Occurrence and metabolism of scylloinositol in the locust

1. scylloInositol has been identified as a component of locust haemolymph, where it occurs in concentrations of 0.2-0.4mg./ml. 2. A simple method for the identification of scylloinositol is described. This has been used to demonstrate the presence of scylloinositol in five other insect species. 3. Locust phospholipids contain myoinositol but no scylloinositol. 4. Radioactivity from [(14)C]glucose is incorporated into myoinositol and scylloinositol by the locust in vivo. 5. Extracts of locust fat body catalyse the conversion of myoinositol into scylloinositol. This seems to take place by a two-step process in which myoinositol is first oxidized with NAD(+) to myoinosose-2, and the myoinosose-2 is stereospecifically reduced with NADPH to scylloinositol.