Jarem Raul Garcia
@uepg.br
Professor at Department of Chemistry
State University of Ponta Grossa
Scopus Publications
Scopus Publications
The possibility of ibotenic acid and muscazone electrochemical determination, assisted by a conducting polymer electrode, has been developed and evaluated from a theoretical point of view. The correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis. The model analysis has shown that, due to the transformation of the ionic form, the oscillatory behavior in this system tends to be more probable than in similar ones. On the other hand, the electroanalytical system will be efficient for both analytes determination and quantification in mushroom pulp and biological liquids.
Alan F.Y. Matsushita, Josias R.V. Nascimento, João M.A. Leite, Christiana A. Pessoa, and Jarem R. Garcia
Elsevier BV
The theoretical description for amavadin-ion electrochemical determination in mushroom pulp has been given for the first time. The correspondent mathematical model has been developed and analyzed by linear stability theory and bifurcation analysis, providing the theoretical investigation of the electrochemical behavior of the electroanalytical system. It has been shown that the system behavior in galvanostatic mode is more dynamic than in potentiostatic mode, which is reflected in the enhancement of the probability of the electrochemical oscillations due to the intense influence of chemical and electrochemical stages on both DEL and surface charge. Nevertheless, the system is efficient for electroanalysis or conducting polymer modification for electroanalytical purposes.
Gustavo Marciniuk, Rodolfo T Ferreira, Alex V Pedroso, Ariane S Ribas, Renan A P Ribeiro, Sérgio R de Lázaro, Eder C F de Souza, Luis F Q Marchesi, and Jarem R Garcia
Springer Science and Business Media LLC
Design and production of α-MnO 2 structures over carbonaceous material is considered as potential strategy for improving electrochemical performance of supercapacitors. This study describes the development of a simple method for hydrothermal synthesis of a composite material with directly anchoring α-MnO 2 over a nanographite matrix. The nanographite matrix was obtained by electrochemical exfoliation of graphite rods (from depleted Leclanché batteries) and characterized by X-ray diffraction (XRD), Raman spectroscopy and field emission gun-scanning electron microscopy (FEG-SEM). The obtained results indicated that nanographite produced presented low levels of defects with a mild oxidized surface. This nanographite was used as anchoring base for producing MnO 2 particles, using the developed hydrothermal procedure. For paralleling, pure MnO 2 particles were also produced in same conditions. The prepared materials were characterized by XRD, Raman spectroscopy and FEG-SEM. XRD patterns proved formation of α-MnO 2 for pure and composite materials. Morphological characterization indicated the formation of nanoneedles in both situations; however, in the composite the α-MnO 2 was produced as smaller nanoneedles homogeneously spread over the nanographite surface. Raman spectra showed that the desired composition was achieved. Electrochemical characterization showed that the adopted strategy was successful in producing materials with improved pseudocapacitive performance, high reversibility, presenting specific capacitance of 279.8 F g −1 and coulombic efficiency of 99.7%.
Guda Mallikarjuna Reddy, Jarem Raul Garcia, Munagapati Venkata Subbaiah, and Jet‐Chau Wen
Wiley
Soraya Blum, Felipe Zahrebelnei, Noemi Nagata, Valtencir Zucolotto, Luiz Mattoso, Jarem Garcia, Christiana Pessoa, and Karen Wohnrath
Brazilian Journal of Analytical Chemistry
Efforts have been made on the development of new modified electrodes to be used in the fast determination of neurotransmitters, either in commercial drugs or in biological samples. Determination of dopamine (DA), for example, is of great importance since the lack of this neurotransmitter is related to many neurological disorders, including Parkinson’s and Alzheimer’s diseases. In this paper, we present a detailed electrochemical characterization, as well as DA detection studies of paste electrodes incorporating carbon materials in different allotropic forms, including carbon black modified with intrinsically conducting polymers (Eeonomers®), pristine carbon black, graphite, and carbon nanotubes. Emphasis is put on the smaller particle size and larger specific surface area of CB Eeonomers® materials, which led to an improved electroanalytical performance for the developed devices. The electrodes fabricated with Eeonomers® modified with polyaniline exhibited the higher current response towards DA detection, in addition to the ability of distinguishing DA from its natural interferent, ascorbic acid. Furthermore, a central composite design was used to investigate the influence of pH and electrode composition (proportion of Eeonomers®) on the electrochemical sensing of DA. A greater sensitivity was achieved for 50:50 (w/w) KP20/KPy20 electrode at pH 7.0. The optimized devices showed to be promising tools to perform quick, cheap and sensitive detection of this neurotransmitter in bioanalytical systems.
Josias Do Rocio Vitor do Nascimento, Karen Wohnrath, and Jarem Raul Garcia
Instituto de Quimica - Univ. Federal do Mato Grosso do Sul
Guda Mallikarjuna Reddy, Vijaya Kumar Reddy Avula, Dmitry S. Kopchuk, Igor S. Kovalev, Grigory V. Zyryanov, Oleg N. Chupakhin, and Jarem Raul Garcia
Informa UK Limited
Venkata Subbaiah Munagapati, Hsin-Yu Wen, Yarramuthi Vijaya, Jet-Chau Wen, Jhy-Horng Wen, Zhong Tian, Guda Mallikarjuna Reddy, and Jarem Raul Garcia
Informa UK Limited
Abstract Aminated avocado seed powder (AASP)—an eco-friendly novel adsorbent has been used for the removal of Acid Yellow 17 (AY 17) and Amaranth (AMR) from an aqueous phase. The AASP (before and after adsorption) was systematically characterized by different analytical techniques such as FT-IR, FESEM, EDX, and N2 adsorption-desorption analysis. Non-linear form of various kinetic (PFO and PSO) and isotherm (Langmuir and Freundlich) models were used to examine the adsorption behavior of AY 17 and AMR onto AASP. The adsorption of AY 17 and AMR onto AASP was well illustrated by the PSO kinetic model and Langmuir isotherm models. At 303 K, the maximum adsorption capacities (obtained from the Langmuir) of the AASP for AY 17 and AMR was 42.7 and 89.2 mg/g, respectively. The AY 17 and AMR adsorption was strongly pH-dependent with an optimum pH value of 2.0. Activation energy was calculated as 12.3 and 16.3 kJ/mol for AY 17 and AMR respectively, suggesting physical adsorption. The positive values of ΔGo and ΔHo indicated that the adsorption process of AY 17 and AMR onto AASP was non-spontaneous and endothermic. The negligible loss of adsorption capacity and excellent regeneration of AASP were observed for the five cycles. Statement of novelty: The present research majorly focused on the synthesis of adsorbent from Avocado seed for the removal of Acid Yellow 17 and Amaranth anionic dyes from aqueous solution. Although the literature is available on direct seed powder as adsorbent, to the best of our knowledge, no chemical modified adsorbent synthesis was not available. Hence, to fill the gap in the literature, we chose the following study that significantly enhanced the adsorption efficiency of the selected anionic dyes.
Ivelise Dimbarre Lao Guimarães, Flávia Marszaukowski, Renan Ribeiro, Sergio Ricardo de Lazaro, Kátia Mara de Oliveira, Alzir Azevedo Batista, Patrícia Castellen, Ellen Wrobel, Jarem Raul Garcia, René T. Boeré,et al.
Elsevier BV
Abstract Neutral Ru(II)-arene complexes [Ru(η6‐p-cymene)(PAr3)Cl2], PAr3 where Ar = 3,5-((CH3)3C)2C6H3–, 3,5-(CH3)2C6H3–, 4-CH3O-3,5-(CH3)2C6H2– and 4-CH3O-C6H4– were synthetized and fully characterized including single-crystal X-ray diffraction. The ligands have empirical logPow = 10.29, 7.38, 7.08, 5.43 (vs. PPh3 = 5.14). They have sufficiently low solubility to form Langmuir monolayers on water in accordance with overall molecular sizes. Density functional theory (DFT) calculations were performed to determine the molecular and electronic structures and to interpret the results of voltammetry and UV-Vis spectroscopy. Cytotoxicity assays were evaluated against MRC-5 (non-tumoral lung), A549 (lung cancer) and MDA-MB-231 (breast cancer) cell lines. The complexes with Ar = 3,5-((CH3)3C)2C6H3–, 4-CH3O-3,5-(CH3)2C6H2– and 4-CH3O-C6H4– show high cytotoxicity, whilst the first complex is inactive towards the (healthy) MRC-5 cell line, indicating a degree of selectivity.
Guda Mallikarjuna Reddy, Alexandre Camilo, and Jarem Raul Garcia
Elsevier BV
A new series of pyrrole analogs were developed via the microwave irradiation synthesis. Consequently, got a high yield of the products. As pyrroles are familiar for showing various biological properties, all obtained compounds were screened for their antioxidant properties, most of the compounds showing significant activity. In fact, the motifs 5e, 5g, 5h and 5m showed outstanding antioxidant properties. Further, to enlighten the biologically energetic behavior underlying the antioxidant activity, compounds DFT studies were performed. Noteworthy results have been attained and the structure activity relationship (SAR) was discussed with the support of this results. It was found that highly biological active compounds exhibited a low HOMO-LUMO energy gap (Eg) and the high Eg value compounds show very low/negligible or inactive antioxidant activities. In other cases, compounds containing high HOMO energy levels also provide high antioxidant activity. The thought-provoking point of our results is that theoretical descriptors of the HOMO-LUMO energy gap and the highest occupied molecular orbital energy are important descriptors in the bioorganic research to support the biological experiments.
Luana Bojko, Gabriela de Jonge, Dhésmon Lima, Luma Clarindo Lopes, Adriano Gonçalves Viana, Jarem Raul Garcia, Christiana Andrade Pessôa, Karen Wohnrath, and Juliana Inaba
Elsevier BV
In the present work, the green synthesis of silver nanoparticles (AgNPs) using the sulfated polysaccharide porphyran (PFR) as capping agent and d-glucose as reducing agent is described. PFR was extracted from red seaweed and characterized by employing 13C NMR and determination of total sugar, protein, and sulfate contents. The obtained AgNPs-PFR were characterized by using UV-VIS spectroscopy, zeta potential determination, FESEM, and TEM, which demonstrated that PFR was effective at capping the AgNPs, yielding stable suspensions. The AgNPs-PFR presented good antimicrobial properties against Gram-positive and Gram-negative bacterial strains (Staphylococcus aureus and Escherichia coli, respectively). The AgNPs-PFR were also employed as the modifier of carbon paste electrodes, which were efficiently applied as electrochemical sensors for the determination of 5-fluorouracil (5-FU), an important anticancer drug, through square wave voltammetry (SWV). The AgNPs-PFR improved the electrochemical properties of the electrodes, and enhanced their electroanalytical performance. The developed sensing device presented detection and quantification limits equal to 10.7 and 35.8 μmol L-1, respectively, towards 5-FU determination. The proposed electrochemical sensor successfully quantified 5-FU in a real pharmaceutical formulation, confirming its potential as a new promising analytical detection tool for 5-FU quality control purposes.
Rafaela D. Oliveira, Cleverson S. Santos, Jarem R. Garcia, Marcio Vidotti, Luís F. Marchesi, and Christiana A. Pessoa
Elsevier BV
Abstract This manuscript presents the electrochemical impedance spectroscopy study regarding the influence of the pH and the range of the applied potential on the IR drop of polyaniline – Gum arabic/graphene oxide (PANI-GA/GOx) electrodes modified by the Layer-by-Layer technique. Using the equivalent circuit modeling methodology, it was discussed the IR drop dependence on parameters such as series and charge-transfer resistances and the double-layer capacitance. Series resistance related to the (PANI-GA/GOx) film conductivity showed to be very influenced by the pH, where a lower value of pH favored the protonation of the polyaniline-based film, increasing the overall conductivity leading to lower values of IR drop. Moreover, the IR drop also showed to be dependent on the range of the applied potential, reflecting in a change at the electrode/electrolyte interface, where an increase at the charge-transfer resistance was found at higher potentials, probably due to the pernigraniline state of PANI.
Guda Mallikarjuna Reddy, Avula Krishna Kumari, Vemulapati Hanuman Reddy, and Jarem Raul Garcia
Elsevier BV
From a medical point of view lot of existing antibiotics became unusable because microbial gained strong antibiotic resistance. The combination of two compounds in one core may lead to kill such type of pathogens. Herein, we developed pyranopyrazole derivatives comprising benzoxazole moiety by green approach strategy and studied their antimicrobial performance on four bacteria and two fungi. As a result, most of the compounds delivered reliable toxicity to kill the pathogens. In those,6aexhibited considerable activity against the microbial pathogens. Moreover,compounds 6d, 6l,and6nshowed prominent antibacterial activity. In addition, molecular docking studies of docked compounds revealed the strong bonding interaction with DNA-Gyrase and were docked into the intercalation location of DNA of the DNA-gyrase complex. The molecule bounded to the DNA stabilized by the H bonds, hydrophobic interactions, and π-π interaction. In addition, the linked 5-chlorobenazoxazole structure stabilized by the DT-8 and DG2009 of the F chain with pi-pi interactions. From the computer-aided results, it was observed that compound6a demonstrated maximum docking score -10.0 kcal/mole towards DNA-gyrase. Overall, this investigation suggested that these biologically active compounds can be utilized as leads for preclinical studies with the goal of developing newer antimicrobial drugs.
Guda Mallikarjuna Reddy, Jarem Raul Garcia, Gutha Yuvaraja, Munagapati Venkata Subbaiah, and Jet‐Chau Wen
Wiley
Rafaela D. Oliveira, Juliane Pscheidt, Cleverson S. Santos, Rodolfo T. Ferreira, Gustavo Marciniuk, Jarem R. Garcia, Marcio Vidotti, Luís F. Marchesi, and Christiana A. Pessoa
The Electrochemical Society
Venkata Subbaiah Munagapati, Hsin-Yu Wen, Jet-Chau Wen, Yuvaraja Gutha, Zhong Tian, Guda Mallikarjuna Reddy, and Jarem Raul Garcia
Informa UK Limited
Turkey tail (Trametes versicolor), cheap fungal biomass (TTFB), was used for the adsorption of CR from aqueous medium. Batch studies conducted to study the effect of pH (2.0–10.0), agitation speed ...
Sravya Gundala, Mallikarjuna Reddy Guda, Albert F. Khasanov, Dmitry S. Kopchuk, Alexey P. Krinochkin, Sougata Santra, Grigory V. Zyryanov, Padmavathi Venkatapuram, Jarem Raul Garcia, and Valery N. Charushin
Elsevier BV
12-(1H-1,2,3-Triazol-1-yl)indolo[2,1-a]isoquinolines are prepared in 51–56% yields using a PASE (pot, atom, step, economic)-based approach, namely, by the reaction between available 5-R-6-Ar-3-(isoquinolin-1-yl)-1,2,4-triazines and in situ generated benzyne. A mechanism comprising domino-transformation was suggested, and the structure of one key product was confirmed by a single crystal X-ray diffraction analysis.
Guda Mallikarjuna Reddy, Jarem Raul Garcia, Nemallapudi Bakthavatchala Reddy, Grigoriy V. Zyryanov, and Gutha Yuvaraja
Wiley