Green Synthesis of Ceria Nanoparticles Using Azadirachta Indica Plant Extract: Characterization, Gas Sensing and Antibacterial Studies

In the present investigation we have fabricated the cerium dioxide (CeO2) nanoparticles by green route. While preparing the cerium dioxide nanoparticles by co-precipitation method, Neem leaf extract mixed into the precursor of cerium. The synthesized nanoparticles of CeO2 were used for the preparation of thick film sensor by using screen printing strategy. The fabricated CeO2 sensor was characterized by XRD, SEM, EDS and TEM techniques. The structural characteristics investigated by x-ray diffraction technique (XRD). XRD confirms the formation of cubic lattice of CeO2 material. The surface, texture, porosity characteristics were investigated from SEM analysis, while chemical composition of the material was analysed by EDS technique. The transmission electron microscopy (TEM) confirms the formation cubic lattice of the cerium dioxide material. The thickness of the films was calculated from mass difference method, the prepared film sensors belong to thick region. The fabricated material CeO2 sensor was applied as gas sensor to sense the gases such as LPG, petrol vapors (PV), toluene vapors (TV) and CO2. The CeO2 sensor showed excellent gas response for LPG and PV, nearly 93.20 % and 78.23 % gas response. The rapid response and recovery of the prepared sensors was observed at the tested gases. CeO2 material also employed for antibacterial study at several pathogenic organism such as pseudomonas, staphylococcus aureus and salmonella typhae. From antibacterial study it was observed that the material is capable of inhibiting the growth of these pathogenic microbes.

Preparation, Characterisation and Antibacterial Activity of Carvacrol Encapsulated in Gellan Gum Hydrogel

Recently, the antibacterial properties of Carvacrol (Carv) have been significantly reported. However, due to the unstable properties of Carv under various environment conditions, research approaches tailored towards its widespread and efficient use in various antimicrobial applications are scarce. Here, we discuss progress towards overcoming this challenge by utilising the encapsulation of Carv in gellan gum hydrogels to form thin films (GG-Carv) containing different concentrations of Carv (0.01–0.32 M). FTIR spectrum of GG-Carv revealed that both functional groups from GG and Carv existed. The carbon, hydrogen and nitrogen elemental analysis further supported the encapsulation of Carv with the changes in the element percentage of GG-Carv. Both swelling and degradation percentage increased with time and the decreasing patterns were observed as the concentration of Carv increased. In an antibacterial study, GG-Carv exhibited significant antibacterial activity against E. coli with the clear inhibition zone of 200 mm and the detection of bacterial growth showed enhancement with continuous decline throughout the study as compared to free-standing Carv.

Heteroleptic C, N- Donor Pd(II) Complexes: Synthesis, Characterization, DNA/BSA Binding Interactions And Biological Studies

A series of trisubstituted pyrazole-based ligands (L1-L6) and corresponding palladium(II) complexes were synthesized and characterized by conductivity measurement, 1H NMR, 13C NMR, Fourier Transform infrared (FT-IR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Synthesized compounds were screened for various biological activities. UV-Vis spectroscopy, viscosity measurement, fluorescence spectroscopy and molecular docking studies were used to determine the binding mode between HS-DNA and complexes, which suggest intercalation mode of binding. The protein binding study of complexes was evaluated by UV-visible spectroscopy. Antibacterial study of the complexes was screened against two Gram (+ve) and three Gram (-ve) bacteria and results show that all complexes are more effective against microorganisms than their respective ligands. The cytotoxicity of the synthesized compounds was tested against brine shrimp and MCF-7 Cells. The LC50 values of the ligand and complexes were found in the range of 9.24-4.12 µg/mL and 5.68-7.94 µg/mL, respectively.

One-Pot Multi Component Microwave Assisted Synthesis of 4H-Pyrano [2, 3-c] Pyrazoles in Methanol and their Antibacterial Study

Upon literature studies, pyrano-pyrazoles were found to exhibit the biological activity as antimicrobial agents. So literature employed conventional stirring and reflux condensing to afford different pyrano-pyrazoles. Recent researches adopted the Microwave method, which is a simple and convenient method for organic synthesis. In this work, we reported the synthesis of different 4H-pyrano [2, 3-c] pyrazoles via two different methods, such as microwave & conventional stirring at room temperature. Ethyl acetoacetate, hydrazine hydrate, malanonitrile, and different substituted carbonyl compounds were made to react in the presence of methanol solvent & potassium ter-butoxide, a base catalyst. The microwave method was adopted for all the reactions and found to be more potent than the conventional method. The prepared compounds were characterized by FT-IR, 1HNMR, and 13CNMR. These compounds were screened for anti-bacterial activity against Staphylococcus aureus and E. coli by well diffusion method and showed the excellent antibacterial property. Our In vitro test for antibacterial study involves excellent MIC (µg/ml) and zone inhibition (mm) measurements of all synthesized compounds. Microwave irradiation synthesis hastens the reaction and is completed very fast. Potassium ter-butoxide, a base catalyst, is proved to be a good catalyst for accelerating the reactions. The yield of all synthesized compounds was good. Different 4H-pyrano [2, 3-c] pyrazoles exhibited good potency against Staphylococcus aureus and E. coli. In the presence of a base catalyst, the reactions are faster than in the absence of a catalyst. The microwave method is a good methodology for the green syntheses. Derivatives of 4H-pyrano [2, 3-c] pyrazoles exhibited excellent MIC (µg/ml) and proved to be as good antibacterial agents.