Echinochrome A

Title: Echinochrome A
CAS Registry Number: 517-82-8
CAS Name: 2-Ethyl-3,5,6,7,8-pentahydroxy-1,4-naphthalenedione
Additional Names: 2-ethyl-3,5,6,7,8-pentahydroxy-1,4-naphthoquinone
Molecular Formula: C12H10O7
Molecular Weight: 266.20
Percent Composition: C 54.14%, H 3.79%, O 42.07%
Literature References: The red pigment of the eggs of the sea urchin (Arbacia pustulosa). Isoln and structure: Kuhn, Wallenfels, Ber. 72, 1407 (1939). Synthesis from 2-ethyl-1,3,4-trimethoxybenzene and dibenzoyloxymaleic anhydride: Wallenfels, Gauhe, Ber. 76, 325 (1943).
Properties: Deep-red needles from dioxane-water, mp 220° (some decompn). Sublimes at 10-4 mm at 120°. Absorption max (chloroform): 533, 497, 462 nm. Very sparingly sol in cold water, yet more than sufficiently sol for chemotaxic effects. Readily sol in carbon disulfide, ether, chloroform, benzene, concd H2SO4.
Melting point: mp 220° (some decompn)
Absorption maximum: Absorption max (chloroform): 533, 497, 462 nm
Echinomycin Echinopsine Echinuline Echitamine Echothiophate Iodide