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排序方式: 共有207条查询结果,搜索用时 15 毫秒
201.
Shaza M. Elhusseiny Taghrid S. El-Mahdy Mohamed F. Awad Nooran S. Elleboudy Mohamed M. S. Farag Mahmoud A. Yassein Khaled M. Aboshanab 《Molecules (Basel, Switzerland)》2021,26(15)
In this study, we examined aqueous extracts of the edible mushrooms Pleurotus ostreatus (oyster mushroom) and Lentinula edodes (shiitake mushroom). Proteome analysis was conducted using LC-Triple TOF-MS and showed the expression of 753 proteins by Pleurotus ostreatus, and 432 proteins by Lentinula edodes. Bioactive peptides: Rab GDP dissociation inhibitor, superoxide dismutase, thioredoxin reductase, serine proteinase and lectin, were identified in both mushrooms. The extracts also included promising bioactive compounds including phenolics, flavonoids, vitamins and amino acids. The extracts showed promising antiviral activities, with a selectivity index (SI) of 4.5 for Pleurotus ostreatus against adenovirus (Ad7), and a slight activity for Lentinula edodes against herpes simplex-II (HSV-2). The extracts were not cytotoxic to normal human peripheral blood mononuclear cells (PBMCs). On the contrary, they showed moderate cytotoxicity against various cancer cell lines. Additionally, antioxidant activity was assessed using DPPH radical scavenging, ABTS radical cation scavenging and ORAC assays. The two extracts showed potential antioxidant activities, with the maximum activity seen for Pleurotus ostreatus (IC50 µg/mL) = 39.46 ± 1.27 for DPPH; 11.22 ± 1.81 for ABTS; and 21.40 ± 2.20 for ORAC assays. This study encourages the use of these mushrooms in medicine in the light of their low cytotoxicity on normal PBMCs vis à vis their antiviral, antitumor and antioxidant capabilities. 相似文献
202.
Eggers PK Darwish N Paddon-Row MN Gooding JJ 《Journal of the American Chemical Society》2012,134(17):7539-7544
Herein, we report the first experimental investigation on the effect of varying the position of redox-active moieties, within the electrical double layer, on the apparent formal potential and on the electron transfer rate constant. This was achieved using a rigid class of molecules, norbornylogous bridges, to place redox species (ferrocene) at a fixed position above the surface of the electrode. Cyclic voltammetry and alternating current voltammetry were used to calculate the apparent formal potential and the electron transfer rate constant for the electron transfer between the ferrocene and the gold electrode. We use the effect of electric field on the apparent formal potential measurement of the surface-bound redox species to calculate the potential drop from the initiation of the electrical double layer to different distances above it. It was found that self-assembled monolayers formed from ω-hydroxyalkanethiol have a potential profile very similar to that described by classical theories for bare metal electrodes. A steep drop in potential in the Stern layer was observed followed by a smaller potential drop in the Gouy-Chapman layer. The electron transfer rate constant was found to decrease as the distance between the ferrocene moiety and the initiation of the double layer is increased. Thus, the electron transfer rate constant appears to be dependent on ion concentration. 相似文献
203.
Gouda YG Abdel-Baky AM Mohamed KM Darwish FM Kasai R Yamasaki K 《Natural product research》2006,20(10):935-939
Further phytochemical investigation of the fruits of Kigelia pinnata DC. has yielded a new phenylpropanoid derivative identified as 6-p-coumaroyl-sucrose (1) together with ten known phenylpropanoid and phenylethanoid derivatives (2-11) and a flavonoid glycoside (12). The structures of the isolated compounds were elucidated using various techniques of NMR and MS spectral analysis. 相似文献
204.
This paper describes the development of a generic spontaneous nonextractive spectrophotometric method for determination of 13 pharmaceutically important 4-quinolone antibiotics. The method was based on the formation of yellow-colored water-soluble ion-pair complexes between 2% (w/v) beta-naphthol reagent and each of the studied drugs in sulfuric acid medium at room temperature. The formed ion-pair chromogens have maximum absorption peaks in the range of 365-391 nm. The concentrations of the reagents and the experimental conditions affecting the reaction were optimized. Under the optimum conditions, linear relationships with good linear coefficients (0.9987-0.9995) were found between the absorbance and concentration of the investigated drugs in the range of 10-350 microg/mL. The assay limits of detection and quantitation were 1-9.9 and 3.4-32.9 microg/mL, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the analysis of the investigated drugs in pure and pharmaceutical dosage forms with good accuracy and precision; the percentages of label claim ranged from 97.8-102.8 +/- 0.35-1.60%. The results obtained by the proposed spectrophotometric method were comparable with those obtained by the official or reported methods. The proposed method is superior to all the previously reported ion-pair formation-based methods in terms of simplicity because it did not involve extraction procedures for the ion-pair complex. Therefore, this method might be recommended for routine use in quality control laboratories for analysis of the investigated 4-quinolone antibiotics in their pure forms, as well as in pharmaceutical dosage forms. 相似文献
205.
206.
S. Darwish S.Y. Al-Tel M.M. Abu-Teir R.M.-L. Kitanah A.A. Legrouze A.M. Saleh 《Solid State Sciences》2009,11(2):544-548
Systematic spectroscopic measurements of the spectral lines in MnF2 have been carried out in the temperature range 10–300 K. Observations of exciton and exciton–magnon sidebands in the fine structures of the 6A1g → 4A1g, 4Eg (4G) state of Mn+2 ions are reported at low temperatures for MnF2. The fine structure of the C-band is mainly attributed to spin multiplicity in the ordered state. In addition, the pure exciton bands have been identified and the ratios for the separation energies between these lines are fitted with the ratios expected form Lande interval rule. 相似文献
207.
Estibaliz Ruiz-Bilbao Dr. Amaia Iturrospe Dr. Santiago Reinoso Dr. Beñat Artetxe Dr. Garikoitz Beobide Dr. Leire San Felices Prof. Luis Lezama Prof. Juan M. Gutiérrez-Zorrilla Dr. Shaza Darwish Dr. Debobroto Sensharma Prof. Michael J. Zaworotko 《Angewandte Chemie (International ed. in English)》2023,62(42):e202307436
The 3D hybrid framework [{Cu(cyclam)}3(κ-Mo8O27)] ⋅ 14H2O ( 1 ) (cyclam=1,4,8,11-tetraazacyclotetradecane) undergoes sequential single-crystal-to-single-crystal transformations upon heating to afford two different anhydrous phases ( 2 a and 3 a ). These transitions modify the framework dimensionality and enable the isomerization of κ-octamolybdate (κ-Mo8) anions into λ ( 2 a ) and μ ( 3 a ) forms through metal migration. Hydration of 3 a involves condensation of one water molecule to the cluster to afford the γ-Mo8 isomer in 4 , which dehydrates back into 3 a through the 6 a intermediate. In contrast, 2 a reversibly hydrates to form 5 , exhibiting the same Mo8 cluster as that of 1 . It is remarkable that three of the Mo8 clusters (κ, λ and μ) are new and that up to three different microporous phases can be isolated from 1 ( 2 a , 3 a , and 6 a ). Water vapor sorption analyses show high recyclability and the highest uptake values for POM-based systems. The isotherms display an abrupt step at low humidity level desirable for humidity control devices or water harvesting in drylands. 相似文献