Zehong Wan

N-Phenyl-N-purin-6-yl ureas: The design and synthesis of p38α MAP kinase inhibitors

The design, synthesis and SAR of a series of 2,6,9-trisubstituted purine inhibitors of p38alpha kinase is reported. Synthetic routes were devised to allow for array synthesis in which all three points of diversity could be facilely explored. The binding of this novel series to p38alpha kinase, which was predicted to have several key interactions in common with SB-203580, was confirmed by X-ray crystallography of 19 (p38 IC(50)=82 nM).

Pyridazine-derived γ-secretase modulators

SAR of a novel series of pyridine-derived γ-secretase modulators is described. Compound 5 was found to be a potent modulator in vitro, which on further profiling, was found to decrease Aβ42 and Aβ40, and maintain (or increase) the levels of total Aβ. Furthermore, representative compounds 1 and 5 demonstrated in vivo efficacy to lower Aβ42 in the brain without altering Notch processing in the peripheral.

γ-Secretase modulators do not induce Aβ-rebound and accumulation of β-C-terminal fragment

J. Neurochem. (2012) 121, 277–286.

Discovery of biphenyl piperazines as novel and long acting muscarinic acetylcholine receptor antagonists.

A series of novel biphenyl piperazines was discovered as highly potent muscarinic acetylcholine receptor antagonists via high throughput screening and subsequent optimization. Compound 5c with respective 500- and 20-fold subtype selectivity for M3 over M2 and M1 exhibited excellent inhibitory activity and long duration of action in a bronchoconstriction in vivo model in mice via intranasal administration. The novel inhaled mAChR antagonists are potentially useful therapeutic agents for the treatment of chronic obstructive pulmonary disease.

A Highly Convergent Synthesis of 2‐Phenyl Quinoline as Dual Antagonists for NK2 and NK3 Receptors

Abstract A novel and highly convergent synthesis leading to 2‐phenyl‐quinolines has been developed. As demonstrated in the preparation of 6‐fluoro‐3‐(3‐oxo‐piperazin‐1‐ylmethyl)‐2‐phenyl‐quinoline‐4‐carboxylic acid [(S)‐1‐cyclohexyl‐ethyl]‐amide (8), the method provides fascile access to this class of analogues via the common intermediate 7.

Design, Synthesis, and Structure-Activity Relationship of Tropane Muscarinic Acetylcholine Receptor Antagonists

Novel tropane derivatives were characterized as muscarinic acetylcholine receptor antagonists (mAChRs). Through optimization of the structure-activity relationship around the tropane scaffold, the quaternary ammonium salt 34 was identified as a very potent M(3) mAChR antagonist. The compound was functionally active and displayed greater than 24 h duration of action in a mouse model of bronchoconstriction.

Orally bioavailable and brain-penetrant pyridazine and pyridine-derived γ-secretase modulators reduced amyloidogenic Aβ peptides in vivo

Accumulation of amyloid β (Aβ) in brain is a pathological hallmark of Alzheimers disease (AD). Aβ is generated after sequential cleavage of its parental molecule, amyloid precursor protein (APP), by β- and γ-secretases. Inhibition of γ-secretase activity is an effective approach for the reduction of Aβ levels. Since γ-secretase targets many different substrates, selective inhibition of its cleavage of APP is believed to be critical in order to avoid undesirable side effects. γ-Secretase modulator (GSM) shifts the cleavage site on APP and production of amyloidogenic to non-amyloidogenic Aβ fragments. Since GSMs only modulate and do not block cleavage of γ-secretase substrates, they are believed less likely to produce untoward adverse reactions. Here, we report in vivo Aβ-lowering profiles of a pyridazine and a pyridine-derived GSM: GSM-C (Wan et al., 2011a) and GSM-D (Wan et al., 2011b). Both compounds reduced Aβ40 and Aβ42 productions, increased shorter Aβ fragments, and had little effect on Notch signaling (∼100-fold selective). They had excellent oral bioavailability (97.8% for GSM-C, ∼100% for GSM-D) and good brain permeability (free brain to free blood AUC ratio of 0.41 and 1.10 for GSM-C and GSM-D, respectively). Oral administration of these compounds in both acute and sub-chronic conditions reduced Aβ levels in plasma and brain in rats in a dose- and time-dependent manner. Therefore, GSM-C and GSM-D represent two GSMs that are orally bioavailable and brain-permeable. They could serve as excellent tools in the investigation of the role of Aβ peptides in AD pathogenesis.

M3 muscarinic acetylcholine receptor antagonists: SAR and optimization of bi-aryl amines

Exploration of multiple regions of a bi-aryl amine template led to the identification of highly potent M(3) muscarinic acetylcholine receptor antagonists such as 14 (pA(2)=11.0) possessing good sub-type selectivity for M(3) over M(2). The structure-activity relationships (SAR) and optimization of the bi-aryl amine series are described.

Discovery of (3-endo)-3-(2-cyano-2,2-diphenylethyl)-8,8-dimethyl-8-azoniabicyclo[3.2.1 ]octane bromide as an efficacious inhaled muscarinic acetylcholine receptor antagonist for the treatment of COPD

Design and syntheses of a novel series of muscarinic antagonists are reported. These efforts have culminated in the discovery of (3-endo)-3-(2-cyano-2,2-diphenylethyl)-8,8-dimethyl-8-azoniabicyclo[3.2.1]octane bromide (4a) as a potent and pan-active muscarinic antagonist as well as a functionally active compound in a murine model of bronchoconstriction. The compound has also displayed pharmacokinetic characteristics suitable for inhaled delivery.

Discovery of 5-substituent-N-arylbenzamide derivatives as potent, selective and orally bioavailable LRRK2 inhibitors

Leucine-rich repeat kinase 2 (LRRK2) has been suggested as a potential therapeutic target for Parkinsons disease. Herein we report the discovery of 5-substituent-N-arylbenzamide derivatives as novel LRRK2 inhibitors. Extensive SAR study led to the discovery of compounds 8e, which demonstrated potent LRRK2 inhibition activity, high selectivity across the kinome, good brain exposure, and high oral bioavailability.