Synthesis of 2-(5-((5-(4-chlorophenyl)furan 2-yl)methylene)-4-oxo-2-thioxo-thiazolidi n-3-yl)acetic acid derivatives and evaluation of their cytotoxicity and induction of apoptosis in human leukemia cells

In order to explore the anticancer effect associated with the thiazolidinone framework, several 2-(5-((5-(4-chlorophenyl)furan-2-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)acetic acid derivatives 5(a-1) were synthesized. Variation in the functional group at C-terminal of the thiazolidinone led to set of compounds bearing amide moiety. Their chemical structures were confirmed by H-1 NMR, IR and Mass Spectra analysis. These thiazolidinone compounds containing furan moiety exhibits moderate to strong antiproliferative activity in a cell cycle stage-dependent and dose dependent manner in two different human leukemia cell lines. The importance of the electron donating groups on thiazolidinone moiety was confirmed by MTT and Trypan blue assays and it was concluded that the 4th position of the substituted aryl ring plays a dominant role for its anticancer property. Among the synthesized compounds, 5e and 5f have shown potent anticancer activity on both the cell lines tested. To rationalize the role of electron donating group in the induction of cytotoxicity we have chosen two molecules (5e and 5k) having different electron donating group at different positions. LDH assay, Flow cytometric analysis and DNA fragmentation suggest that 5e is more cytotoxic and able to induce the apoptosis. (C) 2009 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of novel 1-(4-methoxyphenethyl)-1H-benzimidazole-5-carboxylic acid derivatives and their precursors as antileukemic agents

We report here the synthesis and preliminary evaluation of novel 1-(4-methoxyphenethyl)-1H-benzimidazole-5-carboxylic acid derivatives 6(a–k) and their precursors 5(a–k) as potential chemotherapeutic agents. In each case, the structures of the compounds were determined by FTIR, 1H NMR and mass spectroscopy. Among the synthesized molecules, methyl 1-(4-methoxyphenethyl)-2-(4-fluoro-3-nitrophenyl)-1H-benzimidazole-5-carboxylate (5a) induced maximum cell death in leukemic cells with an IC50 value of 3 μM. Using FACS analysis we show that the compound 5a induces S/G2 cell cycle arrest, which was further supported by the observed down regulation of CDK2, Cyclin B1 and PCNA. The observed downregulation of proapoptotic proteins, upregulation of antiapoptotic proteins, cleavage of PARP and elevated levels of DNA strand breaks indicated the activation of apoptosis by 5a. These results suggest that 5a could be a potent anti-leukemic agent.

Mandelic acid-4-hydroxylase, a new inducible entyme from Image

A soluble fraction of Image catalyzed the hydroxylation of mandelic acid to Image -hydroxymandelic acid. The enzyme had a pH optimum of 5.4 and showed an absolute requirement for Fe2+, tetrahydropteridine, NADPH. Image -Hydroxymandelate, the product of the enzyme reaction was identified by paper chromatography, thin layer chromatography, UV and IR-spectra.

Unique presence of 2-methylthio-ribosylzeatin in the transfer ribonucleic acid of the bacterium Pseudomonas-Aeruginosa

Analysis of 35S labled nucleosides prepared from tRNA of Pseudomonas aeruginosa by phosphocellulose column chromatography, thin layer chromatography and Sephadex LH-20 column chromatography revealed the presence of 2-methylthioribosylzeatin in it. 2iPA, 6-(3-methyl-2-butenylamino)-9-β-D-ribofuranosyl purine; ms-2iPA, 6-(3-methyl-2-butenylamino)-2-methylthio-9-β-D-ribofuranosylpurine; ribosyl-cis-zeatin, 6-(4-hydroxy-3-methyl-cis-2-butenylamino)-9-β-D-ribofuranosylpurine; ribosyl-trans-zeatin, 6-(4-hydroxy-3-methyl-trans-2-butenylamino)-9-β-D-ribofuranosylpurine; ms-ribosylzeatin, 6-(4-hydroxy-3-methyl-2-butenylamino)-2-methylthio-9-β-D-ribofuranosylpurine; s4U2, 4-thiouridine; s2U*, 5-methylaminomethyl-2-thiouridine; s2C, 2-thiocytidine; TLC — thin layer chromatography.

Unique presence of 2-methylthio-ribosylzeatin in the transfer ribonucleic acid of the bacterium Pseudomonas-aeruginosa

Analysis of 35S labled nucleosides prepared from tRNA of Pseudomonas aeruginosa by phosphocellulose column chromatography, thin layer chromatography and Sephadex LH-20 column chromatography revealed the presence of 2-methylthioribosylzeatin in it. 2iPA, 6-(3-methyl-2-butenylamino)-9-β-D-ribofuranosyl purine; ms-2iPA, 6-(3-methyl-2-butenylamino)-2-methylthio-9-β-D-ribofuranosylpurine; ribosyl-cis-zeatin, 6-(4-hydroxy-3-methyl-cis-2-butenylamino)-9-β-D-ribofuranosylpurine; ribosyl-trans-zeatin, 6-(4-hydroxy-3-methyl-trans-2-butenylamino)-9-β-D-ribofuranosylpurine; ms-ribosylzeatin, 6-(4-hydroxy-3-methyl-2-butenylamino)-2-methylthio-9-β-D-ribofuranosylpurine; s4U2, 4-thiouridine; s2U*, 5-methylaminomethyl-2-thiouridine; s2C, 2-thiocytidine; TLC — thin layer chromatography.

Temperature dependence of chlorine NQR in 2-chloro 5-nitrobenzoic acid and 4-chloro 3-nitrobenzoic acid

Temperature dependence of chlorine nuclear quadrupole resonance in 2-chloro 5-nitrobenzoic acid and 4-chloro 3-nitrobenzoic acid has been investigated in the region 77° K to room temperature. No phase transition has been observed. The results are analysed to obtain the torsional frequencies and their temperature dependence. A nonlinear temperature dependence is obtained for the torsional frequencies.

Mandelic Acid 4-Hydroxylase - New Inducible Enzyme From Pseudomonas-Convexa

A soluble fraction of catalyzed the hydroxylation of mandelic acid to -hydroxymandelic acid. The enzyme had a pH optimum of 5.4 and showed an absolute requirement for Fe2+, tetrahydropteridine, NADPH. -Hydroxymandelate, the product of the enzyme reaction was identified by paper chromatography, thin layer chromatography, UV and IR-spectra

Novel organic porous solids with channel and layered structures from 1,3,5-triazine-2,4,6-triaminehexaacetic acid and its calcium salt

Single crystals of a symmetrically substituted molecule, 1,3,5-triazine-2,4,6-triaminehexaacetic acid, (TTHA) and its Ca2+ salt have been synthesized, the analysis of which reveals the existence of novel channel type cavities and helical packing organizations in the crystals.

Selective para metalation of unprotected 3-methoxy and 3,5-dimethoxy benzoic acids with n-butyl lithium-potassium tert-butoxide (LIC-KOR): synthesis of 3,5-dimethoxy-4-methyl benzoic acid

The potassium salt of 3-methoxy and 3,5-dimethoxy benzoic acids undergoes deprotonation at the position para to the carboxylate group selectively when treated with LIC-KOR in THF at -78 degrees C and it has been extended to the synthesis of 3,5-dimethoxy-4-methyl benzoic acid. (C) 2000 Elsevier Science Ltd. All rights reserved.

Enantiospecific synthesis of tricyclo5.2.1.0(4,8)]decanes via acid catalysed rearrangement of isotwistanes

An acid catalysed rearrangement was employed for the enantiospecific conversion of isotwistanol to tricyclo5.2.1.0(4.8)]-decanes, which provided support for the proposed biosynthesis of allopupukeananes from pupukeananes. The strategy has been further extended to the enantiospecific synthesis of a homobrexane. (c) 2005 Elsevier Ltd. All rights reserved.

Isolation and characterization of a novel multibridged tetradentate dianionic form of pyridoxic acid. Crystal structure of tetranuclear [Cu4(PAA)2(Bipyam)4(H2O)2Cl2](NO3)2·CH3OH·10H2O

The X-ray analysis of the tetranuclear copper(II) complex formed from pyridoxic acid and 2,2′-dipyridylamine reveals a novel metal binding mode of pyridoxic acid as a multibridged tetradentate dianion. Here the pyridoxic acid moiety uses all possible sites except the pyridine nitrogen for metal coordination.