Co-Authors:
Svoboda, J.A., Insect and Nematode Hormone Laboratory, ARS, USDA, Beltsville, MD 20705, United States
Rees, H.H., Department of Biochemistry, University of Liverpool, Liverpool, United Kingdom
Thompson, M.J., Insect and Nematode Hormone Laboratory, ARS, USDA, Beltsville, MD 20705, United States
Hoggard, N., Department of Biochemistry, University of Liverpool, Liverpool, United Kingdom
Abstract:
Stigmasterol-24,28-epoxide, 22E-stigmasta-5,22,24(28E)-trien-3β-ol, and 22E-cholesta-5,22,24-trien-3β-ol were identified as normal metabolites of [3H]stigmasterol in Spodoptera littoralis larvae. Relative concentrations of all three of these metabolites increased when a diazasterol inhibitor was fed in combination with stigmasterol in the artificial diet. Identification of these sterols as intermediates in the conversion of stigmasterol to cholesterol in this insect indicates that intermediates analogous to fucosterol and fucosterol-24,28-epoxide in the conversion of sitosterol to cholesterol are produced in the metabolism of stigmasterol. This is the first published identification of stigmasterol-24,28-epoxide and 22E-stigmasta-5,22,24(28E)-trien-3β-ol as intermediates in this pathway in an insect. © 1989.