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排序方式: 共有178条查询结果,搜索用时 15 毫秒
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Niyaz Ahmad Rizwan Ahmad Atta Abbas Naqvi Md Aftab Alam Mohammad Ashafaq Zeenat Iqbal 《液相色谱法及相关技术杂志》2017,40(3):133-146
The study reports a rapid and short analytical technique for separation, characterization, and quantitation along with comparative pharmacological effect of curcuminoids in cerebral ischemia. Flash chromatography, using silica and diol columns along with gradient mobile phase, was utilized to separate three curcuminoids, i.e., curcumin (Cur), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) for the first time. The separated peaks were monitored at 200–360?nm, whereas the purity of compounds (96.2–97.6%) was determined through qualitative analysis such as infrared and 1H and 13C-nuclear magnetic resonance spectroscopy, mass spectrometry (MS), and differential scanning calorimetry. Furthermore, chitosan nanoparticles (CS-NPs) for curcuminoids were prepared and characterized through zeta sizer, zeta potential, scanning electron microscopy, and transmission electron microscopy. The developed ultra performance of liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry/mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) method showed simplified automation and shorter run time for Combi flash over conventional separation techniques. The CS-NPs for all the three curcuminoids and combined-curcuminoids (CCr) (combined and administered together for a synergistic effect), following intranasal administration in middle cerebral artery–occluded rats were evaluated for grip strength, locomotor activity, and histopathological examination where the anti-ischemic activity was observed, in terms of potency, for all three CS-NPs and CCr as CCr>Cur>DMC>>BDMC. Cur-CS-NPs exhibited more potency among Cur, DMC, and BDMC, whereas CCr was the more potent anti-ischemic drug compared to Cur, DMC, and BDMC. For Cur the characteristic activity is proposed because of the presence of methoxy group on the phenyl ring whereas for CCr it is synergistic effect of curcuminoids. 相似文献
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Saira Hussain Ata ur Rehman David J. Luckett Syed Muhammad Saqlan Naqvi Christopher L. Blanchard 《Molecules (Basel, Switzerland)》2021,26(7)
Valorization of vegetable oil waste residues is gaining importance due to their high protein and polyphenol contents. Protease inhibitors (PIs), proteins from these abundantly available waste residues, have recently gained importance in treating chronic diseases. This research aimed to use canola meal of genetically diverse Brassica napus genotypes, BLN-3347 and Rivette, to identify PIs with diverse functionalities in therapeutic and pharmacological applications. The canola meal PI purification steps involved: native PAGE and trypsin inhibition activity, followed by ammonium sulfate fractionation, anion exchange, gel filtration, and reverse-phase chromatography. The purified PI preparations were characterized using SDS-PAGE, isoelectric focusing (IEF), and N terminal sequencing. SDS-PAGE analysis of PI preparations under native reducing and nonreducing conditions revealed three polymorphic PIs in each genotype. The corresponding IEF of the genotype BLN-3347, exhibited three acidic isoforms with isoelectric points (pI) of 4.6, 4.0, and 3.9, while Rivette possessed three isoforms, exhibiting two basic forms of pI 8.65 and 9.9, and one acidic of pI 6.55. Purified PI preparations from both the genotypes displayed dipeptidyl peptidase-IV (DPP-IV) and angiotensin-converting enzyme (ACE) inhibition activities; the BLN-3347 PI preparation exhibited a strong inhibitory effect with lower IC50 values (DPP-IV 37.42 µg/mL; ACE 129 µg/mL) than that from Rivette (DPP-IV 67.97 µg/mL; ACE 376.2 µg/mL). In addition to potential human therapy, these highly polymorphic PIs, which can inhibit damaging serine proteases secreted by canola plant pathogens, have the potential to be used by canola plant breeders to seek qualitative trait locus (QTLs) linked to genes conferring resistance to canola diseases. 相似文献
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A. A. Naqvi F. Z. Khiari Fatai A. Liadi Khateeb-ur-Rehman M. Raashid A. A. Isab 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(3):475-480
Prompt gamma ray analysis of soil samples contaminated with petroleum hydrocarbons(PHC) like benzene was carried out using 14 MeV neutron beams. Intensities of silicon, carbon, oxygen, and hydrogen gamma rays were measured for soil samples containing 2.20–10.4 wt% benzene. With increasing benzene concentration, the intensity of the C gamma rays increased while those of Si, H, and O gamma rays decreased. The reduction in Si, H, and O gamma ray intensities may be due to increasing neutron moderation effect in benzene-contaminated soil samples. The experimental intensities of gamma rays are in good agreement with the calculated intensities.The neutron moderation effects in benzene contaminated soil samples are about 26% weaker than those reported for soil samples containing moisture. From the slopes of silicon gamma ray intensity as a function of benzene concentration as well as moisture concentration, a simple scheme has been suggested to correct for the loss in carbon counts caused by neutron moderation from PHC and moisture in the soil samples. 相似文献
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Andleeb Z. Naqvi Gamal A. Al-dahbali Mohd. Akram Kabir-ud-Din 《Journal of solution chemistry》2013,42(1):172-189
In the present work, the behavior of mixed drug–surfactant systems has been studied by surface tension measurements. The drug used in this work is adiphenine hydrochloride (ADP) and the surfactants are of m-s-m type geminis, i.e., alkanediyl-α,ω-bis(dimethylalkylammonium bromide), with m = (14, 16), s = (4, 5, 6), and conventional alkyltrimethylammonium bromides (CTAB, TTAB). The excess surface concentration (Γ max ) increases and the minimum head group area at the air/water interface (A min) decreases with increasing concentration of surfactant in the drug solution. Both the critical micelle concentration (cmc) and ideal cmc (cmc*) values decrease with mole fraction of surfactants. Also, the cmc values are lower than cmc*, indicating attractive interactions are present in the mixed micelles. The mole fractions of surfactant in the micelles $ \left( {X_{1}^{m} } \right) $ and monolayers $ \left( {X_{1}^{\sigma } } \right) $ , as well as the respective interaction parameters ( $ \beta^{m} $ , $ \beta^{\sigma } $ ), indicate that monolayer formation is easier than micelle formation due to the rigid hydrophobic part of the drug. 相似文献
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Kabir‐ud‐Din Suraiya Khatoon Andleeb Z. Naqvi 《Journal of Dispersion Science and Technology》2013,34(4):485-491
Herein we report the effect of additives (salts and organics) on the cloud point (CP) of nonionic surfactant Triton X‐114 (TX‐114) aqueous solutions. CP showed a concentration dependent variation in the absence of any added compound. Addition of quaternary ammonium (or phosphonium) bromides to 0.8 mM TX‐114 solutions increased the CP. It was found that long chain alcohols and amines decreased the CP of 0.8 mM TX‐114 +80 mM Bu4AmB aqueous system, while it either remained constant or increased in the presence of short chain additives. The effect of first group additives (long chain) can be explained by considering that these additives solubilize in interfacial region and assist in micellar growth. Short chain additives remain in aqueous phase and affect the micelle hydration by affecting the solvent. Pentylamine behaved differently than pentanol: pentylamine increased the CP (like short chain additives) while pentanol decreased the CP. In pentylamine, the hydrophilicity of NH2 group and its dissociation into NH3 + dominates over the hydrophobicity of its alkyl chain. Aliphatic hydrocarbons first decreased and then increased the CP. The overall behavior depended upon the chain length of the hydrocarbon. With decane, the CP decreasing region disappeared completely. 相似文献
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A. A. Naqvi Faris A. Al-Matouq F. Z. Khiari Khateeb-ur-Rehman M. A. Gondal A. A. Isab 《Journal of Radioanalytical and Nuclear Chemistry》2013,296(1):215-221
A thermal neutron capture-based Prompt Gamma ray Activation Analysis setup has been designed to analyze the elemental concentration of environmental bulk samples using a D(d,n) reaction-based portable neutron generator. The performance of the setup was tested through mercury concentration measurements in Hg-contaminated water samples using a large volume cylindrical bismuth germinate (BGO) gamma ray detector. Excellent agreement of experimental count rate of 2.64, 3.19 + 3.29 and 4.67–5.05 MeV Hg prompt gamma rays with theoretical count rate obtained through Monte Carlo simulations, indicates excellent performance of the newly designed portable neutron generator-based PGNAA setup. 相似文献
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Muhammad Akhyar Farrukh Noureen Siraj Iftikhar Imam Naqvi 《Journal of Saudi Chemical Society》2010,14(2):209-212
Iron has been determined in apple and vegetables spectrophotometrically, by complexing it with xylenol orange. 1:1 complex formed in a highly acidic medium is measured for its absorbance at its λmax of 585 nm. The results have been compared by employing atomic absorption technique. Apples and vegetable samples were collected from local markets of Pakistan. Statistical manipulations, t-test and F-test, were performed and it was found that the results from the two techniques have an excellent agreement. 相似文献