Pharmacognosy - Unorganized Drugs

Pharmacognosy Lecture Notes

Unorganized Drugs

  • These drugs lack cellular or definite structures and are derived from plant or animal parts.

  • They are produced normally or pathologically through processes like incision, decoction, and expression.

  • Unorganized drugs are mixtures of chemical substances or decomposition products.

  • They are mostly solids, but some can be semi-solids or fluids like oils and balsams.

Classes of Unorganized Drugs

  1. Gums (e.g., Gum acacia, Gum tragacanth)

  2. Dried Extracts (e.g., Agar, Catechu, Gelatin)

  3. Dried Juice (e.g., Aloe)

  4. Dried Latex (e.g., Opium)

  5. Resins and Resin Combinations (e.g., Colophony, Myrrh, Benzoin)

  6. Oils and Fats (e.g., Evening Primrose Oil, Theobroma Oil)

  7. Waxes

  8. Saccharine Substances (e.g., Honey, Royal Jelly)

Resins and Resin Combinations

  • Resins are amorphous, solid, or semisolid exudates from plants produced normally or pathologically.

  • They are found in oleoresin cells, tissues, ducts, and glands, often produced upon injury for protection (secondary flow) or naturally (primary flow).

  • Chemically, they are exudation products of terpenes from volatile oils and are complex organic substances.

  • Insoluble in water and petroleum ether; soluble in alcohol, chloroform, ether, fixed, and volatile oils.

  • They soften and melt upon heating, burning with a smoky flame.

  • Secondary flow is resin production due to injury; primary flow occurs without injury.

Types of Resins

  • Resin alone (e.g., Guaiacum)

  • Oleoresins (Resin & volatile oil) (e.g., Colophony)

  • Oleo-gum-resins (Volatile oil + Gum + Resin) (e.g., Myrrh)

  • Gum resins (Gum & resin) (e.g., Gamboge)

  • Balsams (Resinous substances with high percentage of balsamic acids like benzoic or cinnamic acid or their esters) (e.g., Benzoin & Peru Balsam)

Resin Preparation

  • Distillation: To separate oil from resin (e.g., Colophony).

  • Heating: To separate resin from plant wood (e.g., Guaiacum resin).

  • Puncturing: Of plant either naturally or artificially.

  • Extraction: Using ethanol, followed by resin precipitation in water.

Colophony (Rosin)

  • Origin: Residue after distilling volatile oil from oleoresin of Pinus palustris, P. toeda, and other Pinus species (Family Pinaceae).

  • Chemical Constituents:

    • Abietic acid (major constituent)

    • Resin (5-6%)

    • Volatile oil (0.5%)

  • Chemical Tests:

    • Abietic Acid Test: Colophony powder + benzene, shake, add copper acetate; a bright blue-green color appears in the organic layer.

  • Pharmaceutical Uses:

    1. Stimulant and diuretic in folk medicine.

    2. Ingredient of ointments and plasters.

    3. Ingredient in varnishes, paints, and surface coatings.

Myrrh

  • Origin: Oleo-gum-resin from stems and branches of Commiphora molmol and other Commiphora species (Family Burseraceae).

  • Chemical Constituents: (oleo gum resin)

    • Gum (57-61%): arabinose, xylose, and galactose associated with oxidase enzyme.

    • Resin (25-40%): α, β, γ-commiphoric acid.

    • Volatile oil (7-17%): contains terpenes, sesquiterpenes, and eugenol, providing the characteristic odor.

  • Chemical Tests:

    1. Nitric Acid Test: Myrrh + diethyl ether, filter, evaporate filtrate in two dishes.

      • Add nitric acid to one dish → violet color.

      • Pass bromine vapors over the other → violet color.

    2. Oxidase test.

  • Pharmaceutical Uses:

    1. Antibacterial and antifungal for sore throats and gingivitis.

    2. Treatment of mild inflammatory skin problems.

    3. Treatment of bilharziasis.

    4. Analgesic in irregular and painful menstruation.

    5. Expectorant.

Balsams

  • Characterized by high percentage of balsamic acids (benzoic & cinnamic acids) and their esters.

  • Produced pathologically as a result of injury.

  • Balsamic resin: Benzoin (Gawi). Benzoin is a stress product, as the trees do not normally have secreting cells or ducts.

Benzoin

  • Sumatra Benzoin:

    • Origin: Incised stems of Styrax benzoin (Family Styraceae).

    • Chemical Constituents:

      • Benzoic acids (10%) and cinnamic acids (20-30%).

      • Esters (75%), mainly vanillin and cinnamyl cinnamate.

      • Resin contains esters of triterpene acids (sumaresinolic acids).

    • Chemical Tests:

      • KMnO4 test: (Powder + KMnO4) → Benzaldehyde odor

      • Negative H2SO4 test: (Ether extract of powder + H2SO4) → Deep red-brown color

      • FeCl3 test: (Alcoholic solution+ FeCl3) → Negative green color

  • Siam Benzoin:

    • Origin: Incised stems of Styrax tonkinensis (Family Styraceae).

    • Chemical Constituents:

      • Benzoic acids (10%).

      • Esters (60-70%), mainly vanillin and coniferyl benzoate.

      • Resin contains alcohols and phenols (siaresinotannol) & esters of triterpene acids (siaresinolic acid).

  • Pharmaceutical Uses of Benzoin:

    1. Antiseptic and stimulant (External use).

    2. Carminative and diuretic (Internal use).

    3. Cough sedative & expectorant for respiratory ailments such as bronchitis (Inhalation).

    4. Perfumes as a fixative for essential oils.

Oils and Fats

Important Terms

  1. Lipids: Fatty compounds like fatty acids, glycerolipids, phospholipids, and sphingolipids.

  2. Sterols

  3. Oils

  4. Fats

  5. Fatty acids (essential and non-essential)

    • Saturated fatty acids

    • Unsaturated fatty acids: Mono-unsaturated, Poly-Unsaturated

Polyunsaturated Fatty Acids (PUFA)

  • Help in reducing harmful LDL cholesterol, improving cholesterol profile, and lowering the rate of coronary heart diseases and cancer.

  • Serve as precursors to eicosanoids, regulating inflammation, immunity, blood vessels, and platelet aggregation.

  • Found in nuts, avocado, and olive oil.

Omega Fatty Acids

Classified by position of unsaturation from the terminal methyl group:

  • Omega-3 (essential FA, PUFA)

  • Omega-6 (essential FA, PUFA)

  • Omega-9 (found in body; non-essential FA, MUFA)

Type of fats:

  • Polyunsaturated fats

    • Omega 3

      • Docosahexaenoic acid (DHA)

      • Oily fish

      • Algae

      • Linseed

    • Omega 6

      • Linoleic acid (LA)

      • Safflower

      • Sunflower

      • Soya Oil

      • Nuts

  • Monounsaturated fats

    • Omega 9

      • Oleic acid (OA)

      • Argan Oil

      • Olive Oil

      • Avocado

  • Saturated fats

    • Palmitic acid (PA)

      • eggs

      • Dairy

      • Coconut Oil

      • Red meat

Evening Primrose Oil (EPO)

  • Origin: Fixed oil from the seeds of Oenothera biennis (Family Onagraceae).

  • Constituents: High percentage of 2 essential unsaturated fatty acids:

    • 70% (Z)-linoleic acid (LA)

    • 10% esterified γ-linolenic acid (GLA)

  • Pharmaceutical Uses:

    1. Dietary supply of GLA in cases of:

      • Diabetic neuropathy

      • Rheumatoid arthritis

      • Atopic eczema

      • Premenstrual symptoms (PMS)

      • Coronary heart diseases and hypertension

      • Affects bone metabolism (osteoporosis)

    2. Cosmetics

Theobroma Oil (Cocoa Butter)

  • Origin: Fixed oil obtained by hot expression of ground kernels of Theobroma cacao (Family Sterculiaceae).

  • Most expensive commercial fixed oil; often adulterated.

  • Contains a natural antioxidant for long shelf life.

  • Constituents: Glycerides of stearic, palmitic, arachidic, & oleic acids.

  • Pharmaceutical Uses:

    1. Suppository preparations (ideal melting point: 31-34°C).

    2. Cosmetics (skin and lip emollients).

Castor Oil

  • Origin: Fixed oil obtained by cold expression of seeds of Ricinus communis (Family Euphorbiaceae) deprived of its testa.

  • The oil is highly viscous.

  • Constituents: Glycosides of ricinoleic acid, isoricinoleic acid, dihydroxy stearic acid, and stearic acids.

  • Pharmaceutical Uses:

    1. Purgative in case of food poisoning and preliminary intestinal examination.

    2. Oils, paints & varnishes.

    3. Cosmetics.

Waxes

  • Solids, occasionally liquid substances, resembling fats and oils physically but differing chemically.

  • Esters of fatty acids with high molecular weight monohydric alcohols.

  • Also contain free fatty acids, alcohols, hydrocarbons, and sterols.

  • Show higher melting points than fats.

  • Examples: Beeswax, Carnauba wax, Soy wax, Candilla wax

Beeswax

  • Origin: Obtained by melting and purifying honeycomb of Apis mellifica and other bees.

    • Yellow and white beeswax

  • Constituents:

    • 80% Myricyl palmitate (myricin)

    • Myricyl stearate

    • 15% Free cerotic acid, aromatic substance cerolin & cholesteryl esters.

  • Pharmaceutical Uses:

    1. Plasters, Ointments

    2. Cosmetics

    3. Polishes

Carnauba Wax

  • Origin: Obtained from leaves of Copernicia cerifera (Family Palmae).

  • Constituents: Myricyl cerotate ester and free alcohols.

  • Pharmaceutical Uses:

    1. Tablet coating.

    2. Replacement for beeswax in cosmetics.

    3. Manufacture of candles and polish.

Saccharine Substances

Purified Honey

  • Origin: Saccharine substance deposited by hive bee, Apis mellifeca and other species in honeycomb cells.

  • Best honey from clover and citrus.

  • Different flowers impart different flavors and qualities.

  • Constituents: Invert sugar, small amounts of sucrose, dextrin, formic, citric, & tartaric acids, volatile oils, wax, pollen grains, amino acids, enzymes, vitamins, and minerals.

  • Pharmaceutical Uses:

    • Component in cough mixtures, sedatives, and expectorants for sore throat.

    • Source of energy & nutrition.

    • Antimicrobial effect (dehydrates bacteria).

    • Externally used in wounds, ulcers & burns (soothing).

    • In cosmetics & beauty products.

  • Adulteration: By artificial invert sugar, sucrose and commercial liquid glucose

  • Detection of Adulterants:

    • Due to hydrolysis of sucrose and starch, artificial invert sugar and glucose have high amounts of chloride and sulphate. Limit test for these two anions are very important.

    • Artificial invert sugar contains furfural (toxic) gives red color with resorcinol in presence of HCl

Royal Jelly

  • Origin: Milky viscous liquid secreted by salivary glands of hive bees to feed the queen bee.

  • Responsible for the queen's superior size, super ovulation, stamina, and high life expectancy.

  • Queen is 40-60% larger than worker bees, lays over 2,000 eggs a day, and lives up to four years (worker bees live just 40 days).

  • Constituents:

    • Super nutrient (vitamins A, C, D, E, and mostly rich in B vitamins)

    • 45% proteins, including 8 essential amino acids

    • 1% Minerals (Cu, Ca, Fe, P & K)

  • Pharmaceutical Uses:

    1. Strong antimicrobial properties for skin and cell regeneration (anti-aging).

    2. Increase immunity and RBCs count.

    3. Sexual tonic for both males and females.

    4. Lowers cholesterol.

    5. General tonic and dietary supplement (elderly).

    6. Used in vision problems.