*N-containing secondary compounds (alkaloid (Classification of alkaloids ,…
*N-containing secondary compounds
• Proper alkaloids
Also known as true alkaloids.
Nitrogen part of a heterocyclic ring system.
Derived biosynthetically from amino acids, especially the cyclic amino acids: (Phe, Tyr, Try, His )
Many physiologically active.
Have limited distributions in the plant kingdom.
• Proto alkaloids
Nitrogen atom is outside the ring system
-ephedrine sympathomimetic amine (Ephedra sp.)
colchicine (Colchicum autumnale) used in the tx of gout
• Pseudo alkaloids
Nitrogen containing (physiologically active) compounds not derived from amino acids
The purine ring is gradually elaborated by piecing together small components from primary metabolism
Types of alkaloids in terms of availability of electrons:
Electron-withdrawing group in close proximity to the nitrogen atom decrease the basicity .
Electron-donating group enhance the basicity.
-The most important nitrogen containing secondary products
-Nitrogen is usually part of a heterocyclic ring with N and C atoms.
Contain N (nitrogen) in molecule.
Can form salts with acids.
Occur in plants.
Classification of alkaloids
terpenoid indole alkaloids
Release the toxic gas hydrogen cyanide
plants must have enzymes to break down the compounds and release a sugar molecule yielding a compound that can decompose to form HCN.
glycosides and enzymes which break them down are usually spatially separated (in different cellular compartments or different tissues)
**-These compounds release volatile defensive substances, “mustard oils”, (often herbivore repellents)
Plants like cabbage, broccoli, and radishes (Brassicaceae family) have these.
Nonprotein amino acids