Sinteza, in vitro antitumorsko ispitivanje i radiosenzitirajuće vrednovanje novih derivata 4-[3-(supstituiranih)tioureido]-N-(kinoksalin-2-il)benzensulfonamida

Sulfonamides and quinoxaline derivatives possess many types of biological activities and have been recently reported to show substantial antitumor activity. This paper reports the synthesis of novel thioureidosulfaquinoxaline derivatives. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against a human liver cell line (HEPG2) and showed higher activity than the reference drug doxorubicin. 4-(3-(4-Ethylbenzoate)thioureido)-N-(quinoxalin-2-yl)benzenesulfonamide (9) (IC50 = 15.6 µmol L1), N-(pyridin-2-yl)-4-(3-(4-(N-quinoxalin-2-yl-sulfamoyl)phenyl)thioureido)benzene-sulfonamide (10) (IC50 = 26.8 µmol L1) and N-(quinoxalin-2-yl)-4-(3-(4-(N-thiazol-2-ylsulfamoyl)phenyl)thioureido)benzenesulfonamide (11) (IC50 = 24.4 µmol L1) were the most potent compared to doxorubicin (IC50 = 71.8 µmol L1). The most potent compounds 9, 10 and 11 were evaluated as radiosensitizing agents by subjecting the compounds to γ-irradiation (8 kGy).Derivati sulfonamida i kinoksalina imaju raznoliko biološko djelovanje, između ostalog i antitumorsko djelovanje. U radu je opisana sinteza novih derivata tioureido sulfakinoksalina. Svim novim spojevima ispitano je antitumorsko djelovanje in vitro na humanoj staničnoj liniji jetre (HEPG 2). Svi ispitani spojevi pokazuju jači učinak nego referentni lijek doksorubicin. Najjači učinak imali su 4-(3-(4-etilbenzoat)tioureido)-N-(kinoksalin-2-il)benzen-sulfonamid (9) (IC50 = 15,6 µmol L1), N-(piridin-2-il)-4-(3-(4-(N-kinoksalin-2-il-sulfamoil)fenil)tioureido)-benzen-sulfonamid (10) (IC50 = 26,8 µmol L1) i N-(kinoksalin-2-il)-4-(3-(4-(N-tiazol-2-ilsulfamoil)fenil)tioureido)benzen-sulfonamid (11) (IC50 = 24,4 µmol L1), dok je IC50 vrijednost bila 71,8 µmol L1. Najaktivniji spojevi 9, 10 i 11 evaluirani su kao radziosenzitirajuća sredstva nakon izlaganja spojeva γ-zračenju (8 kGy)

Characterization of OPC Matrix Containing Dealuminated Kaolin

The suitability of replacing Portland cement by dealuminated calcined kaolin as received waste obtained from an alum production factory through the extraction of aluminium, also by dealuminated samples treated with lime solution, is investigated. The chemical and mineralogical compositions of the samples are measured. Their pozzolanic reactivity and their surface areas were determined. The effect of replacement on  setting time,  flowability, rate of flowability loss and strength of mortars was tested and compared to control OPC samples and others containing silica fumes. It was found that the as received dealuminated kaolin and that treated with lime possess higher pozzolanic reactivity and show larger surface areas than silica fumes. The incorporation of the as received dealuminated kaolin (DK) in OPC paste accelerates the setting time; while the lime-treated samples lead to retardation. The flowability of the OPC mortar is little affected by the as received DK samples and is strongly reduced by the lime-treated one and silica fumes. The three admixtures cause strong flowability loss with time. The 56d-compressive and tensile strengths of the mortars improve with 5 and 10% OPC replacement by DK

Interacción entre cementos de diferente composición y aditivos superplastificantes

The slump behavior of ordinary Portland-, pozzolanic (red brick powder)-, sulfate resistant-, and limestone cement pastes caused by ≤ 1% additions of polycondensates and polycarboxylates superplasticizers are monitored for up to 90 minutes. With the plolycondensates, Portland- and pozzolanic cements gain fluidity at higher dosages than sulfate resistant and limestone cements. Limestone cement shows the best slump retention. The aluminate and sulfate phases play a major role in the fluidity. With the polycarboxylates, all cements gain fluidity with dosages of ≤ 0.3%. A polycarboxylate with no resonance of methyl methylene proton in the main chain identified in the NMR spectra creates good slump retention. This is explained by a low mobility of the structure and the predominance of the steric effect. The polycarboxylate shows also strong ether bands relative to the ester groups in the IR spectra and a low polydispersity observed in the elution of few low molecular weight species in the HPLC chromatogram.Se ha estudiado el efecto fluidificante (hasta 90 minutos) ejercido por la incorporación de entre 0-1% de aditivos policondensados y policarboxilatos en pastas de cemento Portland, puzolánico, resistente a sulfatos y con adición de caliza. Con la incorporación de los aditivos policondensados, se produjo un incremento de la fluidez de los cementos Portland y puzolánico a mayores dosificaciones que las necesarias en los cementos resistente a sulfatos y con adición de caliza. Éste último presentó la mejor retención de la fluidez. Las fases aluminatos y sulfatos juegan un importante papel en la fluidez inducida. Todos los cementos incrementaron su fluidez con la incorporación de aditivos policarboxilatos a dosificaciones menores del 0,3%. El policarboxilato que no presenta en los espectros de RMN, resonancia asignada al protón de los grupos metil metileno, presenta buena retención de la fluidez. Esto es debido a la baja flexibilidad de la estructura y predominancia del efecto estérico. Este aditivo presenta también, mayor relación de grupos eter frente a grupos ester en los espectros IR, asi como una baja polidispersidad observada en la elución de especies de bajo peso molecular a través de HPLC

Removal of Crystal Violet and Hexavalent Chromium using TiO2-Bentonite under Sunlight: Effect of TiO2 Content

The main objective of this study was to investigate the correlation between TiO2 content in photoactive bentonite (B-TiO2) and the pathway by which crystal violet (CV) and hexavalent chromium (Cr (VI)) are removed from water under sunlight. B-TiO2 samples were prepared by impregnation with TiCl4 with different weight ratios (g/g) (namely, 5, 10, 20 and 30%). Materials were characterized using different techniques, among which: SEM, FT-IR, XRD, HRTEM, EDX and Zeta potential measurements. Results show that, only the anatase TiO2 polymorph was formed in the bentonite and the porosity of materials decreases with the increase of TiO2 content. Furthermore, zeta potential measurements indicate that, when TiO2 content increases, the negative charge of materials decreases. On the other hand, experimental results show that these materials combine both adsorption and photocatalytic reactions to remove CV molecules from water. As the TiO2 content increases, the adsorption capacity decreases, while the photocatalytic activity is more important. In the case of Cr (VI) species, all samples show a few adsorption because of the repulsion effect between these species and the negative charge of the bentonite. Therefore, under sunlight, the Cr (VI) removal occurred mainly by the photoreduction reaction that is more efficient when the TiO2 content increases

Dissolution Enhancement and Formulation of Rapid-Release Lornoxicam Mini-Tablets

The aim was to enhance the dissolution of lornoxicam (LOR) and to produce mini-tablets with an optimised system to provide a rapid-release multi-particulate formulation. LOR systems were prepared through co-evaporation with either polyethylene glycol 6000 or Pluronic® F-68 (PLU) and adsorption onto Neusilin® US2 alone or co-adsorption in the presence of different amounts of polysorbate 80. All systems were characterised by FT-IR, differential scanning calorimetry, X-ray diffraction, flowability and dissolution techniques. Mini-tablets were prepared using the system with the optimum dissolution profile and flowability. Tensile strengths, content uniformity and dissolution profiles of the mini-tablets were evaluated. The effects of different excipients and storage conditions on mini-tablet properties were also studied. The optimised rapid-release LOR mini-tablets were further evaluated for their in vivo pharmacokinetic profile. The co-evaporate of LOR with PLU showed significantly faster dissolution and superior flowability and was evaluated together with three directly compressible excipients (Cellactose® 80, StarLac® (STA) and Emcompress®) for mini-tablet formulation. The formulation with STA provided the optimum results in terms of tensile strength content uniformity and rapid drug release following a 3-month stability study and was selected for further in vivo evaluation. The pharmacokinetic profile indicated the potential of the mini-tablets achieving rapid release and increased absorption of LO