The leaves and flowering tops of Melilotus officinalis, Willdenow (Melilotus vulgaris, Eaton and Wright; Trifolium officinale, Linné).
COMMON NAMES: Sweet clover, Yellow melilot, Yellow melilot clover.
ILLUSTRATION: Johnson, Med. Bot. of N. A., Fig. 120.
Botanical Source, History and Description.—Yellow melilot has an erect, sulcate stem, about 3 (2 to 4) feet high, with spreading branches. The leaves are pinnately trifoliate; the leaflets obovate-oblong, obtuse and Smooth, with remote, mucronate teeth. The flowers are yellow, in one-sided, spicate, axillary, loose, paniculate racemes; the calyx half as long as the corolla; the legume ovoid and 2-seeded. The petals in this species are of about equal length. It is an indigenous annual, growing in alluvial meadows, and flowering in June. The whole plant is scented, having nearly the odor of the sweet-scented vernal grass, Anthoxanthum odoratum. The taste of the plant, when dried, is somewhat pungent, aromatic, and bitterish. A closely related species, the Melilotus officinalis of Desrousseaux (M. diffusa, Koch; M. arvensis, Walroth) of Europe, is collected also with the foregoing species. It has light-yellow flowers having short carinas, while the fruit is a transversely-rugose, obovate, usually 1-seeded legume. An American species, having white flowers, probably has virtues similar to yellow melilot. It is the Melilotus alba, Lamarck (Melilotus officinalis, Pursh; Melilotus officinalis, var. alba, Nuttall; Melilotus leucantha, Koch). In this species the standard is longer than the other petals. It is known as White melilot, White melilot clover, or Sweet-scented clover, and is a biennial, with an erect, robust, very branching, sulcate stem, 4 to 6 feet high. The leaflets are variable, oval, ovate, ovate-oblong, truncate, and mucronate at the apex, remotely serrate, and 1 or 2 inches long; stipules setaceous. The flowers are white, numerous, the racemes more loose and longer than in the first species. The petals are unequal, the banner longer than wings or keel, and the calyx shorter than the corolla by more than one-half. This plant grows in similar situations with M. officinalis, flowering in July and August, and having a sweet fragrance, which is improved upon being dried—(W.).
Chemical Composition.—The characteristic constituent of melilotus is the aromatic, crystallizable coumarin (C9H6O2), which is the anhydrid of ortho-coumaric acid (C6H4OH.CHCHCOOH). The latter, and hydrocoumaric (melilotic) acid (C6H4OH.CH2CH2COOH) likewise occur in the plant. Cumarin forms with melilotic acid a crystallizable compound (Zwenger and Bodenbender). Melilotol of Phipson (1875), is a volatile oil, probably the anhydrid (lactone) of melilotic acid. As much as 0.2 per cent has been obtained by distilling the fresh herb with water. Chenopodin, a crystallizable principle occurring quite frequently in various plants, was observed by Reinsch (1867) as a deposit from an alcoholic extract of Melilotus alba; it is probably identical with leucin (amido-caproic acid, C5H10NH2COOH) (Flückiger, Pharmacognosie, 1891).
Coumarin is also the odoriferous principle of many other plants, occurring, e. g., in Tonka beans where it was first discovered; in Liatris, Asperula odorata, etc. (see list of coumarin-bearing plants in Husemann and Hilger, Pflanzenstoffe, p. 1037). It was found in melilotus only in small quantity (about 0.04 per cent, in combination with melilotic acid). Coumarin is now obtained synthetically by the action of acetic anhydrid and sodium acetate upon the sodium compound of salicylic aldehyde (C6H4OHCHO). It forms hard, colorless prisms, melting at 67° C. (152.6° F.), and boiling at 291° C. (608° F.). It sublimes, however, at ordinary temperature, in the form of white needles; sometimes it is found in crystals on the herb. Coumarin is soluble in ether, volatile and fatty oils, in acetic and tartaric acids, also soluble in boiling alcohol, and requires 400 parts of cold, and 45 parts of hot water for solution. Hot alkalies convert it into ortho-coumaric acid.
Ɣ Action, Medical Uses, and Dosage.—Melilotus (species), placed between woolen clothing, is used in Europe to guard against the ravages of the moth. The medicinal properties of melilotus are undoubtedly chiefly due to coumarin. Ɣ Many observers have found it peculiarly effective in certain painful disorders, particularly neuralgias of long standing and associated with debility. It is adapted to idiopathic neuralgic headaches, and to neuralgic affections not depending upon reflex causes, although it has given good results in headaches arising from painful disorders of the stomach. Recurring neuralgia, especially from cold or fatigue, have been promptly relieved by small doses of the drug. It relieves ovarian neuralgia sometimes as if by magic, and in dysmenorrhoea its beneficial effect is observed when lameness and soreness are prominent symptoms, and particularly when the trouble seems to follow the great sciatic nerve. Rheumatic cases, showing marked lameness, are also said to be cases for its exhibition. It is likewise of value in painful dysuria, colic, painful diarrhoea, and menstrual colic. Gastralgia, neuralgia of the stomach, and other abdominal viscera, have been promptly relieved by it, and a prominent symptom in these disorders, that has been met by the drug, is the coldness of the extremities. We should remember melilotus in painful states, with coldness, and marked soreness or tenderness to the touch. Dose of specific melilotus, 1 to 10 drops; of a strong tincture, 1 to 20 drops. The leaves and flowers of these two plants (M. officinalis and M. alba) are boiled in lard, and formed into an ointment, which is found of utility as an application to all kinds of ulcers. The Vanilla, or Seneca grass, used for a stimulant purpose, is the Hierochloë borealis.
Specific Indications and Uses.—Idiopathic headaches; long-standing neuralgias; coldness, tenderness, lameness or marked soreness of parts; painful menstruation with lameness or sensation of cold; menstrual colic; ovarian neuralgia; colic with diarrhoea and much flatus.
Related Drugs.—TONKA BEANS. These are derived from the Dipteryx odorata, Willdenow (Coumarouna odorata, Aublet, a large, papilionaceous tree inhabiting Guiana. The fruit consists of an oblong-ovate, 1-seeded legume. The seed, or part employed, is somewhat 2-edged, appearing compressed, blackish-brown in color, and has a brittle, shining, or fatty-like skin, is deeply rugose, and has an oily, pale-brown kernel. The seeds possess an aromatic, bitterish taste, and a balsamic, agreeable, vanilla-like odor. The chief constituent, and the one upon which its odor depends, is coumarin (see Melilotus), which is often found between the two halves of the seeds, and upon the surface, as an efflorescence. Coumarin was first observed in Tonka beans, in 1820, by Vogel, who held it to be benzoic acid. Guibourt soon afterward declared it to be a different substance, and gave it its present name. Tonka beans are about 2 inches long. A variety known as English Tonka beans, are smoother, smaller, and do not contain as much coumarin as the preceding, 108 grains having been yielded by 1 pound of true Tonka beans. The English Tonka bean is the seed of Dipteryx oppositifolia, Willdenow. Tonka depends undoubtedly upon coumarin for its virtues. Pronounced narcotic effects have been observed from coumarin, which is also a cardiac stimulant, and finally paralyzes the heart. Dr. Laurence Johnson attributes the evil effects of cigarette smoking to this principle, for among the substances used in preparing cigarettes are plants containing coumarin, notably Liatris odoratissima. A fluid extract of Tonka bean has been used in pertussis.
FAHAM LEAVES.—The leaves of Angraecum fragrans, belonging to the Orchidaceae. They have a strong and delicious aroma, and a sharp, aromatic taste. Introduced at one time in France as a substitute for ordinary tea. Fifteen grains are infused in a cup of cold water, brought to a boil for 10 minutes, poured into a closed container, and sweetened when partaken of. It comes from Mauritius and the Isle of Reunion, and contains coumarin.