Alkaloids
"Alkaloids are classified according to the amino acid that provides both the nitrogen and the fundamental portion of the alkaloid skeleton. [Amino acid] Ornithine gives rise to pyrrolidine and tropane alkaloids, lysine to piperdine, quinolizidine, and indolizidine alkaloids, and nicotinic acid to pyridine alkaloids. Tyrosine produces phenylethylamines and simple tetrahydroisoquinoline alkaloids, but also many others in which phenolic oxidative coupling plays an important role, such as modified benzyltetrahydroisoquinoline, phenethylisoquinoline, terpenoid tetrahydroisoquinoline, and Ameryllidaceae alkaloids. Alkaloids derived from tryptophan are subdivided into simple indole, simple beta-carboline, terpenoid indole, quinoline, pyrroloindole, and ergot alkaloids. Anthranilic acts as a precursor to quinazoline, quinoline and acridine alkaloids, whist histidine gives imidazole derivatives. However, many alkaloids are not derived from an amino acid core, but arise by amination of another type of substrate, which may be acetate derived, phenylalanine derived, a terpene or steroid. Purine alkaloids are constructed by pathways that resemble those for purines in nucleic acids." Excerpt from Medicinal Natural Products by Paul M. Dewick
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Quinine has a fascinating history, as well as being a versatile catalyst and ligand in asymmetric synthesis. Quinine, which is isolated from cinchona tree bark, is used in tonic water and was used as a treatment for malaria. Quinine is an excellent framework for use as a base in designing chiral catalysts. Quinine is part of the Cinchona alkaloid family, which consists of quinine's diastereomer quinindine, and another set of diastereomers, cinchonidine and cinchonine, which are missing the methoxy group off of the quinoline ring. For an original poem on quinine, click here.
Morphine is isolated from the opium poppy Papaver somniferum and is a powerful analgesic and narcotic. Morphine is valuable medicinally for relief of severe pain; however, users typically develop physical dependence.
Links to Alkaloid Information
Biosynthesis and More from Staffordshire University
Alkaloids Page from Botany Online
Plants That Make You Loco-Mind Altering Plant Alkaloids
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