Cascade synthetic strategies opening access to medicinal-relevant aliphatic 3- and 4-membered N-heterocyclic scaffolds.

Cascade reactions are often 'employed' by nature to construct structurally diverse nitrogen-containing heterocycles in a highly stereoselective fashion, i.e., secondary metabolites important for pharmacy.

Tandem construction of biological relevant aliphatic 5-membered N-heterocycles.

Nature often uses cascade reactions in a highly stereocontrolled manner for assembly structurally diverse nitrogen-containing heterocyclic scaffolds, i.e. secondary metabolites, important for medicinal chemistry and pharmacy.

Monensin A acid complexes as a model of electrogenic transport of sodium cation.

New Monensin A acid complexes with water molecule, sodium chloride and sodium perchlorate were obtained and studied by X-ray and (1)H, (13)C NMR and FT-IR methods as well as ab initio calculations. The crystal structure of the complexes indicates the complexation of the water molecule and Na(+) cation in the pseudo-cycle conformation of the Monensin acid molecule stabilised by intramolecular hydrogen bonds. Important for stabilisation of this structure is also the intermolecular hydrogen bonds with water molecule or the coordination bonds with Na(+) cation.

Structural characterization and antibacterial activity against clinical isolates of Staphylococcus of N-phenylamide of monensin A and its 1:1 complexes with monovalent cations.

The ability of N-phenylamide of monensin A (M-AM1) to form complexes with Li(+), Na(+) and K(+) cations is studied by ESI MS, (1)H and (13)C NMR, FT-IR spectroscopy and PM5 semi-empirical methods. ESI mass spectrometry indicates that M-AM1 forms complexes with the Li(+), Na(+) and K(+) cations of exclusively 1:1 stoichiometry which are stable up to cv = 90 V, and the formation of the complex with the Na(+) cation is strongly favoured. In the ESI MS spectra measured at cv = 110 V the fragmentation of the respective complexes, involving several dehydration steps, is observed.