33 research outputs found

    Anticancer Activity and Biophysical Reactivity of Copper Complexes of 2-(benzo[d][1,3]dioxol-5-ylmethylene)-N-Alkylhydrazinecarbothioamides

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    A series of copper complexes were synthesized from benzo[d][1,3]dioxole-5-carbaldehyde (piperonal) thiosemicarbazones (RHpTSC where R = H, CH3, C2H5 or C6H5 (Ph)). The complexes show interesting variations in geometry depending on the thiosemicarbazone; a dinuclear complex [Cu(HpTSC)Cl]2, a mononuclear complex [Cu(RHpTSC)2Cl2] (R = CH3 or C2H5) and another mononuclear complex [Cu(PhHpTSC)(PhpTSC)Cl] was generated. The complexes bind in a moderately strong fashion to DNA with binding constants on the order of 104 M− 1. They are also strong binders of human serum albumin with binding constants near 104 M− 1. The complexes show good in vitro cytotoxic profiles against two human colon cancer cell lines (HCT-116 and HT29) and two human breast cancer cell lines (MCF-7 and MDA-MB-231) with IC50 values in the low millimolar concentration range

    Organometallic ruthenium complexes with thiosemicarbazone ligands: Synthesis, structure and cytotoxicity of [(η\u3csup\u3e6\u3c/sup\u3e-p-cymene)Ru(NS)Cl]\u3csup\u3e+\u3c/sup\u3e (NS = 9-anthraldehyde thiosemicarbazones)

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    A series of half-sandwich arene ruthenium complexes containing bidentate thiosemicarbazone ligands have been synthesized and their biological activity investigated. The compounds have the general formula [(6-p-cymene)Ru(R-ATSC)Cl]X (ATSC = 9-anthraldehyde thiosemicarbazone and R = H, CH3 and C6H5). The crystal structure of [(6-p-cymene) Ru(MeATSC)Cl]Cl have been determined and represents the first structurally characterized arene–ruthenium half-sandwich complex with a thiosemicarbazone ligand. The complexes show good cytotoxic profiles against MCF-7 and MDA-MB-231 (breast adenocarcinoma) as well as HCT 116 and HT-29 (colorectal carcinoma) cell lines. [Refer to PDF for graphical abstract

    Synthesis and characterization of mixed-ligand diimine-piperonal thiosemicarbazone complexes of ruthenium(II): Biophysical investigations and biological evaluation as anticancer and antibacterial agents

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    We have used a novel microwave-assisted method developed in our laboratories to synthesize a series of ruthenium-thiosemicarbazone complexes. The new thiosemicarbazone ligands are derived from benzo[d][1,3]dioxole-5-carbaldehyde (piperonal) and the complexes are formulated as [(diimine)2Ru(TSC)](PF6)2 (where the TSC is the bidentate thiosemicarbazone ligand). The diimine in the complexes is either 2,2′-bipyridine or 1,10-phenanthroline. The complexes have been characterized by spectroscopic means (NMR, IR and UV–Vis) as well as by elemental analysis. We have studied the biophysical characteristics of the complexes by investigating their anti-oxidant ability as well as their ability to disrupt the function of the human topoisomerase II enzyme. The complexes are moderately strong binders of DNA with binding constants of 104 M−1. They are also strong binders of human serum albumin having binding constants on the order of 104 M−1. The complexes show good in vitro anticancer activity against human colon cancer cells, Caco-2 and HCT-116 and indeed show some cytotoxic selectivity for cancer cells. The IC50 values range from 7 to 159 μM (after 72 h drug incubation). They also have antibacterial activity against Gram-positive strains of pathogenic bacteria with IC50 values as low as 10 μM; little activity was seen against Gram-negative strains. It has been established that all the compounds are catalytic inhibitors of human topoisomerase II

    Growth and heritability of size traits of Willow Tit Parus montanus nestlings-a supplementary feeding experiment

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    Growth and final body size of passerine birds may be influenced by both genetic and environmental factors, growth often being constrained by food limitation . This study investigates whether the growth of nestling Willow Tits Parus montanus is constrained due to food shortage and if offspring resemble their parents more in body size when parents are given access to additional amount of food (maggots). This was studied by comparing nestling growth in food-supplemented and control broods. During the study year nestling period coincided very well with peak abundance of caterpillars, the main prey of Willow Tits . This resulted in a very good growth of nestlings in the control group. Of the morphometric measurements, only wing length at 13 days of age differed between nestlings in fed broods and unfed controls . To control for the influence of heritable variation in growth a cross-fostering experiment was carried out with six broods. When eliminating the genetic factor, additional food showed a tendency to affect body mass at 13 days. The heritability of tarsus length was very high (h2 = 0.89 ± 0.28) . It is proposed that fast growth rather than large body size per se, is a life history strategy enabling an early nest-leaving and early establishment as a member of a winter flock, which increases an individual's survival chances during the first winter

    O novo ensino médio e o papel da filosofia como antidespótica: o currículo como estratégia política

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