Alkaloids Derived from Histidine

Alkaloids Derived from Histidine:-
The amino acid L-histidine, containing the heterocyclic imidazole ring, is considered to be the right precursor of alkaloids that essentially comprise of this ring-system. A good number of Pilocarpus species, belonging to family Rutaceae, found to contain plethora of alkaloids with an imidazole ring, namely: pilocarpine, isopilocarpine, and pilosene. Pilocarpine constitutes 0.5-1.0% of the dried leaf material. Isopilocarpine appears to vary significantly within a range from 5 to 7.5% of the total alkaloids.
“Jaborandi” is the name of the crude drug prepared from the evergreen plants Pilocarpus jaborandi and Pilocarpus pinnatifolius, (Rutaceae family) which grow wild in South America, especially in Brazil. In South America, 13 plants in this genus are known, and all are used as the material for “Jaborandi,” which is important as the material for the extraction of pilocarpine.
Pilocarpine is a natural alkaloid extracted from plants of the genus Pilocarpus with cholinergic agonist activity. As a cholinergic parasympathomimetic agent, pilocarpine predominantly binds to muscarinic receptors, thereby inducing exocrine gland secretion (it promotes the secretion of sweat, saliva, and tears ) and stimulating smooth muscle in the bronchi, urinary tract, biliary tract, and intestinal tract. When applied topically to eyes, this agent stimulates the sphincter pupillae to contract, resulting in miosis; stimulates the ciliary muscle to contract, resulting in spasm of accommodation and an increase in the outflow of aqueous humor.