A new class of inhibitors of secretory phospholipase A2: enolized 1,3-dioxane-4,6-dione-5-carboxamides
摘要:
Enolized 1,3-dioxane-4,6-dione-5-carboxamides a were identified as a new class of inhibitors of secretory phospholipase A(2) from human polymorphonuclear leucocytes (h-PMN PLA(2)). Among the more than 30 compounds synthesized, the most potent inhibitors (IC50 0.6-10 mu M) were found in the series of 2,4-disubstituted phenyl analogues of a. Compound 1a was selected for evaluation of its biological profile. This substance potently inhibited secretory PLA(2)s from several sources other than human PMNs, with a clear preference for group II over group I PLA(2), whereas human cytosolic PLA(2) and phospholipase C were not significantly affected. Inhibition of h-PMN PLA(2) was calcium-dependent. In intact mammalian cells stimulated in vitro, the release of arachidonic acid and the generation of prostaglandins and leukotrienes were inhibited at concentrations compatible with inhibition of PLA(2) as an underlying mechanism. In animal models in vivo (carragheenan oedema, adjuvant arthritis, pertussis pleurisy) 1a showed antiinflammatory activity, although the effect was rather weak compared with standard reference compounds.
Orthogonal Cu- and Pd-Based Catalyst Systems for the O- and N-Arylation of Aminophenols
摘要:
O- or N-arylated aminophenol products constitute a common structural motif in various potentially useful therapeutic agents and/or drug candidates. We have developed a complementary set of Cu- and Pd-based catalyst systems for the selective O- and N-arylation of unprotected aminophenols using aryl halides. Selective O-arylation of 3- and 4-aminophenols is achieved with copper-catalyzed methods employing picolinic acid or CyDMEDA, trans-N,N'-dimethyl-1,2-cyclohexanediamine, respectively, as the ligand. The selective formation of N-arylated products of 3- and 4-aminophenols can be obtained with BrettPhos precatalyst, a biarylmonophosphine-based palladium catalyst. 2-Aminophenol can be selectively N-arylated with CuI, although no system for the selective O-arylation could be found. Coupling partners with diverse electronic properties and a variety of functional groups can be selectively transformed under these conditions.
Orthogonal Cu- and Pd-Based Catalyst Systems for the O- and N-Arylation of Aminophenols
作者:Debabrata Maiti、Stephen L. Buchwald
DOI:10.1021/ja9081815
日期:2009.12.2
O- or N-arylated aminophenol products constitute a common structural motif in various potentially useful therapeutic agents and/or drug candidates. We have developed a complementary set of Cu- and Pd-based catalyst systems for the selective O- and N-arylation of unprotected aminophenols using aryl halides. Selective O-arylation of 3- and 4-aminophenols is achieved with copper-catalyzed methods employing picolinic acid or CyDMEDA, trans-N,N'-dimethyl-1,2-cyclohexanediamine, respectively, as the ligand. The selective formation of N-arylated products of 3- and 4-aminophenols can be obtained with BrettPhos precatalyst, a biarylmonophosphine-based palladium catalyst. 2-Aminophenol can be selectively N-arylated with CuI, although no system for the selective O-arylation could be found. Coupling partners with diverse electronic properties and a variety of functional groups can be selectively transformed under these conditions.
A new class of inhibitors of secretory phospholipase A2: enolized 1,3-dioxane-4,6-dione-5-carboxamides
Enolized 1,3-dioxane-4,6-dione-5-carboxamides a were identified as a new class of inhibitors of secretory phospholipase A(2) from human polymorphonuclear leucocytes (h-PMN PLA(2)). Among the more than 30 compounds synthesized, the most potent inhibitors (IC50 0.6-10 mu M) were found in the series of 2,4-disubstituted phenyl analogues of a. Compound 1a was selected for evaluation of its biological profile. This substance potently inhibited secretory PLA(2)s from several sources other than human PMNs, with a clear preference for group II over group I PLA(2), whereas human cytosolic PLA(2) and phospholipase C were not significantly affected. Inhibition of h-PMN PLA(2) was calcium-dependent. In intact mammalian cells stimulated in vitro, the release of arachidonic acid and the generation of prostaglandins and leukotrienes were inhibited at concentrations compatible with inhibition of PLA(2) as an underlying mechanism. In animal models in vivo (carragheenan oedema, adjuvant arthritis, pertussis pleurisy) 1a showed antiinflammatory activity, although the effect was rather weak compared with standard reference compounds.