An unprecedented reversible mode of action of β-lactams for the inhibition of human fatty acid amide hydrolase (hFAAH)

Development of TsDPEN based imine-containing ligands for the copper-catalysed asymmetric Kinugasa reaction

A novel class of chiral N,N,N imine-containing ligands derived from TsDPEN (N-(p-tosyl)-1,2-diphenylethylene-1,2-diamine) has been developed and applied to the copper-catalyzed asymmetric Kinugasa reaction. The copper(ii) salt proved to be an efficient catalyst precursor, and it provides an efficient way to synthesize enantioenriched cis-β-lactam. The pathway is air-tolerant and easily manipulated, and the ligands are easy to synthesize. A working model is proposed in which the stereocontrolling step is the [2 + 2] cycloaddition between ketene and imine to explain the observed stereoselectivities.

A novel class of chiral N,N,N imine-containing ligands derived from TsDPEN has been developed and applied to the copper-catalyzed asymmetric Kinugasa reaction.

A chemical genetic screen uncovers a small molecule enhancer of the N-acylethanolamine degrading enzyme, fatty acid amide hydrolase, in Arabidopsis

N-Acylethanolamines (NAEs) are a group of fatty acid amides that play signaling roles in diverse physiological processes in eukaryotes. Fatty acid amide hydrolase (FAAH) degrades NAE into ethanolamine and free fatty acid to terminate its signaling function. In animals, chemical inhibitors of FAAH have been used for therapeutic treatment of pain and as tools to probe deeper into biochemical properties of FAAH. In a chemical genetic screen for small molecules that dampened the inhibitory effect of N-lauroylethanolamine (NAE 12:0) on Arabidopsis thaliana seedling growth, we identified 6-(2-methoxyphenyl)-1,3-dimethyl-5-phenyl-1H-pyrrolo[3,4-d]pyrimidine-2,4(3 H,6 H)-dione (or MDPD). MDPD alleviated the growth inhibitory effects of NAE 12:0, in part by enhancing the enzymatic activity of Arabidopsis FAAH (AtFAAH). In vitro, biochemical assays showed that MDPD enhanced the apparent V_max of AtFAAH but did not alter the affinity of AtFAAH for its NAE substrates. Structural analogs of MDPD did not affect AtFAAH activity or dampen the inhibitory effect of NAE 12:0 on seedling growth indicating that MDPD is a specific synthetic chemical activator of AtFAAH. Collectively, our study demonstrates the feasibility of using an unbiased chemical genetic approach to identify new pharmacological tools for manipulating FAAH- and NAE-mediated physiological processes in plants.

New β-Lactam Derivatives Modulate Cell Adhesion and Signaling Mediated by RGD-Binding and Leukocyte Integrins

A novel series of β-lactam derivatives that was designed and synthesized to target RGD-binding and leukocyte integrins is reported. The compound library was evaluated by investigating the effects on integrin-mediated cell adhesion and cell signaling in cell lines expressing α_vβ₃, α_vβ₅, α_vβ₆, α₅β₁, α_IIbβ₃, α₄β₁, and α_Lβ₂ integrins. SAR analysis of the new series of azetidinones enabled the recognition of structural elements associated with integrin selectivity. We obtained selective and potent agonists that could induce cell adhesion and promote cell signaling mediated by α_vβ₃, α_vβ₅, α₅β₁, or α₄β₁ integrin, and antagonists for the integrins α_vβ₃ and α₅β_1, as well as α₄β₁ and α_Lβ₂, preventing the effects elicited by the respective endogenous agonists.

(S)-1-(Pent-4'-enoyl)-4-(hydroxymethyl)-azetidin-2-one derivatives as inhibitors of human fatty acid amide hydrolase (hFAAH): synthesis, biological evaluation and molecular modelling

A series of lipophilic ester derivatives (2a-g) of (S)-1-(pent-4'-enoyl)-4-(hydroxymethyl)-azetidin-2-one has been synthesised in three steps from (S)-4-(benzyloxycarbonyl)-azetidin-2-one and evaluated as novel, reversible, β-lactamic inhibitors of endocannabinoid-degrading enzymes (human fatty acid amide hydrolase (hFAAH) and monoacylglycerol lipase (hMAGL)). The compounds showed IC50 values in the micromolar range and selectivity for hFAAH versus hMAGL. The unexpected 1000-fold decrease in activity of 2a comparatively to the known regioisomeric structure 1a (i.e. lipophilic chains placed on N1 and C3 positions of the β-lactam core) could be explained on the basis of docking studies into a revisited model of hFAAH active site, considering one or two water molecules in interaction with the catalytic triad.