Design, synthesis, X-ray studies, and biological evaluation of novel BACE1 inhibitors with bicyclic isoxazoline carboxamides as the P3 ligand.

We describe the design, synthesis, X-ray studies, and biological evaluation of novel BACE1 inhibitors containing bicyclic isoxazoline carboxamides as the P3 ligand in combination with methyl cysteine, methylsulfonylalanine and Boc-amino alanine as P2 ligands. Inhibitor 3a displayed a BACE1 K value of 10.9 nM and EC of 343 nM.

Design, synthesis, and X-ray structural studies of BACE-1 inhibitors containing substituted 2-oxopiperazines as P1'-P2' ligands.

We report the design and synthesis of a series of BACE1 inhibitors incorporating mono- and bicyclic 6-substituted 2-oxopiperazines as novel P1' and P2' ligands and isophthalamide derivative as P2-P3 ligands. Among mono-substituted 2-oxopiperazines, inhibitor 5a with N-benzyl-2-oxopiperazine and isophthalamide showed potent BACE1 inhibitory activity (K=2nM). Inhibitor 5g, with N-benzyl-2-oxopiperazine and substituted indole-derived P2-ligand showed a reduction in potency.

Memapsin 2 (beta-secretase) inhibitors: drug development.

Memapsin 2 (beta-secretase, BACE 1) processing of beta-amyloid precursor protein is the first step in the pathway leading to the production of amyloid-beta, thus, it is a major target for the development of inhibitor drug for the treatment of Alzheimers's Disease. Although there are distinctive advantages of this protease as a drug target, the development of drug-like memapsin 2 inhibitors has been somewhat slow since the cloning of the protease seven years ago. Here we review the progress of memapsin 2 inhibitor development using crystal structure-based design cycles.

Potent memapsin 2 (beta-secretase) inhibitors: design, synthesis, protein-ligand X-ray structure, and in vivo evaluation.

Structure-based design, synthesis, and biological evaluation of a series of peptidomimetic beta-secretase inhibitors incorporating hydroxyethylamine isosteres are described. We have identified inhibitor 24 which has shown exceedingly potent activity in memapsin 2 enzyme inhibitory (K(i) 1.8 nM) and cellular (IC(50)=1 nM in Chinese hamster ovary cells) assays.

An expedient, facile and simple one-pot synthesis of 2-methylenealkanoates and alkanenitriles from the Baylis-Hillman bromides in aqueous media.

This protocol is for an expedient and operationally simple one-pot synthesis of 2-methylenealkanoates and alkanenitriles in high yields from the corresponding Baylis-Hillman bromides. The reaction proceeds via the successive treatment with 1,4-diazabicyclo(2.2.

Design, synthesis, and X-ray structure of potent memapsin 2 (beta-secretase) inhibitors with isophthalamide derivatives as the P2-P3-ligands.

Structure-based design and synthesis of a number of potent and selective memapsin 2 inhibitors are described. These inhibitors were designed based upon the X-ray structure of memapsin 2-bound inhibitor 3 that incorporates methylsulfonyl alanine as the P2-ligand and a substituted pyrazole as the P3-ligand. Of particular importance, we examined the ability of the substituted isophthalic acid amide derivative to mimic the key interactions in the S2-S3 regions of the enzyme active sites of 3-bound memapsin 2.

Design, synthesis and X-ray structure of protein-ligand complexes: important insight into selectivity of memapsin 2 (beta-secretase) inhibitors.

Structure-based design, synthesis, and X-ray structure of protein-ligand complexes of memapsin 2 are described. The inhibitors are designed specifically to interact with S2- and S3-active site residues to provide selectivity over memapsin 1 and cathepsin D. Inhibitor 6 has exhibited exceedingly potent inhibitory activity against memapsin 2 and selectivity over memapsin 1 (>3800-fold) and cathepsin D (>2500-fold).

Recent developments of structure based beta-secretase inhibitors for Alzheimer's disease.

The amyloid-beta (Abeta) peptide is the principal components of the senile plaques found in the brains of patients with Alzheimer's disease (AD). The poorly soluble 40-42 amino acid peptide, formed from the cleavage of the Abeta precursor protein (APP) by two proteases, is believed to play a central role in the pathogenesis of AD. Beta-secretase (memapsin 2, BACE1), a membrane-anchored aspartic protease, is responsible for the initial step of APP cleavage leading to the generation of Abeta.

The Baylis-Hillman reaction: one-pot facile synthesis of 2,4-functionalized 1,4-pentadienes.

The Baylis-Hillman coupling between activated alkenes and alkyl 2-(bromomethyl)prop-2-enoates in the presence of DABCO (or DBU) leading to the formation of 2,4-functionalized 1,4-pentadienes, has been described.

Direct catalytic asymmetric aldol reactions of aldehydes.

The development of a direct catalytic enantioselective aldol reaction of aldehydes with activated carbonyl compounds catalyzed by chiral amines is presented and the potential demonstrated by the synthesis of optically active beta-hydroxycarboxylic acid derivatives.

Direct L-proline-catalyzed asymmetric alpha-amination of ketones.

The first direct catalytic asymmetric alpha-amination of ketones catalyzed by l-proline has been developed. The reactions proceed with various azodicarboxylates as the nitrogen source in high yields and excellent enantioselectivities (up to 99% ee). The scope and potential of the reaction are demonstrated by further transformation of the alpha-hydrazino ketones formed to both optically active syn and anti-alpha-amino alcohol derivatives.