Metabolism of 4-hydroxy fatty acids by rat liver slices

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Metabolism of Gamma-Lactones by rat liver preparations in vitro

As part of an attempt to elucidate the mechanism of carcinogenesis by αβ-unsaturated y-lactones, a systematic study of the metabolism of a group of saturated and  αβ-unsaturated lactones was performed. It was shown that the saturated y-lactones are much more rapidly enzymatically hydrolysed than their αβ-unsaturated analogs. while the latter compounds are also conjugated with glutathione which could eventually lead to the excretion of mercapturic acids. On the whole, however. the saturated lactones are more rapidly metabolized

Monomeric linear diaminocarbene complexes of gold(I) show merit in enantioselective catalysis

Striking gold: Rather simple aryl substituents are required to convert acyclic diaminocarbenes (ADCs) into useful pseudo-bidentate ligands for monomeric gold(I), which can enantioselectively catalyze a tandem acetylization/cycloisomerization reaction. Tf=trifluoromethanesulfonyl. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Bis(trimethylphosphine-κP)gold(I) hexafluorophosphate

The title compound, [Au(C3H9P)2PF 6, a linear two-coordi-nate gold(I) complex with coordinated trimethylphosphine ligands and hexafluorophosphate as counter-ion, is isomorphous with [Ag(Me3P)2]PF6 and exhibits similar bond distances to [Au(Me3P)2]Cl, thus unconditionally substantiating previous comparisons and claims that the ionic radius of Au is smaller than that of Ag. The cation has mirror symmetry, so that the P - Au - P axis lies in this plane. Similarly, the anion has mirror symmetry, with the plane containing an F -P - F axis. © 2007 International Union of Crystallography All rights reserved.Articl

One-N, six-membered heterocyclic carbene complexes and the remote heteroatom concept

A whole library of six-membered N-heterocyclic carbene complexes of Ni(ii) and Pd(ii) were prepared by oxidative substitution. In some of these compounds the heteroatom occurs in a position distant from the carbene donor atom. Combined structural and physical data, especially 13C NMR results, indicate carbene character in such ligands. DFT quantum mechanical calculation at the RI-BP56/SVP level allowed the extraction of valuable chemical information predicting that rNHC (r = remote) ligands would bond more strongly than their nNHC (n = normal) isomers. This result is also corroborated by calculations on the metal complexes themselves. Orbital overlap (mainly σ) follows the order N2HC5 < nN1HC6 < rN 1HC6 when ligands derived from halo-imidazolium and halo-pyridinium salts are compared. In C-C coupling catalysis using Pd(ii) and Ni(ii) complexes, the simple one-N, six-membered carbene complexes are superior to simple two-N, five-membered examples but clear differentiation between nNHC and rNHC precatalysts in the former family, is not always possible. © The Royal Society of Chemistry.Articl

Poly[[trimethanolmagnesium]-μ3-sulfato]

The title compound, [Mg(SO4)(CH4O)3], consists of an infinite array of magnesium ions each coordinated by three methanol molecules and three O atoms belonging to different sulfate counter-ions. The octahedral units extend in different directions owing to the bridging association of the sulfate anions. © 2006 International Union of Crystallography All rights reserved.Articl

A third polymorph of (2-thiazolidinethionato)-(triphenylphosphine)gold(I)

The title compound, [Au(C3H4NS2)(C 18H15P)], is a third polymorphic form of a compound previously reported by Grant, Forward & Fackler Jr [Z. Kristallogr. (1996). 211, 483-484], At 100 K, the present polymorph shows triclinic symmetry, as do the other two polymorphs. © 2006 International Union of Crystallography. All rights reserved.Articl

The low-temperature phase of diethylammonium tetrachloridocuprate(II)

The crystal structure of the low-temperature phase of diethyl-ammonium tetra-chloridocuprate(II), (C4H12N)2[CuCl4], has been determined by Simonsen & Harlow [(1977). Am. Crystallogr. Assoc. Ser. 2 Vol. 5, No. 1, Abstract HN5], but no atomic coordinates are available. We therefore redetermined the structure at 100 K. It comprises three crystallographically independent formula units linked by hydrogen bonds into a two-dimensional network. One tetra-chloridocuprate(II) anion is virtually square-planar while the two others are tetra-hedrally distorted. © International Union of Crystallography 2007.Articl

Preparing α,β-unsaturated Fischer-type carbene complexes via an unforeseen route

Four 4-(NH-amino)-1-metalla-1,3-diene carbene complexes, two of which contain novel 4-membered heterometallacycles, formed regioselectively from the reaction of a mixture of [(CH3)2(CH3S)S] [BF4], the acetonitrilium electrophile, CH3CNCH 3+, and the deprotonated alkoxycarbene complexes, (CO)5MC(OCH3)CH2Li (M = Cr, W). The preferred Z-configurations of the alkoxy and amino groups are determined by strong H-bonding in the products. The metal-carbene bonds in the chelates are shorter by 0.08 Å than those in the acyclic compounds. © The Royal Society of Chemistry.Articl

New self-assembled one-dimensional nickel coordination polymers and hydrogen-bonded networks

Reaction of Ni(NCS)2 with aminobenzonitrile (ABN) isomers in solution gave rise to the formation of five coordination polymers of the general formula [Ni(NCS)2(ABN)2]n consisting of one-dimensional chains with adjacent nickel centres linked by bridging NCS- or ABN ligands. The compounds were characterised by single crystal X-ray diffraction, X-ray powder diffraction, infrared spectroscopy, thermogravimetry, differential scanning calorimetry and mass spectrometry.Articl