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Biological evaluation of 8-alkyl xanthines as potential cytotoxic agents  [PDF]
Renuka Suravajhala, Nitasha Suri, Madhulika Bhagat, Ajit Kumar Saxena
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.33035
Abstract:

A series of 8-substituted alkyl xanthines were evaluated in vitro to test the cytotoxocity in cells. For this experiment, we utilized different mammalian cancer cell lines primarily representing prostrate and lung. One of the compounds synthesized, viz. 8-tertbutyl caffeine showed potent anticancer activity at low concentrations against DU145 when compared to adriamycin. Further experiments were carried out to check the cell cycle arrest in the DU145 cells treated with adriamycin, caffeine and 8-tert butyl caffeine. We observed that there was an arrest in G1 phase of cell cycle at 24 hours while at 48 hours of incubation, the cells were constantly distributed (59.71% -70.79%). We conclude that the effect of 8-tertbutyl caffeine is relatively comparable to caffeine whereas in adriamycin treated cells, we observed the cells underwent G2 arrest. We evaluate the studies on these effects by showing potent analogues which could be used as promising anticancer agents.

Non-bridging ligand effects on the kinetics of reduction of chloro- and azido-pentaamminecobalt(III) by some polypyridyl complexes of ruthenium(II)
Olayinka A. Oyetunji, Maipelo Gabalebe, Ngonye Sabure
Bulletin of the Chemical Society of Ethiopia , 2006,
Abstract: Pentaamminecobalt(III) complexes, [Co(NH3)5X]2+ (X = Cl-, N3-), are reduced by [Ru(bipy)3]2+ and [Ru(terpy)(bipy)Cl]+ in aqueous media at a constant ionic strength of 0.5 M (HCl/LiCl). At 308 K, the second order rate constants (M-1 s-1) are as follows: 17.9 for the reduction of the azidocobalt(III) complex by [Ru(bipy)3]2+, and 1.41 and 2.63 for the [Ru(terpy)(bipy)Cl]+ reduction of the azido- and chlorocobalt(III) complexes, respectively. Activation enthalpies (ΔH#) and entropies (ΔS#) were determined from temperature dependence measurements with the following results: ΔH# = 72.1 kJ mol-1 and ΔS# = 13.3 J mol-1 K-1 for the [Ru(bipy)3]2+ reduction of the azidocobalt(III) complex, while for the reduction of the cobalt(III) complexes by [Ru(terpy)(bipy)Cl]+, ΔH#(N3-) = 20.3 kJ mol-1, ΔH#(Cl-) = 40.6 kJ mol-1, ΔS#(N3-) = -177 J mol-1 K-1, and ΔS#(Cl-) = -106 J mol-1 K-1. The relative rates of electron transfer in the different reactions and the influence of π-acceptor ligands on the ruthenium(II) reduction of the cobalt(III) complexes are discussed. KEY WORDS: Non-bridging ligands, Pentaamminecobalt(III) complexes, Azidocobalt(III) complex, Chlorocobalt(III) complex, Kinetics of reduction of cobalt(III) complexes, Ruthenium(II) polypyridyl complexes Bull. Chem. Soc. Ethiop. 2006, 20(2), 227-234.
Non-bridging ligand effects on the kinetics of reduction of chloro- and azido-pentaamminecobalt(III) by some polypyridyl complexes of ruthenium(II)  [cached]
Olayinka A. Oyetunji,Maipelo Gabalebe,Ngonye Sabure
Bulletin of the Chemical Society of Ethiopia , 2006,
Abstract: Pentaamminecobalt(III) complexes, [Co(NH3)5X]2+ (X = Cl-, N3-), are reduced by [Ru(bipy)3]2+ and [Ru(terpy)(bipy)Cl] + in aqueous media at a constant ionic strength of 0.5 M (HCl/LiCl). At 308 K, the second order rate constants (M-1 s-1) are as follows: 17.9 for the reduction of the azidocobalt(III) complex by [Ru(bipy)3]2+, and 1.41 and 2.63 for the [Ru(terpy)(bipy)Cl]+ reduction of the azido- and chlorocobalt(III) complexes, respectively. Activation enthalpies (ΔH ) and entropies (ΔS ) were determined from temperature dependence measurements with the following results: ΔH = 72.1 kJ mol-1 and ΔS = 13.3 J mol-1 K-1 for the [Ru(bipy)3]2+ reduction of the azidocobalt(III) complex, while for the reduction of the cobalt(III) complexes by [Ru(terpy)(bipy)Cl] +, ΔH (N3-) = 20.3 kJ mol-1, ΔH (Cl-) = 40.6 kJ mol-1, ΔS (N3-) = -177 J mol-1 K-1, and ΔS (Cl-) = -106 J mol-1 K-1. The relative rates of electron transfer in the different reactions and the influence of π-acceptor ligands on the ruthenium(II) reduction of the cobalt(III) complexes are discussed.
An efficient and recyclable iron(III)-containing imidazolium salt catalyst for cross-coupling of aryl Grignard reagents with alkyl halides
ChunHui Yan,LinLin Wang,HuanHuan Gao,HongMei Sun,Qi Shen
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-011-4660-3
Abstract: 1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride, [DIPrim]Cl, was used to produce a novel iron(III)-containing imidazolium salt [DIPrim][FeCl4], which included a N,N-diarylimidazolium cation (R = 2,6-diisopropylphenyl), [DIPrim]+, and tetrachloroferrate(III) anion, [FeCl4] . This compound was an effective and easy-to-use catalyst for the cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens. After simply decanting the cross-coupling product in the ether layer, [DIPrim][FeCl4] could be reused in at least four successive runs without significant loss of catalytic activity.
Synthesis and antimicrobial activities of novel 8-(1-alkyl/alkylsulphonyl/alkoxycarbonyl-benzimidazol-2-ylmethoxy)-5-chloroquinolines  [PDF]
RAJU B. CHAUDHARI,SAHEBRAO S. RINDHE
Journal of the Serbian Chemical Society , 2011,
Abstract: The synthesis of a series of novel 8-(1-alkyl/alkylsulphonyl/alkoxycarbonyl-benzimidazol-2-ylmethoxy)-5-chloroquinoline derivatives is reported. These derivatives were prepared by the condensation of o-phenylenediamine with [(5-chloroquinolin-8-yl)oxy]acetic acid, followed by substitution at nitrogen with different electrophilic reagents in presence of an appropriate base to give a series of nitrogen heterocycles containing the benzimidazole and quinoline nuclei. The structures of the compounds were confirmed based on 1H-NMR, 13C-NMR, IR and mass spectral data. Almost all the compounds exhibited promising antibacterial activity against Salmonella typhimurium and Staphylococcus aureus. Some of the compounds showed good antifungal activities against Aspergillus niger but the antifungal activities against Candida albicans were disappointing.
Degradation of octylbenzene sulfonate photoinduced by iron(III) aquacomplexes: Evidence for the fragmentation of the alkyl chain  [PDF]
Nadra Debbache,Gilles Mailhot,Kamel Djebbar,Bernadette Lavedrine,Michèle Bolte
International Journal of Photoenergy , 2005, DOI: 10.1155/s1110662x05000115
Abstract: The degradation of octylbenzene sulfonate (OBS) photoinduced by iron(III) aquacomplexes was investigated upon irradiation at 365 nm and by solar light. The photochemical degradation appears to be due to HO• radicals arising from the electron transfer in Fe(OH)2
Alkyl Thiophene Vinylene Electropolimerization in C8mimPF6, Potential Use in Solar Cells  [PDF]
Vania Rojas, Francisco Martínez, Jean Christian Bernède, Linda Cattin Guenadez, Alexander Efimov, Helge Lemmetyinen
Materials Sciences and Applications (MSA) , 2017, DOI: 10.4236/msa.2017.85028
Abstract: We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the polymer was studied as potential donor component of a multilayer heterojunction organic solar cell (OSC). The monomer used was (E)-1,2-di-(3-octyl-2-thienyl) vinylene (OTV) and the IL used for the electropolymerization was 1-octyl-3-methylimidazole hexafluorophosphate C8mimPF6. Optical properties, stability and morphology of the polymer were analyzed using FT-IR, UV-vis, Raman and XPS spectroscopy. Voltammetry analysis and scanning electron microscopy (SEM-EDX) were also performed on the polymer. The OSC assembled with the polymer of OTV was used as electro donor and C60 as acceptor. Molybdenum trioxide (MoO3) and bathocuproine (BCP) were used as buffer layer between anode and cathode respectively. I-V curves, in the dark and under AM 1.5 solar simulator were performed to measure its efficiency.
Mn(III)-Initiated Facile Oxygenation of Heterocyclic 1,3-Dicarbonyl Compounds  [PDF]
Md. Taifur Rahman,Md. Aminul Haque,Hikaru Igarashi,Hiroshi Nishino
Molecules , 2011, DOI: 10.3390/molecules16119562
Abstract: The Mn(III)-initiated aerobic oxidation of heterocyclic 1,3-dicarbonyl compounds, such as 4-alkyl-1,2-diphenylpyrazolidine-3,5-diones, 1,3-dialkylpyrrolidine-2,4-diones, 3-alkyl-1,5-dimethylbarbituric acids, and 3-butyl-4-hydroxy-2-quinolinone gave excellent to good yields of the corresponding hydroperoxides, which were gradually degraded by exposure to the metal initiator after the reaction to afford the corresponding alcohols. The synthesis of 30 heterocyclic 1,3-dicarbonyl compounds, the corresponding hydroperoxides and the 10 alcohols, their characterization, and the limitations of the procedure are described. In addition, the mechanism of the hydroperoxidation and the redox decomposition of the hydroperoxides are discussed.
General Pathway for a Convenient One-Pot Synthesis of Trifluoromethyl-Containing 2-amino-7-alkyl(aryl/heteroaryl)-1,8-naphthyridines and Fused Cycloalkane Analogues  [PDF]
Helio G. Bonacorso,Rosália Andrighetto,Nícolas Krüger,Nilo Zanatta,Marcos A. P. Martins
Molecules , 2011, DOI: 10.3390/molecules16042817
Abstract: A convenient and general method for the synthesis in 26–73% yields of a new series of 7-alkyl(aryl/heteroaryl)-2-amino-5-trifluoromethyl-1,8-naphthyridines from direct cyclocondensation reactions of 4-alkoxy-1,1,1-trifluoroalk-3-en-2-ones [CF3C(O)CH=C(R1)OR, where R1 = H, Me, Ph, 4-MePh, 4-OMePh, 4-FPh, 4-BrPh, 4-NO2Ph, 2-furyl, 2-thienyl and R = Me, Et] with 2,6-diaminopyridine (2,6-DAP), under mild conditions, is described. Another synthetic route also allowed the synthesis of 2-amino-5-trifluoromethyl-cycloalka[b][1,8]naphthyridines in 33–36% yields, from direct or indirect cyclo-condensation reactions of five-, six- and seven-membered 2-trifluoroacetyl-1-methoxy-cycloalkenes with 2,6-DAP.
A FACILE ONE-POT SYNTHESIS OF NOVEL 1,1′-(ALKANEDIYL)BIS(5-OXO-3- ALKYL/ARALKYL/ARYL-1,2,3,4,5,6,7,8-OCTAHYDROQUINAZOLINES and THEIR ANTI-BACTERIAL ACTIVITIES A FACILE ONE-POT Synthese von neuartigen 1,1 '- (Alkandiyl) BIS (5-oxo-3- ALKYL/ARALKYL/ARYL-1,2,3,4,5,6,7,8-OCTAHYDROQUINAZOLINES and their Anti-bakterielle AKTIVIT TEN  [cached]
Madhusudhan Saha and Jai N. Vishwakarma
Heterocyclic Letters , 2013,
Abstract: A facile one-pot synthesis of novel 1,1′-(alkanediyl)bis(5-oxo-3-alkyl/aralkyl/aryl- 1,2,3,4,5,6,7,8-octahydroquinazolines) 3a-r has been devised by the cyclocondensation of bisenaminones 2a-f with primary amine and formaldehyde. The structures of the products have been established by spectral and analytical data as 1, 1′-(alkanediyl)bis(5-oxo-3-alkyl/ aralkyl/aryl-1,2,3,4,5,6,7,8-octahydroquinazolines). Some of the compounds have been found to possess promising anti-bacterial properties.
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