Novel triazolopyridylbenzamides as potent and selective p38α inhibitors.

A new class of p38α inhibitors based on a biaryl-triazolopyridine scaffold was investigated. X-ray crystallographic data of the initial lead compound cocrystallised with p38α was crucial in order to uncover a unique binding mode of the inhibitor to the hinge region via a pair of water molecules. Synthesis and SAR was directed towards the improvement of binding affinity, as well as ADME properties for this new class of p38α inhibitors and ultimately afforded compounds showing good in vivo efficacy.

Indolin-2-one p38α inhibitors II: Lead optimisation.

Optimisation of a series of indolin-2-one p38α inhibitors was achieved via both blocking of a potential metabolic 'hot spot' and by increasing overall polarity of the lead series leading to non-cytotoxic compounds which showed improved oral bioavailabilities in the rat.

Indolin-2-one p38α inhibitors I: design, profiling and crystallographic binding mode.

The use of structure-based design and molecular modeling led to the discovery of indolin-2-one derivatives as potent and selective p38α inhibitors. The predicted binding mode was confirmed by X-ray crystallography.

Indolin-2-one p38α inhibitors III: bioisosteric amide replacement.

Crystallographic structural information was used in the design and synthesis of a number of bioisosteric derivatives to replace the amide moiety in a lead series of p38α inhibitors which showed general hydrolytic instability in human liver preparations. Triazole derivative 13 was found to have moderate bioavailability in the rat and demonstrated potent in-vivo activity in an acute model of inflammation.

Synthesis and biological evaluation of 2-phenylpyran-4-ones: a new class of orally active cyclooxygenase-2 inhibitors.

A series of 2-phenylpyran-4-ones were prepared and evaluated for their ability to inhibit cyclooxygenase-2 (COX-2). Extensive structure-activity relationship work was carried out within this series, and a number of potent and selective COX-2 inhibitors were identified. Compounds having a p-methylsulfone group at the 2-phenyl ring showed the best COX-2 inhibitory activity. The introduction of a substituted phenoxy ring at position 3 enhanced both the in vitro and in vivo activity within the series. A selected group of 3-phenoxypyran-4-ones exhibited excellent activity in an experimental model of pyresis. The in vivo antiinflammatory activity of these compounds was confirmed with the evaluation of their antiarthritic and analgesic effectiveness. Moreover, their pharmacokinetic profile in rats is compatible with a once a day administration by oral route in humans. Within this novel series, compounds 21, 31, 34, and 35 have been selected for further preclinical and clinical evaluation.

1,7-Naphthyridine 1-oxides as novel potent and selective inhibitors of p38 mitogen activated protein kinase.

The design, synthesis, and ability to inhibit p38α MAP kinase by a novel series of naphthyridine N-oxides will be described. Some of these compounds showed a significant reduction in the LPS-induced TNFα production in human whole blood. Structure-activity relationship studies revealed that N-oxide oxygen was essential for activity and was probably a determinant factor for its marked selectivity against other related kinases. After an extensive SAR exercise, several compounds from this series were identified as very potent p38α inhibitors. In vivo efficacy of some derivatives was demonstrated to reduce TNFα levels in an acute murine model of inflammation (ED(50) = 0.5 mg/kg in LPS-induced TNFα production when dosed orally 1.5 h prior to LPS administration). The oral efficacy was further demonstrated in a chronic model of adjuvant arthritis in rats with established disease when administered orally (ED(50) < 1 mg/kg).

Design, synthesis, and structure-activity relationships of aminopyridine N-oxides, a novel scaffold for the potent and selective inhibition of p38 mitogen activated protein kinase.

A novel series of aminopyridine N-oxides were designed, synthesized, and tested for their ability to inhibit p38alpha MAP kinase. Some of these compounds showed a significant reduction in the LPS-induced TNFalpha production in human whole blood. Structure-activity relationship studies revealed that N-oxide oxygen was essential for activity and was probably a determinant factor for a marked selectivity against other related kinases. Compound 45 was identified as a potent and selective p38alpha inhibitor with an appropriate balance between potency and pharmacokinetics. In vivo efficacy of 45 was demonstrated in reducing TNFalpha levels in an acute murine model of inflammation (ED(50) = 1 mg/kg in LPS-induced TNFalpha production when dosed orally 1.5 h prior to LPS administration). The oral efficacy of 45 was further demonstrated in a chronic model of adjuvant arthritis in rats with established disease when administered orally (ED(50) = 4.5 mg/kg).

Racemic and chiral sulfoxides as potential prodrugs of 4-pyrone COX-2 inhibitors.

The preparation of the sulfoxide analogues 7, 8, and 9 and their enantiomerically pure forms is discussed as well as their ability to act as prodrugs of the potent and selective sulfone-containing COX-2 inhibitors 1, 2, and 3. Sulfoxide derivatives 7 and 9 were shown to be rapidly transformed in vivo into the corresponding sulfone derivatives 1 and 3, after oral administration to rats.

Racemic and chiral sulfoxides as potential prodrugs of the COX-2 inhibitors Vioxx and Arcoxia.

The preparation of the sulfoxide analogues 2 and 4, and their enantiomeric pure forms is discussed as well as their potential to act as prodrugs to the potent and selective sulfone-containing COX-2 inhibitors rofecoxib and etoricoxib. Sulfoxides 2 and 4 were shown to be effectively transformed in vivo into rofecoxib and etoricoxib, respectively, after oral administration in rats. In the case of sulfoxide 2, both a slightly improved pharmacokinetic profile and a better pharmacological activity in an arthritis model were seen when compared with rofecoxib.