A new automatic method for preconcentration and separation of radium in water samples has been developed. Such method combines both multisyringe (MSFIA) and multi-pumping (MPFS) flow analysis techniques allowing to analyze larger sample volumes with a higher throughput than other previous methodologies. Ra adsorbed on MnO(2), deposited on cotton fiber, is eluted with hydroxylamine and subsequen...

A facile and efficient synthetic route to multi-substituted 2-aminopyridines has been developed via a formal [5C + 1N] annulation of readily available 2,4-pentadienenitriles with hydroxylamine (NH(2)OH) under very mild conditions, which involves sequential intermolecular aza-nucleophilic addition of hydroxylamine, intramolecular aza-cyclization, and dehydration reactions.

A series of N-peptidyl-O-acyl hydroxylamines was synthesized and tested as inactivators of cysteine proteinases. Depending on the structure of the peptidyl residue of the inhibitors, rapid and complete irreversible inactivation of the lysosomal cathepsins, B, L and S, may be achieved. The most effective inhibitors display second-order rate constants of the inactivation in the range 10(5)-10(6) ...

SYNTHESIS 2006, No. 19, pp 3316–3340xx.xx.2006 Advanced online publication: 06.09.2006 DOI: 10.1055/s-2006-950231; Art ID: C04506SS © Georg Thieme Verlag Stuttgart · New York Abstract: A combination of palladium(II) acetate, aqueous potassium fluoride, and polymethylhydrosiloxane (PMHS) facilitates the room-temperature reduction of aromatic nitro compounds to anilines. These reactions tend to b...

Arylamines constitute the core structure of many therapeutic agents, agrochemicals, and organic materials. The development of methods for the efficient and selective construction of these structural motifs from simple building blocks is desirable but still challenging. We demonstrate that protonated electron-poor O-aryl hydroxylamines give aminium radicals in the presence of Ru(bpy)3 Cl2 . Thes...

This thesis consists of the exploration of a novel oxygenation procedure and its applicability in the preparation of synthetically useful compounds. Chapter 1 provides a review of methods for the preparation of TV-aryl hydroxylamines. Chapter 2 focuses on the development o f a novel a-oxygenation procedure. It describes work previously carried out within the group and continues with exploration...

Cellular aging is often associated with an increase in protein carbonyl groups arising from oxidation- and glycation-related phenomena and suppressed proteasome activity. These "aged" polypeptides may either be degraded by 20S proteasomes or cross-link to form structures intractable to proteolysis and inhibitory to proteasome activity. Carnosine (beta-alanyl-l-histidine) is present at surprisin...