Alkaloids - nitrogen-containing organic compounds main character, nature, usually of plant origin. Alkaloids have the physiological activity, toxic, but in certain doses (in the form of salts) are widely used as medicines, such as nicotine, atropinum, quinine, papaverine, morphine, codeine, strychnine, caffeine. Symptoms of poisoning with alkaloids and first aid - see Poisoning.

Alkaloids (from the Arabic al-kali - plant ash, caustic and Greek. eidos - view) - nitrogen-containing organic compounds of natural (usually of plant origin the main character. A. have a high physiological activity and are widely used as medicines. Several analogues of the A. (novocaine, Akrikhin, and others) are synthetically and used as medicines.
The main criteria of classification A. it is considered the structure of the nitrogen-containing part of the molecule.
The most important group of alkaloids: derivatives of pyridine - lobelin (see), nicotine; derivatives Trapani - atropine (see), cocaine (see); derivatives of quinoline - quinine (see); derivative of isoquinoline alkaloids group opium - papaverine (see), narcotine, morphine (see), codeine (see), emetine (see); derivative indole - ezerin (see Physostigmine), strychnine (see); A. LPV (see) - ergotamine, ergotoxin, ergometrine; imidazole derivatives - pilocarpine (see); purine derivatives - caffeine (see), theobromine (see), theophylline (see); derivative pyrrolizidine - platifillin (see); acyclic A. - ephedrine (see), sperisen (see); group Aconitum A. - kondelin (see), Latin (see) and others For qualitative detection A. use the method of chromatography on paper. Many A. provide staining with hydrochloric, nitric and sulphuric acids.