| 释义 |
alkaloid Chem.|ˈælkəlɔɪd|
[mod. f. alkali + -oid. Cf. mod.Fr. alcaloïde.]
A body resembling an alkali in properties. Applied gen. to all nitrogenous basic substances, natural or artificial, with alkaline reaction (Nitrogen alkaloids), or to all nitrogenous organic bases, whether animal or vegetable (Organic alkaloids); spec. to the Vegeto-alkaloids or Vegetable alkalis, a series of highly complex organic bases found in many plants, having mostly a very bitter taste, and powerful action on the animal system, the first of which to be discovered was morphine in 1817. Chemically they may be regarded as substitution compounds of ammonia. (The names of organic alkaloids are regularly formed in -ine, as nicotine, strychnine, quinine, aconitine, theine.)
1831Ure Dict. Chem. 135 They are called by the German chemists alkaloids. 1833Penny Cycl. I. 158 The detection of the alkaloids in cases of poisoning by them. 1863Watts Dict. Chem. (1879) I. 120 The number of natural alkaloids now known is very great, and includes many substances which cannot in any strict sense be called alkalis. 1874Roscoe Elem. Chem. 427 The alkaloids act most powerfully on the animal economy; some, such as strychnine, nicotine, &c., form the most violent poisons with which we are acquainted, whilst others, such as quinine and morphine, act as most valuable medicines.
2. attrib. or adj.
1859in Worcester. 1882T. Stevenson in Echo 11 Mar. 3/2 An alkaloid extract which contained a trace of morphia. |