Delphinium consolida, Flowers (Kaempferol)(CHAPTER VII. Flavonol Group.)(Osa artikkelista)

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.

Delphinium consolida is a common European plant belonging to the Larkspur family; its name refers to its powers, real or imaginary, of healing or consolidating wounds. The blue flowers were examined by Perkin and Wilkinson (Chem. Soc. Trans., 1902, 81, 585) to determine if these yield the same colouring matters as those previously isolated from the flowers of the D. zalil (ibid., 1898, 73, 267). The presence of kaempferol only could, however, be detected. For its isolation an aqueous extract of the flowers was digested at the boiling-point with addition of sulphuric acid, and the brown resinous product which separated on keeping, extracted with alcohol and the extract evaporated to a small bulk. Addition of ether to this solution caused the precipitation of resinous impurity, and on evaporating the ethereal liquid a semi-crystalline residue of the crude colouring matter was obtained. The product was crystallised from dilute alcohol, converted into acetyl derivative, and this after purification retransformed into colouring matter in the usual manner. The yield was approximately 1 per cent.

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Kaempferol possesses well-defined dyeing properties, and gives with mordanted woollen cloth the following shades which closely resemble those given by morin (loc. cit.):
Chromium. Brownish-yellow.
Aluminium. Yellow.
Tin. Lemon-yellow.
Iron. Deep olive-brown.

It is also present in the Impatiens balsamina (Chantili Pass), the Erythrina stricta (vernacular name "Kon kathet"), (Perkin and Shulman, Chem. Soc. Proc., 1914, 30, 177), the berries of the Rhamnus catharticus (loc. cit.), and together with quercetin, both apparently as glucosides, in the flowers of the Prunus spinosa (Perkin and Phipps, Chem. Soc. Trans., 1904, 85, 56). For the separation of the two colouring matters a fractional crystallisation from acetic acid was employed, kaempferol in these circumstances being the more sparingly soluble.