This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
Other constituents are a glucosidal acid, ipecacuanhic acid, allied to quillajic acid, calcium oxalate and an abundance of starch.
Emetine, C15H12N02, is a while amorphous alkaloid which darkens on exposure to light, gradually assuming a yellow colour; it yields crystalline salts and has been shown to be methyl-cephaeline, but is less powerfully emetic and about half as toxic as cephaeline. It constitutes about 72 per cent, of the total alkaloid.
Cephaeline, C14H10NO2, crystallises in white, silky needles, but yields un-crystallisable salts; though a more powerful emetic, it is a less efficacious expectorant than emetine. It constitutes about 26 per cent, of the total alkaloid.
Psychotrine exists in small quantity only (about 2 per cent, of the total alkaloid).
1. Matto Grosso: this is the variety above described.
2. Minas: Minas ipecacuanha is the produce of the plant cultivated in the province of Minas Geraes; it very closely resembles the Matto Grosso variety, but usually bears evidence of careful cleaning.
3. Indian or East Indian: this variety also closely resembles the Matto Grosso, but is usually distinctly larger and brighter in colour. It contains about the same amount of total alkaloid.
Cartagena Ipecacuanha. This variety is imported from Colombia; it is distinguished from the Brazilian drug by being usually of larger size and by the annulations which in this case assume the form of narrow, distinct, transverse, raised ridges arranged at a little distance from one another, and the root does not therefore assume the appearance of a number of discs strung together. The starch grains are also rather larger than those of Brazilian ipecacuanha. The drug has been attributed to Psychotria acuminata, Karsten, but definite evidence on this point has not yet been adduced. Cartagena ipecacuanha contains the same alkaloids as Brazilian, and about the same amount. The chief difference in this respect lies in the proportion in which each of the alkaloids emetine and cephaeline is present rather than in the amount of total alkaloid contained in the root. In Cartagena ipecacuanha the emetine amounts to only 40 per cent, of the total alkaloid, whilst the cephaeline reaches as much as 57 per cent.; in other words, it contains twice as much of the latter alkaloid as the Brazilian root, and its physiological action is therefore much more emetic and less expectorant. For this reason the Cartagena variety has been excluded from the Pharmacopoeia.
Ipecacuanha is largely used as an expectorant and emetic; it also possesses diaphoretic and cholagogue properties. One of its most important uses is as a remedy for dysentery, for which purpose large doses are given (30 to 90 grains). In such cases a remarkable tolerance of the drug is often readily established, or the drug deprived of its alkaloids (de-emetinised ipecacuanha) is administered.
Ipecacuanha Stem. Much of the Brazilian drug is imported mixed with the stems of the plant. These are slender and longitudinally-striated, exhibiting no annulations. The transverse section shows a thin bark surrounding a ring of wood within which is a distinct pith. They contain less alkaloid than the root, various assays yielding from 0.97 to 1.8 per cent., and should therefore be excluded from the drug.
Fig. 167. - Undulated Ipecacuanha (Richardsonia sp.). A, root, natural size. B, transverse section, magnified, showing porous wood. (Planchon and Collin).
East Indian Root. Under this name the rhizome of a small monocotyledonous plant, probably Cryptocoryne spiralis, Fischer (N.O. Aroideoe), has been imported from the south of India. It occurs in short, nearly cylindrical pieces, 1.5 to 5 cm. long, often tapering at one end and there bearing the remains of leaves; they are slightly enlarged and constricted at regular intervals, which gives them an annulated appearance somewhat resembling ipecacuanha, and are marked with encircling leaf scars. The transverse section exhibits a typically monocotyledonous structure, and distinguishes this drug at once from genuine ipecacuanha; for instead of the central column of dense wood there is a parenchymatous stele, through which scattered bundles run, surrounded by a white starchy cortex. This substitute for ipecacuanha contains no emetine or cephaeline.
3. Undulated Ipecacuanha, derived from Richardsonia scabra, Saint Hilaire (N.O. Rubiaceoe, Brazil), occurs in tortuous pieces, the upper part being cylindrical and bearing at the crown the remains of numerous very slender aerial stems. On one side of the root the bark is occasionally fissured nearly to the wood, and this gives the drug a somewhat annulated appearance, which, however, is quite different from the regular annulations of Brazilian ipecacuanha. The transverse section exhibits a porous wood, and a thick, starchy bark often violet in colour.
Fig. 168. - Lesser Striated Ipecacuanha (Richardsonia sp.). A, root, natural size, cut transversely to show the dark bark. B, transverse section, magnified, showing the porous wood. (Planchon and Collin).
Lesser Striated Ipecacuanha. This drug, which is occasionally found on the market, is apparently derived from a species of Richardsonia, as it possesses a starchy, violet (often dark violet) bark and porous wood, but is distinguished from the foregoing by its darker colour and stouter aerial stems.
5. Greater Striated Ipecacuanha is the root of Psychotria emetica, Linne. It is about the size of Cartagena ipecacuanha and closely resembles the foregoing, being irregularly constricted, dark in colour, and exhibiting in transverse section a dark, violet-coloured bark; it may be distinguished by its dense wood, and by the presence of sugar in the bark, starch being completely absent. The colour of the bark and the absence of starch easily distinguish this root from either Brazilian or (which it closely resembles in appearance) Cartagena ipecacuanha.
6. White Ipecacuanha is the root of Ionidium Ipecacuanha, Ventena
(N.O. Viotaceoe, Brazil). It is greyish white or yellowish in colour, 1.5 to 3 mm. thick, and frequently branches. The section exhibits a large, porous, yellowish wood and narrow, darker bark.
Trinidad Ipecacuanha. Under this name the rhizome and root of Asclepias curassavica, Linne (N.O. Asclepiadeoe), have been offered for sale. It is 2 to 4 mm. in diameter, yellowish brown externally and whitish internally; it bears wiry rootlets and has an unpleasant bitter taste.
Other roots are occasionally found in the market mixed with or substituted for ipecacuanha; the enumeration of these would be beyond the scope of the present work.
Fig. 169. - Greater Striated Ipecacuanha (Psychotria emetica). A, root, natural size. B, transverse section, magnified, showing the dense wood. (Planchon and Collin).
With the exception of ipecacuanha stem, none of these substitutes, all of which reappear from time to time on the London market, contains any emetine or cephaeline.
The following test for emetine is useful in distinguishing roots containing that alkaloid from numerous substitutes which do not: - 0.5 gramme of the finely powdered root is mixed with 20 c.c. of strong hydrochloric acid and 5 c.c. of water; to 2 c:c. of the filtrate 0.01 gramme of potassium chlorate is added; if emetine is present the liquid assumes a yellow colour, changing in the course of an hour to red.