Rahmiye Ertan

Penetration of the pulp chamber by bleaching agents in teeth restored with various restorative materials.

It is thought that externally applied bleaching agents may penetrate into the pulp chamber. This study was conducted to evaluate the diffusion of peroxide bleaching agents into the pulp chamber of teeth restored with various restorative materials. Sixty-five human extracted anterior maxillary teeth were separated into the 13 groups containing 5 teeth. Five teeth (control group) were not subjected to any cavity preparation and restoration. Standardized class V cavities were prepared in the other 60 teeth and restored using composite resin (Charisma), polyacid modified composite resin (Dyract), or resin-modified glass ionomer cement (Vitremer). All teeth were sectioned 3 mm apical to the cementoenamel junction to remove the intracoronal pulp tissue, and the pulp chamber was filled with acetate buffer to absorb and stabilize any peroxide that might penetrate. Vestibular crown surfaces of teeth in the experimental groups were subjected to four different bleaching agents for 30 min at 37 degrees C, whereas the teeth in the control groups were exposed only to distilled water. Then the acetate buffer solution in the pulp chamber of each tooth was removed, and the pulp chamber of each tooth was rinsed with 100 ml of distilled water twice. Leukocrystal violet and enzyme horseradish peroxidase were added to the mixture of the acetate buffer and rinse water. The optical density of the resulting blue solution was determined spectrophotometrically and converted into microgram equivalents of hydrogen peroxide. Higher hydrogen peroxide concentrations resulted in a higher pulpal peroxide penetration. The highest pulpal peroxide penetration was found in resin-modified glass ionomer cement groups, whereas composite resin groups showed the lowest pulpal peroxide penetration.

Synthesis and biological activity of some new flavonyl-2,4-thiazolidinediones

A new series of flavonyl-2,4-thiazolidinediones (Va-c, VIa-c) was prepared by Knoevenagel reaction. The synthesized compounds were tested for their ability to inhibit rat kidney aldose reductase (AR) and for their insulinotropic activities in INS-1 cells. Compound Vb was able to increase insulin release in the presence of 5.6mmol/l glucose. Compounds VIa-c displayed moderate to high AR inhibitory activity levels. Particularly, compound VIa showed the highest AR inhibitory activity (86.57%).

Synthesis and aldose reductase inhibitory activity of some new chromonyl-2,4-thiazolidinediones.

As it is known that still, there were no any confident ARIs on the market and they have several side effects, we need to approve new ARIs to reduce diabetic complications especially which have effect on the cataract formation. In this study, a new series of chromonyl-2,4-thiazolidinediones (Ia-e, IIa-e, IIIa-e) were prepared by Knoevenagel reaction with substituted 3-formylchromones (3a-e) and unsubstituted (1) or substituted 2,4-thiazolidinedione (2). The synthesized compounds were tested for their ability to inhibit rat kidney AR by an in vitro spectrophotometric assay. Compound IIIe showed the highest inhibitory activity (82.43+/-0.76%). Compounds Ia-e and IIIa-d also showed significant inhibitory activity (42.40+/-5.78, 52.71+/-3.31, 49.69+/-1.55, 50.80+/-3.62, 46.70+/-2.33, 49.44+/-4.53, 61.17+/-4.74, 68.58+/-2.05, 77.28+/-0.26%, respectively).

Synthesis of some novel hydrazone and 2-pyrazoline derivatives: monoamine oxidase inhibitory activities and docking studies.

A novel series of 2-pyrazoline and hydrazone derivatives were synthesized and investigated for their human monoamine oxidase (hMAO) inhibitory activity. All compounds inhibited the hMAO isoforms (MAO-A or MAO-B) competitively and reversibly. With the exception of 5i, which was a selective MAO-B inhibitor, all derivatives inhibited hMAO-A potently and selectively. According to the experimental Ki values, compounds 6e and 6h exhibited the highest inhibitory activity towards the hMAO-A, whereas compound 5j, which carries a bromine atom at R(4) of the A ring of the pyrazoline, appeared to be the most selective MAO-A inhibitor. Tested compounds were docked computationally into the active site of the hMAO-A and hMAO-B isozymes. The computationally obtained results were in good agreement with the corresponding experimental values.

Synthesis and antidiabetic activity of some new chromonyl-2,4-thiazolidinediones

A series of chromonyl-2,4-thiazolidinediones/imidazolidinediones/2-thioxo-imidazolidine-4-ones (IIIa–i, IVa–i) was prepared by Knoevenagel reaction of 2,4-thiazolidinedione/2,4-imidazolidinedione/2-thioxo-imidazolidine-4-one (IIa–c) with 2/3-formyl chromone (Ia–b) and then alkylation with methyl/ethyl iodide. The prepared compounds were tested for their insulinotropic activities in INS-1 cells. Compounds ıVb and ıVc (at lower concentration, 1 μg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose.” should be written as “Compounds IVb and IVc (at lower concentration, 1 µg/mL) and also IIId and IIIg (at higher concentration) were able to increase insulin release in the presence of 5.6 mmol/L glucose. Compounds ıVb and ıVc (at lower concentration, 1 μg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose.

Antioxidant properties of flavone-6(4')-carboxaldehyde oxime ether derivatives.

Thein vitro antioxidant properties of some flavone-6(4)-carboxaldehyde oxime ether derivatives (la-f, lla-f) were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP) levels by measuring the formation of 2-thiobarbituric acid reactive substances. The free radical scavenging properties of the compounds were also examinedin vitro by determining their capacity to scavenge superoxide anions and interact with the stable free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH). The most active compounds,llb (Flavone-4′-carboxaldehyde-O-ethyl oxime) andId (Flavone-6-carboxaldehyde-O-[2-(1-pyrolidino) ethyl] oxime), caused 98 and 79% inhibition of superoxide anion production and DPPH stable free radical at 10p-3 M, respectively.

Some new thiazolyl thiazolidinedione derivatives as aldose reductase inhibitors

In diabetes, increased flux through the polyol pathway has been implicated in the development of diabetic complications such as cataract, retinopathy, neuropathy, and nephropathy. Aldose reductase (AR) appears to be the key factor in the reduction of glucose to sorbitol. Aldose reductase inhibitors have been found to prevent sorbitol accumulation in tissues. A series of thiazolyl-2,4-thiazolidinediones was prepared by Knoevenagel reaction of substituted benzyl-2,4-thiazolidinediones with chlorothiazolecarbaldehydes and were evaluated for their ability to inhibit rat kidney AR by an in vitro spectrophotometric assay. Results showed that compounds containing piperidine at the C-2 position of thiazole ring showed better inhibitory activity than thiazole compounds having 4-chlorobenzylsulfanyl at the same position.

Synthesis of some novel oxime ether derivatives and their activity in the 'behavioral despair test'

Abstract In this study, a new series of 2-aminoethyloxime ether derivatives of some aralkylketones was synthesized. Their structures have been elucidated by UV, IR, 1 H-NMR, 13 C-NMR, mass spectra and elementary analysis. These compounds were then screened for their inhibition of immobility as an indicator of possible antidepressant activities by using the ‘behavioral despair test’. Results showed that all the new compounds decreased the immobility time, however, the inhibition observed with AO3 , AO4 and HO1 was significantly higher compared to fluvoxamine ( p

Synthesis and antidiabetic activity of 2,4-thiazolidindione, imidazolidinedione and 2-thioxo-imidazolidine-4-one derivatives bearing 6-methyl chromonyl pharmacophore

Numerous compounds have been prepared in order to improve the pharmacological profile of insulinotropic activities. In the present paper, we report the synthesis and the in vitro insulin releasing activity of the 6-methyl-chromonyl-2,4-thiazolidinediones (IIIa–c, IVa–c, Va–c). Compounds IIIb, IIIc, IVa–c, Va and Vc (at lower concentration; 0.001 mg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose. In this series, the most potent compound is IVa having methyl group at N3 position of TZD ring.

Synthesis and Screening of Human Monoamine Oxidase-A Inhibitor Effect of New 2-Pyrazoline and Hydrazone Derivatives.

A group of 3,5‐diaryl‐2‐pyrazoline and hydrazone derivatives was prepared via the reaction of various chalcones with hydrazide compounds in ethanol. Twenty original compounds were synthesized. Ten of these original compounds have a pyrazoline structure, nine of these original compounds have a hydrazone structure, and one of these original compounds has a chalcone structure. Structural elucidation of the compounds was performed by IR, 1H NMR, 13C NMR, mass spectral data, and elemental analyses. These compounds were tested for their inhibitory activities toward the A and B isoforms of human monoamine oxidase (MAO). Except for 3k and 6c, all compounds were found to be competitive, reversible, and selective inhibitors for either one of the isoforms (hMAO‐A or MAO‐B). Compounds 3k and 6c were found to be competitive, reversible, but non‐selective MAO inhibitors. Compound 6h showed hMAO‐B inhibitory activity whereas the others potently inhibited hMAO‐A. Compound 5c showed higher selectivity than the standard drug moclobemide. According to the experimental Ki values, compounds 6i, 6d, and 6a exhibited the highest inhibitory activity toward hMAO‐A. The AutoDock 4.2 program was employed to perform automated molecular docking. The calculated results obtained computationally were in good agreement with the experimental values.