Malathi Raghunathan
University of Madras
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Publication
Featured researches published by Malathi Raghunathan.
Bioorganic & Medicinal Chemistry | 2009
Ekambaram Ramesh; Rathna Durga R.S. Manian; R. Raghunathan; Shilpakala Sainath; Malathi Raghunathan
Synthesis of a series of novel tetrahydroquinoline annulated heterocycles has been accomplished by intramolecular imino and bisimino Diels-Alder reaction. These compounds were evaluated for their antibacterial activity. All the synthetic compounds, exhibited good antibacterial activity against microorganisms of which one of them 7 was found to be as active as the antibiotic ciplofloxacin and is found to have MIC value of 2.5 mg/mL against Escherichia coli.
Journal of Biomolecular Structure & Dynamics | 2008
Usha Subbiah; Malathi Raghunathan
Abstract Extensive research is being carried out to analyse the importance of plant products such as resveratrol and genistein, which are known to exert a variety of pharmacological effects. This study aims at evaluating the protective role of these compounds against the apoptosis induced in normal cells by cytotoxic anticancer agents such as cisplatin and mytomycin C during therapy. Despite the broad antineoplastic action of cisplatin and mitomycin C, their genotoxicity in normal cell might lead to the induction of secondary malignancies. Therefore, the problem of identifying plant compounds, which might exert protective action in normal cells, gains lot of significance. We have analyzed the chemoprotective effect of plant compounds on peripheral blood human lymphocytes when exposed to cisplatin and mitomycin C by pre-treating and post-treating them with resveratrol and genistein at 100 μM concentration Biochemical alterations occurring in many cells during apoptosis include loss of plasma membrane phospholipid asymmetry, DNA fragmentation, and activation of caspase-3, et cetera, and have been assessed. Fluorescence microscopy, flow cytometric techniques have clearly demonstrated that resveratrol and genistein are efficient in protecting lymphocytes undergoing DNA damage when exposed to cisplatin and mitomycin C and exerted their activity by reducing the caspase 3 expression. An interesting observation is that, these compounds offered their protective effect by reducing their apoptotic potential on membrane and nucleic acids against cytotoxic agents, cisplatin, and mitomycin C. These results suggest that resveratrol and genistein might be useful for risk assessments in advance of clinical trials and could be considered as a strong candidate in pharmacogenomics or nutriprotective arena.
Molecular Biology Reports | 2009
Sainath Rao Shilpakala; Malathi Raghunathan
The chromosome of E. coli is maintained in a negatively supercoiled state, and supercoiling levels are affected by growth phase and a variety of environmental stimuli. Regulation of DNA supercoiling yields a complex spectrum of effects on the E. coli recA system. Previous studies indicated that inhibition of DNA gyrase by antibiotics that act on the DNA gyrase A subunit results in turning on the recA system. Here we show that antisense ribozymes that act on the DNA gyrase A subunit can also induce recA. We used real time PCR and immunoblot to analyze the impact of DNA gyrase A inhibition by antisense ribozymes on recA expression. When gyrase A was inhibited by the RNase P mediated antisense ribozymes the expression of recA was induced around 130-fold as seen by real time PCR analysis. This suggests that repair pathway is induced by antisense ribozymes against DNA gyrase A and the damage produced by these ribozymes may be similar to that produced by fluroquinolones.
European Journal of Medicinal Chemistry | 2011
Mathesan Jayagobi; R. Raghunathan; Shilpakala Sainath; Malathi Raghunathan
Synthesis of a series of novel pyrroloquinolinone and pyrroloquinoline derivatives has been accomplished by intramolecular domino Knoevenagel hetero Diels-Alder reaction and intramolecular imino Diels-Alder reaction. These compounds were evaluated for their antibacterial activity against bacterial pathogens using disc diffusion and broth dilution methods. The efficacy of binding of these compounds to gyrase, an enzyme known to play a key role in bacterial replication is examined by studying its supercoiling and relaxation and also its gene expression using PCR method. The results indicated that most of the synthesised compounds exhibited good antibacterial activity against the microorganisms with MIC values of 5mM and could inhibit gyrase effectively leading to cell death.
International Journal of Antimicrobial Agents | 2009
Shilpakala Sainath Rao; Raghavachari Raghunathan; Ramesh Ekambaram; Malathi Raghunathan
Two hundred isolates of Mycobacterium tuberculosis were evaluated for their susceptibility to a newly synthesised quinolone derivative, ER-2, compared with ciprofloxacin, ofloxacin, levofloxacin and moxifloxacin. ER-2 and moxifloxacin showed the greatest activity [MIC for 90% of strains tested (MIC(90))=0.5 microg/mL], although levofloxacin and ciprofloxacin showed good activity with an MIC(90) of 1 microg/mL. More importantly, ER-2 showed excellent activity against M. tuberculosis H37Rv both in the lungs and spleen of mice, indicating the potential therapeutic value of ER-2 against M. tuberculosis.
Molecular Biology Reports | 2007
Prathiba Jayaguru; Malathi Raghunathan
Molecular Biology Reports | 2008
Shilpakala Sainath Rao; H. S. Savithri; Malathi Raghunathan
Journal of Antimicrobial Chemotherapy | 2009
Shilpakala Sainath Rao; Malathi Raghunathan
Current Chemical Biology | 2012
Mathesan Jayagobi; R. Raghunathan; Shilpakala Sainath; Malathi Raghunathan
Nature Precedings | 2008
Shilpakala Sainath Rao; Malathi Raghunathan