Publications (34) View all
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Article: Benzimidazole, coumrindione and flavone derivatives as alternate UV laser desorption ionization (LDI) matrices for peptides analysis.
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ABSTRACT: BACKGROUND: Matrix-assisted laser desorption/ionization (MALDI) is a soft ionization mass spectrometric technique, allowing the analysis of bio-molecules and other macromolecules. The matrix molecules require certain characteristic features to serve in the laser desorption/ionization mechanism. Therefore, only a limited number of compounds have been identified as ultraviolet- laser desorption/ionization (UV-LDI) matrices. However, many of these routine matrices generate background signals that useful information is often lost in them. We have reported flavones, coumarindione and benzimidazole derivatives as alternate UV-LDI matrices. RESULTS: Thirty one compounds have been successfully employed by us as matrices for the analysis of low molecular weight (LMW) peptides (up to 2000 Da). Two peptides, bradykinin and renin substrate tetra-decapeptide were analyzed by using the newly developed matrices. The MS measurements were made after mixing the matrix solution with analyte by using dried droplet sample preparation procedures. The synthesized matrix materials showed better S/N ratios and minimal background signals for low mass range. Furthermore, pico molar concentrations of [Glu1]-fibrinopeptide B human could be easily analyzed with these matrices. Finally, BSA-digest was analyzed and identified through database search against Swiss-Prot by using Mascot. CONCLUSIONS: These results validate the good performance of the synthesized UV-laser desorption/ionization (LDI) matrices for the analysis of low molecular weight peptides.Chemistry Central Journal 04/2013; 7(1):77. · 3.28 Impact Factor -
Article: Xanthine Oxidase Inhibition by 5-aryledene N,N’-dimethylbarbituric Acid Derivatives
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ABSTRACT: N,N’-dimethylbarbituric acid derivatives 1-24 were evaluated for their xanthine oxidase (XO) inhibitory activity. Majority of these compounds showed a good to moderate in vitro xanthine oxidase inhibitory activity (IC50 = 20.97 ± 0.29 - 327.0 ± 3.50 μM), while eight compounds were found to be completely inactive. A structure-activity relationship has been discussed, identifying structural features, responsible for varying degree of activity.Journal- Chemical Society of Pakistan 04/2013; 35(2):495-498. · 1.38 Impact Factor -
Article: 5-Chloro-2-(4-meth-oxy-phen-yl)-1,3-benzo-thia-zole.
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ABSTRACT: In the title compound, CHClNOS, the dihedral angle between the benzothia-zole ring system and the meth-oxy-substituted benzene ring is 8.76 (16)°. In the crystal, mol-ecules are stacked in columns along the axis and no significant inter-molecular inter-actions are observed.Acta Crystallographica Section E Structure Reports Online 03/2013; 69(Pt 3):o360. · 0.35 Impact Factor -
Article: Oxindole Derivatives: Synthesis and Antiglycation Activity.
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ABSTRACT: Oxindole derivatives 3-25 have been synthesized from commercially available oxindole by refluxing with different aromatic aldehydes in good yields. Their in vitro antiglycation potential has been evaluated. They showed a varying degree of antiglycation activity with IC50 values ranging between 150.4 - 856.7 µM. 3-[(3-Chlorophenyl)methylidene]-1,3-dihydro-2H-indol-2-one (IC50 = 150.4 ± 2.5 µM) is the most active compound among the series, better than the standard rutin with an IC50 value 294.5 ± 1.50 µM. The structures of the compounds were elucidated by 1H-NMR and mass spectroscopy and elemental analysis. A limited structure-activity relationship has been developed.Medicinal chemistry (Shāriqah (United Arab Emirates)) 11/2012; · 1.64 Impact Factor -
Article: Synthesis of Benzophenonehydrazone Schiff Bases and their In Vitro Antiglycating Activities.
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ABSTRACT: Benzophenonehydrazone Schiff bases 1-25 were synthesized and their in vitro antiglycation potential has been studied. Out of twenty-five compounds, thirteen showed varying degrees of antiglycation activity with IC50values ranging between 25.7 - 305 µM, if compared with the standard rutin (IC50 = 70.5 ± 0.50 µM). Compounds 21 (2,3-dihydroxybenzaldehyde N-(diphenylmethylene)hydrazine) IC50= 25.7 ± 0.003 µM, 14 (diphenylmethanone N-[1-(2,4-dihydroxy-5-nitrophenyl)ethylidene]hydrazine) IC50= 36.6 ± 0.004 µM, 6 (3,4-dihydroxybenzaldehyde N-(diphenylmethylene)hydrazine) IC50= 49.5 ± 0.001 µM, 13 (diphenylmethanone N-[1-(2,5-dihydroxyphenyl)ethylidene] hydrazine) IC50= 52.6 ± 0.023 µM, and 15 (diphenylmethanone N-[1-(3,4-dihydroxyphenyl)ethylidene]hydrazine) IC50 = 57 ± 0.002 µM, showed showed much better antiglycation potential superior to the standard rutin. The compounds 7 (2,5-dihydroxybenzaldehyde N-(diphenylmethylene)hydrazine) IC50 = 66 ± 0.002 µM, and 25 (diphenylmethanone N-[1-(2,5-dihydroxyphenyl)propylidene] hydrazine) IC50= 67.9 ± 0.001 µM compareable good antiglycation activity to standard rutin. All compounds were characterized by spectroscopic techniques and gave satisfactory elemental analysis.Medicinal chemistry (Shāriqah (United Arab Emirates)) 11/2012; · 1.64 Impact Factor
