1,2-Bis(2-benzimidazolyl)-1,2-ethanediol, a chiral, tridentate, facially coordinating ligand

The ligand 1,2-bis(1H-benzimidazol-2-yl)-1,2-ethanediol, 1, and its methylated derivative 2 are readily synthesized from tartaric acid, and act as chiral, facially coordinating tridentate ligands, forming complexes of composition ML2 with octahedral transition metals. The copper(II) complexes show distorted 4 + 2 coordination with benzimidazoles occupying the equatorial sites and alcohol functions weakly binding in the axial sites. Nickel(II) complexes in three different states of protonation show regular octahedral geometry with the alcohols mutually cis. Deprotonation of the coordinated alcohol produces little structural change but the monodeprotonated complex forms a hydrogen bonded dimer. Magnetic measurements show the hydrogen bonded bridge to offer a pathway for weak antiferromagnetic coupling. UV-Visible spectroscopy shows the ligand to have a field intermediate between water and pyridine. The diastereoselectivity of complexation depends on the geometry: nickel(II) shows a weak preference for the homochiral complex, whereas copper(II) forms almost exclusively homochiral complexes.

Fructose-1,6-bisphosphate preserves intracellular glutathione and protects cortical neurons against oxidative stress

Fructose-1,6-bisphosphate (FBP), an endogenous intermediate of glycolysis, protects the brain against ischemia-reperfusion injury. The mechanisms of FBP protection after cerebral ischemia are not well understood. The current study was undertaken to determine whether FBP protects primary neurons against hypoxia and oxidative stress by preserving reduced glutathione (GSH). Cultures of pure cortical neurons were subjected to oxygen deprivation, a donor of nitric oxide and superoxide radicals (3-morpholinosydnonimine), an inhibitor of glutathione synthesis (L-buthionine-sulfoximine) or glutathione reductase (1,3-bis(2-chloroethyl)-1-nitrosourea) in the presence or absence of FBP (3.5 mM). Neuronal viability was determined using an 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. FBP protected neurons against hypoxia-reoxygenation and oxidative stress under conditions of compromised GSH metabolism. The efficacy of FBP depended on duration of hypoxia and was associated with higher intracellular GSH concentration, an effect partly mediated via increased glutathione reductase activity.

Functionalized Adamantane Tectons Used in the Design of Mixed-Ligand Copper(II) 1,2,4-Triazolyl/Carboxylate Metal–Organic Frameworks

Bistriazoles, 1,3-bis(1,2,4-triazol-4-yl)propane (tr2pr) and 1,3-bis(1,2,4-triazol-4-yl)adamantane (tr2ad), were examined in combination with the rigid tetratopic 1,3,5,7-adamantanetetracarboxylic acid (H4-adtc) platform for the construction of neutral heteroleptic copper(II) metal−organic frameworks. Two coordination polymers, [{Cu4(OH)2(H2O)2}{Cu4(OH)2}(tr2pr)2(H-adtc)4]·2H2O (1) and [Cu4(OH)2(tr2ad)2(H-adtc)2(H2O)2]·3H2O (2), were synthesized and structurally characterized. In complexes 1 and 2, the N1,N2-1,2,4-triazolyl (tr) and μ3-OH− groups serve as complementary bridges between adjacent metal centers supporting the tetranuclear dihydroxo clusters. The structure of 1 represents a unique association of two different kinds of centrosymmetrical {Cu4(OH)2} units in a tight 3D framework, while in compound 2, another configuration type of acentric tetranuclear metal clusters is organized in a layered 3,6-hexagonal motif. In both cases, the {Cu4(OH)2} secondary building block and trideprotonated carboxylate H-adtc3− can be viewed as covalently bound six- and three-connected nodes that define the net topology. The tr ligands, showing μ3- or μ4-binding patterns, introduce additional integrating links between the neighboring {Cu4(OH)2} fragments. A variable-temperature magnetic susceptibility study of 2 demonstrates strong antiferromagnetic intracluster coupling (J1 = −109 cm−1 and J2 = −21 cm−1), which combines for the bulk phase with a weak antiferromagnetic intercluster interaction (zj = −2.5 cm−1).

Ein aggressiver Patient in meinem Dienst - Teil 1: Theorie, Epidemiologie und Pathophysiologie zur Aggression

Quintessenz • Jeder zweite Arzt erlebt im Laufe seiner Berufstätigkeit Gewalt. • Höchstes Gewaltrisiko haben medizinisches Personal in Ausbildung, weibliche Angestellte und Mitarbeiter in der Psychiatrie und den Notfallzentren. • Es gibt ex- und intrinsische Risikofaktoren für aggressives Verhalten von Patienten und Angehörigen gegenüber medizinischem Personal. • Internistische, neurologische und psychiatrische Störungen (inklusive Alkohol-/Drogenintoxikation) sowie medikamentöse Therapien können von aggressiven Verhaltensweisen begleitet sein. • Auf neurobiologischer Ebene handelt es sich um ein Ungleichgewicht im System des frontalen Cortex, anterioren Gyrus cinguli und der Amygdala. • Folgen eines Gewaltakts reichen von körperlichen und psychischen Problemen des Betroffenen bis hin zu ständigen Personalwechseln, Rekrutierungsproblemen und Wettrüsten der Institutionen. • Es wird eine «Null-Toleranz-Politik» gegen Gewalt im medizinischen Bereich und die Teilnahme an Kursen für Aggressionsmanagement empfohlen

Allgemeiner Zugang zu Polyaminen mit Ethan-1,2-diamin-Einheiten: Synthese von nicht natürlich vorkommenden homologen und isomerenN1,4-Di(4-cumaroyl)sperminen

The synthesis of the three N,N′-di(4-coumaroyl)tetramines, i.e., of (E,E)-N-{3-[(2-aminoethyl)amino]propyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] (1a), (E,E)-N-{4-[(2-aminoethyl)amino]butyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] (1b), and (E,E)-N-{6-[(2-aminoethyl)amino]hexyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] (1c), is described. It proceeds through stepwise construction of the symmetric polyamine backbone including protection and deprotection steps of the amino functions. Their behavior on TLC in comparison with that of 1,4-di(4-coumaroyl)spermine (=(E,E)-N-{4-[(3-aminopropyl)amino]butyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(propane-1,3-diyl)bis[prop-2-enamide]; 2) is discussed.