Ion Sensor Properties of Fluorescent Schiff Bases Carrying Dipicolylamine Groups. A Simple Spectrofluorimetric Method to Determine Cu (II) in Water Samples.

Four fluorescent Schiff bases carrying dipicolylamine groups were designed and synthesized to determine their ion sensor properties in partial aqueous solution. The corresponding amine compound and the aldehyde compounds such as 1-naphthaldehyde, 9-anthraldehyde, phenanthrene-9-carboxaldehyde and 1-pyrenecarboxaldehyde were used to prepare the new Schiff bases. The influence of many metal cations and anions on the spectroscopic properties of the ligands was investigated in ethanol-water (1:1) by means of emission spectrometry. From the spectrofluorimetric titrations, the complexation stoichiometry and complex stability constants of the ligands with Cd2+, Zn2+, Cu2+ and Hg2+ ions were determined. The ligands did not interact with the anions. However, the Schiff base derived from phenanthrene-9-carboxaldehyde showed sensitivity for Cu2+ among the tested metal ions. The phenanthrene-based Schiff base was used as analytical ligand for the simple and fast determination of Cu2+ ion in water samples. A modified standard addition method was used to eliminate matrix effect. The linear range was from 0.3 mg/L to 3.8 µg/L. Detection and quantification limits were 0.14 and 0.43 mg/L, respectively. Maximum contaminant level goal (MCLG) for copper in drinking water according to EPA is 1.3 mg/L. The proposed method has high sensitivity to determine copper in drinking waters.

A Simple Spectrofluorimetric Method for Iron Determination with a Chalcone-Based Schiff Base.

A chalcone-based Schiff base (5), capable of detecting iron (III) in partially aqueous media, has been designed, then synthesized by the condensation of 3-formyl-2-hydroxyquinoline and acetophenone. To determine iron (III) ion, a simple spectrofluorimetric method was developed by using the synthesized Schiff base. The developed method was validated by analyzing the certified reference material (CRM-SA-C Sandy Soil C). During the process of the determination of iron in food samples, satisfactory accuracy was obtained for spinach and rocket. Nitric acid and hydrogen fluoride were used for the digestion of the certified reference material whereas only nitric acid was used for food samples, in a closed microwave system. Measurements were carried out by using the modified standard addition method. The standard addition graph was linear until 5.0 mg/L. in determination of iron (III). Detection and quantification limits were 0.06 and 0.20 mg/L., respectively. The presented method is simple, time-saving, cost-effective and suitable for determination of iron content of soil and foods.

Metal Complexation Properties of Schiff Bases Containing 1,3,5-Triazine Derived from 2-Hydroxy-1-Naphthaldehyde in Solution. A Simple Spectrofluorimetric Method to Determine Mercury (II).

Four new Schiff base ligands carrying naphthalene groups were prepared from the reaction of 2,4-diamino-6-methyl-1,3,5-triazine and 2,4-diamino-6-undecyl-1,3,5-triazine with 2-hydroxy-1-naphthaldehyde. The influence of a series of metal ions including Cu2+, Co2+, Hg2+, Al3+, Cr3+, Fe3+, Pb2+, Ni2+, Cd2+, Zn2+, Mn2+, Ag+, Ba2+, Ca2+ and Mg2+ on the spectroscopic properties of the ligands was investigated by means of absorption and emission spectrometry. The results of spectrophotometric and spectrofluorimetric titrations disclosed the complexation stoichiometry and complex stability constant of the ligands with metal ions. A simple spectrofluorimetric method was developed using the Schiff base derived from 2,4-diamino-6-undecyl-1,3,5-triazine to determine Hg2+ ion. No cleanup or enrichment of the tap water sample was required. A modified standard addition method was used to eliminate matrix effect. The standard addition graph was linear between 0.2 and 2.6 mg/L in determination of Hg2+. Detection and quantification limits were 0.08 and 0.23 mg/L, respectively. The simple and cost-effective method can be applied to water samples.

A Simple Spectrofluorimetric Method Based on Quenching of a Nickel(II)-Phthalocyanine Complex to Determine Iron (III).

A new nickel(II)-phthalocyanine complex (NiPc) was synthesized and used as a fluorescent ligand in determination of iron in real samples. The NiPc compound, when excited at 350 nm, decreases of emission with increases of the iron(III) concentration at 425 nm were used analytical response in a modified standard addition method. The method was validated by analyzing two certified reference materials (CRM-SA-C Sandy Soil C and Mixed Polish Herbs (INCT-MPH-2). Food and drug samples were digested in a closed microwave system using nitric acid and hydrogen peroxide. Therefore, all iron in the samples converted to iron(III) ion. These solutions were used directly in determination of iron(III) ion. No cleanup or enrichment of the solutions was required. The calibration graph was linear until 14.00 µg mL(-1). Detection limit and quantification limit were 1.29 µg mL(-1) and 3.88 µg mL(-1), respectively. The method provided accurate results for the majority of the food samples tested, including spanich, dill, mint, purslane, rocket, red lentils, dry beans and two iron medicinal tablets. Also, the high recovery (95.6 %) was obtained for a fortified stream water sample. The simple and cost-effective method is suitable for monitoring total iron concentration in foods and drug samples.

Axially diethylaminophenoxypropanoxy substituted new subphthalocyanines: synthesis and electropolymerization properties.

The treatment of boron(III) subphthalocyanine chloride with 1,3-bis[3-(diethylamino)phenoxy]propan-2-ol 2 and 2,3-bis[3-(diethylamino)phenoxy]propan-1-ol 4 in toluene gave the corresponding axially substituted boron(III) subphthalocyanine compounds 3 and 5. The novel axially diethylaminophenoxypropanoxy substituted subphthalocyanines were characterized by standard spectroscopy methods. The electropolymerization properties of new axially diethylaminophenoxypropanoxy substituted subphthalocyanines were also characterized by using cyclic and square wave voltammetry techniques. This study is the first example of electropolymerization of axially substituted subphthalocyanines in the literature.

Electropolymerizable peripherally tetra-{2-[3-(diethylamino)phenoxy]ethoxy} substituted as well as axially (4-phenylpiperazin-1-yl)propanoxy-disubstituted silicon phthalocyanines and their electrochemistry.

A novel type of peripherally tetra-substituted as well as axially disubstituted silicon(iv) phthalocyanine containing electropolymerizable ligands was designed and synthesized for the first time. Axial bis-hydroxy silicon phthalocyanine 2 was prepared from 2(3),9(10),16(17),23(24)-tetrakis-{2-[3-(diethylamino)phenoxy]ethoxy}phthalocyanine 1 in dichloromethane by using 1.8-diazabicyclo[5.4.0]undec-7-ene (DBU) and trichlorosilane. Peripherally tetra and axially di-substituted silicon phthalocyanine 4 was synthesized from 2(3),9(10),16(17),23(24)-tetrakis-{2-[3-(diethylamino)phenoxy]ethoxy}silicon(iv)phthalocyanine dihydroxide 2 with 1-(3-chloropropyl)-4-phenylpiperazine 3 in toluene in the presence of NaH at 120 °C. These complexes were fully characterized by various spectroscopy techniques such as (1)H-NMR, (13)C-NMR, IR, UV-Vis, and MALDI-TOF spectroscopy and elemental analysis as well. Electropolymerization properties of silicon(IV) phthalocyanine complexes were investigated by cyclic and square wave voltammetry. Electrochemical studies reveal that silicon(IV) phthalocyanine complexes were electropolymerized on the working electrode during the anodic potential scan. This study is the first example of electropolymerization of both peripherally tetra and axially di-substituted silicon phthalocyanines on the same molecule.

Non-aggregated axially disubstituted silicon phthalocyanines bearing electropolymerizable ligands and their aggregation, electropolymerizaton and thermal properties.

A novel series of axially disubstituted silicon(iv) phthalocyanines bearing electropolymerizable ligands were designed and synthesized for the first time. The silicon(iv) phthalocyanines were characterized by various spectroscopic techniques as well as elemental analysis. The aggregation behavior of the SiPcs were examined in different solvents and at different concentrations in chloroform. In all the studied solvents and concentrations, the SiPcs were non-aggregated. The thermal behavior of the silicon(iv) phthalocyanines was also studied. The electropolymerization properties of the silicon(iv) phthalocyanines were investigated by cyclic and square wave voltammetry. This study is the first example of the electropolymerization of axially disubstituted silicon phthalocyanines. The type of axial ligand on the phthalocyanine ring did not show any effect on the absorption and thermal properties but influenced the electropolymerization of the phthalocyanines.

Simple time-saving method for iron determination based on fluorescence quenching of an azaflavanon-3-ol compound.

A simple and time-saving spectrofluorometric method developed using an azaflavanon-3-ol compound was used for the determination of iron in various food samples. Nitric acid and hydrogen peroxide were used for digestion of samples in a closed microwave system. The method was validated by analyzing two certified reference materials (CRM-SA-C Sandy Soil C and Mixed Polish Herbs INCT-MPH-2). Measurements were carried out using a modified standard addition method. The standard addition graph was linear until 21.6 mg/L in the determination of iron(III). Detection and quantification limits were 0.81 and 2.4 mg/L, respectively. Satisfactory accuracy was obtained for spinach, dill, mint, purslane, rocket, red lentils, dry beans, and two iron medicinal tablets. High recoveries were found for streamwater samples fortified at three different concentrations. The method is simple, time-saving, cost-effective, and suitable for the determination of the iron content of foods.

DNA damage in children with obstructive adenotonsillar hypertrophy.

The objective of this prospective, controlled study was to evaluate oxidative DNA damage in children with obstructive adenotonsillar hypertrophy. This study included 30 patients with obstructive adenotonsillar hypertrophy (male/female ratio, 3:2; age range, 3-9 y) scheduled to undergo tonsillectomy and adenoidectomy and 25 control subjects of similar age and sex with no adenotonsillar disease or airway obstruction. Urine and blood samples were obtained from each child for 8-hydroxy 2-deoxyguanosine (8-OhdG) and malondialdehyde (MDA) concentrations. There were significant differences in leukocyte (3.28 [0.69/10] vs 0.70 [0.15/10] dG) and urine 8-OhdG (8.22 [2.27/10] vs 5.26 [1.3/10] dG) levels in patients with obstructive adenotonsillar hypertrophy and healthy subjects (P < 0.001 for both). Plasma (2.98 [1.31] vs 1.14 [0.64] µM) and urine (1.77 [0.84] vs 0.56 [0.32] µM) MDA levels were also different (P < 0.001 for both). There were positive correlations between 8-OhdG in leukocyte DNA and plasma MDA (r = 0.648, P < 0.001) and between levels of urine 8-OhdG excretion and urine MDA (r = 0.588, P < 0.001). The DNA damage in children with adenotonsillar hypertrophy should be kept in mind, but further studies must be done with larger patient groups.

Accelerated atherosclerosis in haemodialysis patients; correlation of endothelial function with oxidative DNA damage.

BACKGROUND: Accelerated atherosclerosis is the major cause of mortality in patients on chronic haemodialysis (HD). The aim of this study was to evaluate the relationship between oxidative DNA damage [8-hydroxy-2'-deoxyguanosine/deoxyguanosine ratio (8-OHdG/dG ratio)], oxidative stress biomarkers and endothelial function in HD patients as an indicator of atherosclerosis. METHODS: Forty-four chronic HD patients without known atherosclerotic disease and 55 age- and sex-matched healthy individuals were included in the study. Plasma malondialdehyde (MDA) levels and 8-OHdG/dG ratio were determined as oxidative stress markers. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured as antioxidants. Endothelial function was assessed by ultrasonography. RESULTS: 8-OHdG/dG ratio and MDA levels were higher in HD patients than controls while SOD and GPx activities were lower in HD patients compared to controls. Flow-mediated dilatation FMD% in HD patients were lower than the control group (7.28 ± 0.79 versus 11.18 ± 0.82, P < 0.001). There was a significant negative correlation between FMD% and 8-OHdG/dG ratio (r = -0.678, P < 0.01) and MDA levels (r = -0.517, P < 0.01), while there was a significant positive correlation between FMD% and SOD (r = 0.538, P < 0.01) and GPx levels (r = 0.720, P < 0.01). CONCLUSIONS: Our data have demonstrated that HD patients exhibit increased oxidative DNA damage and decreased antioxidant activity. We propose that endothelial function is negatively correlated with 8-OHdG/dG ratio and positively correlated with antioxidant enzymes. To our knowledge, this is the first study to demonstrate the inverse relationship between endothelial function and plasma oxidative DNA damage in HD patients.

Oxidative DNA damage in patients with cataract.

PURPOSE: This study examines the levels of oxidative damage in patients with cataract. METHODS: Blood samples were collected from 60 patients with cataract and 60 age- and gender-matched healthy individuals to measure 8-hydroxy 2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) levels. RESULTS: A significant difference was observed in leukocyte 8-OHdG levels in patients with cataract in comparison with healthy persons (p < 0.001). Similarly, a significant difference was observed in plasma MDA levels in patients with cataract in comparison with healthy persons (p<0.001). In addition, a significant correlation was found between levels of 8-OHdG in leukocyte DNA and plasma MDA (r = 0.859, p < 0.001). CONCLUSION: This study measured the oxidative DNA damage by measuring the 8-OHdG in the leukocyte DNA in patients with cataract. In addition, the level of MDA - a marker for lipid peroxidation - was measured to determine lipid peroxidation.

Chemical composition of natural colophony from Pinus brutia and comparison with synthetic colophony.

The compositions of colophony resins obtained from Pinus brutia Ten trees by three different methods (acid paste, carved hole and scraping) from Ayvacik, Gökova and Kemalpasa in Turkey were analyzed by capillary GC-MS. The main components were the monoterpenes alpha-pinene, beta-pinene, and delta3-carene, and the diterpenic resin acids palustric, abietic, kaur-9(11)-16-en-18-oic and neoabietic acid. The synthetic colophony resins exhibited similar contents to those of the natural resins obtained from the Gökova and Kemalpasa regions of Turkey. However, colophony resins from Ayvacik exhibited only half the diterpenic acid content as those of the Gökova and Kemalpasa resins. Out of the three techniques, the carved hole method caused rather different percentages in the constituents of the essential oils.

Selective recognition of cobalt (II) ion by a new cryptand compound with N2O2S2 donor atom possessing 2-hydroxy-1-naphthylidene Schiff base moiety.

A new cryptand compound carrying 2-hydroxy-1-naphthylidene Schiff base moiety (3) was designed and synthesized by reaction of the corresponding macrobicyclic amine compound (1) and 2-hydroxy-1-naphthaldehyde (2). The influence of metal cations such as Mg2+, Ca2+, Sr2+, Fe2+,Co2+, Mn2+, Zn2+, Cd2+, Hg2+, Al3+ and Pb2+ on the spectroscopic properties of the new fluoroionophore was investigated in acetonitrile-dichloromethane solution (9.5/0.5) by means of absorption and emission spectrometry. The blue shifts on the fluorescence spectrum were observed for all metal cations at 504 nm. At the same time the fluorescence spectrum of the ligand showed quenching in the intensity of the signal at 504 nm for all metal cations except for Zn2+. Interaction of Co2+ with the ligand caused quenching of naphtyl fluorescence higher than 84%. The method showed good selectivity and sensitivity for Co2+ with respect to other metal cations with linear range and detection limit of 1.5 x 10(-7) to 3.3 x 10(-6) M and 4.8 x 10(-8) M respectively.

Synthesis and metal ion binding properties of thiaaza crown macrocycles.

Two new macrocyclic ligands (3) and (4), containing nitrogen-sulfur donor atoms, were designed and synthesized in a multi-step reaction sequence. The macrocycles (3) and (4) were used in solvent extraction of metal picrates such as Ag(+), Hg(2+), Cd(2+), Zn(2+), Cu(2+), Ni(2+), Mn(2+), Co(2+), and Pb(2+) from aqueous phase to the organic phase. The metal picrate extractions were investigated at 25+/-0.1 degrees C by using UV-visible spectrometry. The extractability and selectivity of the mentioned metal picrates were evaluated according to the organic solvents. The values of the extraction constants (logK(ex)) and the complex compositions were determined for the extracted complexes.