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排序方式: 共有160条查询结果,搜索用时 968 毫秒
1.
Sheikdawood Parveen Thathan Premkumar Subbiyan Poornima Subbiah Govindarajan 《Journal of Saudi Chemical Society》2019,23(6):691-701
Metal complexes ([ML2], where M = Fe, Co, or Zn; HL = 2-[(6-ethyl-5-oxo-4,5-dihydro-2H-[1,2,4]triazin-3-ylidene)-hydrazono]-butyric acid, C9H13N5O3) of a Schiff base derived from α-ketobutyric acid (α-KBA) and diaminoguanidine (Damgu) were synthesized and characterized using elemental, spectral, and thermal studies. The metal complexes exhibited similar decomposition behavior, with a highly exothermic final decomposition step resulting in the formation of metal oxides. Isomorphism among the complexes was revealed using a powder X-ray diffraction (PXRD) technique. Solid solution precursors ([Zn1/3M2/3(L)2], where M = Fe, Co) were synthesized and characterized using various physico-chemical techniques. A thermal decomposition technique was used to prepare spinel-type zinc cobaltite (ZnCo2O4) and zinc ferrite (ZnFe2O4) nanocrystalline particles with the synthesized single source precursors. Structural studies using PXRD ascertained the predominant crystal phase to be spinel. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) showed a mean nanoparticle size of 18 ± 2 nm. Magnetic measurements revealed a weak magnetic behavior in the synthesized spinels. In the aqueous phase, the spinels exhibited catalytic activity, reducing 4-nitrophenol (4-NP) in the presence of NaBH4 at room temperature. Additionally, the study demonstrated that the catalyst can be recovered and reused for five cycles with a more than 85% conversion efficiency. 相似文献
2.
An efficient synthetic method of heterocyclic flavone benzofuran fused derivatives is reported in good to excellent yield (75–90%) via Ullmann type coupling reaction. The protocol involves catalytic amount of CuI (10 mol%) and K2CO3 base for the intramolecular CO bond formation under mild reaction conditions. 相似文献
3.
Nazish Parveen Mohammad Omaish Ansari Thi Hiep Han Moo Hwan Cho 《Journal of Solid State Electrochemistry》2017,21(1):57-68
This paper reports a simple methodology for the synthesis of a polyaniline/titanium oxide/graphene hybrid (Pani/TiO2/GN) using a simple methodology, and their application as a supercapacitor electrode material for energy storage. The Pani/TiO2/GN hybrid was prepared by a simple approach by simultaneous generation of Pani and TiO2 in situ from aniline and titanium iso-propoxide, respectively, in the presence of GN under ice bath conditions. The incorporation of GN improved the electrical conductivity of Pani and helped to decrease the charge transfer resistance, whereas TiO2 generation by an in situ method increased the surface area considerably and enhanced the capacitance of the Pani/TiO2/GN hybrid. TEM showed that Pani and TiO2 were well incorporated and coated on the GN successfully. The shift of the peaks in the FTIR spectrum and XRD pattern of the Pani/TiO2/GN hybrid compared to their pure counterparts suggested that TiO2 and Pani had been perfectly coated on the GN, and there was a strong interaction among Pani, GN, and TiO2 particles. The electrochemical performance of the as-prepared Pani/TiO2/GN hybrid electrode showed a high specific capacitance of 403.2 F g?1 at a current density of 2 A g?1 and excellent cycling stability for up to 1000 cycles. This suggested that the effective incorporation of GN and TiO2 into Pani and the high surface area could simultaneously increase the electrochemical capacitance and cyclic stability of the Pani/TiO2/GN hybrid, leading to superior electrochemical performance. 相似文献
4.
Sanjoy Pal Trinath Chowdhury Kishalay Paria Sounik Manna Sana Parveen Manjeet Singh Pralay Sharma Sk Saruk Islam Sk Md Abu Imam Saadi Santi M. Mandal 《印度化学会志》2022,99(1):100244
BackgroundThe recent pandemic by COVID-19 is a global threat to human health. The disease is caused by SARS-CoV-2 and the infection rate is increased more quickly than MERS and SARS as their rapid adaptation to varied climatic conditions through rapid mutations. It becomes more severe due to the lack of proper therapeutic drugs, insufficient diagnostic tool, scarcity of appropriate drug, life supporting medical facility and mostly lack of awareness. Therefore, preventive measure is one of the important strategies to control. In this context, herbal medicinal plants received a noticeable attention to treat COVID-19 in Indian subcontinent. Here, 44 Indian traditional plants have been discussed with their novel phytochemicals that prevent the novel corona virus. The basic of SARS-CoV-2, their common way of transmission including their effect on immune and nervous system have been discussed. We have analysed their mechanism of action against COVID-19 following in-silico analysis. Their probable mechanism and therapeutic approaches behind the activity of phytochemicals to stimulate immune response as well as inhibition of viral multiplication discussed rationally. Thus, mixtures of active secondary metabolites/phytochemicals are the only choice to prevent the disease in countries where vaccination will take long time due to overcrowded population density. 相似文献
5.
Qamar Uddin Ahmed Abdul Hasib Mohd Ali Sayeed Mukhtar Meshari A. Alsharif Humaira Parveen Awis Sukarni Mohmad Sabere Mohamed Sufian Mohd. Nawi Alfi Khatib Mohammad Jamshed Siddiqui Abdulrashid Umar Alhassan Muhammad Alhassan 《Molecules (Basel, Switzerland)》2020,25(23)
In recent years, there is emerging evidence that isoflavonoids, either dietary or obtained from traditional medicinal plants, could play an important role as a supplementary drug in the management of type 2 diabetes mellitus (T2DM) due to their reported pronounced biological effects in relation to multiple metabolic factors associated with diabetes. Hence, in this regard, we have comprehensively reviewed the potential biological effects of isoflavonoids, particularly biochanin A, genistein, daidzein, glycitein, and formononetin on metabolic disorders and long-term complications induced by T2DM in order to understand whether they can be future candidates as a safe antidiabetic agent. Based on in-depth in vitro and in vivo studies evaluations, isoflavonoids have been found to activate gene expression through the stimulation of peroxisome proliferator-activated receptors (PPARs) (α, γ), modulate carbohydrate metabolism, regulate hyperglycemia, induce dyslipidemia, lessen insulin resistance, and modify adipocyte differentiation and tissue metabolism. Moreover, these natural compounds have also been found to attenuate oxidative stress through the oxidative signaling process and inflammatory mechanism. Hence, isoflavonoids have been envisioned to be able to prevent and slow down the progression of long-term diabetes complications including cardiovascular disease, nephropathy, neuropathy, and retinopathy. Further thoroughgoing investigations in human clinical studies are strongly recommended to obtain the optimum and specific dose and regimen required for supplementation with isoflavonoids and derivatives in diabetic patients. 相似文献
6.
S. Parveen S. Singh D. Shukla M. Yasmin M. Gupta J. P. Shukla 《Journal of solution chemistry》2012,41(1):156-172
Ultrasonic velocity, density, refractive index and viscosity of binary mixtures of aniline with acetic acid (AA) and propionic
acid (PA) have been measured at 293.15, 303.15 and 313.15 K over the entire composition range. Further, the specific heat
ratio, heat capacity, effective Debye temperature and pseudo-Gruensisen parameter and non-linearity parameter have been evaluated
using ultrasonic absorption data. The deviation in isentropic compressibility, excess molar volume, excess intermolecular
free length, deviation in molar refraction, deviation in viscosity, relaxation time, enthalpy, entropy and Gibbs energy of
activation have been calculated from the experimental data and fitted with the Redlich-Kister polynomial equation. A comparative
study has also been made between experimental and theoretically calculated values of densities using the HBT and Rackett density
models. Mixing rules for the prediction of refractive index, e.g. Lorentz-Lorenz (L-L), Eykmen (Eyk), Weiner (W), Heller (H),
Gladstone-Dale (G-D), Arago-Biot (A-B) and Newton (N) have been applied to these binary mixtures. 相似文献
7.
Singh Mhaveer Kamal Yunus T.-K. Tamboli Ennus T. Parveen Rabea Ansari Shahid H. Ahmad Sayeed 《平面色谱法杂志一现代薄层色谱法》2013,26(3):267-273
JPC – Journal of Planar Chromatography – Modern TLC - A novel HPTLC method has been developed for the estimation of glabridin in Licorice rhizome and its Unani polyherbal formulation... 相似文献
8.
3-Phenyl-1-(thiophen-2-yl)prop-2-en-1-one obtained by Claisen–Schmidt condensation of 2-acetyl thiophene with benzaldehyde was converted into 2,3-dibromo-3-phenyl-1-(thiophen-2-yl)propan-1-one, which on treatment with various thiosemicarbazides in the presence of triethylamine in absolute ethanol, yielded the corresponding hydroxy pyrazolines 3a–h. All the compounds were characterized by IR, 1H NMR, and 13C NMR spectra. 相似文献
9.
Manuel G. Ricardo Ameena M. Ali Jacek Plewka Ewa Surmiak Beata Labuzek Constantinos G. Neochoritis Jack Atmaj Lukasz Skalniak Ran Zhang Tad A. Holak Matthew Groves Daniel G. Rivera Alexander Dmling 《Angewandte Chemie (International ed. in English)》2020,59(13):5235-5241
Stapled peptides are chemical entities in‐between biologics and small molecules, which have proven to be the solution to high affinity protein–protein interaction antagonism, while keeping control over pharmacological performance such as stability and membrane penetration. We demonstrate that the multicomponent reaction‐based stapling is an effective strategy for the development of α‐helical peptides with highly potent dual antagonistic action of MDM2 and MDMX binding p53. Such a potent inhibitory activity of p53‐MDM2/X interactions was assessed by fluorescence polarization, microscale thermophoresis, and 2D NMR, while several cocrystal structures with MDM2 were obtained. This MCR stapling protocol proved efficient and versatile in terms of diversity generation at the staple, as evidenced by the incorporation of both exo‐ and endo‐cyclic hydrophobic moieties at the side chain cross‐linkers. The interaction of the Ugi‐staple fragments with the target protein was demonstrated by crystallography. 相似文献
10.
Eltayeb Fadul Arsalan Nizamani Saima Rasheed Achyut Adhikari Sammer Yousuf Shahida Parveen 《Natural product research》2020,34(17):2456-2464
AbstractA new sesquiterpene lactone geigerianoloide (1) and four known flavonoids axillarin (2), quercetin (3), 3-methoxy-5,7,3',4'-tetrahydroxy-flavone (4) and hispidulin (5) were isolated from Geigeria alata (DC) Oliv. & Hiern. (Asteraceae). Structures were deduced using 1H- and 13C- NMR spectroscopy, mass spectrometry, while the structure of compound 1 was also deduced using X-ray crystallography technique.Geigeria alata is traditionally used for diabetes, therefore compounds were tested for anti-glycation activity, in which compounds 2 and 3 showed potent activities (IC50 values of 246.97?±?0.83 and 262.37?±?0.22 µM, respectively) compared to IC50 value 294.50?±?1.5 µM of rutin. Moreover, compound 4 exhibited a comparable activity to rutin (IC50?=?293.28?±?1.34 µM). Compound 5 showed a weak activity.Compounds 2, 3, and 4 exhibited potent DPPH radical scavenging activity (IC50?=?0.1?±?0.00, 0.13?±?0.00 and 0.15?±?0.01 µM, respectively). Compounds 2, 3, and 4 demonstrated significant superoxide anion scavenging activity with IC50 values of 0.14?±?0.001, 0.17?±?0.00, and 0.11?±?0.006 µM, respectively. 相似文献