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Abdel-Rehim, MohamedORCID iD iconorcid.org/0000-0002-3862-8878
Publications (6 of 6) Show all publications
Aboul-Enein, M. N., El-Azzouny, A. A., Attia, M. I., Maklad, Y. A., Amin, K. M., Abdel-Rehim, M. & El-Behairy, M. F. (2012). Design and synthesis of novel stiripentol analogues as potential anticonvulsants. European Journal of Medicinal Chemistry, 47, 360-369
Open this publication in new window or tab >>Design and synthesis of novel stiripentol analogues as potential anticonvulsants
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2012 (English)In: European Journal of Medicinal Chemistry, ISSN 0223-5234, E-ISSN 1768-3254, Vol. 47, p. 360-369Article in journal (Refereed) Published
Abstract [en]

A series of stiripentol (SIP) analogues namely, 2-1(1E)-1-(1,3-benzodioxol-5-yl)-4,4-dimethylpent-1-en-3-ylidene]-N-(aryl/H)hydrazinecarboxamides 7a-h, (+/-)-(5RS)-N-(aryl/H)-(1,3-benzodioxol-5-yl)-3-tert-butyl-4,5-dihydro-1H-pyrazole-1-carboxamides (+/-)-8a-h, and (+/-)-[(5RS)-(1,3-benzodioxol-5-yl)-3-tert-butyl-4,5-dihydro-1H-pyrazol-1-yl](aryl)methanones (+/-)-13a-f was synthesized by adopting appropriate synthetic routes and was pharmacologically evaluated in the preliminary anticonvulsant screens. The selected bioactive new chemical entities were subjected to ED50 determination and neurotoxicity evaluation. The most active congeners are 7h in MES screen and (+/-)-13b in scPTZ screen which displayed ED50 values of 87 and 110 mg/kg, respectively, as compared to that of STP (ED50 = 277.7 and 115 mg/kg in MES and scPTZ, respectively). (C) 2011 Elsevier Masson SAS. All rights reserved.

Keywords
Stiripentol, Epilepsy, Semicarbazones, Pyrazolines, Anticonvulsants
National Category
Biomedical Laboratory Science/Technology
Research subject
Biomedical Laboratory Science
Identifiers
urn:nbn:se:kau:diva-41875 (URN)10.1016/j.ejmech.2011.11.004 (DOI)000301169800039 ()22118828 (PubMedID)
Available from: 2016-04-25 Created: 2016-04-22 Last updated: 2017-11-30Bibliographically approved
Hegazy, M.-E. F., El-Beih, A. A., Moustafa, A. Y., Hamdy, A. A., Alhammady, M. A., Selim, R. M., . . . Pare, P. W. (2011). Cytotoxic Cembranoids from the Red Sea Soft Coral Sarcophyton glaucum. Natural Product Communications, 6(12), 1809-1812
Open this publication in new window or tab >>Cytotoxic Cembranoids from the Red Sea Soft Coral Sarcophyton glaucum
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2011 (English)In: Natural Product Communications, ISSN 1934-578X, E-ISSN 1555-9475, Vol. 6, no 12, p. 1809-1812Article in journal (Refereed) Published
Abstract [en]

One new cembrane diterpene, 2R,7R,8R-dihydroxydeepoxysarcophine (1), together with three known compounds, 7 alpha,8 beta-dihydroxydecpoxysarcophine (2), 7 beta-acetoxy-8 alpha-hydroxydeepoxysarcophine (3), and sarcophine (4), have been isolated from the Red Sea soft coral Sarcophyton glaucum. Their structures were determined using 1D and 2D NMR spectroscopy. 7 beta-Acetoxy-8 alpha-hydroxydeepoxysarcophine (3) exhibits cytotoxic activity against HepG2, HCT-116, and HeLa cells with IC(50) values of 3.6, 2.3, and 6.7 mu g/mL, respectively.

Keywords
Sarcophyton glaucum, cembrane diterpenes, dihydroxydeepoxysarcophine, sarcophine
National Category
Chemical Sciences
Research subject
Chemistry
Identifiers
urn:nbn:se:kau:diva-40599 (URN)000298445300005 ()22312712 (PubMedID)
Available from: 2016-02-22 Created: 2016-02-22 Last updated: 2017-11-30Bibliographically approved
Abdel-Rehim, M. (2011). Microextraction by packed sorbent (MEPS): A tutorial. Analytica Chimica Acta, 701(2), 119-128
Open this publication in new window or tab >>Microextraction by packed sorbent (MEPS): A tutorial
2011 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 701, no 2, p. 119-128Article in journal (Refereed) Published
Abstract [en]

This tutorial provides an overview on a new technique for sample preparation, microextraction by packed sorbent (MEPS). Not only the automation process by MEPS is the advantage but also the much smaller volumes of the samples, solvents and dead volumes in the system. Other significant advantages such as the speed and the simplicity of the sample preparation process are provided. In this tutorial the main concepts of MEPS will be elucidated. Different practical aspects in MEPS are addressed. The factors affecting MEPS performance will be discussed. The application of MEPS in clinical and pre-clinical studies for quantification of drugs and metabolites in blood, plasma and urine will be provided. A comparison between MEPS and other extraction techniques such as SPE, LLE, SPME and SBSE will be discussed. (C) 2011 Elsevier B.V. All rights reserved.

Keywords
Sample preparation, MEPS, GC-MS, LC-MS, Drug analysis
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Chemistry
Identifiers
urn:nbn:se:kau:diva-40603 (URN)10.1016/j.aca.2011.05.037 (DOI)000294144400001 ()21801877 (PubMedID)
Available from: 2016-02-22 Created: 2016-02-22 Last updated: 2017-11-30Bibliographically approved
Abdel-Rehim, M. (2011). On-Line Whole Blood Analysis Using Microextraction by Packed Sorbent and LC-MS-MS. LC GC North America, 29(7), 612-618
Open this publication in new window or tab >>On-Line Whole Blood Analysis Using Microextraction by Packed Sorbent and LC-MS-MS
2011 (English)In: LC GC North America, ISSN 1527-5949, E-ISSN 1939-1889, Vol. 29, no 7, p. 612-618Article in journal (Refereed) Published
Abstract [en]

Microextraction by packed sorbent (MEPS) is a new technique for sample preparation that can be connected on-line with liquid chromatography (LC) or gas chromatography (GC) systems without any modifications. This article describes the use of MEPS in clinical and preclinical studies to quantify different drugs in whole blood samples. MEPS was used to determine cyclophosphamide in mouse blood from preclinical g studies using 20 mu L of blood samples. The interday accuracies and 0 precisions ranged from 107-109% and from 2.0-7.0%, respectively. The determination of four immunosuppressive drugs in human blood by MEPS and liquid chromatography-mass spectrometry (LC-MS) is described. The method showed a good selectivity and sensitivity. The calibration curves for everolimus, sirolimus, and tacrolimus ranged from 0.5 to 50 ng/mL and for cyclosporine from 3.0 to 1500 ng/mL. Intraday precisions for the studied immunosuppressive drugs were 2.0-11.7% and interday precision ranged from 5.1 to 13.7% (CV).

National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Biomedical Sciences
Identifiers
urn:nbn:se:kau:diva-40615 (URN)000293320900008 ()
Available from: 2016-02-22 Created: 2016-02-22 Last updated: 2017-11-30Bibliographically approved
Ashri, N. Y. & Abdel-Rehim, M. (2011). Sample treatment based on extraction techniques in biological matrices. Bioanalysis, 3(17), 2003-2018
Open this publication in new window or tab >>Sample treatment based on extraction techniques in biological matrices
2011 (English)In: Bioanalysis, ISSN 1757-6180, E-ISSN 1757-6199, Vol. 3, no 17, p. 2003-2018Article, review/survey (Refereed) Published
Abstract [en]

The importance of sample preparation methods as the first stage in bioanalysis is described. In this article, the sample preparation concept and strategies will be discussed, along with the requirements for good sample preparation. The most widely used sample preparation methods in the pharmaceutical industry are presented; for example, the need for same-day rotation of results from large numbers of biological samples in pharmaceutical industry makes high throughput bioanalysis more essential. In this article, high-throughput sample preparation techniques are presented; examples are given of the extraction and concentration of analytes from biological matrices, including protein precipitation, solid-phase extraction, liquid-liquid extraction and microextraction-related techniques. Finally, the potential role of selective extraction methods, including molecular imprinted phases, is considered.

National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Biomedical Sciences
Identifiers
urn:nbn:se:kau:diva-40607 (URN)10.4155/BIO.11.201 (DOI)000295210300017 ()21899508 (PubMedID)
Available from: 2016-02-22 Created: 2016-02-22 Last updated: 2017-11-30Bibliographically approved
Said, R., Kamel, M., El-Beqqali, A. & Abdel-Rehim, M. (2010). Microextraction by packed sorbent for LC-MS/MS determination of drugs in whole blood samples. Bioanalysis, 2(2), 197-205
Open this publication in new window or tab >>Microextraction by packed sorbent for LC-MS/MS determination of drugs in whole blood samples
2010 (English)In: Bioanalysis, ISSN 1757-6180, E-ISSN 1757-6199, Vol. 2, no 2, p. 197-205Article in journal (Refereed) Published
Abstract [en]

Background: Microextraction by packed sorbent (MEPS) is used as an online sample-preparation method. The determination of local anesthetics lidocaine, ropivacaine and bupivacaine directly in human blood was performed using MEPS online with LC-MS/MS. Results: The range of the calibration curves in whole blood was 10-10000 nmol/l. The lower limit of quantification was set to 10.0 nmol/l. The accuracy of the quality control samples ranged from 85 to 97%. The interday precision of the studied analytes was within the range 1-5%. The regression correlation coefficient (r(2)) was over 0.995 for all runs. The present method is rapid, reliable and robust and may be used for therapeutic drug monitoring of studied analytes in whole blood. Conclusion: This assay allows the analysis of drugs in human blood directly. Sample preparation is simple and automated. The assay reduced the handling time and the cost, and could handle small volumes of whole blood samples (25 mu l).

National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Biomedical Sciences
Identifiers
urn:nbn:se:kau:diva-40517 (URN)10.4155/BIO.09.187 (DOI)000281410200014 ()21083303 (PubMedID)
Available from: 2016-02-22 Created: 2016-02-17 Last updated: 2017-11-30Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-3862-8878

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