Solid-Phase Syntheses of Furopyridine and Furoquinoline Systems

Chimeric Protein-Protein Interface Inhibitors Allow Efficient Inhibition of Type III Secretion Machinery and Pseudomonas aeruginosa Virulence

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen naturally resistant to many common antibiotics and acquires new resistance traits at an alarming pace. Targeting the bacterial virulence factors by an antivirulence strategy, therefore, represents a promising alternative approach besides antibiotic therapy. The Type III secretion system (T3SS) of P. aeruginosa is one of its main virulence factors. It consists of more than 20 proteins building a complex syringe-like machinery enabling the injection of toxin into host cells. Previous works showed that disrupting interactions between components of this machinery efficiently lowers the bacterial virulence. Using automated target-based screening of commercial and in-house libraries of small molecules, we identified compounds inhibiting the protein-protein interaction between PscE and PscG, the two cognate chaperones of the needle subunit PscF of P. aeruginosa T3SS. Two hits were selected and assembled using Split/Mix/Click chemistry to build larger hybrid analogues. Their efficacy and toxicity were evaluated using phenotypic analysis including automated microscopy and image analysis. Two nontoxic hybrid leads specifically inhibited the T3SS and reduced the ex vivo cytotoxicity of bacteria and their virulence in Galleria mellonella.

A novel one-pot method for the synthesis of substituted furopyridines: iodine-mediated oxidation of enaminones by tandem metal-free cyclization

A novel iodine-mediated oxidative tandem cyclization reaction of simple enaminones has been developed for the synthesis of substituted furopyridines through C–C/C–N/C–O bond formation in a one-pot procedure.

Solid-phase peptide synthesis (SPPS), C-terminal vs. side-chain anchoring: a reality or a myth

Here we review the strategies for the solid-phase synthesis of peptides starting from the side chain of the C-terminal amino acid. Furthermore, we provide experimental data to support that C-terminal and side-chain syntheses give similar results in terms of purity. However, the stability of the two bonds that anchor the peptide to the polymer may determine the overall yield and this should be considered for the large-scale production of peptides. In addition, resins/linkers which do not subject to side reactions can be preferred for some peptides.

Concise syntheses of meridianins and meriolins using a catalytic domino amino-palladation reaction

A synthesis of natural and synthetic members of the meridianin family of kinase inhibitory natural products has been developed. The sequence utilizes a variation of the Cacchi palladium-catalyzed domino reaction to efficiently construct the heterocyclic framework of the meridianins and meriolins from monocyclic precursors.

A Nonacid Degradable Linker for Solid-Phase Synthesis

Synthesis and applications of two new nonacid degradable linkers as an alternative to the Wang linker for solid-phase synthesis are described. Resin from linker 2 looks superior to linker 1 in terms of yields for both anchoring of the first building block and cleavage and in terms of higher purity of the final product. Use of linker 2 avoids side reactions associated with the use of Wang resin due to an undesired cleavage during final acid treatment.