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Gender differences in the burden of cardiovascular disease (CVD) have been observed worldwide. In this study, plasmatic levels of trimethylamine (TMA) and blood oxidative biomarkers have been evaluated in 358 men (89 controls and 269 CVD patients) and 189 women (64 control and 125 CVD patients). The fluorescence technique was applied to determine erythrocyte membrane fluidity using 1,6-diphenyl-1,3,5-hexatriene (DPH) and Laurdan, while lipid hydroperoxides were assessed by diphenyl−1-pyrenylphosphine (DPPP). Results show that levels of plasmatic TMA were higher in healthy men with respect to healthy women (p = 0.0001). Significantly lower TMA was observed in male CVD patients (0.609 ± 0.104 μM) compared to healthy male controls (0.680 ± 0.118 μM) (p < 0.001), while higher levels of TMA were measured in female CVD patients (0.595 ± 0.115 μM) with respect to female controls (0.529 ± 0.073 μM) (p < 0.001). DPPP was significantly higher in healthy control men than in women (p < 0.001). Male CVD patients displayed a lower value of DPPP (2777 ± 1924) compared to healthy controls (5528 ± 2222) (p < 0.001), while no significant changes were measured in females with or without CVD (p > 0.05). Membrane fluidity was significantly higher (p < 0.001) in the hydrophobic bilayer only in control male subjects. In conclusion, gender differences were observed in blood oxidative biomarkers, and DPPP value might be suggested as a biomarker predictive of CVD only in men.

The direct combination reaction of tropylium tetrafluoroborate with a range of mono- and bi-dentate phosphines in chlorinated solvents leads to the formation of a series of cycloheptatriene-phosphonium derivatives in excellent yields. Multi-nuclear NMR and single-crystal X-ray diffraction studies confirm the addition of the tropylium ligand to the phosphorous centre to form cycloheptatriene derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] • A mononuclear palladacycle complex is synthesized, and fully characterized. • Square planar geometry of complex 2 was confirmed by X-ray crystallography. • The new PdII complex exhibits catalytic activity towards Suzuki coupling reaction. • Anticancer activity of complex was investigated on three human cancer cell lines. • Theoretical study of protein interaction was done by molecular docking simulation. A new palladium (II) complex of the type [Pd{ C,N -C 6 H 4 {C(Me) = NOH}-2}(dppp)]ClO 4 (2) has been prepared by the reaction of the cyclopalladated oxime complex [Pd{ C,N -C 6 H 4 {C(Me) = NOH}-2}(μ -Cl)] 2 (1) with 1,3-Bis(diphenylphosphino)propane (dppp). The new complex has been synthesized via a bridge-splitting reaction in the presence of NaClO 4 under mild conditions. Complex 2 was fully characterized by elemental analysis (CHN), spectroscopic methods (IR, 1H-, 31P-, 13C NMR) and single-crystal X-ray diffraction analysis. The structure shows the palladium atom to be in a slightly distorted square-planar geometry surrounded by one C, N -chelating oxime ligand and one P,P-chelating dppp ligand forming five- and a six-membered metallocyclic rings, respectively. The catalytic activity of complex 2 has been evaluated using Suzuki cross coupling reactions. The coupled products of these reactions were obtained in good to excellent yields and purity, low catalyst loading and short reaction times. The cytotoxic activity of complexes 1 and 2 were comparatively studied against HeLa, A549, and 1321 N1 cell lines, which showed a greater efficiency of the mononuclear complex 2 over the binuclear complex 1. Finally, molecular docking simulation was employed as a computational method to investigate the interactions of complexes 1 and 2 with the protein involved in apoptosis. [ABSTRACT FROM AUTHOR]

Abstract: The crystal structures of a yellowish-red pigment, 1,4-diketo-3,6-diphenylpyrrolo(3,4-c)pyrrole (DPP), and its derivative with high proton affinity, 1,4-diketo-3,6-bis(4′-dipyridyl)-pyrrolo-[3,4-c]pyrrole(DPPP), were predicted using Polymorph Predictor in Materials Studio 4.4. The possible structures were generated using Monte Carlo method and they were minimized with COMPASS and Dreiding forcefields. Among the predicted structures with the space groups same as those of the experimental X-ray crystal structures, structures fitting best to the experimental structures were searched. The resulting structures are in good agreement with the experimental structures showing that Monte Carlo simulated annealing is an efficient method for predicting crystal structures of DPP derivatives. [ABSTRACT FROM AUTHOR]

Abstract: By means of two alternative methods lipid and protein hydroperoxides (HP) were determined by fluorometry using the diphenyl-1-pyrenylphosphine (DPPP) probe. It has been shown that the formation of the fluorescence was influenced by the type of solvent and HP whereas the presence in the media of antioxidants such tocopherol and butylated hydroxytoluene had no effect. The combination of the chloroform:methanol (2:1, v/v) solvent mixture that is widely used for lipid extraction was combined with suitable solvents to develop a method with the maximum performance in determining HP in lipid extracts. Using a variety of lipids and lipid extracts, the final method proposed agreed well with the thiocyanate method for HP determination. In addition, the DPPP method was very sensitive, precise, accurate, free of interferences and specific for the determination of lipid soluble HP. DPPP can be also used to measure HP soluble in hydroalcoholic media. This alternative procedure showed a similar performance to its lipid soluble equivalent and was able to measure hydrogen peroxide promoted peroxidation of bovine serum albumin and water soluble HP in protein extracts. With the addition of triphenylphosphine the hydroalcoholic method is specific for the determination of protein HP. [Copyright &y& Elsevier]

Abstract: The influence of the operating conditions on the productivity on the CO–ethene copolymerisation catalysed by the title complex used in combination with TsOH and on the average numerical molecular weight, the limiting viscosity number and the average viscosity molecular weight of the resulting polyketone has been studied. The productivity, LVN and pass through a maximum for a TsOH/Pd ratio=6/1, whereas reaches a plateau and remains practically constant at higher acid concentration. They increase upon increasing the pressures of the monomers when employed in the ratio 1/1 as well as upon increasing the pressure of CO keeping constant the pressure of the other monomer; the productivity as well as increase, whereas the LVN and pass through a maximum upon increasing the pressure of ethene, keeping constant the pressure of CO. A power law rate equation for the productivity has been obtained. The productivity decreases whereas the molecular weights increase upon lowering the temperature; the productivity decreases upon increasing the reaction time, whereas the molecular weights are little influenced. The results are discussed in the light of the copolymerisation mechanism. [Copyright &y& Elsevier]

An efficient synthetic method for diphenyl-1-pyrenylphosphine, DPPP, has been developed involving a low temperature Li-Br exchange reaction using the commercially available 1-bromopyrene. An estimate of the donor ability of this phosphine has been obtained by measuring the A 1 υ(CO) band of the Ni(CO) 3 L complex which was found to be 0.4 wave numbers lower than that from the PPh 3 complex indicating that DPPP is a slightly better donor than PPh 3 . The BH 3 adduct of DPPP has been prepared and, as the situation for the oxide of DPPP, this adduct is fluorescent. It is estimated that the fluorescence intensity is about half that of DPPPO. An x-ray structure of this adduct has been obtained, and the bond lengths and angles appear to be in expected ranges. [ABSTRACT FROM AUTHOR]

Polyketones are obtained by the copolymerization of carbon monoxide and ethylene in the presence of a palladium catalyst formed in situ from Pd(OAc)2, dppp and formic acid in methanol which acted as a solvent. The productivity (g polymer/g Pd* h) is significantly influenced by the concentration of formic acid. Using the ratio Pd/dppp/HCOOH=1/1/3000 at 90 °C and 45 atm, a productivity of 7500 h−1 is obtained. It is suggested that the efficiency of HCOOH as a promoter is due to its capability to act as a source of Pd-hydride species, which initiates the catalytic cycle. [Copyright &y& Elsevier]

• Krill oil is a good source for omega-3 oils and contains high levels of phospholipid and astaxanthin. • Peroxide value in krill oil and/or krill oil-in water emulsion system cannot be detected by classical methods. • DPPP fluorescence method accurately and sensitively worked to determine lipid hydroperoxides in krill oil-in water emulsion system. • The formation rate of secondary oxidation products was verified that DPPP fluorescence method was accurate and sensitive at different environmental conditions. In this study, lipid oxidation evaluation methods were compared for a krill-oil-in-water emulsion system. With this aim, thiocyanate and DPPP (diphenyl-1-pyrenylphosphine) fluorescence methods were comparatively examined to determine primary oxidation products. 2-thiobarbituric acid reactive substances (TBARS), hexanal and propanal formation were also monitored as secondary oxidations products. All oxidation experiments were performed via both auto-oxidation at 45 °C and light-riboflavin induced photooxidation at 37 °C. The results have shown that thiocyanate method was not suitable to measure lipid hydroperoxides by the both in auto- and photo-oxidation systems. On the other hand, fluorescence intensity of samples containing the DPPP probe increased during incubation period which indicates the formation of lipid hydroperoxides could be detected via this method. TBARS, hexanal and propanal concentrations also increased during storage period and the formation kinetics of secondary oxidation products was confirmed that the DPPP fluorescence method was accurate and reliable at different environmental conditions. [ABSTRACT FROM AUTHOR]

Gender differences in the burden of cardiovascular disease (CVD) have been observed worldwide. In this study, plasmatic levels of trimethylamine (TMA) and blood oxidative biomarkers have been evaluated in 358 men (89 controls and 269 CVD patients) and 189 women (64 control and 125 CVD patients). The fluorescence technique was applied to determine erythrocyte membrane fluidity using 1,6-diphenyl-1,3,5-hexatriene (DPH) and Laurdan, while lipid hydroperoxides were assessed by diphenyl−1-pyrenylphosphine (DPPP). Results show that levels of plasmatic TMA were higher in healthy men with respect to healthy women (p = 0.0001). Significantly lower TMA was observed in male CVD patients (0.609 ± 0.104 μM) compared to healthy male controls (0.680 ± 0.118 μM) (p < 0.001), while higher levels of TMA were measured in female CVD patients (0.595 ± 0.115 μM) with respect to female controls (0.529 ± 0.073 μM) (p < 0.001). DPPP was significantly higher in healthy control men than in women (p < 0.001). Male CVD patients displayed a lower value of DPPP (2777 ± 1924) compared to healthy controls (5528 ± 2222) (p < 0.001), while no significant changes were measured in females with or without CVD (p > 0.05). Membrane fluidity was significantly higher (p < 0.001) in the hydrophobic bilayer only in control male subjects. In conclusion, gender differences were observed in blood oxidative biomarkers, and DPPP value might be suggested as a biomarker predictive of CVD only in men. [ABSTRACT FROM AUTHOR]

A new fluorimetric assay for simultaneous determination of lipid and protein hydroperoxides in muscle foods by the use of diphenyl-1-pyrenylphosphine (DPPP) was proposed in the study. Non-fluorescent DPPP that reacts with hydroperoxides stoichiometrically to yield fluorescent DPPP oxide, was used as a fluorescent dye to determine lipid and protein peroxidation in fish samples during frozen storage. The novel sensitive DPPP-assay developed for analysis under fluorescence microscopy conditions was based on this reaction. A good linear correlation between the amount of lipid hydroperoxides measured by the developed DPPP-assay and the peroxide value measured by iodometric titration was observed. Also, increase in fluorescence intensity from the reaction of DPPP with protein hydroperoxides in fish samples showed linear relation to the amount of cumene hydroxide added over a wide concentration range. The method was successfully applied on fish samples and can be used for fast assessment of primary oxidation stress in muscle foods. • The DPPP method is precise and correlated well with the iodometric titration assay. • Fluorescence microscopy allowed quantification of both lipid and protein peroxides. • Fluorescence microscopy visualized both lipid and protein peroxides. • The iodometric titration and fluorescence microscopy assays were compared. [ABSTRACT FROM AUTHOR]

Background: Free radical-mediated lipid peroxidation has been implicated in a number of human diseases. Diverse methods have been developed and applied to measure lipid peroxidation products as potential biomarkers to assess oxidative stress status in vivo, discover early indication of disease, diagnose progression of disease, and evaluate the effectiveness of drugs and antioxidants for treatment of disease and maintenance of health, respectively. However, standardized methods are not yet established., Scope of Review: Characteristics of various lipid peroxidation products as biomarkers are reviewed on the basis of mechanisms and dynamics of their formation and metabolism and also on the methods of measurement, with an emphasis on the advantages and limitations., Major Conclusions: Lipid hydroxides such as hydroxyoctadecadienoic acids (HODE), hydroxyeicosatetraenoic acids (HETE), and hydroxycholesterols may be recommended as reliable biomarkers. Notably, the four HODEs, 9-cis,trans, 9-trans,trans, 13-cis,trans, and 13-trans,trans-HODE, can be measured separately by LC-MS/MS and the trans,trans-forms are specific marker of free radical mediated lipid peroxidation. Further, isoprostanes and neuroprostanes are useful biomarker of lipid peroxidation. It is important to examine the distribution and temporal change of these biomarkers., General Significance: Despite the fact that lipid peroxidation products are non-specific biomarkers, they will enable to assess oxidative stress status, disease state, and effects of drugs and antioxidants. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Oxidative stress can damage cellular components including DNA, proteins or lipids, and may cause several skin diseases. To protect from this damage and addressing consumer's appeal to natural products, antioxidants obtained from algal and vegetal extracts are being proposed as antioxidants to be incorporated into formulations. Thus, the development of reliable, quick and economic in vitro methods to study the cytoactivity of these products is a meaningful requirement. A combination of erythrocyte and cell line-based assays was performed on two extracts from Sargassum muticum, one from Ulva lactuca, and one from Castanea sativa. Antioxidant properties were assessed in erythrocytes by the TBARS and AAPH assays, and cytotoxicity and antioxidant cytoprotection were assessed in HaCaT and 3T3 cells by the MTT assay. The extracts showed no antioxidant activity on the TBARS assay, whereas their antioxidant capacity in the AAPH assay was demonstrated. On the cytotoxicity assays, extracts showed low toxicity, with IC50 values higher than 200μg/mL. C. sativa extract showed the most favourable antioxidant properties on the antioxidant cytoprotection assays; while S. muticum and U. lactuca extracts showed a slight antioxidant activity. This battery of methods was useful to characterise the biological antioxidant properties of these natural extracts., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Polyphenols are largely studied for their beneficial action in various pathologies, but the correlation with their effects on cell membranes is still elusive. In the present study we assessed the effects exerted in vitro by quercetin, epigallocatechin gallate and curcumin on membrane fluidity and transmembrane potential of human umbilical vein endothelial cells and Jurkat T lymphoblasts, in experimental conditions mimicking diabetes mellitus, i.e. high glucose conditions or increased concentration of advanced glycation end products. Results showed that the investigated polyphenols had beneficial effects on cell membranes altered in diabetic conditions, by restoring transmembrane potential and by membrane "stiffening". Moreover, they limited the release of pro-inflammatory factors, like monocyte chemotactic protein-1. These effects were more obvious for cells exposed to advanced glycation end products specific for the late stages of diabetes. Apparently, the inhibitory action of polyphenols on lipid peroxidation was associated with a decrease of membrane fluidity. Concluding, our in vitro study highlighted the potential beneficial action of polyphenols mainly in the late stages of diabetes, exerted at the level of membrane fluidity and transmembrane potential, accompanied by an anti-inflammatory effect on endothelial and immune cells., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Cholesterol hydroperoxides (ChOOHs) are included as lipid peroxidation products in the skin exposed to ultraviolet (UV) light irradiation. They may exert physicochemical actions affecting biomembrane rigidity because cholesterol is one of the major components of cell membranes. We investigated the distribution of isomeric ChOOHs in heterogeneous cell membranes with different lipid profiles using mouse fibroblast NIH-3T3 cells as a model of the dermis. Before and after UVA irradiation in the presence of hematoporphyrin, cell membranes were partitioned to microdomains (lipid rafts and caveolae) containing a higher amount of cholesterol and non-microdomains (containing a lower amount of cholesterol) by ultracentrifugation. By a combination of diphenylpyrenylphosphine-thin-layer chromatography blotting analyses and gas chromatography-electron ionization-mass spectrometry/selected ion monitoring analyses, ChOOH isomers were determined as their trimethylsilyloxyl derivatives. Cholesterol 5α-, 7α- and 7β-hydroperoxide were found as isomeric ChOOHs before irradiation. The amounts of the three ChOOH isomers increased significantly after photoirradiation for 2h. No difference was observed between microdomains and non-microdomains with regard to the ratio of the amounts of isomeric ChOOHs to that of cholesterol, suggesting that these ChOOH isomers were distributed equally in both parts depending on cholesterol content. When cells were treated with a purified mixture of ChOOH isomers, cell membranes incorporated ChOOHs into microdomains as well as non-microdomains evenly. Cellular matrix metalloproteinase-9 (MMP-9) activity was elevated by treatment with the purified mixture of ChOOH isomers. These results strongly suggest that ChOOHs accumulate in cell membranes irrespective of the heterogeneous microstructure and promote MMP activity if dermal cells are exposed to photodynamic actions., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)