Akademik

   The term alkaloid is indebted to the Latin noun alkali, which in turn stems from the classic Arabic expression al qily, commonly translated as 'he roasted', or 'he grilled'. The expression al qily is said to refer to the scorched ashes of the hairy seablite (i.e. Bassia hirsuta). In biology and biochemistry, the term alkaloid is used as an umbrella term for one of the largest and most diverse groups of secondary metabolites occurring in living organisms. Among the 50,000 or so known natural products, over 12,000 substances are classified as alkaloids. They are defined by the American chemist S. William Pelletier as follows: "An alkaloid is a cyclic compound containing nitrogen in a negative oxidation state which is of limited distribution in living organisms." Using the criterion of psychoactive effect as a guiding principle, alkaloids possessing hallucinogenic properties (when administered in a sufficiently high dose) have been classified as * deliriants. Many — although certainly not all — alkaloids are derived from amino acids. Traditionally, they have been isolated from flowering plants. However, they are also known to occur in micro-organisms, marine invertebrates, insects, and higher animals. Due to their chemical structure, some of the biologically active alkaloids are able to bind to, and interact with, the receptors of neurotransmitters in humans. Thus some of them have the potential to stimulate or inhibit the action of chemical transmitter substances in the CNS such as acetylcholine, epinephrine, nore-pinephrine, gamma-amino butyric acid (GABA), dopamine, and serotonin. Alkaloids have been used since ancient times as poisons, potions, therapeutics, * entheogens, * hallucinogens, and for many other purposes. Assyrian clay tablets from around 2,000 BC are indicative of an early knowledge of alkaloid-containing plants such as Papaver somniferum, Atropa belladonna, and Mandragora officinarum. Some of the alkaloids traditionally used as arrow poisons in Africa and South America have proved to be potent therapeutics. Ouabain and k-strophantin are used to treat acute cardiac insufficiency, quinine to prevent as well as treat malaria, physostig-mine to treat glaucoma and myasthenia gravis, * reserpine to manage hypertension, and ajma-line to treat cardiac arrhythmias. Some well-known alkaloids that are used for both therapeutic and recreational purposes are caffeine (an alkaloid of the purine group), nicotine (pyri-dine group), opium (isoquinoline group), mescaline and amphetamine (phenethylamine group), and psilocybin, dimethyltryptamine (DMT), and bufotenine (indole group). A person intentionally employing alkaloids for the purpose of exploring the psyche may be called a * psychonaut.

   References

   Pelletier, S.W., ed. (1983). Alkaloids: Chemical and biological perspectives. Volume 1. New York, NY: Wiley.

   Roberts, M.F., Wink, M. (1998). Alkaloids. Biochemistry, ecology, and medicinal applications. New York, NY: Plenum Press.