Publications by authors named "Jean-Marie Gomis"
A simple and efficient method for constructing sulfur heterocycles was developed using a phosphine-catalyzed tandem umpolung addition and intramolecular cyclization of bifunctional sulfur pronucleophiles on arylpropiolates. The reaction offers a promising route to synthetically useful as well as biologically active heterocycles under neutral conditions.
View Article and Find Full Text PDFBiologically active cyclic tetrapeptides, usually found among fungi metabolites, exhibit phytotoxic or cytostatic activities that are likely to be governed by specific conformations adopted in solution. For conformational studies and drug design, there is a strong interest in using fast and reliable methods to determine correctly the conformational population of cyclotetrapeptides. We show here that standard molecular mechanics computational approach gives satisfactory results.
View Article and Find Full Text PDFArticle Synopsis
- Tentoxin is a phytotoxic cyclic tetrapeptide produced by Alternaria alternata fungi, and previous synthesis methods have struggled with low yields due to challenging steps.
- A new method uses a modified Erlenmeyer aldolization reaction to stereospecifically introduce Z-dehydrophenylalanine into a linear tetrapeptide, yielding 72%.
- A comparative study of cyclization reagents revealed HATU to be the most effective, achieving an 81% cyclization yield and leading to a total yield of 60% for tentoxin, opening pathways for synthesizing similar compounds.
Article Synopsis
- The study examines how tentoxin, a fungal cyclotetrapeptide, inhibits and can reactivate chloroplast ATP-synthase, using various experimental techniques including photolabeling and kinetic analysis.
- The research demonstrates that tentoxin binds specifically to the alpha-subunit of chloroplast F(1)-ATPase, and a 3D model helps identify its binding site, while also showing that the enzyme from a thermophilic bacterium is similarly affected.
- Results suggest that tentoxin attaches preferentially to an ADP-loaded alpha/beta pair, hindering the conversion to the ATP-loaded form, and reveal interaction dynamics between the toxin's binding sites that impacts the mechanism of ATP-synthase inhibition and reactivation.