Antilipidemic activity of 4-oxo-functionalized ethyl 6-chlorochroman-2-carboxylate analogs and a related tricyclic lactone in three rat models.

The synthesis of ethyl cis-6-chloro-4-hydroxychroman-2-carboxylate (IV) and 6-chloro-4-hydroxy-chroman-2-carboxylic acid lactone (V) are reported. The antilipidemic properties of these compounds in 3 rat models were compared to the activity obtained for the previously synthesized related analogs ethyl 6-chlorochroman-2-carboxylate (II), ethyl 6-chlorochromanone-2-carboxylate (III) and clofibrate (I). The biologically most interesting analog, ethyl 6-chlorochroman-2-carboyxlate (II) like clofibrate (I), was an effective antitriglyceridemic and anticholesterolemic agent in Triton WR-1339 hyperlipidemic rats, sucrose-fed hyperlipidemic rats and chow-fed normolipemic rats. Ethyl 6-chlorochromanone-2-carboxylate (III) was found to be active after 7 days of administration to sucrose-fed rats. In sucrose-fed, male Sprague-Dawley rats, the comparative effects of these analogs on various hepatic drug parameters also were carried out. Consistent with previous findings, results obtained with these compounds provide evidence showing that changes in hepatic HMG-CoA reductase activity bear no relationship to serum cholesterol lowering in the sucrose-fed model.