Quercetin extraction from small onion skin (Allium cepa L. var. aggregatum Don.) and its antioxidant activity.

In the present study, the maximum yield of quercetin was optimized for the ethanol extraction of small onions (Allium cepa L. var. aggregatum Don.), and the antioxidant activity was investigated in vitro. The extraction of quercetin from the small onion skin was carried out through ethanol solvent extraction with different ratios of ethanol and water. Ethanol: water ratio produced the highest quercetin from the onion skin. RP-HPLC analysis of the extracted material showed 2, 122 mg/g of quercetin and 0.34 mg/g of isorhamnetin. A total of 301.03 mg GAE/g dry weight and 156 mg/g quercetin equivalents were found in the onion skin extract. DPPH and ABTS free radical scavenging potentials of the tested extract (90:10 v/v) were dose-dependent, with IC50 values of 62.27 µg/mL and 53.65 µg/mL, respectively. Therefore, the present study reports that small onion skin extract rich in quercetin may serve as a promising antioxidant and anticancer agent.

Green synthesized Cobalt oxide nanoparticles using Curcuma longa for anti-oxidant, antimicrobial, dye degradation and anti-cancer property.

In the present study, cobalt oxide nanoparticles have been synthesized using the root extract of Curcuma longa in a manner that is both environmentally friendly and economical. Initially, the synthesized nanoparticles were characterized using a UV-Vis spectroscopy analysis, in which plasma resonance at 345 nm was observed, which confirmed that CL-Cobalt oxide nanoparticles were synthesized. While FTIR analysis showed a peak at 597.37 cm-1 indicating Co-O stretching vibration. In addition, DLS, SEM and XRD analyses confirmed the synthesis of polydispersed (average size distribution of 97.5 ± 35.1 nm), cubic phase structure, and spherical-shaped CL-Cobalt oxide nanoparticles. CL-Cobalt oxide nanoparticles synthesized from green materials showed antioxidant and antimicrobial properties. CL-Cobalt oxide nanoparticles exhibited antibacterial activity against Gram negative (Klebsiella pneumoniae and Escherichia coli) and Gram positive bacteria (Bacillus subtilis, Staphylococcus aureus), while CL-Cobalt oxide nanoparticles additionally displayed significant antifungal activity against Aspergillus niger. CL-Cobalt oxide also showed application in a bioremediation perspective by showing strong photocatalytic degradation of methyl red, methyl orange and methyl blue dye. In addition, CL-Cobalt oxide also demonstrated anticancer activity against MDA-MB-468 cancer cell lines with an IC50 value of 150.8 µg/ml. Therefore, this is the first and foremost report on CL-Cobalt oxide nanoparticles synthesized using Curcuma longa showing antioxidant, antibacterial, antifungal, dye degradation and anticancer applications.

Ultra-fast photocatalytic degradation and seed germination of band gap tunable nickel doping ceria nanoparticles.

Doping transition metal ions into cerium oxide (CeO2) results in interesting modifications to the material, including an increase in surface area, a high isoelectric point, biocompatibility, greater ionic conductivity, and catalytic activity. Herein, various concentrations (1-5%, 10% and 20%) of nickel (Ni) doped CeO2 nanoparticle have been made by a facile chemical process. Using a variety of cutting-edge analytical techniques, the structural, optical, and photocatalytic properties of undoped and varied concentrations (1-5%, 10%, and 20%) of Ni doped CeO2 nanoparticles have been investigated. Pure cubic fluorite structure with average crystallite sizes in the region of 12-15 nm was determined by X-ray diffraction (XRD) investigation. Transmission electron microscopy (TEM), which revealed highly homogeneous hexagonal shape of the particles with average size of 15 nm, was also used to determine microstructural information. According to the optical absorption, the band gaps of Ni doped and undoped CeO2 nanoparticles were found to be 2.96 eV and 1.95 eV, respectively. When exposed to sunlight, the narrow band gap Ni doped CeO2 nanoparticles worked as an active visible light catalyst to remove the dyes Rose Bengal (RB) and Direct Yellow (DY). The best photodegradation efficiencies for RB and DY dyes were found about 93% and 97%, respectively, using the 5% Ni-doped CeO2 catalyst. The apparent rate constant values of 0.039 for RB and 0.040 min-1 were attained for DY. As well, the treated, untreated dye solution and control solutions were utilized to assess the toxicity of commercially accessible Vigna Radiata seeds. In this study exhibits percentages of length and germination increased by 30-35% when compared to dye pollutant solution. The Ni doped CeO2 can provide a substantial alternative for current industrial waste management because of its quick photocatalytic activity and remarkable seed germination results.