Yellowish coloration of oyster Crassostrea gigas
1987 Volume 53 Issue 4 Pages 677-680
Details
1987 Volume 53 Issue 4 Pages 677-680
Recently yellowish colored oysters, so called “Kigaki”, were found in Kesennuma Bay, Maizuru Bay and Hiroshima Bay. They showed yellow body fluid in the normal colored soft body. The yellowish coloration of oysters was temporazy and the yellow pigment disappeared in a few weeks (half time 2-3 days).
The yellow pigment was extracted with water and isolated by DEAF-Sephadex A-25 ion exchange chromatography, Bio-Gel P-6 gel filtration, silica gel thin layer chromatography andpaper chromatography. The properties of purified yellow pigment were as follows; soluble in water, 95%MeOH, 80%EtOH. Insoluble in ether, chloroform, acetone, benzene, buthanol, ethylacetate, methylethylketone, methylene chloride. Decomposed in boiling water. Stable in 1 N NaOH. Unstable in 0.1 N HCl. UV max. (nm) 257, (300), 460 (water), 260, (307), 462 (MeOH). IR (cm-1 KBr) 3400, 1600, 1500, 1380-1390, 1300, 1200, 1120, 1040, 900, 600. Ninhydrin reac-tion, Dragendorff reaction, alkaline silver nitrate reaction, iron (III) chloride reaction, Gmelin reaction and sodium-o-pentacyanoammine ferroate reaction were negative. Formaldehyde-o-dinitrobenzene reaction was positive. Trimethylsilylation (2 OH groups) and reduction with sodium borohydride were positive. This pigment did not pass the ultrafilter (Toyo UH-1, MW1000). These results suggest that this pigment has aromatic structure, 2 OH groups, o-diketone, C=N or amide structure.
