Publications by authors named "George Kolokythas"

Some new 2,6-disubstituted pyrano- and 1,2-dihydropyrano[2,3-c]xanthen-7-ones have been synthesized and their antiproliferative activity has been evaluated against MDA-MB-231 breast cancer cells. The antiproliferative activity evaluation of the compounds provided evidence that a dimethylamino substituted side chain and the presence of 1,2 double bond play a key role in cell growth inhibition. Among the tested derivatives the 6-dimethylaminoethylamino-2-nitropyranoxanthenone analogue possessed a significant inhibitory effect in a wide range of concentrations.

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Some novel aminosubstituted azapyranoxanthenones, bearing structural similarity to the acridone alkaloid acronycine, have been designed and synthesized. Their in vitro cytotoxicities against the murine L1210 leukemia and the human solid tumor HT-29 cell lines have been investigated. Their eventual selective effect on a phase of the cell cycle was evaluated, using HT-29 cells.

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The pollution of the surface waters of Greece from the priority compounds of 76/464/EEC Directive was evaluated. The occurrence of 92 toxic compounds, 64 of which belong to priority compounds of List II, candidates for List I, of 76/464/EEC Directive, was studied in surface waters and wastewater through the developed network of 62 sampling stations, which covers the whole Greek territory. The analytical determination was performed by Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds (VOCs), Gas Chromatography-Electron Capture Detection for organochlorine insecticides, Gas Chromatography-Nitrogen Phosphorous Detection for organophosphorous insecticides, High Performance Liquid Chromatography-Photodiode Array Detection for herbicides, and Electrothermal Atomic Absorption Spectrophotometry and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) for metals and the toluene extractable organotin compounds.

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A series of novel azapyranoxanthenones, bearing structural similarity to the acridone alkaloid acronycine have been designed and synthesized. Their in vitro cytotoxicities against the murine L1210 leukemia and the human solid tumor HT-29 cell lines have been investigated. The new derivatives exhibited interesting cytotoxic activity and were more potent than the parent compound.

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The priority substances of List I, 76/464/EEC Directive, some of which belong to the new Water Framework Directive 2000/60/EC, have been monitored in the surface waters of Greece through the developed network of 53 sampling stations. The analytical methods used for the determination of these substances included Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds, Gas Chromatography-Electron Capture Detection for organochlorine insecticides, High Performance Liquid Chromatography for pentachlorophenol and Atomic Absorption Spectrometry for metals. The results have shown the presence of several priority substances in Greek surface waters, in most cases at concentrations well below the regulatory limits.

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The occurrence of volatile organic compounds (VOCs) was studied in river water, lake water, seawater and treated wastewater in Greece from October 1998 to September 1999. The determination of 41 VOCs was performed with a Purge and Trap-Gas Chromatography-Mass Spectrometry method. Samples were collected seasonally from 10 rivers, seven lakes, three gulfs and four wastewater treatment plants.

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The synthesis, DNA binding and in vitro cytotoxicity of a series of novel pyranoxanthones, analogues of the acridone alcaloid acronycine, are described. The new compounds proved to bind weakly to DNA. On the contrary, they exhibited interesting cytotoxic activity against murine leukemia L1210 cell line, as well as against some human solid tumor cell lines.

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