. Arabic acid hydrolyses into L-arabinose, L-rhamnose, D-galactose, D-glucuronic acid.

Therapeutic Efficacy: Used as demulcent, emulsifying agent, thickening agent, binding agent in tablet formulations. Colloidal stabiliser.

5.18.5. Tragacanth

Synonyms: Gum tragacanth, Gum dragon

Biological Source: Air dried gummy exudate from stems of Astragalus gummifer. Family: Leguminosae.

Chemical Constituents: Two major fractions—tragacanthin (water-soluble) and bassorin (water-insoluble).

Therapeutic Efficacy: Used as demulcent, emollient, thickening agent, suspending agent, emulsifying agent. Used as binder in tablet formulations.

5.18.6. Sodium Alginate

Synonyms: Sodium polymannuronate

Biological Source: Sodium salt of alginic acid from brown seaweed—Macrocystis pyrifera, Laminaria hyperborea. Family: Phaeophyceae.

Chemical Constituents: Linear polymer of L-guluronic acid and D-mannuronic acid.

Therapeutic Efficacy: Used as suspending agent, thickening agent, binding agent, disintegrating agent in tablets. Used in pastes, creams, and emulsions.

5.18.7. Agar

Synonyms: Agar-agar, Vegetable gelatin, Gelose

Biological Source: Dried hydrophilic colloidal polysaccharide from red algae—Gelidium amansii, Gracilaria, Pterocladia. Family: Gelidaceae.

Chemical Constituents: Agarose (gel strength) and agaropectin (viscosity). Contains D-galactose and 3-6 anhydro L-galactose units.

Therapeutic Efficacy: Used as emulsifying agent, bulk laxative, suspending agent. Used for bacteriological culture medium. Used in ointments and medicinal encapsulations.

5.18.8. Guar Gum

Synonyms: Guar flour, Jaguar gum, Guaran

Biological Source: Powder of endosperm of seeds of Cyamopsis tetragonolobus. Family: Leguminosae.

Chemical Constituents: Galactomannan (guaran)—linear chains of (1→4)-β-D mannopyranosyl units with α-D-galactopyranosyl units (ratio 1:2). Contains 5-7% proteins.

Therapeutic Efficacy: Used as bulk laxative, protective colloid, thickener (5-8 times more than starch). Used in peptic ulcer, suspensions, emulsions, lotions, creams, toothpastes.

5.18.9. Gelatin

Synonyms: Gel foam, Gelatinum

Biological Source: Partial hydrolysis of collagen from skin, tendons, ligaments, bones of ox (Bos taurus) or sheep (Ovis aries). Family: Bovidae.

Chemical Constituents: Gluten protein hydrolyses into amino acids—glycine (25.5%), alanine (8.7%), valine (2.5%), leucine (3.2%), proline (16.3%), glutamic acid (11.4%), arginine (8.1%), lysine (4.1%).

Therapeutic Efficacy: Used in pastilles, pastes, suppositories, capsules, pill-coatings, gelatin sponge. Used as suspending agent, tablet binder, coating agent, stabiliser, thickener.

5.19. MISCELLANEOUS

5.19.1. Squill

Synonyms: Jangali pyaj, Sea onion

Biological Source: Dried slices of bulb of Urginea maritima. Family: Liliaceae.

Chemical Constituents: Cardiac glycosides—scillaren A and B (bufadienolide type), scillarenase enzyme, xanthoscillide, mucilage (4-11%), sinistrin, calcium oxalate.

Therapeutic Efficacy: Increases vigour while decreasing cardiac frequency. Strong expectorant. Red squill used as rat poison.

5.19.2. Galls

Synonyms: Nutgalls, Turkey galls, Aleppo galls

Biological Source: Vegetative outgrowths caused by gall wasp (Adleria gallaetinctorae) on twigs of Quercus infectoria. Family: Cynipidae and Fagaceae.

Chemical Constituents: Gallotannic acid, gallic acid, ellagic acid, sitosterol, methyl betulate, methyl oleanolate, starch, calcium oxalate.

Therapeutic Efficacy: Used in production of astringents, tanning, dyeing. Used in production of tannic acid and ink.

5.19.3. Ashwagandha

Synonyms: Withania root, Winter cherry

Biological Source: Dried roots and rhizomes of Withania somnifera. Family: Solanaceae.

Chemical Constituents: Alkaloids—ashwagandhine, withanine, isopelietierine, anaferine. Steroidal lactones—withanolides, withaferins. Phytosterols—sitoindosides, β-sitosterol.

Therapeutic Efficacy: Sedative, hypnotic, hypotensive, immunomodulatory. Used in rheumatism, gout, hypertension, nervine, skin diseases.

5.19.4. Tulsi

Synonyms: Holy Basil, Rama Tulsi, Shyama Tulsi

Biological Source: Dried leaves of Ocimum sanctum. Family: Lamiaceae.

Chemical Constituents: Volatile oil (0.1-0.9%)—eugenol (70%), carvacrol (3%), eugenol-methyl-ether (20%), caryophyllene. Contains alkaloids, glycosides, saponin tannins, vitamin C, ursolic acid.

Therapeutic Efficacy: Diaphoretic, carminative, stimulant, demulcent, diuretic, anthelmintic, febrifuge. Antimicrobial, anti-inflammatory. Used in respiratory tract infections.

5.19.5. Guggul

Synonyms: Palankasha, Devadhupa

Biological Source: Oleo-gum-resin from bark of Commiphora wightii. Family: Burseraceae.

Chemical Constituents: Steroids, diterpenoids, aliphatic esters, amino acids. Guggulsterones (I-V), Z-guggulsterone, E-guggulsterone, 16-β-hydroxyprogesterone.

Therapeutic Efficacy: Used in obesity, arthritis, rheumatism. Anti-inflammatory, hypocholesterolemic. Semi-purified form ‘Gugulip’ marketed by Cipla shows antihyperlipidemic activity.

Dpharmguru’s exam insights:

This comprehensive chapter covers a wide range of crude drugs. Remember the key drugs: Aloe (barbaloin), Senna (sennosides), Digitalis (cardiac glycosides), Rauwolfia (reserpine), Vinca (vincristine, vinblastine), Cinchona (quinine), Ergot (ergotamine), Turmeric (curcumin), Neem (nimbidin), Tulsi (eugenol), Ashwagandha (withanolides), Guggul (guggulsterones). These are frequently tested in exams—know their biological sources, chemical constituents, and therapeutic uses!

FREQUENTLY ASKED QUESTIONS (FAQs)

1. What is the biological source of Senna?

Senna is the dried leaflets of Cassia angustifolia, belonging to the family Leguminosae.

2. What is the active constituent of Digitalis?

The active constituents of Digitalis are cardiac glycosides (cardenolides)—Purpurea glycosides A and B, and glucogitaloxin.

3. What is the chemical constituent responsible for the purgative action of Senna?

Sennosides A and B (not less than 2.5%) are the anthraquinone glycosides responsible for the purgative action of Senna.

4. What is the difference between true and pseudo alkaloids?

True alkaloids are derived from amino acids and contain nitrogen in a heterocyclic ring. Pseudo alkaloids are basic in nature but are not derived from amino acid precursors (e.g., caffeine).

5. What is the biological source of Rauwolfia?

Rauwolfia is the dried roots of Rauwolfia serpentina, belonging to the family Apocynaceae.

6. What is the active principle of Vinca?

The active principles of Vinca are vincristine and vinblastine—dimeric indole dihydroindole alkaloids with oncolytic (anti-cancer) activity.

7. What is the therapeutic use of Colchicum?

Colchicum is the drug of choice for rheumatism and gout. It also possesses anti-tumour and anti-arthritic activity.

SUMMARY

This comprehensive guide covered the biological sources, chemical constituents, and therapeutic efficacy of a wide range of crude drugs:

• Laxatives: Aloe, Castor Oil, Ispaghula, Senna
• Cardiotonics: Digitalis, Arjuna
• Carminatives: Coriander, Fennel, Cardamom, Ginger, Clove, Black Pepper, Asafoetida, Nutmeg, Cinnamon
• Astringents: Myrobalan, Black Catechu, Pale Catechu
• Nervous System Drugs: Hyoscyamus, Belladonna, Ephedra, Opium, Tea, Coffee, Coca
• Antihypertensives: Rauwolfia
• Antitussives: Vasaka, Tolu Balsam
• Antirheumatic: Colchicum
• Antitumour: Vinca, Podophyllum
• Antidiabetics: Pterocarpus, Gymnema
• Diuretics: Gokhru, Punarnava
• Antidysenteric: Ipecacuanha
• Antiseptics: Benzoin, Myrrh, Neem, Turmeric
• Antimalarials: Cinchona, Artemisia
• Oxytocic: Ergot
• Vitamins: Cod Liver Oil, Shark Liver Oil
• Enzymes: Papaya, Diastase, Pancreatin, Yeast
• Pharmaceutical Aids: Kaolin, Lanolin, Beeswax, Acacia, Tragacanth, Sodium Alginate, Agar, Guar Gum, Gelatin
• Miscellaneous: Squill, Galls, Ashwagandha, Tulsi, Guggul

As I always tell my students: “Understanding the biological source, chemical constituents, and therapeutic efficacy of crude drugs is the foundation of pharmacognosy. It connects the plant to the patient and the chemistry to the cure.”

REFERENCES AND FURTHER READING

• Pharmacy Council of India (PCI). (2022). Pharmacognosy Syllabus. New Delhi: PCI.
• Tyler, V. E., Brady, L. R., & Robbers, J. E. (2020). Pharmacognosy and Pharmacobiotechnology (9th ed.). Wolters Kluwer.
• Trease, G. E., & Evans, W. C. (2019). Trease and Evans’ Pharmacognosy (16th ed.). Elsevier.
• Kokate, C. K., Purohit, A. P., & Gokhale, S. B. (2020). Pharmacognosy (50th ed.). Nirali Prakashan.
• Indian Pharmacopoeia Commission. (2018). Indian Pharmacopoeia (8th ed.). Ghaziabad: IPC.
• World Health Organization (WHO). (2022). Guidelines on Quality Control of Herbal Medicines. Retrieved from https://www.who.int.

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult qualified healthcare professionals for medical concerns. Pharmaceutical regulations and guidelines may vary by region—always refer to your local regulatory authorities for specific requirements.

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