title: 22-Hydroxycholesterol derivatives as HMG CoA reductase suppressors and serum cholesterol lowering agents.
abstract: A series of 22-hydroxycholesterol derivatives with a modified side chain terminus was prepared. These agents were evaluated in vitro and in vivo for their ability to suppress HMG CoA reductase, the rate-limiting enzyme of cholesterol biosynthesis. In tissue culture assays, 22-hydroxycholesterol as well as the side chain modified analogues were potent inhibitors of HMG CoA reductase. However, only those sterols with a modified side chain terminus were effective suppressors of liver reductase when administered ig to rats. 22-Hydroxy-25-methylcholesterol (4a) and 25-fluoro-22-hydroxycholesterol (15a) significantly lowered serum cholesterol levels when administered ig to primates; 25-chloro-22-hydroxycholesterol (15b) and the analogue with a cyclopropyl terminus, 20b, were ineffective. The cholesterol-lowering sterols did not significantly alter lipoprotein levels; however, the two compounds have been shown to inhibit acyl-coenzyme A:cholesterol acyl-transferase (ACAT) in tissue culture studies.
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000097:blood*; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D006888:Hydroxycholesterols / Q000494:pharmacology*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008074:Lipoproteins / Q000097:blood; D008253:Macaca mulatta; D008297:Male; D051381:Rats
chemical_list: D006888:Hydroxycholesterols; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008074:Lipoproteins; C003585:22-hydroxycholesterol; D002784:Cholesterol