Amines as Natural Products

The ease with which amines are extracted into aqueous acid, combined with their regeneration on treatment with base, makes it a simple matter to separate amines from other plant materials, and nitrogen-containing natural products were among the earliest organic compounds to be studied. Because of their basic properties, amines obtained from plants were called alkaloids. The number of known alkaloids now exceeds 5000. They are of special interest because most are characterized by a high level of biological activity. Some examples include cocaine, coniline, and morphine.

Many alkaloids, such as nicotine and quinine, contain two (or more) nitrogen atoms.

Several naturally occurring amines mediate the transmission of nerve impulses and are referred to as neurotransmitters. Two examples are epinephrine and serotonin. (Strictly speaking, these compounds are not classified as alkaloids, because they are not isolated from plants.)