Peter Andrew Mccarthy

Efficacy, tissue distribution and biliary excretion of methyl (3R∗,5S∗)-(E)-3,5-dihydroxy-9,9-diphenyl-6, 8-nonadienoate (CP-83101), A hepatoselective inhibitor of HMG-CoA reductase activity in the rat

Methyl (3R*,5S*)-(E)-3,5-dihydroxy-9,9-diphenyl-6,8-nonadienoate, CP-83101, was identified as a potent competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity, inhibiting enzyme activity in vitro with an IC50 of 8.5 +/- 0.7 microM and a Ki with respect to HMG-CoA of 2.6 microM. CP-83101 also inhibited rat hepatic sterol biosynthesis by 39 +/- 7% at a dose of 100 mg/kg. [3H]CP-83101, administered orally to rats, exhibited peak plasma levels at approximately 1 hr that declined thereafter with an apparent half-time of 2-3 hr. Peak tissue levels also occurred 1 hr following oral administration of [3H]CP-83101. The decline in radioactivity in the liver, however, was considerably slower than that noted in blood, whereas the half-life in non-hepatic tissues was approximately 1 hr. Liver/blood ratios of 14, and liver/lens ratios of greater than 3000, following oral administration of [3H]CP-83101, were similar to those previously reported for other HMG-CoA reductase inhibitors, suggesting a high degree of tissue selectivity. In addition, liver/adrenal and liver/ovary ratios were approximately 1000 at all time points examined between 30 min and 24 hr following oral [3H]CP-83101 administration, indicating a high specificity for hepatic versus other steroidogenic tissues. Evaluation of intravenous versus oral administration of the water-soluble, free acid, sodium salt of [3H]CP-83101 in bile duct canulated rats indicated that approximately 20% of orally administered CP-83101 is absorbed from the gastrointestinal tract, and that absorbed CP-83101 is cleared rapidly from the plasma via the liver and from the liver via the bile. In addition, several lines of evidence suggest that CP-83101 may undergo enterohepatic recirculation. Agents of this synthetic series may thus possess advantages over other HMG-CoA reductase inhibitors with respect to tissue kinetics and specificity.

Synthesis of [2,2,3α,4,4-D5]CP-88,818 (tiqueside), an internal standard for a quantitative HPLC/MS assay system

Abstract A polydeuterated form of CP-88,818 ( 1 , tiqueside) was needed as an internal standard for a quantitative HPLC/MS assay system. [2,2,3α,4,4-D 5 ]CP-88,818 ( 11 ) with undetectable D 0 content was synthesized in five steps from tigogenin ( 2 ). The low D 0 content was achieved through two sequential incorporation procedures which gave results superior to those achieved through a single incorporation procedure. A preparatively useful procedure for removing spirostane impurities found in naturally occurring tigogenin was also discovered.

Synthesis of α,α-difluoroketones: Novel synthesis of α,α-difluoroketones from α,α-difluoroacylsilanes

Abstract α,α-Difluoroketones, targets of interest as potential transition state mimics and enzyme inhibitors, have been synthesized from the corresponding α,α-difluoroacylsilanes by treatment with diazoalkanes.