Crocetin

Description

A bright yellow natural dyestuff. Crocetin is the primary colorant in Saffron, crocus, Wongsky, unki, gunari, and flowers of Nyctanthes arbor-tristis. Crocetin is a Substantive dye that produces a strong yellow color on Alum mordanted and unmordanted Wool. Copper mordanting produces a greenish yellow shade.

Synonyms and Related Terms

8,8'-diaporcarotenedioic acid; CI 75100; crocetina (Esp., It., Port.)

Physical and Chemical Properties

• Soluble dilute alkali solutions and pyridine. Slightly soluble in water, organic solvents.
• Forms a blue solution in concentrated sulfuric acid.
• Forms dark red crystals from acetic anhydride extract.
• Abs. max 464, 436, 411 nm

Composition	C20H24O4
CAS	27876-94-4
Melting Point	285 C

Resources and Citations

• Helmut Schweppe, Schweppe color collection index and information book

• The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 2578

• Colour Index International online at www.colour-index.org

• Judith Hofenk-de Graaff, Natural Dyestuffs: Origin, Chemical Constitution, Identification, Central Research Laboratory for Objects of Art and Science, Amsterdam, 1969