Rhamnetin

Description

A yellow to green organic colorant extract from small berries from any shrub of the buckthorn family, such as Rhamnus infectorius, R. amygdalinus, R.oleodies, or R.alaternus. Rhamnetin is a water-soluble colorant composed of the methyl ester of a tri-hydroxyflavonol. It was extracted from the berries for use in textiles, wood stains, and lake pigments. The unripe berries produce a yellow juice used to make sap green lake. The ripe berries were used to make Dutch pink, a yellow lake.

Synonyms and Related Terms

3,3′,4′,5-Tetrahydroxy-7-methoxyflavone; Natural Green 2; 7-Methylquercetin; Rhamnocitrin; Kaempferol; 7-O-methyl ether

Physical and Chemical Properties

• Soluble in hot water, methanol, acetone.
• Composition = C16H12O7
• Molecular Weight = 316.27

Resources and Citations

• Wikipedia: Rhamnetin