Metabolic Profiling of Chronic Cadmium Exposure in the Rat
摘要:
A confounding problem with studying the effects of environmental exposure to contaminants in wild populations is that analytical techniques are invasive, particularly where the physiological effects of the toxin are assessed. In this study, a metabonomic approach to investigate the biochemical effects of chronic oral exposure to environmentally realistic doses of CdCl2 (low, 8 mg/kg; high, 40 mg/kg) is presented. H-1 NMR spectra of urine from exposed animals were analyzed using pattern recognition methods to identify biomarkers for a 94 day exposure period. Creatinuria and both increased excretion and complexation of citrate was detected after 19 days of exposure in both exposure groups. This was accompanied by a decrease in plasma Ca2+/Mg2+ ratio in blood plasma after 94 days. Post mortem, magic angle spinning (MAS) H-1 NMR spectroscopy was used alongside conventional analytical techniques to investigate intact tissue directly. According to atomic absorption sectroscopy, kidney tissue accumulated 26.8 +/- 2.5 mug of Cd2+/g dry wt (low) and 75.9 +/- 4.3 mug of Cd2+/g dry wt (high). Using high-resolution MAS H-1 NMR spectroscopy altered lipid content was detected in kidneys from animals exposed to Cd2+. However, unlike acute exposure, no testicular damage was evident. This systemic approach to metabolism demonstrated the different physiological effects of chronic subacute compared with an acute exposure to Cd2+.
Hydrogenolysis of the scorpionate-supported calcium benzyl complex [(TpAd,iPr)Ca(p-CH2C6H4-Me)(THP)] (TpAd,iPr = hydrotris(3-adamantyl-5-isopropyl-pyrazolyl)borate, THP = tetrahydropyran) (2-THP) afforded the mononuclear calcium hydridocomplex [(TpAd,iPr)Ca(H)(THP)] (3). Under mild conditions (40 °C, 10 atm H2, 5 mol% cat.), complex 3 effectively catalyzed the hydrogenation of a variety of alkenes
series of bulky alkalineearth (Ae) metal amide complexes have been prepared: Ae[N(TRIP)2 ]2 (1-Ae) and Ae[N(TRIP)(DIPP)]2 (2-Ae) (Ae=Mg, Ca, Sr, Ba; TRIP=SiiPr3 , DIPP=2,6-diisopropylphenyl). While monomeric 1-Ca was already known, the new complexes have been structurally characterized. Monomers 1-Ae are highly linear while the monomers 2-Ae are slightly bent. The bulkier amide complexes 1-Ae are by far
Zero valent iron complexes as base partners in frustrated Lewis pair chemistry
作者:Hendrik Tinnermann、Craig Fraser、Rowan D. Young
DOI:10.1039/d0dt03551c
日期:——
The prototypical iron(0) complex [Fe(CO)3(PMe3)2] (1) forms a frustratedLewispair (FLP) with B(C6F5)3 (BCF). In this FLP, the iron complex acts as the Lewisbase partner, and the borane as the Lewis acid partner. This FLP is able to cleave H–H, H–Cl, H–O and H–S bonds in H2, HCl, H2O and HSPh. The FLP 1/BCF is shown to catalyze the hydrogenation of alkenes under mild conditions, where terminal alkenes
Antibacterial compounds of formula (I) are provided, as well as stereoisomers and pharmaceutically acceptable salts and esters thereof; pharmaceutical compositions comprising such compounds; methods of treating bacterial infections by the administration of such compounds; and processes for the preparation of such compounds.