sources of drugs
In this blog we describe about sources drugs, what is the sources of drugs present in nature, in this blog, we are the going know about the sources of medicine, from were do we get medicines that we eat. So let us read the blog till the end to know about the sources of drugs.
What are the sources of drugs?
Drugs are obtained from a variety of sources like; plants, animals, microbes, minerals, synthetic chemistry, biotechnology etc.
• Drugs obtained from plants: many plants contain substances and are the oldest source of drugs. Clues about medicinal plants were obtained from traditional system of medicine prevalent in various parts of the world; e.g. use of opium, belladonna, ephedra, cinchona, curare, foxglove, sarpagandha, qinghaosu has been learnt from Egyptian, Greek, Aztec, ayurvedic, Chinese and other systems of medicine.
A. Chemically the active ingredients of plants:
1. Alkaloids: These are alkaline nitrogenous bases having potent activity and are the most important category of vegetable origin drugs, prominent examples are; morphine, atropine, nicotine, ergotamine, reserpine, quinine, vincristine, etc.
2. Glycosides: These compounds consists of a heterocyclic nonsugar moiety through ether linkage, cardiac glycosides (digoxin, ouabain) are the best known glycosidic drugs. The active principal of Senna and similar plant purgatives are anthraquinone glycosides. Aminoglycosides (gentamicin, etc.) are antibiotic obtained from microorganisms, and have an aminosugar in place of a sugar moiety.
3. Oils: These are viscous, inflammable liquids, insoluble in water. Fixed ( non-volatile) oils are calorie yielding triglycerides of higher fatty acids; mostly used for food and as emollients, e.g. groundnut oil, coconut oil, sesame oil, etc. Castor oil is a stimulant purgative. Essential (volatile) oils, mostly obtained from flowers or leaves by steam distillation are aromatic (fragrant) terpene hydrocarbons that have no food value. They are used as flavouring agents, carminatives, counterirritants and astringents; example are eucalyptus oil, pepermint oil, nilgiri oil, etc. Clove oil is used to allay dental pain. Menthol, thymol, camphor are volatile oils are solid at room temperature.
Mineral oil are not plant products, but obtained from petroleum; liquid paraffin is a lubricant laxative, soft and hard paraffin are used as emollient and as ointment bases.
B. Animals: Though animal parts have been used as cure since early times, it was exploration of activity of organ extracts in the late 19th and early 20th century that led to introduction of animals products into medicine, e.g. adrenaline, thyroxine, insulin, liver extracts (vit. B12). Antisera and few vaccines are also produced from animals.
C. Microbes: Most antibiotics are obtained from fungi, actinomycetes and bacteria, e.g. penicillin, gentamicin, tetracycline, erythromycin, polymyxin B, actinomycin D (anticancer). Some enzymes, e.g. diastase from a fungus and streptokinase from streptococci have a microbial source. Vaccines are produced by the use of microbes.
D. Minerals: Few minerals, e.g. iron salts, calcium salts, lithium carbonate, magnesium / aluminum hydroxide, iodine are used as medicinal substances.
F. Synthetic chemistry: made its debut in this 19th century, and is now the largest source of medicine. Synthetic drugs have advantage of purity and uniformly of the product. They can be manufactured in any quantity as per need. In contrast to drugs from nature sources whose availability may be limited. Not only diverse congeners of naturally obtained drugs (atropine substitutes, adrenergic beta2 agonists, synthetic glucocorticoids / progestins / cephalosporin s, etc.) have been introduced to achieve greater selectivity of action or even novel types of activity, but many entirely synthetic families of drugs, e.g. benzodiazepines, thaizides, benzimidazoles, fluoroquinolones, etc. etc. have been produced. Many drugs are being synthesized to target specific biomolecules, e.g. ACE inhibitors, glycoproteins llb / llla receptor antagonists, HIV-reverse transcriptase inhibitors, etc. Synthetic drugs that are chiral can also be produced as single active enantiomers products, which may be therapeutically superior.
G. Biotechnology: several drugs, especially peptides and proteins are now produced by recombinant DNA technology, e.g. human growth hormone, human insulin, altaplase, interferon, etc. Monoclonal antibodies, regulator peptides, erythropoietin and other growth factors are the newer drugs of biotechnological origin. Protein therapeutics is rapidly expanding, because specifically designed and customized proteins can not be produced.
0 टिप्पणियाँ