The main sources of organic compounds are plant and animal kingdoms. Organic compounds are isolated from these two natural sources by solvent extraction followed by purification. These two sources are again converted naturally into petroleum oil, natural gas and coal. Now-a-days synthesis is the most important source of organic compounds. So, the sources of organic compounds, in short, are-
- Plants and animals: By using suitable methods of isolation most of the organic compounds were obtained directly from plants and animals in the past and at present, these methods are continuing. The compounds which are obtained from these sources are—
Carbohydrates: Cellulose, starch, sugar, lactose etc.
Protein: Food proteins, wool, silk, casein etc.
Fats and oils: Cottonseed, soya bean oil, lard, butter etc.
Alkaloids: Quinine, morphine, ephedrine etc.
Perfumes: Citral, limonen, mascone etc.
Vitamins: Vit. C, B2, B6, etc.
Hormones, Resins, rubber etc.
- Petroleum oil and natural gas: Hundreds of hydrocarbons such as methane, octane, kerosene, petrol, benzene, toluene and other petrochemicals are obtained which are further used as raw materials of polymers, plastics, synthetic rubber, explosives etc. The main energy source, fuel is obtained from natural gas and crude petroleum oil. Urea is a good example which is obtained from natural gas in our
- Coal: Another fossil fuel coal is the major source of organic compounds, coal-tar are raw materials of many aromatic compounds.
- Synthesis: Many useful organic compounds including drugs, vitamins, plastics, dyes etc. are prepared from simple raw materials by multistep synthesis.