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481.
Piyush Kashyap Mamta Thakur Nidhi Singh Deep Shikha Shiv Kumar Poonam Baniwal Yogender Singh Yadav Minaxi Sharma Kandi Sridhar Baskaran Stephen Inbaraj 《Molecules (Basel, Switzerland)》2022,27(19)
The recent coronavirus disease (COVID-19) outbreak in Wuhan, China, has led to millions of infections and the death of approximately one million people. No targeted therapeutics are currently available, and only a few efficient treatment options are accessible. Many researchers are investigating active compounds from natural plant sources that may inhibit COVID-19 proliferation. Flavonoids are generally present in our diet, as well as traditional medicines and are effective against various diseases. Thus, here, we reviewed the potential of flavonoids against crucial proteins involved in the coronavirus infectious cycle. The fundamentals of coronaviruses, the structures of SARS-CoV-2, and the mechanism of its entry into the host’s body have also been discussed. In silico studies have been successfully employed to study the interaction of flavonoids against COVID-19 Mpro, spike protein PLpro, and other interactive sites for its possible inhibition. Recent studies showed that many flavonoids such as hesperidin, amentoflavone, rutin, diosmin, apiin, and many other flavonoids have a higher affinity with Mpro and lower binding energy than currently used drugs such as hydroxylchloroquine, nelfinavir, ritonavir, and lopinavir. Thus, these compounds can be developed as specific therapeutic agents against COVID-19, but need further in vitro and in vivo studies to validate these compounds and pave the way for drug discovery. 相似文献
482.
Falguni Pattnaik Nidhi Hans Biswa R. Patra Sonil Nanda Vivek Kumar Satya Narayan Naik Ajay K. Dalai 《Molecules (Basel, Switzerland)》2023,28(1)
Supercritical CO2 extraction (SCCO2) extraction of cannabis oil from Indian cannabis (Cannabis indica) leaves was optimized through a central composite design using CO2 pressure (150–250 bar), temperature (30–50 °C) and time (1–2 h). From the regression model, the optimal CO2 pressure, extraction temperature and time were 250 bar, 43 °C and 1.7 h, respectively resulting in the experimental yield of 4.9 wt% of cannabis oil via SCCO2 extraction. The extract contained cannabidiol, tetrahydrocannabivarin, Δ9-tetrahydrocannabinol and Δ8-tetrahydrocannabinol as well as two terpenoids such as cis-caryophyllene and α-humulene. Besides SCCO2 extraction of cannabis oil, the raffinate biomass was utilized to extract polyphenols using water as the extraction medium. Cannabis oil and water extractive were investigated for their half-maximal inhibitory concentration (IC50) values, which were found to be 1.3 and 0.6 mg/mL, respectively. This is comparable to the commercially available antioxidant such as butylated hydroxytoluene with an IC50 value of 0.5 mg/mL. This work on SCCO2 extraction of cannabinoids and other valuable bioactive compounds provides an environmentally sustainable technique to valorize cannabis leaves. 相似文献
483.
A dithiobissuccinimidyl propionate (DTSP) self-assembled monolayer (SAM) prepared onto a gold (Au) surface has been utilized for covalent immobilization of cholesterol oxidase (ChOx) and cholesterol esterase (ChEt). These ChOx-ChEt/DTSP/Au bio-electrodes have been characterized using electrochemical impedance and cyclic voltammetric (CV) techniques, respectively. Differential pulse voltammetry (DPV) has been used for enzymatic assay of immobilized ChOx and ChEt onto the DTSP modified gold surface as a function of cholesterol oleate concentration. The response measurement conducted on ChOx-ChEt/DTSP/Au bio-electrode reveal the value of Michaelis-Menten constant (Km) as 0.95 mM suggesting enhanced affinity of enzymes (ChOx and ChEt). The ChOx-ChEt/DTSP/Au bio-electrodes show linearity in range of 50 to 400 mg dl(-1) of cholesterol oleate and the shelf-life of more than 50 days when stored at 4 degrees C. This biosensing electrode shows correlation coefficient of 0.9973 and standard deviation of regression as 0.859 microA. 相似文献
484.
Positron annihilation studies are reported on polycarbonate polyethersulphone and polysulphone over the temperature range 260–370 K. The data were analysed into three components, the longest lifetime-o-component is associated with the pick-off mechanism; a linear variation of that component with temperature was observed. Using ultrasonic velocity data, the free volume distribution was calculated; its magnitude and temperature dependence are discussed in relation to the mechanical properties of the polymer. 相似文献
485.
Nidhi Gupta Nidhi Badhwar Bonamali Pal 《Journal of Sol-Gel Science and Technology》2013,68(2):284-293
Core–shell silica (SiO2) coated CdS nanorods (NR) and nanospheres (NS) were prepared (SiO2@CdS) by deposition of a Si–O–Si amorphous layer over the CdS surface through the hydrolysis of 3-mercaptopropyltrimethoxysilane and tetraethylorthosilicate. Nanoporous SiO2 matrix (NPSM), hollow SiO2 nanotubes (HSNT) and nanospheres (HSNS) useful for efficient adsorption and catalytic processes were prepared by chemical dissolution of CdS–NS (size: 9–10 nm) and CdS–NR (length: 116–128 nm and width: 6–11 nm) template from SiO2@CdS with 2 M HNO3. These SiO2 nanostructures were characterized by optical absorption, TEM, EDX, SAED and BET surface area analysis. TEM images revealed the fabrication of slightly distorted HSNS (size: 9–12 nm) and closed HSNT (length: 30–45 nm and diameter: 9–14 nm) of shorter dimensions than the CdS–NR template used. The BET surface area (112–134 m2 g?1) of NPSM and HSNS is found to be larger than the surface area (29–51 m2 g?1) of SiO2@CdS composites indicating hollow SiO2 morphology. Silica coated Au (SiO2@Au) composites formed by CdS dissolution from Au (2 wt%) deposited CdS–NR core-encapsulated into SiO2 shell (SiO2@Au–CdS–NR) exhibited a surface plasmon band at 550 nm and displayed high catalytic activity for 4-nitrophenol reduction by Au nanoparticle. 相似文献
486.
Nidhi Renu Gupta Tanu Sharma Sanjeev Aggarwal S. Kumar 《Indian Journal of Physics》2009,83(7):921-926
The samples of CR-39 polymer (TASTRAK, Bristol, England) were annealled thermally at various temperatures ranging from 100°C
to 180°C for 1 hour, in air. FTIR spectroscopy reveals the structural degradation of CR-39 polymer due to thermal annealing
above its glass transition temperature. Optical band gap of pristine and thermally annealed samples has been determined using
UV-Visible absorption spectra. It has been observed that the optical band gap decreases continuously as a result of annealing.
相似文献
487.
488.
We describe the construction of a polyaniline (PANI), multiwalled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) modified Au electrode for determination of hydrogen peroxide without using peroxidase (HRP). The AuNPs/MWCNT/PANI composite film deposited on Au electrode was characterized by Scanning Electron Microscopy (SEM) and electrochemical methods. Cyclic voltammetric (CV) studies of the electrode at different stages of construction demonstrated that the modified electrode had enhanced electrochemical oxidation of H(2)O(2), which offers a number of attractive features to develop amperometric sensors based on split of H(2)O(2). The amperometric response to H(2)O(2) showed a linear relationship in the range from 3.0 μM to 600.0 μM with a detection limit of 0.3 μM (S/N = 3) and with high sensitivity of 3.3 mA μM(-1). The sensor gave accurate and satisfactory results, when employed for determination of H(2)O(2) in milk and urine. 相似文献
489.
Nanosized Pd17Se15 and PdP2 were synthesized at moderate temperature (using less toxic TOPO in case of PdP2) and explored for the first time to catalyze transfer hydrogenation (TH) of aldehydes / ketones using 2-propanol as a source of hydrogen. The optimum catalyst loading was equivalent to 1.0 mol % of Pd. The round shaped Pd17Se15 NPs (15 to 30 nm), resulted on reacting (3-(phenylseleno)propylamine) with Na2PdCl4 in a mixture (1 : 1) of olylamine and 1-octadecene at 250 °C for 50 min. Nanoflowers of PdP2 (25 to 55 nm) were obtained by reacting Na2PdCl4 with trioctylphosphine oxide (TOPO) in a similar solvent mixture at 350 °C for 60 min. Both the NPs were found air insensitive and authenticated with powder X-ray diffraction, HR-TEM, SEM, SEM-EDX and XPS. The conversion was found more efficient for aldehydes in comparison to that of ketones. In comparison to most of the other Pd based nano-phases, reported earlier, the present NPs are somewhat better activators for TH. 相似文献
490.