خصائص الألوة والأفيون

Course Information

• Course Title: Pharmacognosy II
• Course Code: PHG 213
• Week number: 13
• Lecture number: 11
• Lecturer: Dr. Hanan Samir Marzouk
• Fall 2024/2025

Lecture Objectives

• Identify Latex, Juices, Extracts and gums.
• Describe the formation of Latex, Juices, Extracts and gums.
• Examine the physical and chemical characteristics of each class of unorganized drugs.
• Define Opium, Aloe, Agar, Gelatin, Gum acacia and gum tragacanth.

Unorganized Drugs (Part II)

• This part of the lecture focuses on unorganized drugs such as Dried Latex, Dried Juices, Resins, Oleoresins, Oleogumresins, Glycoresins, Balsams, Gums, Dried Extracts, etc.

Dried Latex

• Definition: Latex is an emulsion or suspension. The continuous phase is an aqueous solution of mineral salts, proteins, sugars, tannins, alkaloids, etc. Suspended particles include oil droplets, resin, gum, protein, or starch.
• Properties: Latex can be white (as in opium), yellow (as in Argemone mexicana), or red (as in the rhizome of Sanguinaria canadensis). Latex is found in special plant structures called laticiferous cells, tubes, or vessels.
• Opium: Air-dried latex obtained by incision from the fully grown but unripe capsule of Papaver somniferum (Papaveraceae family).
• Opium physical description: Rounded or cubical, flattened or brick-shaped masses, 8-10 cm in diameter, commonly weighing 250-1000 gm. Externally, it's dark brown to chocolate brown. When fresh it's elastic, becoming hard or brittle over time. It has a strong narcotic odor and a very bitter taste.

Opium Constituents

• Opium contains around 30 different alkaloids. These alkaloids belong to different chemical groups. They are combined with meconic acid (5% present) and sulphuric acid. Some key alkaloids include:
  • Morphine (10-20%)
  • Codeine (methyl morphine 0.3-0.4%)
  • Narcotine (2-8%)
  • Thebaine (0.2-0.5%)
  • Narceine (remaining alkaloids in small quantities, making up more than 1% of the drug).

Opium Test for Meconic Acid

• Procedure: Warm about 20-30 mg of powdered opium in 2-3 ml of water for a few minutes, then filter. Add a few drops of 5% ferric chloride solution to the filtrate.
• Observation: A purplish red color is produced, and this color does not change (remain purplish red) when exposed to dilute hydrochloric acid or 5% mercuric chloride solution.

Opium Uses

• Opium is used as a hypnotic and sedative.
• It relieves pain and calms excitement
• It's an astringent in diarrhea and dysentery.
• Acts as a sedative for certain types of coughs. All important alkaloids exhibit narcotic effects.

Dried Juices (e.g., Aloe)

• Aloe: Solid residue obtained by evaporating the juice that drains from cut leaves of Aloe ferox (and its hybrids). Commercially known as Cape Aloe, Curacao Aloe, or Aloe Perryi (known as Socotrine or Zanzibar Aloe).
• Aloes Description: Typically dark brown or greenish brown glassy masses. Thin fragments are deep olive colored and semi-transparent. The powder is greenish yellow, with a bitter and nauseous taste.

Aloe Constituents

• Containing anthraquinone glycosides (barbaloin), which is pale yellow crystalline substance.
• α and β- barbaloin and Isobarbaloin.
• Isobarbaloin is crystalline and non-crystalline.

Aloe Test for Identity (Borax Test)

• Procedure: Boil 0.5 gm of powdered Aloe with 50 ml of water for 2-3 minutes, then filter. Add 0.25 gm of borax to 10 ml of the filtrate and heat. Pour some of the dark fluid into water.
• Observation: A green fluorescence is produced.

Aloe Uses

• Aloe varieties show purgative properties.
• Used in creams for diabetic ulcers and promoting hair growth.

Extracts

• Includes drugs prepared by evaporating aqueous decoction of plant or animal parts.
• Examples, Gelatin.

Gelatin

• Origin: Protein obtained from boiling collagenous tissues (skin, tendons, ligaments, bones) with water and drying the residue. Derived from various animals like oxen, sheep.
• Constituents: Consists of the protein gluten.
• Uses: Nutrient, base for glycerin suppositories, pastilles, and growth media for bacteria.

Gelatin Chemical Test

• Procedure: Heat powdered gelatin with soda lime (ammonia is released, showing nitrogen).
• Procedure: Add tannic acid or picric acid to a gelatin solution in water.
• Observation: A precipitate/heavy yellow precipitate will form.
• Procedure: Add CuSO4 + 20% NaOH.
• Observation: Violet colour (Biurette test).

Agar-Agar

• Origin: Dried mucilaginous substance from Gelidium corneum, G. cartilageneum, and related red algae.
• Constituents: Heterogenous polysaccharide, composed of agarose and agaropectin.
• Uses: Constipation treatment. Also used as an emulsifying agent.

Gums

• General Characteristics: Amorphous, translucent solids; insoluble in alcohol and most organic solvents, but soluble in water to create viscous solutions.
• Composition: Calcium, potassium, magnesium salts of complex substances (polyuronides).
• Production: Pathological conversion of cell walls of tissue into gums, often by enzymatic processes (gummosis).
• Natural Gums: Acacia, Tragacanth.

Gum Acacia

• Origin: Dried exudate from Acacia Senegal or other species (Family Fabaceae, Leguminosae).
• Constituents: Almost entirely glycosidal acid (Arabic acid), combined with potassium, magnesium, calcium; also contains diastase and oxidase enzymes.

Gum Tragacanth

• Origin: Dried exudation from Astragalus gummifer or related Asiatic species (Family Fabaceae, Leguminosae).
• Constituents: Two parts: Tragacanthin (water-soluble) and Basorin (water-insoluble). Also contains traces of starch, cellulose, and nitrogenous substances.

Gum Acacia and Gum Tragacanth Tests for Identity

• Acacia: Dissolve powdered gum in water, add hydrogen peroxide and benzidine; a blue or greenish blue colour indicates oxidase enzyme presence.
• Tragacanth: Add iodine solution to powdered gum on a porcelain plate; olive green colour indicates starch presence.

Uses of Gums

• Acacia Gum: Used as a demulcent, suspending, and emulsifying agent for oils.
• Tragacanth Gum: Used as a suspending agent for insoluble powders and as a binding agent for pills and tablets.