The synthesis and characterization of a new ligand, tris((6-phenyl-2-pyridyl)methyl)amine (TPPA) and some of its copper complexes are described. The complexes [Cu(TPPA)]BPh (7) and [Cu(TPPA)(AN)](ClO& (8) (AN = acetonitrile) were prepared and their X-ray crystal structures and redox potentials were determined. The X-ray structure of 7 (triclinic space group, P1; a = 14.603(3), b = 15.137(3), c = 12.974(3) A, a = 91.76(3), p = 105.87(3), y = 117.00(3)", V = 2417.4( 12) A3, Z = 2) displays a copper(1) atom with a distorted trigonal pyramidal coordination sphere, but the X-ray structure of 8 (triclinic space group, Poi; a = 13.458(3), b = 13.586(3) c = 11.082(2) A, a = 113.00(3), p = 94.48(3), y = 90.53(3)", V = 1857.7(9) A3, Z = 2 ) indicates that the copper(I1) atom has the expected trigonal bipyramid geometry. The reduction potential of 8 in dimethylformamide, dimethylacetamide, acetonitrile, and isobutyronitrile is quite positive compared to [Cu(TPA)](ClO& (TPA = tris(2-pyridylmethy1)amine) under identical conditions. The various factors that may contribute to the difference in oxidation potential are discussed. The positive redox potential combined with steric factors accounts for the lack of reactivity of [Cu(TPPA)]PF6 with molecular 0 2 .
A novel series of HCV NS5B RNA-dependent RNA polymerase inhibitors containing a pyrano[3,4-b]indole scaffold is described leading to the discovery of compound 16, a highly potent and selective inhibitor that is active in the replicon system.
The structural characterization of Cu(1) and Cu(I1) complexes of tris(6-phenyl-2-pyridylmethyl)amine (tppa), a derivative of the known tris(2-pyridylmethy1)amine (tpa), was recently reported.
The phenyl substituents in [Cu(tppa)AN](CIOJ, stabilize the Cu(1) state by 300-480 mV relative to [Cu(tpa)AN](CIO,),. Reported here is the synthesis of the compounds bis(2-pyridylmethyl)-6-phenyl-2-pyridylmethylamine (Phtpa) and bis(6-phenyl-2-pyridylmethyl)-2-pyridylmethylamine (Ph,tpa) and the synthesis and cyclic voltammetry studies of their Cu(I1) perchlorate complexes.The mechanism by whiCh the phenyl groups increase the redox potential was found to be solvent-dependent: in AN, the increase in potential is primarily due to reduced local dielectric: in IBN, DMF, and DMA, the steric interaction between coordinated solvent and the phenyl substituents becomes important. The redox behavior of these complexes is consistent with anticipated modes of binding of solvent molecules in the inner sphere of the Cu(I1) complexes.
Through high throughput screening, substituted proline sulfonamide 6 was identified as HCV NS5b RNA-dependent RNA polymerase inhibitor. Optimization of various regions of the lead molecule resulted in compounds that displayed good potency and selectivity. The crystal structure of 6 and NS5b polymerase complex confirmed the binding near the active site region. The optimization approach and SAR are discussed in detail.
3-Monochloro-1,2-propanediol (3-MCPD) is a food contaminant that is often found in foods containing acid-hydrolyzed (AH) protein, like seasonings and savory food products. The purpose of the present study was to investigate the effects of 3-MCPD on male fertility, sperm, and hormonal levels and its antifertility mechanism. In vivo male fertility testing was performed to observe the adverse effects of 3-MCPD on the functioning of the male reproductive system and pregnancy outcome. 3-MCPD (0.01-5 mg/kg) was administered daily by gavage to Sprague-Dawley (SD) male rats for 4 wk. At the end of the pretreatment period, male rats were mated overnight with untreated females. Males successfully inducing pregnancy were sacrificed to assess sperm parameters, reproductive organ histopathology, and spermatogenesis. The resulting pregnant females were sacrificed on 20 of gestation to evaluate pregnancy outcome. The paternal administration of 3-MCPD (5 mg/kg) was found to result in adverse effects on male fertility and pregnancy outcome without inducing remarkable histopathological changes in testes and epididymides. Additionally, 3-MCPD (5 mg/kg) significantly reduced sperm motility, copulation, fertility indices, and the number of live fetuses showed steep dose-response curves. 3-MCPD did not affect spermatogenesis or induce hormonal changes in the blood and testes of male rats. An in vitro hormone assay using primary isolated Leydig cells showed no significant changes in related hormone levels after 3-MCPD treatment. To evaluate the effects of 3-MCPD on apoptotic induction and H+-ATPase levels in the testis and epididymis, 10 or 100 mg/kg of 3-MCPD was administered by gavage to male rats and testes and epididymides were examined at 3, 6, 12, and 24 h later. Apoptosis was not detected in the testes of animals treated with 100 mg/kg 3-MCPD. However, the level of H+-ATPase in the cauda epididymis was reduced by 3-MCPD treatment. These results indicate that 3-MCPD induced a spermatotoxic effect, which was mediated by reduced H+-ATPase expression in the cauda epididymis, and suggest that an altered pH level in the cauda epididymis might lead to a disruption of sperm maturation and the acquisition of motility.
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