Morinda umbellata or Mang-Koudu(CHAPTER I. The Anthraquinone Group.)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

The dyeing material, variously named oungkoudou, jong-koutong, etc., is the root-bark of Morinda umbellata (Linn.) and is met with, in Eastern commerce in the form of small, reddish-brown, irregular rolls of bark, much wrinkled in appearance. Its cost is or was about 6d. per lb. In Java it is largely used for producing the fast reds in the native calico prints, well known under the name of "baticks ".

Although the shrub from which the root- bark is obtained is met with in Ceylon and the hilly regions of Eastern, Southern, and Southwestern India, as well as in the Malay Peninsula and Java, the material does not appear to be considered as of any special importance by the Hindoo dyers, unless, indeed, as is very probable, they use the root as a whole under the general designation "al root," of which it must simply be regarded as a variety.

The following are a few of its Indian vernacular names: Ál (Bomb); núna (Tamil); múlúghúdú (Telugu); mang-kudu (Malay).

The older literature connected with mang-koudu is extremely limited, brief reference to its dyeing properties only being found in the following publications: "Philosophy of Permanent Colours" (1813), Bancroft; "Bulletin de la Societe Industrielle de Mulhouse" (1832), E. Schwartz and D. Koechlin; "L'Art de la Teinture des Laines" (1849), Gonfreville; "Monograph on the Dyestuffs and Tanning Matters of India," etc. (1878), T. Wardle; Watt's "Dictionary of the Economic Products of India" (1891), J. Murray.

The examination of this dyestuff by Perkin and Hummel (Chem. Soc. Trans., 65, 851) has indicated its close chemical resemblance to the Morinda citrifolia. It contains a glucoside of the nature of morindin, which yields by hydrolysis morindon, but which, according to Perkin (Chem. Soc. Proc., 1908, 24, 149), is best represented by the formula C₂₆H₂₈O₁₄, and is identical with that suggested by Thorpe and Greenall (Chem. Soc. Trans., 1887, 51, 52) for the morindin derived from the Morinda citrifolia. The acetyl derivative C₂₆H₂₀O₁₄(C₂H₃O)₈ is very sparingly soluble in alcohol, and melts at 246-248°, and the sugar produced from the glucoside yields an osazone melting at 202-203°, which is not readily dissolved by alcohol.

This root-bark contains a considerable quantity of chlorogenin (cf. Madder), together with a small amount of non-tinctorial yellow derivatives of anthraquinone. A quantitative examination of the extract from 200 grams of the material with sulphurous acid (cf. Madder) gave 9,47 grams of green precipitate, which yielded: Crude chlororubin … 8.075 grams = 4.03 per cent.
Pure morindon … 1.187 grams = 0.59 per cent.
Yellow substances … 0.208 grams = 0.104 per cent.

These yellow substances proved to consist of a mixture of at least six distinct compounds. The main constituent isolated in yellow needles, melting at 171-173°, possessed the formula C₁₆H₁₂O₅, and had properties in harmony with those required by a monomethyl ether of a trihydroxymethylanthraquinone. The diacetyl derivative C₁₆H₁₀O₆(C₂H_3O)₂ melts at 148°.

A second compound, C₁₅H₁₀O₄, crystallised in yellow needles, melting at 269, and was found to consist of the methylpurpuroxanthin prepared synthetically (Marchlewski, Chem. Soc. Trans., 1893, 63, 1142) by the condensation of metadihydroxybenzoic acid with paramethylbenzoic acid.

The remaining yellow substances, (a) C₁₆H₁₂O₆, orange-red needles, melting-point 258°, (b) C₁₆H₁₀O₅. lemon-yellow needles, melting-point 198-199°, (f) C₁₆H₁₀O₅, needles, melting-point 208°, were isolated in such small amount that a determination of their constitution could not be attempted.

Dyeing properties.

This dyestuff is largely employed by the Javanese for producing the fast reds in their celebrated "baticks". The colours it yields are practically identical with those given by morinda root, but much fuller, a fact not to be wondered at, for it is well known that in ordinary morinda root the colouring principle is situated chiefly in the root bark. In its ordinary condition mang-kudu is not useful in dyeing, but as in the case of al root, a preliminary washing or steeping in water suffices to remove the deleterious acid principles present, and thus to transform it into a valuable red dyestuff.