Difference between revisions of "Crocetin"
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== Description == | == Description == | ||
| − | A bright yellow natural dyestuff. Crocetin is the primary colorant in [http://cameo.mfa.org/materials/fullrecord.asp?name=saffron saffron], crocus, [http://cameo.mfa.org/materials/fullrecord.asp?name=wongsky wongsky], unki, gunari, and flowers of ''Nyctanthes arbor-tristis''. Crocetin is a [http://cameo.mfa.org/materials/fullrecord.asp?name=substantive | + | A bright yellow natural dyestuff. Crocetin is the primary colorant in [http://cameo.mfa.org/materials/fullrecord.asp?name=saffron saffron], crocus, [http://cameo.mfa.org/materials/fullrecord.asp?name=wongsky wongsky], unki, gunari, and flowers of ''Nyctanthes arbor-tristis''. Crocetin is a [http://cameo.mfa.org/materials/fullrecord.asp?name=substantive%20dye substantive dye] that produces a strong yellow color on [http://cameo.mfa.org/materials/fullrecord.asp?name=alum alum] mordanted and unmordanted [http://cameo.mfa.org/materials/fullrecord.asp?name=wool wool]. Copper mordanting produces a greenish yellow shade. |
== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
Revision as of 12:02, 13 June 2013
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.)
Other 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 |
Authority
- Helmut Schweppe, 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, Judith Hofenk-de Graaff, Natural Dyestuffs: Origin, Chemical Constitution, Identification, Central Research Laboratory for Objects of Art and Science, Amsterdam, 1969