Hyriopsis schlegelii

Besides these major glycolipids, minor glycosphingolipid components were isolated from the spermatozoa of Hyriopsis schlegelii. These are oligosylceramides264 having a shorter carbohydrate chain, and lacking any amino sugars, namely, the ceramide disaccharides /3-Gal-(l - 4)-Glc-Cer... 

The Biwa pearl mussel, Hyriopsis schlegelii, is probably the most famous of the freshwater mussels. It was native to Lake Biwa in Japan, though the stocks are now very depleted. It was used in the production of Biwa pearls, which were the first freshwater, non-nucleated cultured pearls to come on the market. They were of an irregular oval shape. 

Enterochrome-566 is a very similar pigment to helicorubin and is also found in gastropods as well as pelecypods. It has been purified from the gut fluid of Hyriopsis schlegelii, Cristaria plicata, Euhadra amaliae, and Euhardra sandai (286). Absorption peaks occur at 566, 530, and 430 nm in the reduced form and at 416 nm in the oxidized form. Its Ea is 200 mV at pH 6.4 and 150 mV at pH 7.8 (286). The biological function of both helicorubin and enterochrome-566 is not known. 

The bivalves Hyriopsis schlegelii and Corbicula sandai contain manno-lipids derived from glucosylceramide, in which xylosyl groups occur as a branch, fucosyl residues can be internal in the saccharide chain and, in one case, 4- Omethylglucuronic acid is found (Hori etal, 1977a, b, 1977 Itasaka and Hori, 1979). A tentative set of biosynthetic relationships is put forward in Figure 4.20. 

C18H33NO15 503.456 Constit. of glycolipid from the spermatozoa of bivalve Hyriopsis schlegelii. Isol. from the acetolysis product of a sialogly-copeptide p obtd. by enzymatic hydrolysis of avian ovomucoid. 

Each of three globosides from spermatozoa of the fresh-water bivalve Hyriopsis schlegelii contains D-mannose instead of D-galactose in the carbohydrate portion of the molecule. The structure (17) was deduced for one of them on the basis of methylation analysis, enzymic hydrolysis, and oxidation with chromium trioxide. 

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