Crystal structure of the GDP-bound GTPase Era from Staphylococcus aureus.

GTPase Era from Staphylococcus aureus belongs to the TRAFAC superfamily of the TrmE-Era-EngA-EngB-Septin-like GTPases class and plays a significant role in the vital activity of this pathogenic microorganism as a maturation factor of the 30S ribosome subunit. However, the functions of this protein are not fully understood, making it a promising object for further study. Here, the 2.

Phosphine-Catalyzed Synthesis and Cytotoxic Evaluation of Michael Adducts of the Sesquiterpene Lactone Arglabin.

A general method for chemo- and diastereoselective modification of anticancer natural product arglabin with nitrogen- and carbon-centered pronucleophiles under the influence of nucleophilic phosphine catalysts was developed. The locked s-cis-geometry of α-methylene-γ-butyrolactone moiety of arglabin favors for the additional stabilization of the zwitterionic intermediate by electrostatic interaction between phosphonium and enolate oxygen centers, leading to the unprecedentedly high efficiency of the phosphine-catalyzed Michael additions to this sesquiterpene lactone. Using n-BuP as the catalyst, pyrazole, phthalimide, 2-oxazolidinone, 4-quinazolinone, uracil, thymine, cytosine, and adenine adducts of arglabin were obtained.

α-Umpolung/Michael Addition/Quaternization Tandem Reaction to provide α-Imido-β-phosphonium Propanoates with Broad Spectrum of Biological Activity.

This paper has been supported by the Kazan Federal University Strategic Academic Leadership Program ('PRIORITY-2030'). HRMS data were obtained in the CSF-SAC FRC KSC RAS by support of the State Assignment of the Federal Research Center "Kazan Scientific Center", Russian Academy of Sciences. A.

Linkage of the Dinuclear Gold(I) Complex Luminescence and Origin of Endocyclic Amino Group of Cyclic PN-Bridging Ligands.

Gold(I) complexes of LAuCl composition based on PN ligands, namely 1,5-diaza-3,7-diphosphacyclooctanes, containing ethylpyridyl substituents at the phosphorus atoms and sp- or sp-hybridized endocyclic nitrogen atoms were synthesized. The SCXRD analysis indicated the strong impact of the geometry of the nitrogen atom on the structure and conformational flexibility of the complexes. The -aryl substituted ligand with the planar endocyclic nitrogen atom provides higher flexibility of the complex and an ability to bind the solvent molecules in the "host-guest" mode, whereas that kind of behavior is forbidden for the complex with an -alkyl substituted ligand with a pyramidal nitrogen atom.