Pomegranate fruit extract modulates UV-B-mediated phosphorylation of mitogen-activated protein kinases and activation of nuclear factor kappa B in normal human epidermal keratinocytes paragraph sign

Excessive exposure of solar ultraviolet (UV) radiation, particularly its UV-B component, to humans causes many adverse effects that include erythema, hyperplasia, hyperpigmentation, immunosuppression, photoaging and skin cancer. In recent years, there is increasing use of botanical agents in skin care products. Pomegranate derived from the tree Punica granatum contains anthocyanins (such as delphinidin, cyanidin and pelargonidin) and hydrolyzable tannins (such as punicalin, pedunculagin, punicalagin, gallagic and ellagic acid esters of glucose) and possesses strong antioxidant and anti-inflammatory properties. Recently, we have shown that pomegranate fruit extract (PFE) possesses antitumor promoting effects in a mouse model of chemical carcinogenesis. To begin to establish the effect of PFE for humans in this study, we determined its effect on UV-B-induced adverse effects in normal human epidermal keratinocytes (NHEK). We first assessed the effect of PFE on UV-B-mediated phosphorylation of mitogen-activated protein kinases (MAPK) pathway in NHEK. Immunoblot analysis demonstrated that the treatment of NHEK with PFE (10-40 microg/mL) for 24 h before UV-B (40 mJ/cm(2)) exposure dose dependently inhibited UV-B-mediated phosphorylation of ERKl/2, JNK1/2 and p38 protein. We also observed that PFE (20 microg/mL) inhibited UV-B-mediated phosphorylation of MAPK in a time-dependent manner. Furthermore, in dose- and time-dependent studies, we evaluated the effect of PFE on UV-B-mediated activation of nuclear factor kappa B (NF-kappaB) pathway. Using Western blot analysis, we found that PFE treatment of NHEK resulted in a dose- and time-dependent inhibition of UV-B-mediated degradation and phosphorylation of IkappaBalpha and activation of IKKalpha. Using immunoblot analysis, enzyme-linked immunosorbent assay and electrophoretic mobility shift assay, we found that PFE treatment to NHEK resulted in a dose- and time-dependent inhibition of UV-B-mediated nuclear translocation and phosphorylation of NF-kappaB/p65 at Ser(536). Taken together, our data shows that PFE protects against the adverse effects of UV-B radiation by inhibiting UV-B-induced modulations of NF-kappaB and MAPK pathways and provides a molecular basis for the photochemopreventive effects of PFE.     

Identification of fentanyl, alfentanil, sufentanil, remifentanil and their major metabolites in human urine by liquid chromatography/tandem mass spectrometry for doping control purposes

Since January 2005, the list of prohibited substances established by the World Anti-Doping Agency prohibits the opioid agent fentanyl as well as its related drugs in professional and amateur sports. Fast, reliable and robust analytical assays are required that allow the sensitive determination of these compounds or respective metabolites in human urine, and liquid chromatography interfaced to mass spectrometry has proven to be a suitable and powerful tool for drug testing for several years. A screening and confirmation method was developed that enables the identification of fentanyl, alfentanil, remifentanil and sufentanil as well as their N-dealkylated or de-esterified metabolites utilizing solid-phase extraction of a 2 mL urine aliquot followed by LC-electrospray-MS/MS analysis. The procedure was validated in terms of recovery (95.8-104.9%), lower limit of detection (0.5 ng mL-1), specificity and interday precision (3.9-19.8%) for the four opioid drugs and the metabolic product norfentanyl. In addition, the mass spectrometric behavior of fentanyl after electrospray ionization and collision-induced dissociation was studied by synthesis and analysis of structurally related compounds, and dissociation pathways were proposed allowing the characterization of target analytes and corresponding metabolites.     

Anti-oxidant and pro-oxidant reactivities of copper(II), manganese(II) and iron(III) 3,5-di-<Emphasis Type="Italic">i</Emphasis>-propylsalicylate chelates during peroxidation of alkylbenzenes

Bioactive copper(II), iron(III), and manganese(II) 3,5-di-i-propylsalicylate (3,5-DIPS) chelates were investigated in order to determine their ability to inhibit the free radical initiated chain reactions leading to the peroxidation of isopropylbenzene (i-PrPh) and ethylbenzene (EtPh). Quantitative kinetic studies of these chelates established the following order of anti-oxidant reactivities: manganese(II)-(3,5-DIPS)₂>iron(III)(3,5-DIPS)₃>copper(II)₂(3,5-DIPS)₄> > 3,5-DIPS acid. The mechanism of anti-oxidant reactivity of these three chelates is established as being due, in part, to their chain-breaking capacity resulting from the chemical reduction of the generated peroxyl radical to yield alkybenzenelhydroperoxides via reaction of the 3,5-DIPS ligand with the peroxyl radical. In the case of manganese(II)3,5-di-i-propylsalicylate, the central metalloelement also interacts with the peroxyl radical. The manganese(II)-(3,5-DIPS)₂ and copper(II)₂(3,5-DIPS)₄ chelates were also found to exhibit alkylhydroperoxide pro-oxidative reactivity leading to the formation of the alkylbenzeneperoxyl radical. In addition, the manganese(II) atom underwent oxidation to manganese(III) with the formation of the alkylbenzenehydroperoxide or superoxide with air oxygen oxidation. Amyl acetate and dipropylamine (n-Pr₂NH) were added to the reaction mixture to model the biochemical presence of ester or amine cellular components. Addition of amyl acetate to the reaction mixture increased the anti-oxidant reactivity of manganese(II)-(3,5-DIPS)₂ while decreasing its pro-oxidant reactivity. The weaker anti-oxidant reactivites of iron(III)(3,5-DIPS)₃ and copper(II)₂(3,5-DIPS)₄ were less affected by the addition of amyl acetate and the pro-oxidant reactivity of copper(II)₂(3,5-DIPS)₄ was not changed by the addition of amyl acetate, while the pro-oxidant property of iron(III)(3,5-DIPS)₃ was eliminated. In contrast to 2,6-di-t-butyl-4-methylphenol, butylated hydroxy toluene (BHT), anti-oxidant reactivities of copper(II), iron(III), and manganese(II) 3,5-DIPS chelates were dramatically enhanced by the addition of n-Pr₂NH to the reaction mixture. It is concluded that all three metalloelement chelates react with and remove alkylbenzeneperoxyl radicals and the hydroperoxyl radical. The manganese(II)-(3,5-DIPS)₂ and copper(II)₂(3,5-DIPS)₄ chelates may also be useful in removing hydroperoxides in vivo. These reactivities, in addition to their established superoxide dismutase (SOD)-mimetic and catalase-mimetic reactivities, are suggested to possibly permit anti-oxidant and pro-oxidant reactivities in aqueous and organic cellular compartments.     

Si-E (E = N, O, F) bonding in a hexacoordinated silicon complex: new facts from experimental and theoretical charge density studies

The concept of hypervalency in molecules, which hold more than eight valence electrons at the central atom, still is a topic of constant debate. There is general interest in silicon compounds with more than four substituents at the central silicon atom. The dispute, whether this silicon is hypervalent or highly coordinated, is enlightened by the first experimental charge density determination and subsequent topological analysis of three different highly polar Si-E (E = N, O, F) bonds in a hexacoordinated compound. The experiment reveals predominantly ionic bonding and much less covalent contribution than commonly anticipated. For comparison gas-phase ab initio calculations were performed on this compound. The results of the theoretical calculations underline the findings of the experiment.     

Influence of the halogen ligand on the near-UV-visible spectrum of [Ru(X)(Me)(CO)2(alpha-diimine)] (X = Cl, I; alpha-diimine = Me-DAB, iPr-DAB; DAB = 1,4-diaza-1,3-butadiene): an ab initio and TD-DFT analysis

The near-UV-vis electronic spectroscopy of [Ru(X)(Me)(CO)(2)(iPr-DAB)] (X = Cl or I; iPr-DAB = N,N'-di-isopropyl-1,4-diaza-1,3-butadiene) is investigated through CASSCF/CASPT2 and TD-DFT calculations on the model complexes [Ru(X)(Me)(CO)(2)(Me-DAB)] (X = Cl or I). Convergence of the calculated transition energies for the low-lying metal-to-ligand charge-transfer (MLCT), X-to-ligand charge-transfer (XLCT, X halide ligand), or sigma-bond-to-ligand charge-transfer (SBLCT) to experimental values is analyzed for both methods. On the basis of these accurate calculations, it is shown that whereas the lowest singlet state can be assigned to a nearly pure XLCT state in [Ru(I)(Me)(CO)(2)(Me-DAB)], its character is mainly MLCT in [Ru(Cl)(Me)(CO)(2)(Me-DAB)]. These results are in agreement with time-resolved emission/IR and resonance Raman experimental data. The experimental UV-vis bands are well reproduced by the CASSCF/CASPT2 calculations. The TD-DFT transition energies to the long-range charge transfer states are dramatically affected by the nature of the functional, with lowering leading to meaningless values in the case of nonhybrid functionals. Both methods reproduce well the red shift of the absorption bands on going from the chloride to the iodide complex as well as the shift of the strongly absorbing higher MLCT transition from the visible to the UV domain of energy.     

Determination of essential and toxic elements in Libyan foodstuff using instrumental neutron activation analysis (INAA)

Since there is no database in Libya defining the intake of the individuals from different essential (minor and trace) and toxic elements provided through food, drinking water and aerosol, a project has been proposed with the cooperation of IAEA to determine the concentration of a number of elements such as Cs, Fe, Cr, Rb, Sc, Se, Co, Zn in the three mentioned sources. Emphasis was placed on the use of nuclear and nuclear-related techniques. In this paper, the primary results are presented for the concentration of minor and trace elements in some vegetables, spices and other foods which are widely used in the Libyan meals. Instrumental neutron activation analysis utilizing a 10 MW water pool reactor and a γ-ray spectroscopy facility was employed. For quality control, certified reference materials were analyzed simultaneosly with the samples which show good agreements compared with the certified data. Emphasis was given to both elements iron and zinc for their importance.     

Unambiguous Proof for Alcoxycarbonyl-group Migration in Wagner-Meerwein Rearrangements

In HSO₃F/SO₂ClF the β-hydroxy esters Ph-CHOH-CMe₂-COOR ( 1 , R?Me, Et) are doubly protonated, then transformed into the fluorosulfates 7 and (partly) into the fluorides 8. At ?15°, both 7 and 8 undergo a rearrangement, forming derivatives of Me₂C?C(Ph)COOR ( 2 ). By labelling 1 with ¹³C, singly (¹³C(3)) and doubly (¹³C(1,3)), it could be shown that exclusively the ROOC groups undergo a 1,2-shift. Compound 2 is also formed in HSO₃F/SO₂ClF from the isomeric Me₂COH-CHPh-COOR ( 3 ) by elimination, and less easily from the α-hydroxy ester Ph-CMe₂-CHOH-COOR (5) via a phenyl 1,2-shift. Another isomer, Ph-C(OH)Me-CHMe-COOR (4) gives products different from 2 . Using more acidic systems containing SbF₅, the free carbenium ions 13 (Ph-CH⁺-CMe₂-COOR) can be stabilized; they do not form 2 , possibly because of complexation of the ester group with SbF₅. The energy profile and the mechanism of the rearrangement 1 → 2 are discussed.     

Theoretical study of structure,vibrational and electronic spectra of isomers of methyl-3-methoxy-2-propenoate

A systematic quantum mechanical study of the possible conformations, their relative stabilities, vibrational and electronic spectra and thermodynamic parameters of methyl-3-methoxy-2-propenoate has been reported for the electronic ground (S₀) and first excited (S₁) states using time-dependent and time-independent Density Functional Theory (DFT) and RHF methods in extended basis sets. Detailed studies have been restricted to the E-isomer, which is found to be substantially more stable than the Z-isomer. Four possible conformers c′Cc, c′Tc, t′Cc, t′Tc, of which the first two are most stable, have been identified in the S₀ and S₁ states. Electronic excitation to S₁ state is accompanied with a reversal in the relative stability of the c′Cc and c′Tc conformers and a substantial reduction in the rotational barrier between them, as compared with the S₀ state. Optimized geometries of these conformers in the S₀ and S₁ states are being reported. Based on suitably scaled RHF/6-31G^** and DFT/6-311G^** calculations, assignments have been provided to the fundamental vibrational bands of both these conformers in terms of frequency, form and intensity of vibrations and potential energy distribution across the symmetry coordinates in the S₀ state. A complete interpretation of the electronic spectra of the conformers has been provided.     

Highly diastereoselective desymmetrizations of cyclo(Pro,Pro): an enantioselective strategy toward phakellstatin and phakellin

[reaction: see text] Monoenolates of C(2)-symmetric, proline-derived piperazine-2,5-diones were generated and trapped with a variety of electrophiles to produce, in a highly diastereoselective fashion, functionalized diketopiperazines (DKPs). These reactions provide the basis for an asymmetric, desymmetrization strategy toward the marine alkaloids phakellstatin and phakellin. The relative stereochemistry of the functionalized DKPs was confirmed by single-crystal X-ray analysis and/or NOE experiments. Bis-functionalization of the DKPs was also found to proceed with high levels of diastereoselectivity.     

Stereochemical Consequences of the Bismuth Atom Electron Lone Pair, a Comparison between MX(6)E and MX(6) Systems. Crystal and Molecular Structures of Tris[N-(P,P-diphenylphosphinoyl)-P,P-diphenylphosphinimidato]bismuth(III), [Bi{(OPPh(2))(2)N}(3)], -indium(III), [In{(OPPh(2))(2)N}(3)].C(6)H(6), and -gallium(III), [Ga{(OPPh(2))(2)N}(3)].CH(2)Cl(2)

The tetraphenylimidodiphosphinate [N-(P,P-diphenylphosphinoyl)-P,P-diphenylphosphinimidate] ion forms stable tris-chelates with the Bi(III), In(III), and Ga(III) cations. The crystal and molecular structures of [M{(OPPh(2))(2)N}(3)] (M = Ga, In, Bi) were determined by X-ray diffractometry. The geometry around the bismuth atom in compound 3 displays an approximately C(3)(v)() symmetry. This arrangement suggests the presence of a stereoactive lone pair of electrons, which is located in one of the triangular octahedral faces. Derivative 3 crystallizes in the triclinic space group P&onemacr; with Z = 2, a = 14.006(6) ?, b = 14.185(4) ?, c = 17.609(8) ?, alpha = 88.45(2) degrees, beta = 79.34(2) degrees, and gamma = 78.23(2) degrees. The structures of the gallium(III) and indium(III) tris-chelate oxygen-based complexes (1 and 2, respectively) were compared with the bismuth analogue in order to determine the ligand steric bulk influence on the coordination sphere in the absence of the electron lone pair. Complex 1 crystallizes as the [Ga{(OPPh(2))(2)N}(3)].CH(2)Cl(2) solvate in the triclinic space group P&onemacr;; Z = 2, a = 13.534(4) ?, b = 13.855(4) ?, c = 18.732(7) ?, alpha = 95.48(2) degrees, beta = 98.26(2) degrees, and gamma = 97.84(2) degrees. Crystal data for the benzene solvate of 2, [In{(OPPh(2))(2)N}(3)].C(6)H(6): triclinic space group P&onemacr;, Z = 2, a = 13.542(9) ?, b = 15.622(3) ?, c = 18.063(5) ?, alpha = 98.21(1) degrees, beta = 104.77(0) degrees, and gamma = 92.260(0) degrees.