Co-Authors:
Svoboda, J.A., Insect Physiology Laboratory, Entomology Research Division, Agricultural Research Service, Beltsville, MD 20705, United States
Thompson, M.J., Insect Physiology Laboratory, Entomology Research Division, Agricultural Research Service, Beltsville, MD 20705, United States
Robbins, W.E., Insect Physiology Laboratory, Entomology Research Division, Agricultural Research Service, Beltsville, MD 20705, United States
Abstract:
A commercial sample of β-sitosterol contained impurities that inhibited the conversion of β-sitosterol to cholesterol at the terminal step-the conversion of desmosterol to cholesterol-in the tobacco hornworm. The compounds responsible for this biological activity were isolated and shown to be 3β-hydroxy-24-norchol-5-en-23-oic acid and 3β-hydroxy-23,24-dinorchol-5-en-22-oic acid. The 23-carbon acid is the most active component, being several times more active than the 22-carbon acid as an inhibitor of Δ24-sterol reductase in vivo. The synthesis of 3β-hydroxy-24-norchol-5-en-23-oic acid is described. © 1968.