The correlation of gas-liquid chromatographic behaviour and structure of steroids.

1. Extracts prepared from Epidinium ecaudatum by two disintegration procedures contain oc-galactosidase and isomaltase activities. Nearly all of the oc-galactosidase is extracted by water. 2. The oc-galactosidase hydrolyses galactosylgalactosylglycerol faster than it does melibiose and hydrolyses other compounds containing m-(1l-6)linked galactose more slowly than melibiose. 4-aGalactosylgalactose is also hydrolysed but melibiitol is scarcely attacked and methyl ,B-L-arabinopyranoside not at all. 3. Galactose is liberated from intact clover galactosyl-lipids, although no lipase activity could be demonstrated in the extracts. ,B-Galactosylglycerol is not hydrolysed by the epidinial extracts. 4. The ac-galactosidase has optimum activity over the pH range 5-0-5-5 and temperature range 38550, and acts as a transferase in the presence of 2 % of melibiose, galactose or galactosylgalactosylglycerol. 5. The isomaltase, which appears to be a separate enzyme, has optimum activity at pH 6-0. One of us (B.H.H.) acknowledges the receipt of a New Zealand D.S.I.R. Senior Research Fellowship. Thanks are also due to Mr R. 0. Weenink for the gift ofpure galactosylgalactosyl-lipid.