Convallariae Flores, Convallamarin, Convallarinum.
Synonym.—Lily of the Valley.
Convallaria flowers are obtained from Convallaria majalis, Linn. (N.O. Liliaceae), a small plant, with a perennial creeping rhizome, indigenous to England, and distributed over Europe, North America, and Northern Asia. The whole plant is collected when in flower, and dried for medicinal use, but the inflorescence is said to be the most active part of the herb and should alone be used for medicinal purposes. The inflorescence is a scape which bears three to eight pedicellate, campanulate white flowers. When dried it becomes brownish-yellow. The perianth has six recurved teeth, and bears six anthers on its inner surface. The ovary is superior and three-celled, and contains from four to six ovules in each cell, the fruit being a berry, and becoming red when ripe. The dried flowers have a slight, fragrant odour and a bitter taste. Convallaria, U.S.P., consists of the dried rhizome and roots. The rhizome is of a varying length, and about 3 millimetres thick. It is cylindrical, wrinkled, whitish, or pale brown, and marked with circular scars. The nodes are annulated and bear the scars of roots, or the long, thin, tortuous branched roots. The fracture is fibrous, and exhibits a white interior. The odour is slight, the taste sweet, yet bitter and slightly acrid. It contains the same constituents as the flowers; the average dose of Convallaria, U.S.P., is 5 decigrams (7 ½ grains).
Constituents.—The chief constituents of the drug are two glucosides, convallamarin and convallarin. Convallamarin, C23H44O12, has been obtained as a white crystalline powder with a bitter taste; convallarin, C34H62O11, is also crystalline.
Action and Uses.—Convallaria flowers are used chiefly in the form of tincture, which may be prescribed in the same manner as Tinctura Digitalis. The difference between the action of convallaria and that of digitalis has not yet been defined. An extract and a liquid extract of convallaria are also prepared.
- Extractum Convallariae, B.P.C.—EXTRACT OF CONVALLARIA.
- Best given in the form of pills. Dose.—1 to 5 decigrams (2 to 8 grains).
- Extractum Convallariae Liquidum, B.P.C.—LIQUID EXTRACT OF CONVALLARIA. 1 in 1.
- May be prescribed in mixtures when a stronger preparation than the tincture is required. Dose.—3 to 6 decimils (0.3 to 0.6 milliliters) (5 to 10 minims).
- Fluidextractum Convallariae, U.S.P.—Similar to Extractum Convallariae Liquidum, B.P.C., but prepared from the dried rhizome and roots of Convallaria majalis, Linn.
- Tinctura Convallariae, B.P.C.—TINCTURE OF CONVALLARIA, 1 in 8.
- Used for its action on the heart and circulation in the same manner as tincture of digitalis. Dose.—3 to 12 decimils (0.3 to 1.2 milliliters) (5 to 20 minims).
C23H44O12 = 512.352.
Convallamarin, C23H44O12, is a glucoside found in Convallaria majalis. It maybe obtained by boiling the entire plant first with water and then with alcohol. The extract thus obtained is freed from resinous bodies by means of lead acetate, filtered, and then precipitated with tannic acid. The tannic acid precipitate is collected and extracted with alcohol, the alcoholic solution treated with lead hydroxide, and the filtrate, after removal of lead by hydrogen sulphide, evaporated. The crude product is purified by repeated precipitation by tannic acid. It occurs as a yellowish-white, crystalline powder, with a bitter taste. It is split up by heating with diluted acids into glucose and convallamaretin. If it be moistened, and then treated with sulphuric acid, a violet colouration is produced, which disappears on the addition of water.
Soluble in water or alcohol, slightly soluble in ether; insoluble in chloroform or amyl alcohol.
Action and Uses.—Convallamarin has a digitalis-like action on the heart and circulation. It is used as a cardiac tonic and diuretic, and has been recommended as more uniform and certain in its action than tincture of convallaria (see Convallariae Flores). It may be administered in pills; or in a solution for hypodermic use containing 10 milligrams (⅙ grain) in 6 decimils (0.6 milliliters) (10 minims). In cases of poisoning by convallamarin, administer emetics, and use the stomach-pump; atropine and the nitrites may prove useful.
Dose.—1 to 9 centigrams (⅙ to 1 ½ grains); subcutaneously, 5 to 20 milligrams (1/12 to ⅓ grain).
C34H62O11 = 646.496.
Convallarin, C34H62O11, is a glucoside found in Convallaria majalis, and may be obtained from the alcoholic extract of the residue from which the convallamarin has been removed with water. The alcoholic solution is treated with lead acetate, the filtrate freed from lead by hydrogen sulphide, and crystallised by concentration. It occurs in the form of rectangular prisms, or as a crystalline powder, and has an acrid taste. An aqueous solution froths like soap and water when shaken. By long boiling with diluted acids it is split up into sugar and convallaretin, which separates in crystalline form, and is soluble in ether.
Slightly soluble in water, freely soluble in alcohol; insoluble in ether.
Action and Uses.—Convallarin causes gastric pain, nausea, and diarrhoea; it is very little used.
Dose.—1 to 3 decigrams (2 to 5 grains).