Quantum chemical computational studies on bis-thiourea zinc acetate

In this study, quantum chemical calculations of vibrational spectra, Raman spectra, electronic properties (total energy, dipole moment, electronegativity, chemical hardness and softness), Mulliken atomic charges and thermodynamic parameters of bis-thiourea zinc acetate (BTZA) have been performed using Gaussian 09 program. Additionally, nonlinear optical (NLO), conformational, natural bond orbital (NBO) analyses of BTZA have been carried out using the same program. The structural and spectroscopic data of the molecule in the ground state have been calculated using Hartree-Fock (HF) and density functional method (DFT/B3LYP) with the 6-311++G(d,p) basis set. In addition, the molecular frontier orbital energies (HOMO, HOMO-1, LUMO and LUMO+1) of the title compound have been calculated at the HF and B3LYP levels. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Finally, the calculated results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the experimental ones.     

Determination of Optimum Conditions and the Kinetics of Methanol Oxidation

In this study, the catalytic oxidation of methanol to formaldehyde was investigated in a laboratory‐scale fixed‐bed catalytic reactor, under a large number of different conditions. Iron‐molybdate catalysts supported by silica or alumina with a molybdenium/iron (Mo/Fe) ratio of 1.5, 3 and 5 were studied for the gas phase reaction. In order to obtain the optimum conditions, six different temperatures in the range of 250–375 °C and three different space times of 50.63, 33.75 and 20.25 g/(mol/h) were investigated. After determining the optimum conditions for this reaction, experiments aimed at understanding the reaction kinetics, were carried out. These experiments were performed on the catalyst favoring the formation of formaldehyde, which has a (Mo/Fe) ratio of 5 on a silica support. Seven reaction models derived by the mechanisms cited in the literature were tested to elucidate the kinetics of the reaction and the surface reaction controlling model was found to be the most suitable reaction mechanism.     

Coenzyme Q10 supplementation and diastolic heart functions in hemodialysis patients: A randomized double‐blind placebo‐controlled trial

Coenzyme Q10 (CoQ10) supplementation has been shown to improve diastolic heart function in various patient cohorts. Systolic and diastolic dysfunctions are common in patients with end‐stage renal disease. Favorable effects of CoQ10 on cardiac functions are yet to be seen in hemodialysis patients. We aimed to evaluate effect of CoQ10 supplementation on diastolic function in a cohort of maintenance hemodialysis patients. This was a prospective, double‐blind, placebo‐controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d during the 8 weeks in each phase, with a 4‐week washout period. Participants underwent conventional and tissue Doppler echocardiography before and after each study phase. Parameters characterizing left ventricle diastolic function and other standard echocardiographic measurements were recorded. Twenty‐eight patients were randomized, but 22 patients completed study protocol. Intraventricular septum (IVS) thickness and left ventricle mass were significantly decreased in CoQ10 group (P = 0.03 and P = 0.01, respectively). Myocardial peak systolic and early diastolic velocities derived from IVS were significantly increased (P = 0.048 and P = 0.04, respectively). Isovolumetric relaxation time and E/Em ratio calculated for IVS also significantly reduced in CoQ10 group (p = 0.02 and p = 0.04, respectively). There was no significant difference in any of the studied echocardiographic parameters in placebo group. The results of this study showed that CoQ10 supplementation did not significantly improved diastolic heart functions compared with placebo in maintenance hemodialysis patients.     

Cancer Cell Cytotoxicities of 1-(4-Substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine Derivatives

A series of novel 1-(4-substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine derivatives 5a-g was designed by a nucleophilic substitution reaction of 1-(4-chlorobenzhydryl)piperazine with various benzoyl chlorides and characterized by elemental analyses, IR and (1)H nuclear magnetic resonance spectra. Cytotoxicity of the compounds was demonstrated on cancer cell lines from liver (HUH7, FOCUS, MAHLAVU, HEPG2, HEP3B), breast (MCF7, BT20, T47D, CAMA-1), colon (HCT-116), gastric (KATO-3) and endometrial (MFE-296) cancer cell lines. Time-dependent cytotoxicity analysis of compound 5a indicated the long-term in situ stability of this compound. All compounds showed significant cell growth inhibitory activity on the selected cancer cell lines.     

Screening of antioxidative properties of the methanolic extracts of Pelargonium endlicherianum Fenzl., Verbascum wiedemannianum Fisch. & Mey., Sideritis libanotica Labill. subsp. linearis (Bentham) Borm., Centaurea mucronifera DC. and Hieracium cappadocicum Freyn from Turkish flora

Five extracts from five plants, of which four are endemic to Turkish flora, were screened for their possible in vitro antioxidant activities by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid. In the first case, Pelargonium endlicherianum extract exerted greater antioxidant activity than those of other plant extracts studied with an IC₅₀ value of 7.43 ± 0.47 μg/ml, followed by Hieracium cappadocicum (30.0 ± 0.14 μg/ml). When compared to the synthetic antioxidant BHT (18.0 ± 0.40 μg/ml), the methanolic extract of P. endlicherianum exhibited more than two fold greater antioxidant activity. In the β-carotene/linoleic acid test system, the most active plant was P. endlicherianum with 72.6% ± 2.96 inhibition rate, followed by H. cappadocicum (55.1% ± 2.33) and Verbascum wiedemannianum (52.5% ± 3.11). Antioxidant activities of curcumin and ascorbic acid were also determined as positive controls in parallel experiments.     

Antimicrobial and antioxidant properties of the essential oils and methanol extract from Mentha longifolia L. ssp. longifolia

This study was designed to evaluate antimicrobial and antioxidant activities of the essential oil and methanol extract from Mentha longifolia ssp. longifolia. The essential oil showed strong antimicrobial activity against all 30 microorganisms tested whereas the methanol extract almost remained inactive. In contrast, the extract showed much better activity than the essential oil in antioxidant activity assays employed, e.g. in the inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene/linoleic acid systems. In the former, the extract was able to reduce the stable free radical DPPH with an IC₅₀ of 57.4 μg/ml while that of the oils was 10 700 μg/ml. When compared to BHT, a synthetic antioxidant, both showed weaker antioxidative potential. Similarly, in β-carotene/linoleic acid assay, these samples were not effectively able to inhibit the linoleic acid oxidation; exhibiting only 24% and 36% inhibitions at 2 mg/ml, respectively; both were far below than that of BHT. Total phenolic constituent of the extract was 4.5 g/100 g as gallic acid equivalent. GC–MS analysis of the oil resulted in the identification of 45 constituents, cis-piperitone epoxide, pulegone and piperitenone oxide being the main components.     

Investigation of the antioxidant properties of Ferula orientalis L. using a suitable extraction procedure

The present work examines the in vitro antioxidant properties of the essential oil and various extracts prepared from the herbal parts of Ferula orientalis A. (Apiaceae). The highest 2,2-diphenyl-l-picrylhydrazyl (DPPH) radical-scavenging activity was found in the polar extract, e.g. methanol–water (1:1), obtained from non-deodorised materials with IC₅₀ values at 99.1 μg/ml. In the β-carotene/linoleic acid assay, the deodorised acetone extract exhibited stronger activity than the polar one. The relative antioxidant activities (RAA%) of the extracts ranged from 10.1% to 76.1%, respectively. Extraction with methanol–water (1:1) mixture was concluded to be the most appropriate method in terms of higher extract yield, as well as effectiveness, observed in both assays. Although the essential oil showed antioxidative potential, it was not as strong as that of positive control (BHT). GC/MS analysis of the essential oil resulted in the identification of 39 compounds, β-phellandrene (23.6%), (E)-β-ocimene (13.8%), α-pinene (12.5%), α-phellandrene (11.5%) and dehydro-sesquicineole (10.1%) being the major components.     

Shear bond strengths of two newly marketed self-adhesive resin cements to different substrates: A light and scanning electron microscopy evaluation

The purpose of this in vitro study was to compare the shear bond strengths (SBSs) of two newly marketed self-adhesive resin cements (RCs) to enamel, dentin, and lithium disilicate (LiSi) glass ceramic block. Forty-eight enamel and 48 dentin substrates were obtained from sound human molars. Additionally, 6 × 7 × 5 -mm- sized 24 specimens were produced from LiSi glass ceramic blocks. The tooth specimens were randomly assigned into four groups (n = 12) according to the surface treatments: (1) G-CEM ONE (GCO), (2) G-CEM ONE Adhesive Enhancing Primer (GCO-AEP) + GCO, (3) RelyX Universal (RXU), and (4) Scotchbond Universal Plus (SUP) + RXU. LiSi specimens were randomly divided into two groups (n = 12): (1) G-MultiPrimer (GMP) + GCO and (2) SUP + RXU. Following the RC applications, all specimens were kept in 100% humidity at 37°C for 24 hr and then submitted for SBS testing in a universal testing machine (1 mm/min). Data were analyzed by Welch's, one-way analysis of variance and two independent samples t tests. The nature of failures was examined under a light microscope, and scanning electron microscopy analyses were also performed for interfaces. GCO and RXU showed similar SBS to enamel (p > .05), and the use of adhesives resulted in improved SBS (p < .05). No difference was detected between GCO-AEP + GCO and SUP + RXU. The GCO-AEP + GCO exhibited the highest SBS to dentin (p < .05), followed by GCO ≥ SUP + RXU > RXU (p < .05). There was no significant difference between SBSs of two RCs to LiSi blocks (p > .05). No cohesive failure was determined for the tested groups by light microscope. The use of adhesives prior to the application of self-adhesive RCs improved their bonding to tooth tissues. GCO demonstrated superior SBS to dentin, whereas both self-adhesive RCs generated similar SBS to enamel and LiSi glass ceramic surfaces.