Prunus emarginata (?)(CHAPTER VII. Flavonol 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 bark of a spurious substitute for that of the Prunus serotina, probably P. emarginata, has been shown by Finnemore (Pharm. Journ., 1910, (iv.), 31, 604) to contain in addition to quercimeritrin (Perkin, Chem. Soc. Trans., 1909, 95, 243) a glucoside prunitrin, C₂₂H₂₄O₁₁, 4H₂O, fine needles, which when hydrolysed yields prunetin and glucose.

Prunetin, C₁₅H₉O₄.OCH₃, colourless needles, melting-point 242°, dissolves in alkalis with a slight yellow colour, and is sparingly soluble in all the usual solvents. Monacetylprunetin, C₁₆H₁₁O₅(C₂H₃O), pale yellow needles, melting-point 190°; diacetylprunetin, C₁₆H₁₀O₅(C₂H₃O)₂, melting-point 224-226°; benzoylprunetin, C₁₆H₁₀O₅(C₇H₅O)₂, needles, melting-point 215°; dimethylprunetin, C₁₅H₈O₃(OCH₃)₂, needles, melting- point 145°; and acetyldimethylprunetin, C₁₅H₇O₃(OCH₃)₂C₂H₃O, have been prepared.

Fused with caustic potash at 250°, prunetin gives phloroglucinol and p-hydroxyphenylacetic acid.

Prunetol, C₁₅H₁₀O₅, colourless needles, melting-point 290°, is formed by the demethylation of prunetin with hydriodic acid, and yields acetylprunetol, Cl5H7O5(C₂HO)₃, prunetol sulphate, C₁₅H₁₀O₅.H₂SO₄, yellow needles. On methylation with methyl iodide prunetol dimethyl ether, identical with prunetin monomethyl ether, and a sparingly soluble methyl ether, the acetyl derivative of which melts at about 186°, are produced (Finnemore, Chem. Soc. Trans., 1910, 98, 1102).

It is considered by this author that prunetin is closely related to scutellarein (Molisch and Goldschmiedt, loc. cit.) and may have the constitution [KUVA PUUTTUU]