Novel class of benzoic acid ester derivatives as potent PDE4 inhibitors for inhaled administration in the treatment of respiratory diseases.

The first steps in the selection process of a new anti-inflammatory drug for the inhaled treatment of asthma and chronic obstructive pulmonary disease are herein described. A series of novel ester derivatives of 1-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(3,5-dichloropyridin-4-yl) ethanol have been synthesized and evaluated for inhibitory activity toward cAMP-specific phosphodiesterase-4 (PDE4). In particular, esters of variously substituted benzoic acids were extensively explored, and structural modification of the alcoholic and benzoic moieties were performed to maximize the inhibitory potency. Several compounds with high activity in cell-free and cell-based assays were obtained. Through the evaluation of opportune in vitro ADME properties, a potential candidate suitable for inhaled administration in respiratory diseases was identified and tested in an in vivo model of pulmonary inflammation, proving its efficacy.

Gamma-secretase modulation and its promise for Alzheimer's disease: a medicinal chemistry perspective.

Gamma-secretase modulation holds the promise for the development of a disease-modifying therapy for Alzheimer's disease (AD). This novel concept of manipulating the cleavage specificity of the gamma secretase enzyme by pharmacological means implies that steady state levels of the potentially disease-causing amyloid-beta(1-42) peptide can be lowered without the undesired side effects associated with full inhibition of this aspartyl-type protease. Following on from the initial discovery that certain non-steroidal anti-inflammatory drugs (NSAIDs) exhibit properties characteristic of gamma secretase modulators, this class of compounds has been extensively studied and exploited, leading to the discovery of NSAIDs derivatives endowed with improved potency for the reduction of amyloid-beta(1-42) peptide production. In addition, a very limited number of non-NSAID derived gamma secretase modulators has also been recently claimed in the patent literature, suggesting that only a restricted number of pharmacophores might be involved in the modulation of gamma-secretase.

Discovery of diaryl imidazolidin-2-one derivatives, a novel class of muscarinic M3 selective antagonists (Part 1).

Pharmacophore-based structural identification, synthesis, and structure-activity relationships of a new class of muscarinic M3 receptor antagonists, the diaryl imidazolidin-2-one derivatives, are described. The versatility of the discovered scaffold allowed for several structural modifications that resulted in the discovery of two distinct classes of compounds, specifically a class of tertiary amine derivatives (potentially useful for the treatment of overactive bladder by oral administration) and a class of quaternary ammonium salt derivatives (potentially useful for the treatment of respiratory diseases by the inhalation route of administration). In this paper, we describe the synthesis and biological activity of tertiary amine derivatives. For these compounds, selectivity for the M3 receptor toward the M2 receptor was crucial, because the M2 receptor subtype is mainly responsible for adverse systemic side effects of currently marketed muscarinic antagonists. Compound 50 showed the highest selectivity versus M2 receptor, with binding affinity for M3 receptor Ki = 4.8 nM and for M2 receptor Ki = 1141 nM. Functional in vitro studies on selected compounds confirmed the antagonist activity toward the M3 receptor and functional selectivity toward the M2 receptor.

Discovery of diaryl imidazolidin-2-one derivatives, a novel class of muscarinic M3 selective antagonists (Part 2).

Synthesis and biological activity of a novel class of quaternary ammonium salt muscarinic M3 receptor antagonists, showing high selectivity versus the M2 receptor, are described. Selected compounds exhibited potent anticholinergic properties, in isolated guinea-pig trachea, and good functional selectivity for trachea over atria. In vivo, the same compounds potently inhibited acetylcholine-induced bronchoconstriction after intratracheal administration in the guinea pig.

Solid-phase convergent synthesis of a benzimidazolone library via the combination of two smaller arrays of carboxylic acids and secondary amines.

The concept of convergent synthesis can be extended to combinatorial chemistry in order to obtain collections of products characterized by considerable chemical diversity and a certain molecular complexity. In this work, a library consisting of three carboxylic acids containing a benzimidazolonic functionality with variations at two positions was synthesized on solid phase. After cleavage, this library was combined with a second library consisting of 16 solid-supported amines containing two points of variation. IRORI technology was used for the split-and-mix synthesis of the final 48 members library.