Related entries: Opium - Poppy Capsules - Cotarnine - Cotarnine Hydrochloride - Morphine - Morphine Acetate - Morphine Hydrochloride - Morphine Sulphate - Morphine Tartrate - Narceine - Narcotine - Red poppy petals - Meconic acid
C22H23NO7 = 413.194.
Narcotine, C19H14(OCH3)3NO4, is an alkaloid obtained from opium, in which it exists to the extent of 2 to 10 per cent., for the most part in the free state. It may be obtained directly from opium with ether, or extracted by digesting with diluted hydrochloric acid the residue left after exhausting opium with water; this solution is precipitated with sodium carbonate, the precipitate obtained boiled with alcohol, and the alcoholic solution concentrated and allowed to crystallise. It occurs in the form of colourless, odourless, tasteless, shining, rhombic prisms, or long needles. Its acid solutions taste bitter, and are dextrorotatory; the neutral solutions are laevorotatory. Melting-point, 176°. At a higher temperature, narcotine is decomposed with evolution of ammonia. On ignition, it should leave no residue. With concentrated sulphuric acid, the alkaloid dissolves with a greenish-yellow colour, which on warming becomes red, and on boiling, violet. Nitric acid produces a yellow-coloured solution. Concentrated sulphuric acid containing a trace of nitric acid produces a blood-red colour. If narcotine be shaken with a 5 per cent. solution of sodium hydroxide and filtered, the filtrate should not, on the addition of ammonium chloride, show a separation of crystals after twenty-four hours (absence of morphine). When shaken with a 2 per cent. solution of acetic acid (in which it is insoluble), and the mixture filtered, the filtrate on evaporation should not leave any residue (absence of the other alkaloids of opium).
Insoluble in water; soluble in ether, boiling alcohol, acetic ether, chloroform; soluble to some extent in benzol (distinction from morphine, which is quite insoluble); soluble in diluted mineral acids; insoluble in cold, but soluble in boiling alkaline solutions.
Action and Uses.—Narcotine has at first a mildly depressant action upon the cerebral hemispheres. This effect is like that of morphine on the sensory cells, but it is much less decided than that of morphine; this action is followed by exaggerated reflexes due to stimulation of the spinal cord, resulting in restlessness and tremors. It is probable that the convulsions and pronounced excitement, which have at times been noted when a patient addicted to opium has received a large dose from a new batch, is due to the opium containing an excessive amount of narcotine. Narcotine has been recommended for use as an antiperiodic in place of quinine in ague, but is rarely employed in medicine. It is much less poisonous than either morphine or codeine. Its chief significance depends on the fact that large amounts are present in some varieties of opium. It is used in the preparation of cotarnine.
Dose.—½ to 2 decigrams (1 to 3 grains).