A potent, selective, orally active LXR agonist was identified from focused libraries of tertiary amines. GW3965 (12) recruits the steroid receptor coactivator 1 to human LXRalpha in a cell-free ligand-sensing assay with an EC(50) of 125 nM and profiles as a full agonist on hLXRalpha and hLXRbeta in cell-based reporter gene assays with EC(50)'s of 190 and 30 nM, respectively. After oral dosing at 10 mg/kg to C57BL/6 mice, 12 increased expression of the reverse cholesterol transporter ABCA1 in the small intestine and peripheral macrophages and increased the plasma concentrations of HDL cholesterol by 30%. 12 will be a valuable chemical tool to investigate the role of LXR in the regulation of reverse cholesterol transport and lipid metabolism.

No abstract

BMS-663749, a phosphonooxymethyl prodrug 4 of the HIV-1 attachment inhibitor 2-(4-benzoyl-1-piperazinyl)-1-(4,7-dimethoxy-1H-pyrrolo[2,3-c]pyridin-3-yl)-2-oxoethanone (BMS-488043) (2) was prepared and profiled in a variety of preclinical in vitro and in vivo models designed to assess its ability to deliver parent drug following oral administration. The data showed that prodrug 4 had excellent potential to significantly reduce dissolution rate-limited absorption following oral dosing in humans. Clinical studies in normal healthy subjects confirmed the potential of 4, revealing that the prodrug significantly increased both the AUC and C(max) of 2 compared to a solid capsule formulation containing the parent drug upon dose escalation. These data provided guidance for further efforts to obtain an effective HIV-1 attachment inhibitor.

The backbone cleavages of protonated tripeptide ions of the series Gly-Gly-Xxx, where Xxx = Gly, Ala, Val, &Leu, I-Leu, Ile, Phe, Tyr, Trp, Pro, Met and Glu, were studied in a hybrid tandem mass spectrometer. CTerminal y-type ions and N-terminal a-and Ctype ions were noted. A linear relationship between log (y1/b2) and the proton affinity of the C-terminal amino acid substituents was found: as the proton affinity of the C-terminal residue increases, the fraction of y1 ion formation increases. When the C-terminal substituent was more basic than Trp, the b, ion was not observed. It is likely that the site of protonation changes from peptide bond to side-chain for just these residues, Lys, His and Arg.