Fukugi(CHAPTER V. The Flavone 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 Japanese dyestuff "fukugi" (botanical origin unknown) [EDIT: Garcinia subelliptica] has, at least until recently, been employed to a considerable extent in Japan as a mordant dyestuff. It consists of the wood of a tree which when ground forms an almost colourless powder, the extract of which is sold in the form of brittle rectangular cakes of a yellowish-brown colour.

Fukugetin, C₁₇H₁₂O₆, the colouring matter, forms minute canary-yellow prismatic needles melting at 288-290° (Perkin and Phipps, Chem. Soc. Trans., 1904, 85, 58). It dissolves in alkaline solutions with a yellow colour, and gives with alcoholic lead acetate an orange-yellow precipitate and with alcoholic ferric chloride a brown-black coloration.

Crystalline acetyl and benzoyl derivatives of this colouring matter could not be obtained, but the bromine compound, C₁₇H₁₀O₆Br₂, minute flat needles, melting-point 280°, is readily prepared by the action of bromine on fukugetin in the presence of acetic acid. Fukugetin dyes mordanted fabrics shades which are almost identical with those given by luteolin - Chromium. Dull orange-yellow,
Aluminium. Orange-yellow,
Tin. Bright yellow,
Iron. Olive brown,
and resembles this colouring matter in that its alkaline solution is not oxidised on exposure to air. By fusion with alkali fukugetin gives phloroglucinol and protocatechuic acid.

The dyeing properties of "fukugi" are analogous to those of weld. The similarity in shade indeed is so marked that except in point of strength for fukugi is a stronger dye than weld it is impossible to distinguish between them.