The Constituents of Organic Drugs PDF

THE CONSTITUENTS OF ORGANIC DRUGS These may be classified into: 1. The Active Constituents. The active constituents may be active in two different ways, viz.: pharmacologically active, i. e., having an action on living animal tissues, and pharmaceutically active, i. e., capable of causin...

THE CONSTITUENTS OF ORGANIC DRUGS These may be classified into: 1. The Active Constituents. The active constituents may be active in two different ways, viz.: pharmacologically active, i. e., having an action on living animal tissues, and pharmaceutically active, i. e., capable of causing precipitation or otherwise notable chemical changes in a prescription or preparation. Both kinds are found in cinchona bark, which contains not only quinine and other alkaloids upon which its pharmacological activity depends, but also tannic acid, an astringent drug. In an ordinary dose of cinchona the tannic acid is too little in amount to have any important astringent effect, and is, therefore, not pharmacologically active; yet if the cinchona preparation is mixed with a preparation of iron, the tannic acid becomes pharmaceutically active and changes the iron salt into ink. A constituent is called an active principle when to it may be attributed, either wholly or in part, the physiologic action of the drug. The active constituents of organic drugs may be either: a. Single chemic bodies, or b. Mixtures of such a nature that separation into their components is not advantageous. The classes of active constituents are: A. The Single Chemicals. 1. Plant acids and their salts.2. Alkaloids.3. Neutral principles.4. Toxalbumins.5. Ferments. 6. Sugars, starches, and gums.7. Tannins. B. The Mixtures. 1. Fixed oils, fats, and waxes.2. Volatile oils.3. Resins.4. Oleoresins.5. Gum-resins.6. Balsams. The last three are natural exudations from plants. Alkaloids Alkaloids is a group of naturally occurring plant constituents, chemical compounds, that contain nitrogen atoms and is produced by a large variety of organisms. Alkaloid containing plants have been a part of our history for both therapeutic and recreational uses. Some well-known examples include caffeine, nicotine and cocaine. They have a variety of purposes in plants, including storage and transport of acids, antioxidant protection and anti-predation effects. Glycosides A group of sugar ethers that are usually classified according to their chemical nature because they have vast medicinal applications and found in most therapeutic plants. Some categories of glycosides include alcohol (found in the genus Salix), coumarines as mentioned below, flavanoids, cyanogenic glycosides (used a sedative and relaxant), saponins (see further down), steviol and thioglycosides. Cardio Glycosides Cardio Glycosides are an organic compound containing a sugar called glycoside that act on heart muscles. They include glycosides like digitoxin, digoxin, gitoxin. An example is Foxglove, where the leaves are used as a cardio stimulant in congestive heart failure. Minerals Minerals such as Calcium (sesame seeds, celery), Copper (cocoa), Germanium (garlic), Iodine, Iron (all green herbs), Manganese, Phosphorus (watercress), Potassium (dandelion) and Zinc (pumpkin seeds) are important in a healthy organism and preventing illness. Tannins Tannins are produced in various amounts by all plants and the harsh taste makes them unpalatable to insects and animals. They draw tissues together (in varicose veins for example) and improve resistance to infections. They can also be used to dry up excessive watery secretions (diarrhea), protect damaged tissue (skin), help to stop bleeding (in heavy menstrual flow) etc. (3). There are some safety concerns with tannins. An example is Raspberry leaves and fruit which can reduce post-partum hemorrhage, heavy menses etc. Amino Acids Amino Acids are a group of a few hundred organic compounds that consist of carbon, hydrogen, oxygen, and nitrogen elements. They are called the basic building blocks of proteins. Their sequence determines the geometric structure of the protein they create, which amazingly determines the type and function of the protein they create. They play unique and interchangeable roles in plant and animal metabolism. An example is Tryptophan, called an essential amino acid because it iss essential for human life and cannot be synthesized by ourselves (needs to be included in diet from things like chocolate, yoghurt, eggs, sesame, some seeds, bananas etc.), is the precursor for serotonin, which for example can be converted to melatonin, these play a big role in mood. Coumarins Coumarins is a substance found in many plants with a variety of different actions, including blood thinning, anti-inflammatory, anti-hypertension, antiseptic, appetite suppressing etc. A good example is Celery, which is a sedative, anti-septic, anti-fungal, anti-inflammatory, analgesic, carminative, diuretic, uricosuric, anti-rheumatic, anti-gout, antispasmodic, stimulant, hypotensive, bitter, digestive tonic, galactagogue and a uterine stimulant. The coumarin Bergapten is found in celergy seeds Mucilage Mucilage are found in many plants and are large sugar molecules that soak up water that produce jelly-like structures. They can protect against irritation, acidity and inflammation in the digestive tract (1). It is also said to absorb toxins and use for coughs and urinary spasms. Examples include Slippery Elm, Plantain, Fenugreek and Comfrey. Volatile oils Volatile oils are extracted from plants to produce various essential oils. In some plants it is the most important active constituent. According to Dr. Marciano they are a complex mixtures of many compounds and vary widely chemically. Volatile oils are usually combined with a carrier oil like olive oil or diluted in some other way with water or in foods. Some examples include lemon balm, ginger, peppermint, chamomile, ginger, eucalyptus, and garlic. Anthraquinones Anthraquinones are active constituents that have an irritant or stimulating effect on the large intestine and are usually used to relieve constipation. An example is Aloe-emodin, found in aloe latex. Flavonoids Flavonoids are distinctive and found in many plants. They have a range of actions including anti-inflammatory, cancer, anti-bacterial and cardiovascular diseases such as maintaining healthy circulation. They are found in parsley, blueberries, black tea, marigold, chamomile, hops and citrus. Marigold for example has many medicinal actions, including: anti-inflammatory, anti-spasmodic, vulnerary, demulcent, styptic, antiseptic, antiviral, antiprotozoal, anti-fungal, anti-bacterial, cholagogue, diaphoretic, lymphatic, phytoestrogenic). Saponins Saponins are found in many different plants and is either a Steroid or Triterpene fat-soluble chemical base joined to a water-soluble sugar molecule. Their actions can include include alterative, diuretic, expectorant, anti-catarrhal, anti-inflammatory, antispasmodic, aphrodisiac, antioxidant, emmenagogue, cardiac stimulant, hormone modulating, hepatoprotective, and adrenal adaptogenic effects.Liquorice / licorice and Alfalfa are two examples. Vitamins While medicinal plants usually contain vitamins there are some plants that contain a notable amount of a specific vitamin. According to various sources vitamins are organic compounds that cannot be synthesized by humans in sufficient quantities and must be obtained from diet and according to Wikipedia they are classified by their biological or chemical activity. According to the Encyclopaedia of Medicinal Plants some of the most notable plants that prevent illness through vitamins include: Vitamin A from carrots and apricots, pumpkin, spinach; Vitamin B from potatoes, bananas, green beans, asparagus, mushrooms, avocado, nuts; Vitamin C in parsley and lemon; Vitamin E from seed oils and nuts; Vitamin K from Alfalfa and other leafy green vegetables like spinach. 2.Inert Constituents The Inert Constituents are the latter are the cellulose, wood, and other structural parts of the drug, and in some instances starch, albumen, fat, wax, coloring-matter, and other substances which have no distinct pharmacologic action, though their presence in a preparation may have a modifying effect on the absorbability and activity of the active pharmacologic constituents. The chemical compounds, though present in plant and animal kingdom, which do not possess any definite therapeutic values as such, but are useful as an adjunct either in the formulation of a ‘drug’ or in surgery are collectively known as inert constituents. Examples: (a) Plant Drugs: The following inert constituents are invariably present in plants, namely: Cellulose : Microcrystalline forms of cellulose are used as combination binder disintegrants in tabletting. Colloidal cellulose particles aid in stabilization and emulsification of liquid; Lignin : To precipitate proteins, and to stablise asphalt emulsions; Suberin : Esters of higher monohydric alcohols and fatty acids; Cutin : -do- Starch : As pharmaceutic aid i.e.; tablet filler, binder and disintegrant; Albumin : Soyabean albumins–as emulsifiers; Colouring Matters : Cochineal for colouring food products and pharmaceuticals. (b) Animal Drugs: The under mentioned inert constituents are mostly present in animals, namely: Keratin : For coating “enteric pills” that are unaffected in the stomach but dissolved by the alkaline into intestinal secretions; Chitin : Deacylated chitin (chitosan)–for treatment of water; sulphated chitin– as anticoagulant in laboratory animals. It has been observed that the very presence of ‘Inert Constituents’ either act towards modifying or check the absorbance and the therapeutic index of the ‘active constituents’. Obviously, to get at the right active constituents one has to get rid of the host of ‘inert constituents’ by adopting various known methods of separation, purification and crystallization. Therefore, most literatures invariably refer to the former as ‘secondary’ plant products. The presence of these secondary plant products (active constituents) are governed by two school of thoughts, namely:  (a) Superfluous Metabolites: i.e., substances that have no value as such and perhaps their presence are due to the lack of exceretory mechanism in them and ultimately result as the ‘residual lock-up’ superfluous metabolites, and (b) Characteristic Survival Substances: i.e., substances which exert a positive survival value on the plant wherein they are actually present. They offer more or less a ‘natural defencemechanism’ whereby these host plants are survived from destruction owing to their astringent, odorous and unpalatable features. Examples: Poisonous alkaloidal containing plants; astringent containing shrubs; and pungent volatile oil-containing trees etc. 1. Genetic Composition (or Heredity): In reality, genetic effects exert both qualitative and quantitative alterations of the active constituents in medicinal plants. Examples: (i) Eugenol: It is naturally present in two different species in varying quantities as follows: Eugenia caryophyllus (Sprengel) Bullock et Harrison: 70–95% Syzgium aromaticm (L.) Merr et L.M. Perry: Not less then 85%.