Showing papers by "Ponnurengam Malliappan Sivakumar published in 2010"
TL;DR: In this article, the antibacterial activity of the coated cotton was tested against three organisms namely Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa in terms of live bacterial load, as measured by the colony forming units (CFU), adhered on the cotton surface.
89 citations
TL;DR: Topology, shape, charge distribution and hydrophobic nature of the molecules had pronounced effect on the antibacterial activity of these dispiropyrrolidines.
82 citations
TL;DR: Novel sixteen chalcones and thirteen 1,3,5‐triphenyl‐2‐pyrazolines were synthesized and characterized andHydrophilic/lipophilic balance of the compounds plays a major role in their antibacterial activity.
Abstract: Novel sixteen chalcones and thirteen 1,3,5-triphenyl-2-pyrazolines were synthesized and characterized using FT-IR, HR-Mass, NMR (¹H-NMR, ¹³C-NMR, 135 DEPT, ¹H-¹H CoSY and ¹H and ¹³C CoSY) and XRD. These compounds were evaluated for their antibacterial activity against six micro-organisms, namely Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM 5021, Salmonella typhi NCIM 2501, Enterobacter aerogenes NCIM 5139, Pseudomonas aeruginosa NCIM 5029, and Proteus vulgaris NCIM 2813 by twofold dilution method using resazurin as the indicator dye. In the case of chalcones, compounds with hydroxyl and bromo substitutions in the B-ring favor activity and benzyloxy substitution irrespective of its position in the A-ring. In the case of 1,3,5-triphenyl-2-pyrazolines, chloro substitution in the A-ring favors activity. Hydrophilic/lipophilic balance of the compounds plays a major role in their antibacterial activity.
79 citations
TL;DR: Since pyrazolines are reported to inhibit the activity of p-glycoprotein, they may prevent drug resistance developed by microorganism.
37 citations
TL;DR: Reasonably good correlation was observed between the CFU (Colony Forming Units) ratio at the 24th hour against both hydrophobicity of the microorganism and roughness of the coated polymeric surfaces, which means the chalcone coated polymers can be used in the development of newer biomaterials.
31 citations
TL;DR: The in vitro antifouling activity of 47 synthesized chalcone derivatives was investigated by estimating the minimum inhibitory concentration against these organisms using a twofold dilution technique and spatial, structural and electronic descriptors were found to be predominantly affecting the antibacterial activity of these compounds.
Abstract: Biofouling in the marine environment is a major problem. In this study, three marine organisms, namely Bacillus flexus (LD1), Pseudomonas fluorescens (MD3) and Vibrio natriegens (MD6), were isolated from biofilms formed on polymer and metal surfaces immersed in ocean water. Phylogenetic analysis of these three organisms indicated that they were good model systems for studying marine biofouling. The in vitro antifouling activity of 47 synthesized chalcone derivatives was investigated by estimating the minimum inhibitory concentration against these organisms using a twofold dilution technique. Compounds C-5, C-16, C-24, C-33, C-34 and C-37 were found to be the most active. In the majority of the cases it was found that these active compounds had hydroxyl substitutions. A quantitative structure-activity relationship (QSAR) was developed after dividing the total data into training and test sets. The statistical measures r(2), [image omitted] (>0.6) q(2) (>0.5) and the F-ratio were found to be satisfactory. Spatial, structural and electronic descriptors were found to be predominantly affecting the antibiofouling activity of these compounds. Among the spatial descriptors, Jurs descriptors showed their contribution in all the three antibacterial QSARs.
30 citations
TL;DR: The low amount of biofilm formed in the presence of dichlorochalcone can be associated to its antibacterial and slimicidal activity and also its ability to reduce the hydrophobicity of the surface.
25 citations
TL;DR: Topology, shape, charge distribution and hydrophobic nature of the molecules had pronounced effect on the antibacterial activity of this series of novel dispiropyrrolidines.
Abstract: Cycloaddition of an azomethine ylide, generated in situ from isatins (IV) and sarcosine (V), with the dipolarophile (III) yields the dispiropyrrolidines (VI) in good yields.