Related entries: Opium - Poppy Capsules - Cotarnine - Cotarnine Hydrochloride - Morphine - Morphine Acetate - Morphine Hydrochloride - Morphine Sulphate - Morphine Tartrate - Narceine - Narcotine - Red poppy petals - Meconic acid
C28H27NO8, 3H2O = 499.274.
Narceine, C23H27NO8, 3H2O, is an alkaloid obtained from opium, by adding excess of sodium acetate to a solution of the opium bases in hydrochloric acid, and allowing to stand for twenty-four hours; the filtrate evaporated to a small bulk on a water-bath deposits narceine on standing. It exists in opium to the extent of 0.1 to 0.2 per cent. It occurs in odourless, white prisms, or fine, silky needles, having a slightly bitter taste. Its solution in hot water is neutral and optically inactive. Melting-point, 170°; the anhydrous base melts at 140° to 145°. On ignition, it leaves no residue. Concentrated sulphuric acid dissolves it with a greenish-brown colouration, slowly changing to cherry-red on standing, more quickly on warming. A mixture of solutions of potassium ferricyanide and ferric chloride is not immediately coloured blue by narceine (absence of morphine). With nitric acid it gives a rapidly fading yellow colour. Very weak iodine solution (about 1 in 500) gives a dark blue colour. Narceine is precipitated by solutions of iodine in potassium iodide, mercuric potassium iodide, bismuth potassium iodide, and tannic acid. With chlorine water, followed by ammonia, a bluish-red colouration is produced. On adding diluted sulphuric acid to the solid narceine, and concentrating on a water-bath, a violet colouration is produced, changing to cherry-red on further heating; this, when cold, yields, on the addition of a trace of nitric acid or potassium nitrate, streaks of a blue-violet colour.
Slightly soluble in water, readily in hot water; slightly soluble in alcohol, readily in hot alcohol; insoluble in ether, and almost insoluble in chloroform, petroleum ether, or benzol; somewhat soluble in solution of ammonia, and in diluted solution of potassium hydroxide.
Action and Uses.—Narceine has a weak morphine-like action, but is not much used in medicine. It may be administered in a pill, as a mild hypnotic and to allay cough; it is less depressant than morphine and does not constipate.
Dose.—3 to 6 centigrams (½ to 1 grain).