The optimization of pyridazinone series of glucan synthase inhibitors.

A detailed structure-activity relationship study of a novel series of pyridazine-based small molecule glucan synthase inhibitors is described. The optimization of the PK profile of this series led to the discovery of compound 11g, which demonstrated in vivo potency ip in a lethal fungal infection model.

Discovery of oxazole-based PDE4 inhibitors with picomolar potency.

Optimization of oxazole-based PDE4 inhibitors has led to the discovery of a series of quinolyl oxazoles, with 4-benzylcarboxamide and 5-α-aminoethyl groups which exhibit picomolar potency against PDE4. Selectivity profiles and in vivo biological activity are also reported.

SAR studies of pyridazinone derivatives as novel glucan synthase inhibitors.

A novel series of pyridazinone analogs has been developed as potent ß-1,3-glucan synthase inhibitors through structure-activity relationship study of the lead 5-[4-(benzylsulfonyl)piperazin-1-yl]-4-morpholino-2-phenyl-pyridazin-3(2H)-one (1). The effect of changes to the core structure is described in detail. Optimization of the sulfonamide moiety led to the identification of important compounds with much improved systematic exposure while retaining good antifungal activity against the fungal strains Candida glabrata and Candida albicans.

The synthesis and structure-activity relationship of pyridazinones as glucan synthase inhibitors.

A structure-activity relationship study of the lead 5-[4-(benzylsulfonyl)piperazin-1-yl]-4-morpholino-2-phenyl-pyridazin-3(2H)-one 1 has resulted in the identification of 2-(3,5-difluorophenyl)-4-(3-fluorocyclopentyloxy)-5-[4-(isopropylsulfonyl)piperazin-1-yl]-pyridazin-3(2H)-one 11c as a ß-1,3-glucan synthase inhibitor. Compound 11c exhibited significant efficacy in an in vivo mouse model of Candida glabrata infection.

Discovery of a highly potent series of oxazole-based phosphodiesterase 4 inhibitors.

Substituted quinolyl oxazoles were discovered as a novel and highly potent series of phosphodiesterase 4 (PDE4) inhibitors. Structure-activity relationship studies revealed that the oxazole core, with 4-carboxamide and 5-aminomethyl groups, is a novel PDE4 inhibitory pharmacophore. Selectivity profiles and in vivo biological activity are also reported.

Supercritical fluid chromatography/tandem mass spectrometric method for analysis of pharmaceutical compounds in metabolic stability samples.

Packed-column supercritical fluid chromatography (pSFC) coupled to an atmospheric pressure chemical ionization (APCI) source and a tandem mass spectrometer (MS/MS) for rapid and simultaneous determination of clozapine, ondansetron, tolbutamide and primidone in in vitro samples was developed in support of metabolic stability experiments. The effects of the eluent flow-rate and composition as well as the nebulizer temperatures on the ionization efficiency of the analytes in positive ion mode under normal phase pSFC conditions were studied. The metabolic stability of the test drug components through microsomal incubation by the proposed pSFC-APCI/MS/MS approaches requiring approximately 1 min per samples were evaluated with respect to specificity, durability and accuracy. These metabolic stability results obtained by pSFC-MS/MS methods are in a good agreement with those obtained by fast high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) method.

Novel histamine H3 receptor antagonists based on the 4-[(1H-imidazol-4-yl)methyl]piperidine scaffold.

We report the discovery of novel histamine H(3) receptor antagonists based on 4-[(1H-imidazol-4-yl)methyl]piperidine. The most potent compounds in the series (e.g., 7) result from the attachment of a substituted aniline amide to the main pharmacophore piperidine via a two-methylene linker.

Cyclic urea derivatives as potent NK1 selective antagonists. Part II: Effects of fluoro and benzylic methyl substitutions.

A series of novel five-membered urea derivatives as potent NK1 receptor antagonists is described. The effects of substitution of a 4-fluoro group at the phenyl ring and the introduction of an alpha-methyl group at the benzylic position to improve potency and duration of in vivo activity are discussed. Several compounds with high affinity and sustained in vivo activity were identified.

Cyclic urea derivatives as potent NK1 selective antagonists.

A series of novel five- and six-membered ring urea derivatives have been described as potent and selective NK1 receptor antagonists. Several compounds in this series exhibited good oral activity and brain penetration. Syntheses of these compounds are also described herein.

Synthesis and structure-activity relationships of oxime neurokinin antagonists: discovery of potent arylamides.

The structural modification of the benzylic ether region of oxime 1 has resulted in the identification of several novel aryl amides as selective or dual NK(1)/NK(2) antagonists.