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41.
42.
Mudit M Behery FA Wali VB Sylvester PW El Sayed KA 《Natural product communications》2010,5(10):1623-1626
4-Hydroxyphenylmethylene hydantoin (PMH, 1), isolated from the Red Sea sponge Hemimycale arabica, and delta-tocotrienol (3), isolated from the tocotrienol-rich fraction of palm oil, are important antimetastatic and antiproliferative natural products that proved effective against metastatic prostate and breast cancers, respectively. New fluorescent derivatives of PMH (2) and delta-tocotrienol (4) were synthesized by Steglich esterification. Both 2 and 4 retained good anti-migratory and antiproliferative activities, respectively. Fluorescent analogues 2 and 4 can be used for the identification of molecular targets of 1 and 3 in tumor cell cultures. 相似文献
43.
44.
Mohamed Y. El-Sheikh Abdel-Fatah M. Habib Fathy M. Ashmawy Ali H. Gemeay Ahmed B. Zaki 《Transition Metal Chemistry》1988,13(2):96-100
Summary Dowex 50 W resin in the form of an ethylamine-Cu11 complex ion was used as potentially active catalyst for the decomposition of H2O2 in aqueous medium. The stoichiometry of the amine-Cu11 complex on the resin, determined experimentally, was found to have the total [Cu2+]: [ethylamine]=14 concentration ratio. The kinetics of the decomposition was studied and the calculated rate constant (per g of dry resin) was found to decrease with increase the degree of resin crosslinking. The active species, formed as an intermediate at the beginning of the reaction, had an inhibiting effect on the reaction rate. The brown peroxo-copper complex formed as a result of H2O2 decomposition, was found to contain the catalytic active species. The order of the reaction increased with decreasing initial H2O2 concentration, a sign of a step-wise mechanism. A quantitative treatment of the decomposition of H2O2 was provided in terms of activation parameters. 相似文献
45.
Mohamed M. Omar Fathy A. A. El-Seify 《Monatshefte für Chemie / Chemical Monthly》1991,122(6-7):445-452
Summary The complexation of 2-(4-benzimidazolylazo)-R-acid and 5-(4-benzimidazolylazo)-8-hydroxy-quinoline with Mn(II), Co(II), Ni(II), and Cu(II) have been studied potentiometrically using the Calvin-Bjerrum titration technique as employed by Irving and Rossotti. Protonation constants of the ligands and stability constants of the metal complexes have been determined at constant temperature (25|dgC) and ionic strength (0.1 µ NaCl). The order of stability constants (log1), Mn(II) < Co(II) < Ni(II) < Cu(II) is in conformity with the Irving-Williams order. The structures of the solid complexes have been assigned on the basis of elemental analysis and IR spectroscopy. Also conductimetric titrations have been made to characterize the composition of the complexes.
Metallchelate von Benzimidazolylazo-Derivaten
Zusammenfassung Es wurde die Komplexierung von 2-(4-Benzimidazolylazo)-2-hydroxynaphthalin-3,6-disulfonsäure und 5-(4-Benzimidazolylazo)-8-hydroxychinolin mit Mn(II), Co(II), Ni(II) und Cu(II) potentiometrisch mittels der Calvin-Bjerrum-Titrationsmethode in der Modifikation von Irving-Rossotti untersucht. Die Protonierungskonstanten der Liganden und die Stabilitätskonstanten der Metallkomplexe wurden für eine Temperatur von 25|dgC und eine Ionenstärke von 0.1 µ (NaCl) bestimmt. Die Reihung nach Stabilitätskonstanten (log 1), Mn(II) < Co(II) < Ni(II) < Cu(II), ist in Übereinstimmung mit der Irving-Williams-Ordnung. Die Strukturen wurden mittels Elementar-analyse und IR-Spektroskopie charakterisiert. Zur Ermittlung der Zusammensetzung der gebildeten Komplexe wurden auch Leitfähigkeitsmessungen durchgeführt.相似文献
46.
Fathy Mohamad Abdel Aziz El‐Taweel 《Journal of heterocyclic chemistry》2005,42(5):943-946
Several new benzo[ij]pyrano[2,3‐b]quinolizine‐8‐ones 5 and 4H‐pyrano[2,3‐b]pyridine 8 derivatives were synthesized from 4‐hydroxyquinolines 1 . Reacting 3‐acetyl‐4‐hydroxy‐1‐phenyl‐1H‐quinoline‐2‐one with dimethylformamide dimethylacetal afforded 3‐(3‐Dimethylarnino‐acryloyl)‐4‐hydroxy‐1‐phenyl‐1H‐quinolin‐2‐one 9 . This reacted with hippuric acid and diethyl 3‐oxoglutarate to give 2H‐pyran‐2‐one 13 and pyranopyridoquinoline 17 respectively. 相似文献
47.
V. E. Cosslett D. Fathy T. G. Sparrow U. Valdr 《Crystal Research and Technology》1979,14(10):1177-1184
This paper reviews work carried out in-situ on semiconductor devices by means of a high voltage electron microscope equipped with facilities for scanning transmission electron microscopy, electron beam induced conductivity and energy loss spectrometry. These combined techniques have allowed simultaneous and unambiguous correlations to be established between crystallographic, electrical and elemental properties of semiconductor materials and devices. Examples of these correlations are given, and mention is made to facilities (scanning deep level transient spectroscopy and cathodoluminescence) which may further increase the potential of high voltage scanning transmission electron microscopy. 相似文献
48.
Mohamed Nabil Abd Al Moaty El Sayed Helmy El Ashry Laila Fathy Awad Nihal Ahmed Ibrahim Marwa Muhammad Abu-Serie Assem Barakat Mezna Saleh Altowyan Mohamed Teleb 《Molecules (Basel, Switzerland)》2022,27(8)
The role of metalloenzymes in tumor progression had broadened their application in cancer therapy. Of these, MMPs and CAs are validated druggable targets that share some pivotal signaling pathways. The majority of MMPs or CAs inhibitors are designed as single-target agents. Despite their transient efficacy, these agents are often susceptible to resistance. This set the stage to introduce dual inhibitors of correlated MMPs and CAs. The next step is expected to target the common vital signaling nodes as well. In this regard, VEGFR-2 is central to various tumorigenesis events involving both families, especially MMP-2 and CA II. Herein, we report simultaneous inhibition of MMP-2, CA II, and VEGFR-2 via rationally designed hybrid 1,2,4-triazolo[4,3-a]pyrimidinone acyclo C-nucleosides. The promising derivatives were nanomolar inhibitors of VEGFR-2 (8; IC50 = 5.89 nM, 9; IC50 = 10.52 nM) and MMP-2 (8; IC50 = 17.44 nM, 9; IC50 = 30.93 nM) and submicromolar inhibitors of CA II (8; IC50 = 0.21 µM, 9; IC50 = 0.36 µM). Docking studies predicted their binding modes into the enzyme active sites and the structural determinants of activity regarding substitution and regioselectivity. MTT assay demonstrated that both compounds were 12 folds safer than doxorubicin with superior anticancer activities against three human cancers recording single-digit nanomolar IC50, thus echoing their enzymatic activities. Up to our knowledge, this study introduces the first in class triazolopyrimidinone acyclo C-nucleosides VEGFR-2/MMP-2/CA II inhibitors that deserve further investigation. 相似文献
49.
Fathy Hassan Masuki Kawamoto Krishnachary Salikolimi Daisuke Hashizume Takuji Hirose Yoshihiro Ito 《Tetrahedron letters》2018,59(2):99-102
An operationally simple ring closure of racemic 1,1′-bi-2-naphthol (BINOL) yielded the heterocyclic aromatic compound 7H-dibenzo[c,g]carbazole (DBC). This one-pot method gave a good conversion and is suitable for gram-scale synthesis. DBC derivatives have high thermal durability, amorphous and crystalline structures with unique morphological properties, and semi-conducting behavior with potential applications in organic electronics. 相似文献
50.
In the present work different optical properties of xTiO2-(60 − x)SiO2-40Na2O (wt%) optical glasses are determined. The characterization is done over a wide energy range, 0.41-6.2 eV. The refractive index and the extinction coefficient data are used to measure the absorption coefficient of the different glass compositions. Studying the UV-absorption edge, both direct and indirect allowed transitions with their optical energy gaps are carried out. In the same time, the Urbach energy is evaluated. From the extinction coefficient data, the Fermi energy of the glasses is calculated. The molar refraction, electronic polarizability and the optical basicity are obtained using the measured glass refractive indices. 相似文献