Studies on the Water-Soluble Extract of Shellfish Setashijimi (Corbicula sandai Reinhardt)

Abstract

The domestic shellfish, Setashijimi, Corbicula sandai Reinhardt, gathered in the middle of November, was soaked in hot water and the aqueous digest was separated and analyzed when the shells opened. Adenine, hypoxanthine, histidine, arginine, glycocolbetaine, N-methyl-pyridinium hydroxide, trimethylamine, ammonia, taurine and succinic acid were isolated. At the same time, from lysine portion, an unknown base, giving an aurate of m.p. 134° and a picrate of m.p. 190-191°, was isolated. A seasonal change in the extract component was examined by the analyses of nitrogen of various forms in the extracts of samples collected in November, January and March. The amount of total nitrogen-containing compounds was found larger in winter, and the amount of arginine was the largest in the spring. Throughout the four seasons, the amount of basic substances in the extract of Corbicula sandai was larger than that of monoamino acids, which was also found in the extract of Anodonta and seems to be the common property in fresh-water shellfish.