ALKALOIDS

ALKALOIDS

Subject : Science & tech

Context : The Central government has decided to rope in the private sector to commence production of concentrated poppy straw from India’s opium crop to boost their yield of alkaloids, used for medical purposes and exported to several countries.

Concept :

• Alkaloids are a group of naturally occurring chemical compounds that mostly contain basic nitrogen atoms.
• This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar structure are also termed alkaloids.
• In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulphur.
• Alkaloids are produced by a large variety of organisms including bacteria, fungi, plants, and animals.
• They can be purified from crude extracts of these organisms by acid-base extraction. They have a wide range of pharmacological activities including antimalarial (e.g. quinine), antiasthma (e.g. ephedrine), anticancer etc.
• The boundary between alkaloids and other nitrogen-containing natural compounds is not clear-cut.Compounds like amino acid peptides, proteins, nucleotides, nucleic acid, amines, and antibiotics are usually not called alkaloids.

Properties

• Most contain oxygen in their molecular structure; those compounds are usually colorless crystals at ambient conditions. Oxygen-free alkaloids, such as nicotine or coniine, are typically volatile, colorless, oily liquids.
• Most have a bitter taste or are poisonous when ingested. Alkaloid production in plants appeared to have evolved in response to feeding by herbivorous animals.
• Most are weak bases.

Extraction

• Because of the structural diversity of alkaloids, there is no single method of their extraction from natural raw materials.
• Most methods exploit the property of most alkaloids to be soluble in organic solvents but not in water, and the opposite tendency of their salts.