Metabolic studies of marine sterols by Copepods

We have hypothesized that the unusual structures of marine sterols play a role in the chemical ecology of marine algae by impacting the nutrition and perhaps the hormones of their predators. As the the first step of a test of this hypothesis, a series of sterols, including those found in harmful algal blooms, were synthesized with ¹³C-label at position-22 and used to probe the metabolism of marine copepods in feeding experiments. 151MHz ¹³C-NMR was used to analyze the outcomes. As an experimental control, a sterol known to be converted by crustaceans into cholesterol was synthesized labeled at C-26, and added at 10% of the total test sterol. The synthesis of ¹³C-labeled marine sterols and the metabolic results in copepods will be presented.