Browsing by Author "Gopalan, Subashini"

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AN EFFICIENT NEW DUAL FLUORESCENT PYRENE BASED CHEMOSENSOR FOR THE DETECTION OF BISMUTH (III) AND ALUMINIUM (III) IONS AND ITS APPLICATIONS IN BIO-IMAGING
(Elsevier, 2019-06) Arjunan, Saravanan; Selvaraj, Shyamsivappan; Thangaraj, Suresh; Gopalan, Subashini; Krishna, Kadirvelu; Nanjan, Bhuvanesh; Raju, Nandhakumar; Palathurai, Subramaniam Mohan
A new simple pyrene based schiff base chemosensor 1 (nicotinic acid pyren-1-ylmethylene-hydrazide) has been constructed and is prepared from 1-pyrenecarboxaldehyde and nicotinic hydrazide. Notably, the chemosensor 1 exhibited remarkable colour changes while in the presence of trivalent metal ions like Bi3+ & Al3+ ion in DMSO-H2O, (1:1 v/v, HEPES = 50 mM, pH = 7.4). The UV–Vis spectral investigation of chemosensor 1 showed that the maximum absorption peak appeared at 378 nm. In emission studies, chemosensor 1 develops weak fluorescence, while upon the addition of Bi3+ and Al3+ ions, it exhibits an enhancement of fluorescence intensity. Nevertheless, rest of metal ions have no changes in the emission spectra. The association constant of chemosensor 1 for binding to Bi3+ & Al3+ system had a value of 1.27 × 104 M−1 and 1.53 × 104 M−1. The detection limits were 0.12 µM for Bi3+ and 0.17 µM for Al3+ respectively. The overall results reveal that chemosensor 1 can act as a dual-channel, highly selective, and sensitive probe for Bi3+ and Al3+ ions. Moreover, the fluorescence imaging of chemosensor 1 was applied in RAW 264.7 cell line and cytotoxicity assay prove that this chemosensor 1 is non-toxic as well as highly biocompatible.
AN EFFICIENT NEW DUAL FLUORESCENT PYRENE BASED CHEMOSENSOR FOR THE DETECTION OF BISMUTH (III) AND ALUMINIUM (III) IONS AND ITS APPLICATIONS IN BIO-IMAGING
(Elsevier B.V, 2019-06) Arjunan, Saravanan; Selvaraj, Shyamsivappan; Thangaraj, Suresh; Gopalan, Subashini; Krishna, Kadirvelu; Nanjan, Bhuvanesh; Raju, Nandhakumar; Palathurai, Subramaniam Mohan
A new simple pyrene based schiff base chemosensor 1 (nicotinic acid pyren-1-ylmethylene-hydrazide) has been constructed and is prepared from 1-pyrenecarboxaldehyde and nicotinic hydrazide. Notably, the chemosensor 1 exhibited remarkable colour changes while in the presence of trivalent metal ions like Bi3+ & Al3+ ion in DMSO-H2O, (1:1 v/v, HEPES = 50 mM, pH = 7.4). The UV-Vis spectral investigation of chemosensor 1 showed that the maximum absorption peak appeared at 378 nm. In emission studies, chemosensor 1 develops weak fluorescence, while upon the addition of Bi3+ and Al3+ ions, it exhibits an enhancement of fluorescence intensity. Nevertheless, rest of metal ions have no changes in the emission spectra. The association constant of chemosensor 1 for binding to Bi3+ & Al3+ system had a value of 1.27 × 104 M-1 and 1.53 × 104 M-1. The detection limits were 0.12 µM for Bi3+ and 0.17 µM for Al3+ respectively. The overall results reveal that chemosensor 1 can act as a dual-channel, highly selective, and sensitive probe for Bi3+ and Al3+ ions. Moreover, the fluorescence imaging of chemosensor 1 was applied in RAW 264.7 cell line and cytotoxicity assay prove that this chemosensor 1 is non-toxic as well as highly biocompatible.
EVALUATION OF NOVEL L-HISTIDINE-BASED SCHIFF BASE DERIVATIVES AS MICROBIAL-HO INHIBITORS AND THEIR ANTIMICROBIAL AND MOLECULAR DOCKING STUDIES
(Elsevier, 2022-12-15) Kalieswaran, Vidhya; Kumar, Praveen Kumar; Shanmughavel, Piramanayagam; Mani, Arulkumar; Janani, Balraj; Karunyadevi, Jairaman; Gopalan, Subashini; Jayaraman, Angayarkanni
Amino acid-derived Schiff base complexes had been well explored as antimicrobial agents and the imidazole-based Heme oxygenase (HO) inhibitors were proposed as novel antimicrobial agents with a novel mechanism of action i.e., inhibition of microbial-HO, an enzyme essential for microbial survival in the human host. In line with this, we have synthesized and characterized three novel L-Histidine-based Schiff base derivatives (HKA-1,2 and 3) as inhibitors of microbial-HO. All the compounds were confirmed to be non-hemolytic and possess microbial-HO inhibitory activity against the microbial-HO's tested. HKA-1 showed good antimicrobial activity against Bacillus subtilis (6.25 µM), Escherichia coli (0.78 µM), Candida albicans (3.125 µM), and Saccharomyces cerevisiae (0.78 µM) whereas HKA-2 and HKA-3 showed good antimicrobial activity against Pseudomonas aeruginosa (3.125 µM) and Staphylococcus aureus (0.78 µM) respectively. According to molecular docking analysis, the HKA-1 with quinoline moiety showed better interaction with all the microbial HO's tested with a Glide Score extending from -9.71 to -5.51 Kcal/Mol whereas HKA-2 and HKA-3 with bi-phenyl moiety showed interaction with certain microbial-HO's with a Glide Score extending from -7.9 to -2.22 Kcal/Mol and -8.49 to -3.14 Kcal/Mol respectively. The formation of hydrogen bonds between ligand-protein interactions confirmed the stability of the complexes and the compounds reported in the present study could be used to treat drug-resistant pathogens.
EVALUATION OF NOVEL L-HISTIDINE-BASED SCHIFF BASE DERIVATIVES AS MICROBIAL-HO INHIBITORS AND THEIR ANTIMICROBIAL AND MOLECULAR DOCKING STUDIES
(Elsevier, 2022-11-15) Kalieswaran, Vidhya; Kumar, Praveen Kumar; Shanmughavel, Piramanayagam; Mani, Arulkumar; Janani, Balraj; Karunyadevi, Jairaman; Gopalan, Subashini; Jayaraman, Angayarkanni
Amino acid-derived Schiff base complexes had been well explored as antimicrobial agents and the imidazole-based Heme oxygenase (HO) inhibitors were proposed as novel antimicrobial agents with a novel mechanism of action i.e., inhibition of microbial-HO, an enzyme essential for microbial survival in the human host. In line with this, we have synthesized and characterized three novel L-Histidine-based Schiff base derivatives (HKA-1,2 and 3) as inhibitors of microbial-HO. All the compounds were confirmed to be non-hemolytic and possess microbial-HO inhibitory activity against the microbial-HO's tested. HKA-1 showed good antimicrobial activity against Bacillus subtilis (6.25 µM), Escherichia coli (0.78 µM), Candida albicans (3.125 µM), and Saccharomyces cerevisiae (0.78 µM) whereas HKA-2 and HKA-3 showed good antimicrobial activity against Pseudomonas aeruginosa (3.125 µM) and Staphylococcus aureus (0.78 µM) respectively. According to molecular docking analysis, the HKA-1 with quinoline moiety showed better interaction with all the microbial HO's tested with a Glide Score extending from -9.71 to -5.51 Kcal/Mol whereas HKA-2 and HKA-3 with bi-phenyl moiety showed interaction with certain microbial-HO's with a Glide Score extending from -7.9 to -2.22 Kcal/Mol and -8.49 to -3.14 Kcal/Mol respectively. The formation of hydrogen bonds between ligand-protein interactions confirmed the stability of the complexes and the compounds reported in the present study could be used to treat drug-resistant pathogens.
SYNTHESIS AND X-RAY STUDY OF DISPIRO 8-NITROQUINOLONE ANALOGUES AND THEIR CYTOTOXIC PROPERTIES AGAINST HUMAN CERVICAL CANCER HELA CELLS
(The Royal Society of Chemistry, 2019-01) Selvaraj, Shyamsivappan; Raju, Vivek; Arjunan, Saravanan; Thangaraj, Arasakumar; Gopalan, Subashini; Thangaraj, Suresh; Ramasamy, Shankar; Palathurai, Subramaniam Mohan
A series of unique dispiro analogues containing an oxindole pyrrolidine 8-nitroquinolone hybrid has been obtained through a one-pot three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the condensation of isatins and benzylamine with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolones. The structures of the newly synthesized compounds were characterized by using different spectroscopic techniques and by X-ray diffraction studies of their regio- and stereochemistry. All the synthesized compounds were screened for in vitro cytotoxic activity against the human cervical cancer cell line HeLa. The compounds have exhibited potent inhibition against human cervical cancer cells and insignificant toxicity to normal cells. The compounds 6d, 6a, 6h, 6b, and 6e induced apoptosis of HeLa cells, through ROS influx. The expression levels of proteins involved in the mitochondrion-related pathways were detected, and Western blot analysis showed that apoptosis occurred via activation of caspase-3.
SYNTHESIS AND X-RAY STUDY OF DISPIRO 8-NITROQUINOLONE ANALOGUES AND THEIR CYTOTOXIC PROPERTIES AGAINST HUMAN CERVICAL CANCER HELA CELLS
(Royal Society of Chemistry, 2019-01-22) Selvaraj, Shyamsivappan; Raju, Vivek; Arjunan, Saravanan; Thangaraj, Arasakumar; Gopalan, Subashini; Thangaraj, Suresh; Ramasamy, Shankar; Palathurai, Subramaniam Mohan
A series of unique dispiro analogues containing an oxindole pyrrolidine 8-nitroquinolone hybrid has been obtained through a one-pot three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the condensation of isatins and benzylamine with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolones. The structures of the newly synthesized compounds were characterized by using different spectroscopic techniques and by X-ray diffraction studies of their regio- and stereochemistry. All the synthesized compounds were screened for in vitro cytotoxic activity against the human cervical cancer cell line HeLa. The compounds have exhibited potent inhibition against human cervical cancer cells and insignificant toxicity to normal cells. The compounds 6d, 6a, 6h, 6b, and 6e induced apoptosis of HeLa cells, through ROS influx. The expression levels of proteins involved in the mitochondrion-related pathways were detected, and Western blot analysis showed that apoptosis occurred via activation of caspase-3.
SYNTHESIS AND X-RAY STUDY OF DISPIRO 8-NITROQUINOLONE ANALOGUES AND THEIR CYTOTOXIC PROPERTIES AGAINST HUMAN CERVICAL CANCER HELA CELLS
(Med Chem Comm, 2019-01-22) Selvaraj, Shyamsivappan; Raju, Vivek; Arjunan, Saravanan; Thangaraj, Arasakumar; Gopalan, Subashini; Thangaraj, Suresh; Ramasamy, Shankar; Palathurai, Subramaniam Mohan
A series of unique dispiro analogues containing an oxindole pyrrolidine 8-nitroquinolone hybrid has been obtained through a one-pot three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the condensation of isatins and benzylamine with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolones. The structures of the newly synthesized compounds were characterized by using different spectroscopic techniques and by X-ray diffraction studies of their regio- and stereochemistry. All the synthesized compounds were screened for in vitro cytotoxic activity against the human cervical cancer cell line HeLa. The compounds have exhibited potent inhibition against human cervical cancer cells and insignificant toxicity to normal cells. The compounds 6d, 6a, 6h, 6b, and 6e induced apoptosis of HeLa cells, through ROS influx. The expression levels of proteins involved in the mitochondrion-related pathways were detected, and Western blot analysis showed that apoptosis occurred via activation of caspase-3.
A VERSATILE “ON-OFF-ON” QUINOLINE PYRAZOLINE HYBRID FOR SEQUENTIAL DETECTION OF CU2+ AND S− IONS TOWARDS BIO IMAGING AND TANNERY EFFLUENT MONITORING
(Elsevier, 2018-11-01) Gopalan, Subashini; Arjunan, Saravanan; Selvaraj, Shyamsivappan; Thangaraj, Arasakumar; Viswanathan, Mahalingam; Ramasamy, Shankar; Palathurai, Subramaniam Mohan
A quinoline-pyrazoline (QTP) module has been designed, synthesized and characterized as a fluorescence sensor for sequential detection of Cu2+ and S2− ions. The dual functional probe showed “on-off-on” property through displacement approach and because of fast kinetics between Cu2+ and S2− ion. Fluorescence imaging experiments with MG 63 cell lines exclusively demonstrate the applicability of Cu (II) imaging in biological systems. It is also used for the real-time analysis of sulphide ion in tannery effluent for environmental monitoring.