Browsing by Author "Serag, Ahmed"

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Application of molecular imprinting approach for alkaloids analysis in food and nutraceuticals: review and perspective
(Springer Netherlands, 2023-10) Emara, Samy; Kamal, Maha; Sallam, Ibrahim E; Serag, Ahmed; Farag, Mohamed A
Alkaloids are major dietary components well known for their pharmacological activities. Herbal matrices require extensive processing due to their high level of complexity in order to isolate their alkaloidal contents. Molecularly imprinted polymers (MIPs) are tailored receptors with a highly specific molecular recognition, which is the most important function of receptors. They can hence be utilized in applications wherein selective binding activities are of significance, such as solid phase extraction (SPE), chromatographic separation and chemical sensors. This review presents on recent applications of MIPs to analyze alkaloids in plants and bio-fluid samples as well as herbal formulations. We discuss the develop- ment of nano-sized MIPs for various applications, particularly in biomimetic sensors for electrochemical detection of various alkaloids. Due to its easier phase separation compared to common MISPEs, magnetic MISPEs were also discussed in order to explore the potential benefits of this approach for further phyto- chemical applications.
Different approaches in manipulating ratio spectra applied for the analysis of Cefprozil in presence of its alkaline-induced degradation product: A comparative study
(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed
Four simple, accurate and precise stability-indicating spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of Cefprozil (CZ) and its alkaline-induced degradation product (DCZ) without prior separation namely; ratio difference, mean centering, derivative ratio using Savitsky-Golay filter and continuous wavelet transform. The accuracy, precision and linearity ranges of the proposed methods were determined. The methods were validated and the specificity was assessed by analyzing synthetic mixtures containing the drug and its degradate. The four methods were applied for the determination of the cited drug in tablets and the obtained results were statistically compared with those of a reported method. The comparison showed that there are no significant differences between the proposed methods and the reported method regarding both accuracy and precision. (C) 2015 Elsevier B.V. All rights reserved.
Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study
(PERGAMON-ELSEVIER SCIENCE LTD, 2016) Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed
Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FIX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA The proposed methods were found to be rapid, simple and required no preliminary separation steps. (c) 2015 Elsevier B.V. All rights reserved.
Identification and analysis of toxic phytochemicals
(Elsevier, 2021-03) Salem, Mohamed A; Serag, Ahmed; El-Seedi, Hesham R.; Hamdan, Dalia I; Ezzat, Shahira M; Zayed, Ahmed
Plants and plant products are used in food and medicine for thousands of years ago. It was thought that natural means safe, but this is not always the case as many plants or plant constituents are toxic or even poisonous especially those containing cardiac, cyanogenic, and thio-glycosides and certain types of alkaloids. Toxic natural products may cause hepatotoxicity, neurotoxicity, gastrointestinal toxicity, renal toxicity, and cytotoxicity. Analysis of toxic plants and plant constituents is facing a great challenge because of their different chemical and physicochemical properties. Novel extraction techniques have been proposed such as ultrasonic-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, and accelerated solvent extraction. In this chapter, we will have an overview of some of the toxic plants and phytochemicals as well as the methods for their qualitative and quantitative analysis.
Molecular and Quantum Mechanical Study for the Separation of Cefprozil in the Presence of Its Alkaline Degradation Product Using RP-HPLC with UV Detection
(AOAC INT, 2017) Attia, Khalid; Nassar, Mohammed; El-Zeiny, Mohamed; Serag, Ahmed
A reversed-phase HPLC method (RP-HPLC) with UV detection was developed and validated for the quantitative determination of cefprozil, a second-generation cephalosporin. Due to beta-lactam ring instability under alkaline conditions, this RP-HPLC method was applied for the determination of cefprozil in the presence of its possible degradation product. The interactions that govern the separation process with stationary phase were investigated at both molecular and quantum mechanical levels. Moreover, electrostatic potential maps were generated to determine the sites of interaction with mobile phase. The suggested method was validated in compliance with International Conference on Harmonization guidelines and successfully applied for the determination of cefprozil in its commercial pharmaceutical formulation
Stability indicating methods for the analysis of cefprozil in the presence of its alkaline induced degradation product
(PERGAMON-ELSEVIER SCIENCE LTD, 4/15/2016) Serag, Ahmed; El-Zeiny, Mohamed B; Nassar, Mohammed W. I; Attia, Khalid A. M
Three simple, specific, accurate and precise spectrophotometric methods were developed for the determination of cefprozil (CZ) in the presence of its alkaline induced degradation product (DCZ). The first method was the bivariate method, while the two other multivariate methods were partial least squares (PLS) and spectral residual augmented classical least squares (SRACLS). The multivariate methods were applied with and without variable selection procedure (genetic algorithm GA). These methods were tested by analyzing laboratory prepared mixtures of the above drug with its alkaline induced degradation product and they were applied to its commercial pharmaceutical products. (C) 2016 Elsevier B.V. All rights reserved.
Zero order and signal processing spectrophotometric techniques applied for resolving interference of metronidazole with ciprofloxacin in their pharmaceutical dosage form
(PERGAMON-ELSEVIER SCIENCE LTD, 2016) Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed
Four rapid, simple, accurate and precise spectrophotometric methods were used for the determination of ciprofloxacin in the presence of metronidazole as interference. The methods under study are area under the curve, simultaneous equation in addition to smart signal processing techniques of manipulating ratio spectra namely Savitsky-Golay filters and continuous wavelet transform. All the methods were validated according to the ICH guidelines where accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can therefore be used for the routine analysis of ciprofloxacin in quality-control laboratories. (C) 2015 Elsevier B.V. All rights reserved.