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Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral〔(IUPAC. Compendium of Chemical Terminology ), 2nd ed. (The "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997) ISBN 0-9678550-9-8 〕 and even weakly acidic properties.〔R. H. F. Manske. ''The Alkaloids. Chemistry and Physiology''. Volume VIII. – New York: Academic Press, 1965, p. 673〕 Some synthetic compounds of similar structure are also termed alkaloids.〔Robert Alan Lewis. (''Lewis' dictionary of toxicology'' ). CRC Press, 1998, p. 51 ISBN 1-56670-223-2〕 In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and, more rarely, other elements such as chlorine, bromine, and phosphorus.〔(Chemical Encyclopedia: alkaloids ). xumuk.ru〕 Alkaloids are produced by a large variety of organisms including bacteria, fungi, plants, and animals. They can be purified from crude extracts of these organisms by acid-base extraction. Alkaloids have a wide range of pharmacological activities including antimalarial (e.g. quinine), antiasthma (e.g. ephedrine), anticancer (e.g. homoharringtonine), cholinomimetic (e.g. galantamine), vasodilatory (e.g. vincamine), antiarrhythmic (e.g. quinidine), analgesic (e.g. morphine), antibacterial (e.g. chelerythrine), and antihyperglycemic activities (e.g. piperine). Many have found use in traditional or modern medicine, or as starting points for drug discovery. Other alkaloids possess psychotropic (e.g. psilocin) and stimulant activities (e.g. cocaine, caffeine, nicotine), and have been used in entheogenic rituals or as recreational drugs. Alkaloids can be toxic too (e.g. atropine, tubocurarine). Although alkaloids act on a diversity of metabolic systems in humans and other animals, they almost uniformly evoke a bitter taste. The boundary between alkaloids and other nitrogen-containing natural compounds is not clear-cut.〔Robert A. Meyers ''Encyclopedia of Physical Science and Technology'' – Alkaloids, 3rd edition. ISBN 0-12-227411-3〕 Compounds like amino acid peptides, proteins, nucleotides, nucleic acid, amines, and antibiotics are usually not called alkaloids.〔 Natural compounds containing nitrogen in the exocyclic position (mescaline, serotonin, dopamine, etc.) are usually classified as amines rather than as alkaloids.〔Leland J. Cseke (Natural Products from Plants ) Second Edition. – CRC, 2006, p. 30 ISBN 0-8493-2976-0〕 Some authors, however, consider alkaloids a special case of amines.〔A. William Johnson (Invitation to Organic Chemistry ), Jones and Bartlett, 1999, p. 433 ISBN 0-7637-0432-6〕〔Raj K Bansal (A Text Book of Organic Chemistry ). 4th Edition, New Age International, 2004, p. 644 ISBN 81-224-1459-1〕〔Aniszewski, p. 110〕 ==Naming== The name "alkaloids" ((ドイツ語:Alkaloide)) was introduced in 1819 by the German chemist Carl Friedrich Wilhelm Meißner, and is derived from late Latin root ''(ラテン語:alkali)'' (which, in turn, comes from the Arabic ''al-qalwī'' – "ashes of plants") and the suffix ''(ギリシア語:-οειδής)'' – "like".〔In the penultimate sentence of his article – W. Meissner (1819) "Über Pflanzenalkalien: II. Über ein neues Pflanzenalkali (Alkaloid)" (On plant alkalis: II. On a new plant alkali (alkaloid)), ''Journal für Chemie und Physik'', 25 : 379–381 ; available on-line at: (Hathi Trust ) – Meissner wrote: "''Überhaupt scheint es mir auch angemessen, die bis jetzt bekannten Pflanzenstoffe nicht mit dem Namen Alkalien, sondern Alkaloide zu belegen, da sie doch in manchen Eigenschaften von den Alkalien sehr abweichen, sie würden daher in dem Abschnitt der Pflanzenchemie vor den Pflanzensäuren ihre Stelle finden''." (In general, it seems appropriate to me to impose on the currently known plant substances not the name "alkalis" but "alkaloids", since they differ greatly in some properties from the alkalis; among the chapters of plant chemistry, they would therefore find their place before plant acids ("Alkaloid" would precede "Säure" (acid) ).)〕 However, the term came into wide use only after the publication of a review article by Oscar Jacobsen in the chemical dictionary of Albert Ladenburg in the 1880s.〔Hesse, pp. 1–3〕〔Oscar Jacobsen, "Alkaloide" in: Ladenburg, ''Handwörterbuch der Chemie'' (Breslau, Germany: Eduard Trewendt, 1882), vol. 1, (pp. 213–422 ).〕 There is no unique method of naming alkaloids.〔Hesse, p. 5〕 Many individual names are formed by adding the suffix "ine" to the species or genus name.〔The suffix "ine" is a Greek feminine patronymic suffix and means "daughter of"; hence, for example, "atropine" means "daughter of Atropa (belladonna)": (Development of Systematic Names for the Simple Alkanes ). yale.edu〕 For example, atropine is isolated from the plant ''Atropa belladonna'', strychnine is obtained from the seed of Strychnine tree (''Strychnos nux-vomica'' L.).〔 If several alkaloids are extracted from one plant then their names often contain suffixes "idine", "anine", "aline", "inine" etc. There are also at least 86 alkaloids whose names contain the root "vin" because they are extracted from vinca plants such as ''Vinca rosea'' (''Catharanthus roseus'');〔Hesse, p. 7〕 these are called vinca alkaloids. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alkaloid」の詳細全文を読む スポンサード リンク
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