VIJAYAKUMAR B
@velhightech.com
Professor, Chemistry
RESEARCH INTERESTS
Catalysis, electrode materials, polymer composites
Scopus Publications
Scopus Publications
P. Rajeswaran, A. Alfind Paul Frit, R. Rajesh, B. Vijayakumar, Pradeep Katta, N.R. Sheela, and S. Muthu
Elsevier BV
J. Vinoth Arul Raj, R. Praveen Kumar, B. Vijayakumar, Edgard Gnansounou, and B. Bharathiraja
Elsevier BV
J. Vinoth Arul Raj, B. Bharathiraja, B. Vijayakumar, S. Arokiyaraj, J. Iyyappan, and R. Praveen Kumar
Elsevier BV
Kondaiah Seku, Anil Kumar Yamala, Mahesh Kancherla, Kishore Kumar K, and Vijayakumar Badathala
Springer Science and Business Media LLC
BackgroundThe drug-metal complexes are used to control the growth of pathogens and parasites which are harmful to humans. Moxifloxacin (MOX) is a new fourth generation 8- methoxy fluoroquinolone. Its chemical name is [1-cyclopropyl-7-(S,S)-2,8-diazabicyclo(4.3.0)- non-8-yl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinoline carboxylic acid hydrochloride]. Many researchers have reported Moxifloxacin-metal complexes with transition metals and studied their biological applications. We have synthesized novel moxifloxacin- Au(III) and Ag(I) metal complexes ([Au(MOX) 2 (Cl) 2 ].2H 2 O and [Ag (MOX) 2 ].2H 2 O), characterized, and found their biological activities.MethodsMoxifloxacin- Au(III) and Ag(I) metal complexes were prepared by adding corresponding aqueous solutions of Au(III) and Ag(I) metal salts to methanolic solution of Moxifloxacin. These metal complexes were characterized by physio-chemical techniques like UV-Vis, 1 H- NMR, FTIR, XRD, DSC, TGA, SEM and microanalytical data. The disc diffusion method was used to study the antibacterial activity of the Moxifloxacin-metal complexes.ResultsThe structural assessment of these complexes has been carried out based on physio- chemical and spectroscopic methods. The powder X-ray diffraction data of the metal complexes revealed moderate crystallinity. SEM analysis confirms that [Ag(MOX) 2 ].2H 2 O complex has small rods like morphology whereas [Au(MOX) 2 (Cl) 2 ].2H 2 O has well crystalline rods like morphology. The results from DSC of moxifloxacin- Au(III) and Ag(I) metal complexes revealed the interaction between the drug and metals. Further, Au & Ag moxifloxacin metal complexes have shown significant antibacterial activity against gram-positive and gram-negative bacteria.ConclusionsThe spectral and analytical results clearly confirmed the coordination chemistry of Au (III) and Ag (I) Moxifloxacin metal complexes. The IR, electronic transition and elemental data led to the conclusion that the geometry of the complex of Au(III) is octahedral and that of Ag (I) complex is tetrahedral. The [Ag(MOX) 2 ].2H 2 O complex has showed good antibacterial activity compared to [Au (MOX) 2 (Cl) 2 ].2H 2 O metal complex. The antibacterial activity studies indicate the metal complexes have more biological activity than free ligand.
Mahesh Kancherla and Vijayakumar Badathala
Springer Science and Business Media LLC
Aluminium exchanged Indian clay (Al3+-ExIC) catalyzed synthesis of 2, 3-dihydroquinazolin-4(1H)-one derivatives in good to excellent yields has been reported. The catalyst has been characterized for its physico-chemical properties. Effects of solvent, molar ratio, amount of catalyst and reaction time on the yield of 2-phenyl-2, 3-dihydroquinazolin-4(1H)-one and recyclability of the catalyst have been investigated. Various 2, 3-dihydroquinazolin-4(1H)-one derivatives have been obtained in good to excellent yields.
Kondaiah Seku, Vijayakumar Badathala, Venkata Rao Velivela, and Srinivasa Desireddy
Bentham Science Publishers Ltd.
B. Vijayakumar, V. Kannappan, and V. Sathyanarayanamoorthi
Elsevier BV
Vijayakumar Badathala and Justin Ponniah
Elsevier BV
Vijayakumar Badathala
Springer Science and Business Media LLC
The preparation, characterization, and catalytic properties of acid treated clay (ATC) are reported. ATC has been characterized by XRD (basal spacing, 14.82 Å), specific surface area (66 m2/g), pore volume and pore width using BET method, UV–Vis DRS, TGA, SEM, and surface acidity by TPD of NH3. The activity of was investigated by the reaction of benzil with o-phenylene diamine. Among the catalysts, ATC was found to be more active. The reaction of various substituted o-phenylenediamines with benzil was studied on ATC to obtain corresponding quinoxalines in good yields. The regeneration and reusability of ATC has also been investigated.
B Vijayakumar, K O Anjana, and G Ranga Rao
IOP Publishing
Preparation of polyaniline (PAni)/clay nanocomposites by reacting aniline with ammonium persulphate in presence of clay at 0-5 °C for 12 h. The composites were characterized by X-ray diffraction, infrared spectroscopy, UV-vis diffuse reflectance spectroscopy and thermogravimetric analysis for their physicochemical properties. Morphology was studied by scanning electron microscopy. The electrochemical studies of PAni/clay nanocomposites were carried out using cyclic voltammetry in 0.5 M H2SO4 aqueous electrolyte. The PAni/clay nanocomposites showed specific capacitances of 415-455 Fg−1 at a scan rate of 10 mVs−1.
Selvaraj Arokiyaraj, Seong Choi, Yoonseok Lee, Rajaraman Bharanidharan, Villianur Hairul-Islam, Badathala Vijayakumar, Young Oh, Vannam Dinesh-Kumar, Savariar Vincent, and Kyoung Kim
MDPI AG
In the present study, chemical composition and the antibacterial mechanism of ambrette seed oil are investigated. Chemical composition of the oil was analysed by gas chromatography-mass spectrometry (GC-MS). Thirty-five compounds were identified and the major compounds were found to be farnesol acetate (51.45%) and ambrettolide (12.96%). The antibacterial activity was performed by well diffusion assay and the mechanisms were studied by measuring the alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and protein leakage assays. The antibacterial effect of the ambrette seed oil showed inhibitory effect against Bacillus subtilis, Staphylococcus aureus and Enterococcus faecalis. The LDH activity was high in all tested bacteria compared with control, whereas the ALP and protein concentrations were also increased in E. faecalis. Molecular docking revealed the ligands farnesol acetate and ambrettolide had satisfactory binding energy towards the beta lactamase TEM-72 and dihydrofolate reductase (DHFR) protein. Due to its better antibacterial properties, the ambrette seed oil could be used as a source of antibacterial agents.
S. Arokiyaraj, M. Saravanan, N.K. Udaya Prakash, M. Valan Arasu, B. Vijayakumar, and S. Vincent
Elsevier BV
B. Vijayakumar and G. Ranga Rao
Springer Science and Business Media LLC
ZrOCl2·8H2O supported on montmorillonite K10 (ZrOCl2/mont K10) catalyzed Biginelli reaction under solvent-free conditions is reported. The catalysts were characterized by XRD, FTIR, BET surface area analysis, and thermogravimetric analysis. The activity of montmorillonite K10, montmorillonite KSF, ZrOCl2·8H2O, SO42−/ZrO2, and ZrOCl2/mont K10s was investigated by Biginelli reaction of benzaldehyde, ethylacetoacetate and urea. The reactions were carried out by addition of ZrOCl2/mont K10 to a mixture of aldehyde, ethylacetoacetate and urea/thiourea with thorough stirring in the absence of solvent under conventional heating or microwave irradiation to prepare 3,4-dihydropyrimidin-2(1H)-one/thione derivatives at 80 °C in good yields.
B. Vijayakumar and G. Ranga Rao
Springer Science and Business Media LLC
Abstract12-Tungstophosphoric acid supported on montmorillonite K10 (PWA/mont-K10) catalysed Pechmann condensation reaction was reported. The catalyst was characterized by XRD, FTIR, UV–Vis DRS, surface area and pore size analysis, TGA and acidity by DRIFTS using pyridine. The morphology of the catalyst was studied by SEM. The activity of mont-K10, mont-KSF, $$ {{{\\text{SO}}_{ 4}^{{ 2 {-}}} } \\mathord{\\left/ {\\vphantom {{{\\text{SO}}_{ 4}^{{ 2 {-}}} } {{\\text{ZrO}}_{ 2} }}} \\right. \\kern-\\nulldelimiterspace} {{\\text{ZrO}}_{ 2} }} $$, 12-tungstophosphoric acid, and PWA/mont-K10 was investigated by condensation reaction of resorcinol with ethyl acetoacetate in the absence of solvent. Effect of molar ratio, amount of catalyst, reaction temperature and time on the yield of 7-hydroxy-4-methylcoumarin had been investigated on PWA/mont-K10. PWA/mont-K10 catalysed condensation of ethyl acetoacetate with phenol and a few substituted phenols had also been carried out to yield corresponding coumarins. The recycled catalyst showed reduced activity after single use. 15 wt% PWA on mont-K10 was found to be effective for synthesis of coumarin derivatives without employing any solvent.
B. Vijayakumar, N. Mahadevaiah, Gopalpur Nagendrappa, and B. S. Jai Prakash
Springer Science and Business Media LLC
The esterification of stearic acid with p-cresol using modified Indian bentonite clay catalysts has been reported. The reaction was studied over exchanged clays, acid activated clays, exchanged acid activated clays, aluminium pillared clay, aluminium pillared acid activated clay, molecular sieve Al-MCM-41, zeolite Hβ, ZrO2, S-ZrO2, p-TSA, montmorillonite K10, and montmorillonite KSF in o-xylene for 6 h. The catalysts were characterized by X-ray diffraction and surface area measurements. The acidity was determined by n-butylamine back-titration method and DRIFTS after pyridine adsorption. Acid activated Indian bentonite (AAIB) was found to be a better catalyst compared to other catalysts in the esterification of stearic acid with p-cresol.
N. Mahadevaiah, B. Vijayakumar, K. Hemalatha, and B. S. Jai Prakash
Springer Science and Business Media LLC
Organo-clay was prepared by incorporating different amounts (in terms of CEC, ranging from 134–840 mg of quaternary ammonium cation (QACs) such as hexadecytrimethylammonium bromide ([C19H42N]Br) into the montmorillonite clay. Prepared organo-clays are characterized by CHN analyser and XRD to measure the amount of elemental content and interlayer spacing of surfactant modified clay. The batch experiments of sorption of permanganate from aqueous media by organo-clays was studied at different acidic strengths (pH 1–7). The experimental results show that the rate and amount of adsorption of permanganate was higher at lower pH compared to raw montmorillonite. Laboratory fixed bed experiments were conducted to evaluate the breakthrough time and nature of breakthrough curves. The shape of the breakthrough curves shows that the initial cationic surfactant loadings at 1·0 CEC of the clay is enough to enter the permanganate ions in to the interlamellar region of the surfactant modified smectile clays. These fixed bed studies were also applied to quantify the effect of bed-depth and breakthrough time during the uptake of permanganate. Calculation of thermodynamic parameters shows that the sorption of permanganate is spontaneous and follows the first order kinetics.
B. Vijayakumar, Gopalpur Nagendrappa, and B. S. Jai Prakash
Springer Science and Business Media LLC
The preparation, characterization, and catalytic properties of acid activated Indian bentonite (AAIB) are reported. AAIB has been characterized by XRD (basal spacing, 15.05 Å), specific surface area (273 m2/g), pore volume and pore diameter using BET method, TGA, SEM, and surface acidity by n-butylamine back titration method and infrared spectroscopy using pyridine as a probe molecule. The activity of Montmorillonite K10, ZrO2, S–ZrO2, p-toluenesulfonic acid (p-TSA), Indian bentonite (IB), and AAIB was investigated by the esterification of p-cresol with stearic acid. Among the catalysts, AAIB was found to be more active. The esterification of various carboxylic acids with phenols and alcohols was studied on AAIB to obtain corresponding esters in good yields. The regeneration and reusability of AAIB has also been investigated.