Rutin

Japanese pagoda tree (Sophora japonica)

Description

A yellow colorant found in flower buds of the Japanese pagoda tree (Sophora japonica), forsythia flowers (Forsythia suspensa), tobacco leaves (Nicotiana tobacum), and buckwheat kernels (Fagopyrum esculentum). Rutin precipitates as pale yellow crystals from a hot water extract. The color darkens to brown with exposure to light or heat.

Synonyms and Related Terms

rutoside; quercetin-3-rutinoside; 3,3',4',5,7-pentahydroxyflavone-3-rutinoside; melin; phytomelin; eldrin; ilixathin; sophorin; globularicitrin; enju (Jap.); Japanese pagoda tree (Sophora japonica); forsythia (Forsythia suspensa); tobacco (Nicotiana tobacum); buckwheat (Fagopyrum esculentum).

Forsythia flowers

Physical and Chemical Properties

• Soluble in hot water, hot alcohol, acetic acid, alkalis, pyridine, formamide.
• Slightly soluble in alcohol, acetone, ethyl acetate. Insoluble in cold water, ether, chloroform, benzene.
• Dilute solutions turn green with the addition of ferric chloride.
• ISO R105 Lightfastness Classification = 3 (mordanted with aluminum acetate)

Resources and Citations

• The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 8164

• Encyclopedia Britannica, http://www.britannica.com Comment: "pagoda tree" [Accessed October 5, 2001].

• R.Feller, M.Curran, C.Bailie, 'Identification of Traditional Organic Colorants Employed in Japanese Prints and Determination of their Rates of Fading', Japanese Woodblock Prints, Allen Memorial Art Museum, Oberlin College, Oberlin, 1984

• F. Crace-Calvert, Dyeing and Calico Printing, Palmer & Howe, London, 1876 Comment: p. 298

• Wikipedia: http://en.wikipedia.org/wiki/Forsythia (Accessed Dec. 9, 2005)