12 results on '"Alnabulsi S"'
Search Results
2. Scuffing behavior of gray iron and 1080 steel in reciprocating and rotational sliding
- Author
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Han, J.M., Zhang, R., Ajayi, O.O., Barber, G.C., Zou, Q., Guessous, L., Schall, D., and Alnabulsi, S.
- Published
- 2011
- Full Text
- View/download PDF
3. Evaluation of analogues of furan-amidines as inhibitors of NQO2
- Author
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Alnabulsi, S., Hussein, B., Santina, E., Alsalahat, I., Kadirvel, M., Magwaza, R.N., Bryce, R.A., Schwalbe, Carl H, Baldwin, A.G., Russo, I., Stratford, I.J., Freeman, S., Alnabulsi, S., Hussein, B., Santina, E., Alsalahat, I., Kadirvel, M., Magwaza, R.N., Bryce, R.A., Schwalbe, Carl H, Baldwin, A.G., Russo, I., Stratford, I.J., and Freeman, S.
- Abstract
Inhibitors of the enzyme NQO2 (NRH: quinone oxidoreductase 2) are of potential use in cancer chemotherapy and malaria. We have previously reported that non-symmetrical furan amidines are potent inhibitors of NQO2 and here novel analogues are evaluated. The furan ring has been changed to other heterocycles (imidazole, N-methylimidazole, oxazole, thiophene) and the amidine group has been replaced with imidate, reversed amidine, N-arylamide and amidoxime to probe NQO2 activity, improve solubility and decrease basicity of the lead furan amidine. All compounds were fully characterised spectroscopically and the structure of the unexpected product N-hydroxy-4-(5-methyl-4-phenylfuran-2-yl)benzamidine was established by X-ray crystallography. The analogues were evaluated for inhibition of NQO2, which showed lower activity than the lead furan amidine. The observed structure-activity relationship for the furan-amidine series with NQO2 was rationalized by preliminary molecular docking and binding mode analysis. In addition, the oxazole-amidine analogue inhibited the growth of Plasmodium falciparum with an IC50 value of 0.3 μM.
- Published
- 2018
4. Sputtering of Organic Materials with a C60+ Ion Beam
- Author
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Bryan, SR, primary, Fisher, GL, additional, Alnabulsi, S, additional, Raman, S, additional, Moulder, J, additional, Hammond, JS, additional, Sanada, N, additional, and Iida, S-I, additional
- Published
- 2010
- Full Text
- View/download PDF
5. Modern Auger Electron Spectroscopy for Chemical Surface Analysis
- Author
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Paul, D, primary, Watson, D, additional, Moulder, J, additional, Bryan, S, additional, and Alnabulsi, S, additional
- Published
- 2006
- Full Text
- View/download PDF
6. Weak complexation of 5-fluorouracil with β-cyclodextrin, carbonate, and dianhydride crosslinked β-cyclodextrin: in vitro and in silico studies.
- Author
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Mashaqbeh H, Obaidat R, Al-Shar'i NA, El-Elimat T, and Alnabulsi S
- Abstract
Background and Purpose: Several pharmaceutical formulations were investigated to improve the solubility of 5-fluorouracil to enhance bioavailability and therapeutic efficacy. This study aimed to examine the potential use of cyclodextrin-based nanosponges for the incorporation of 5-fluorouracil and to investigate the use of different crosslinking agents on the properties of the resulting drug carrier. 5-Fluorouracil complexation with β-cyclodextrin was also studied to explain the unexpected results of weak 5-fluorouracil incorporation in nanosponge., Experimental Approach: Nanosponges were synthesized by crosslinking β-cyclodextrin with two different crosslinkers; diphenyl carbonate and ethylenediaminetetraacetic dianhydride. The incorporation of 5-fluorouracil into β-cyclodextrin and the prepared nanosponges were assessed by NMR, FTIR, PXRD, DSC, and TGA. In addition, an in vitro release study was carried out to evaluate the potential use of β-cyclodextrin- based nanosponges as pharmaceutical formulations for 5-fluorouracil., Findings / Results: Physicochemical characterization of the dried formulations indicated the complexation of 5-fluorouracil with the β-cyclodextrin polymer. Despite that, no clear manifestation of 5-fluorouracil encapsulation in the prepared β-cyclodextrin-based nanosponge was detected. Furthermore, no significant differences were observed in the release profiles of 5-fluorouracil, β-cyclodextrin complex, and β- cyclodextrin-based nanosponge, suggesting weak complexation and instability in aqueous solutions. EDTA- crosslinked β-cyclodextrin-based nanosponge showed a slight improvement in 5-fluorouracil solubility with a faster initial rate of 5-fluorouracil release., Conclusion and Implications: This study suggested weak complexation between 5-fluorouracil and the β- cyclodextrin polymer or nanosponges. Crosslinking of β-cyclodextrin with EDTA dianhydride crosslinker showed an enhancement in 5-fluorouracil saturation solubility combined with a faster initial rate of drug release., Competing Interests: All authors declared no conflict of interest in this study., (Copyright: © 2022 Research in Pharmaceutical Sciences.)
- Published
- 2022
- Full Text
- View/download PDF
7. High Performance Liquid Chromatography (HPLC) with Fluorescence Detection for Quantification of Steroids in Clinical, Pharmaceutical, and Environmental Samples: A Review.
- Author
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Hameedat F, Hawamdeh S, Alnabulsi S, and Zayed A
- Subjects
- Chromatography, High Pressure Liquid methods, Pharmaceutical Preparations, Spectrometry, Fluorescence methods, Coloring Agents, Steroids
- Abstract
Steroids are compounds widely available in nature and synthesized for therapeutic and medical purposes. Although several analytical techniques are available for the quantification of steroids, their analysis is challenging due to their low levels and complex matrices of the samples. The efficiency and quick separation of the HPLC combined with the sensitivity, selectivity, simplicity, and cost-efficiency of fluorescence, make HPLC coupled to fluorescence detection (HPLC-FLD) an ideal tool for routine measurement and detection of steroids. In this review, we covered HPLC-FLD methods reported in the literature for the steroids quantification in clinical, pharmaceutical, and environmental applications, focusing on the various approaches of fluorescent derivatization. The aspects related to analytical methodology including sample preparation, derivatization reagents, and chromatographic conditions will be discussed.
- Published
- 2022
- Full Text
- View/download PDF
8. Pim kinase inhibitors in cancer: medicinal chemistry insights into their activity and selectivity.
- Author
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Alnabulsi S and Al-Hurani EA
- Abstract
The oncogenic Pim kinase proteins (Pim-1/2/3) regulate tumorigenesis through phosphorylating essential proteins that control cell cycle and proliferation. Pim kinase is a potential chemotherapeutic target in cancer and its inhibition is currently the focus of intensive drug design and development efforts. The distinctive presence of proline amino acids in the hinge region provides an opportunity to inhibit Pim kinase while conserving the physiological functions of other kinases and reducing the toxicity profiles of the inhibitors. Various Pim kinase inhibitors have been clinically evaluated for the treatment of hematological cancers, yet none has reached the clinic. In this review, we discuss the design and development of selective and potent Pim inhibitors with novel chemotypes focusing on structural features essential for high potency and selectivity., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
9. Amino-carboxamide benzothiazoles as potential LSD1 hit inhibitors. Part I: Computational fragment-based drug design.
- Author
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Alnabulsi S, Al-Hurani EA, Al-Shar'i NA, and El-Elimat T
- Subjects
- Drug Design, Humans, Molecular Docking Simulation, Structure-Activity Relationship, Benzothiazoles chemistry, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Histone Demethylases antagonists & inhibitors
- Abstract
The lysine specific demethylase enzyme LSD1 regulates the function of histone proteins in cells through the demethylation of specific lysine amino acid residues. Being overexpressed in various cancers, LSD1 is considered as a validated target for cancer treatment. In this study, we describe the discovery of novel LSD1 inhibitors using computational fragment-based drug design approach. Structure-based screening of the Maybridge Ro3 2000 Diversity Fragment Library had identified two sets of fragments that bind to two different regions within the LSD1 active site. De Novo and Multiple Copy Simultaneous search (MCSS) docking, ligand efficiency (LE), and binding energy calculations (BE) had assisted the selection of the best scoring fragments that were grown to produce lead-like compounds. The final grown compounds were docked into the active site of the enzyme using flexible docking and their total binding energies were calculated in order to aid the selection of potential LSD1 inhibitors that will be synthesized and biologically evaluated. Six compounds were synthesized and biologically tested, of which two had showed a promising activity against LSD1. Compound 37, with an amino-carboxamide benzothiazole scaffold, showed the best inhibitory activity with an IC
50 value of 18.4 μM. Compound 37 was chosen as an LSD1 hit inhibitor worthy of further optimization., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
10. Evaluation of analogues of furan-amidines as inhibitors of NQO2.
- Author
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Alnabulsi S, Hussein B, Santina E, Alsalahat I, Kadirvel M, Magwaza RN, Bryce RA, Schwalbe CH, Baldwin AG, Russo I, Stratford IJ, and Freeman S
- Subjects
- Amidines chemical synthesis, Amidines chemistry, Antimalarials chemical synthesis, Antimalarials chemistry, Antimalarials pharmacology, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors chemistry, Furans chemical synthesis, Furans chemistry, Imidazoles chemical synthesis, Imidazoles chemistry, Imidazoles pharmacology, Molecular Structure, Oxazoles chemical synthesis, Oxazoles chemistry, Oxazoles pharmacology, Oximes chemical synthesis, Oximes chemistry, Oximes pharmacology, Plasmodium falciparum drug effects, Structure-Activity Relationship, Thiophenes chemical synthesis, Thiophenes chemistry, Thiophenes pharmacology, Amidines pharmacology, Enzyme Inhibitors pharmacology, Furans pharmacology, Quinone Reductases antagonists & inhibitors
- Abstract
Inhibitors of the enzyme NQO2 (NRH: quinone oxidoreductase 2) are of potential use in cancer chemotherapy and malaria. We have previously reported that non-symmetrical furan amidines are potent inhibitors of NQO2 and here novel analogues are evaluated. The furan ring has been changed to other heterocycles (imidazole, N-methylimidazole, oxazole, thiophene) and the amidine group has been replaced with imidate, reversed amidine, N-arylamide and amidoxime to probe NQO2 activity, improve solubility and decrease basicity of the lead furan amidine. All compounds were fully characterised spectroscopically and the structure of the unexpected product N-hydroxy-4-(5-methyl-4-phenylfuran-2-yl)benzamidine was established by X-ray crystallography. The analogues were evaluated for inhibition of NQO2, which showed lower activity than the lead furan amidine. The observed structure-activity relationship for the furan-amidine series with NQO2 was rationalized by preliminary molecular docking and binding mode analysis. In addition, the oxazole-amidine analogue inhibited the growth of Plasmodium falciparum with an IC
50 value of 0.3 μM., (Copyright © 2018. Published by Elsevier Ltd.)- Published
- 2018
- Full Text
- View/download PDF
11. XPS depth profiling of an ultrathin bioorganic film with an argon gas cluster ion beam.
- Author
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Dietrich PM, Nietzold C, Weise M, Unger WE, Alnabulsi S, and Moulder J
- Subjects
- Argon, Gases, Ions, Biophysical Phenomena, Coated Materials, Biocompatible
- Abstract
The growing interest in artificial bioorganic interfaces as a platform for applications in emerging areas as personalized medicine, clinical diagnostics, biosensing, biofilms, prevention of biofouling, and other fields of bioengineering is the origin of a need for in detail multitechnique characterizations of such layers and interfaces. The in-depth analysis of biointerfaces is of special interest as the properties of functional bioorganic coatings can be dramatically affected by in-depth variations of composition. In worst cases, the functionality of a device produced using such coatings can be substantially reduced or even fully lost.
- Published
- 2016
- Full Text
- View/download PDF
12. Non-symmetrical furan-amidines as novel leads for the treatment of cancer and malaria.
- Author
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Alnabulsi S, Santina E, Russo I, Hussein B, Kadirvel M, Chadwick A, Bichenkova EV, Bryce RA, Nolan K, Demonacos C, Stratford IJ, and Freeman S
- Subjects
- Amidines chemical synthesis, Amidines chemistry, Antimalarials chemical synthesis, Antimalarials chemistry, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Cell Proliferation drug effects, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, Furans chemical synthesis, Furans chemistry, Humans, Models, Molecular, Molecular Structure, Parasitic Sensitivity Tests, Structure-Activity Relationship, Amidines pharmacology, Antimalarials pharmacology, Antineoplastic Agents pharmacology, Furans pharmacology, Malaria drug therapy, Plasmodium drug effects
- Abstract
NRH:quinone oxidoreductase 2 enzyme (NQO2) is a potential therapeutic target in cancer and neurodegenerative diseases, with roles in either chemoprevention or chemotherapy. Here we report the design, synthesis and evaluation of non-symmetrical furan-amidines and their analogues as novel selective NQO2 inhibitors with reduced adverse off-target effects, such as binding to DNA. A pathway for the synthesis of the non-symmetrical furan-amidines was established from the corresponding 1,4-diketones. The synthesized non-symmetrical furan-amidines and their analogues showed potent NQO2 inhibition activity with nano-molar IC50 values. The most active compounds were non-symmetrical furan-amidines with meta- and para-nitro substitution on the aromatic ring, with IC50 values of 15 nM. In contrast to the symmetric furan-amidines, which showed potent intercalation in the minor grooves of DNA, the synthesized non-symmetrical furan-amidines showed no affinity towards DNA, as demonstrated by DNA melting temperature experiments. In addition, Plasmodium parasites, which possess their own quinone oxidoreductase PfNDH2, were inhibited by the non-symmetrical furan-amidines, the most active possessing a para-fluoro substituent (IC50 9.6 nM). The high NQO2 inhibition activity and nanomolar antimalarial effect of some of these analogues suggest the lead compounds are worthy of further development and optimization as potential drugs for novel anti-cancer and antimalarial strategies., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
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