Gas sensing materials have been widely explored recently owing to their versatile environmental and agriculture monitoring applications. The present study advocates the electronic response of Zn-decorated inorganic B 12 P 12 nanoclusters to CO 2 gas. Herein, a series of systems CO 2 −Zn−B 12 P 12 (E1−E4) are designed by adsorption of CO 2 on Zn-decorated B 12 P 12 nanoclusters, and their electronic properties are explored by density functional theory. Initially, placement of Zn on B 12 P 12 delivers four geometries named as D1−D4, with adsorption energy values of −57.12, −22.94, −21.03, and −14.07 kJ/mol, respectively, and CO 2 adsorption on a pure B 12 P 12 nanocage delivers one geometry with an adsorption energy of −4.88 kJ/mol. However, the interaction of CO 2 with D1−D4 systems confers four geometries named as E1 (E ad = −75.12 kJ/mol), E2 (E ad = −25.89 kJ/mol), E3 (E ad = −42.43 kJ/mol), and E4 (E ad = −28.73 kJ/mol). Various electronic parameters such as dipole moment, molecular electrostatic potential analysis, frontier molecular orbital analysis, Q NBO , global descriptor of reactivity, and density of states are also estimated in order to understand the unique interaction mechanism. The results of these analyses suggested that Zn decoration on B 12 P 12 significantly favors CO 2 gas adsorption, and a maximum charge separation is also noted when CO 2 is adsorbed on the Zn−B 12 P 12 nanocages. Therefore, the Zn-decorated B 12 P 12 nanocages are considered as potential candidates for application in CO 2 sensors.
RESUMEN
Evaluación de la actividad antioxidante de extractos de salvado de arroz mediante differentes ensayosSe evalúa la actividad antioxidante diferentes extractos (100% metanol, 80% metanol, 100% acetona and 80% acetona) de salvado de arroz -var. Super Kernel-mediante diferentes ensayos y utilizando aceite de girasol como substrato. Los ensayos utilizados fueron la estimación del % de inhibición de la peroxidación en sistemas con ácido linoleico, el contenido total en compuestos fenólicos y la pérdida de β-caroteno en sistemas con ácido linoleico. Adicionalmente, los concentrados de extractos de salvado de arroz se añadieron a aceite de girasol y las muestras se almacenaron a temperatura ambiente. La extensión de la oxidación se evaluó mediante el índice de peróxidos, el índice de p-anisidina, así como la formación de dienos y trienos conjugados.El orden de la eficacia antioxidante de los extractos de salvado de arroz fue el siguiente: 80 % metanol> 100 % metanol > 80 % acetona > 100% acetona. Los resultados demostraron que los extractos del salvado de arroz de la variedad Super Kernel del arroz indígena de Paquistán son una fuente viable de antioxidantes naturales y podrían ser explotados como alimentos funcionales.
PALABRAS-CLAVE: Antioxidantes-Ensayos de actividad antioxidante -Fenoles totales-Oxidación -Porcentaje de inhibición.
SUMMARY Evaluation of the antioxidant activity of rice bran extracts using different antioxidant assaysIn the present work the antioxidant activity of different solvent (100% methanol, 80% methanol, 100% acetone, 80% acetone) extracts of rice bran was evaluated following different antioxidant assays and using sunflower oil as oxidation substrate. The rice bran extracts were evaluated from the estimate of % inhibition of peroxidation in linoleic acid system, total phenolics content (TPC) and loss of β-carotene in a linoleic acid system. Additionally, crude concentrated rice bran extracts were added into the sunflower oil samples and stored under ambient conditions. The extent of oxidative deterioration was followed by the measurement of peroxide-, p-anisidine-, conjugated diene-, and triene-values. The general order of antioxidant efficacy of rice bran extracts as determined by various antioxidant assays was 80% methanolic extract > 100% methanolic Evaluation of the antioxidant activity of rice bran extracts using different antioxidant assays
Herbal medicines are widely used for the treatment of different types of diseases like skin and throat infections and other diseases in developing countries. Syzygium cumini (L.) Skeels fruit, leaves and bark were used for the remedies of different diseases anciently. The aim of the present study was to evaluate the chemical profile of Syzygium cumini leaves essential oil (EO) from Punjab, Pakistan. The essential oil was isolated using hydrodistillation technique and analyzed by gas chromatography (GC) and gas chromatography‐mass spectrometry (GC/MS). Free radical scavenging capacity and antioxidant activity were assessed by using DPPH radical scavenging ability, inhibition of linoleic acid peroxidation, bleaching of β‐carotene in linoleic acid system and reducing power assays. Antimicrobial potential was assessed by disc diffusion assay and measurement of minimum inhibitory concentration (MIC) using resazurin microtiter‐plate assay. The anti‐heme biocrystallization activity of EO was also assessed. The major components (>3%) found in Syzygium cumini leaves EO were β‐farnesene (3.42 %), caryophyllenol (3.46 %), terpinen‐4‐ol (3.61 %), β‐myrcene (3.90 %), γ‐cadinene (4.09 %), fenchol (4.22 %), cis‐β‐ocimene (4.40 %) and 5‐methyl‐1,3,6‐heptatriene (4.90 %). Excellent antioxidant, antimicrobial and weak antimalarial potential was observed. It can be concluded that Syzygium cumini leaves EO has potential application for food and pharmaceutical industries.
This work was carried out to investigate the antioxidant activity and free radical scavenging capacity of leaves and stem bark extracts of Terminalia arjuna (arjuna) prepared in aqueous ethanol (water: ethanol 20:80v/v) and aqueous methanol (water: methanol 20:80v/v) solvents. The extraction yields of extracts were ranged from 6.66-19.09g/100g (w/w) on dry weight basis. It was observed that arjuna extracts contained appreciable amount of TPC (6.02-11.00 g/100g, as gallic acid equivalent) and TFC (1.75-5.96 g/100g, as catechin equivalent) as well as exhibited good DPPH radical scavenging activity (IC 50 2.71-7.68 µg/ mL), inhibition of peroxidation (64.79-71.43%) and reducing power (0.001-1.584 mg/mL). The results of the present investigation clearly demonstrated the significant (p ≤ 0.05) variations in antioxidant properties of different solvent extracts of arjuna. It can be concluded from the results that arjuna extracts were good source of natural antioxidants.
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