Increasing numbers of patients who recover from COVID-19 report lasting symptoms, such as fatigue... more Increasing numbers of patients who recover from COVID-19 report lasting symptoms, such as fatigue, muscle weakness, dementia, and insomnia, known collectively as post-acute COVID syndrome or long COVID. These lasting symptoms have been examined in different studies and found to influence multiple organs, sometimes resulting in life-threating conditions. In this review, these symptoms are discussed in connection to the COVID-19 and long-COVID-19 immune changes, highlighting oral and psychiatric health, as this work focuses on the gut microbiota’s link to long-COVID-19 manifestations in the liver, heart, kidney, brain, and spleen. A model of this is presented to show the biological and clinical implications of gut microbiota in SARS-CoV-2 infection and how they could possibly affect the therapeutic aspects of the disease. Probiotics can support the body’s systems in fighting viral infections. This review focuses on current knowledge about the use of probiotics as adjuvant therapies fo...
Background: Erlotinib (ERL) and gefitinib (GEF) are extensively metabolized by CYP450 enzymes. As... more Background: Erlotinib (ERL) and gefitinib (GEF) are extensively metabolized by CYP450 enzymes. Aspartame (ASP), an artificial sweetener, induces CYP2E1 and CYP3A2 enzymes in the brain and could increase liver enzymes. In this work, the influence of ASP on the pharmacokinetics (PK) of ERL and GEF in Wistar rats was evaluated. Methods: The PKs of ERL and GEF were evaluated after receiving 175 mg/kg or 1000 mg/kg of ASP for four weeks using UPLC-MS/MS. Levels of liver enzymes after four weeks of ASP consumption were also evaluated. Results: ASP 175 mg/kg was able to significantly alter levels of Cmax (36% increase for ERL, 38% decrease for GEF), AUC0–72 (205% increase for ERL, 41% increase for GEF), and AUC0–∞ (112% increase for ERL, 14% increase for GEF). Moreover, ASP 175 mg/kg decreased the apparent oral clearance ERL and GEF by 58% and 13%, respectively. ASP 1000 mg/kg increased Cmax of ERL by 159% and decreased GEF’s Cmax by and 73%. Both AUC0–72 and AUC0–∞ were increased by ASP 1...
Delonix elata (L.) Gamble (Fabaceae) is an important, traditionally used plant in Saudi Arabia. I... more Delonix elata (L.) Gamble (Fabaceae) is an important, traditionally used plant in Saudi Arabia. It is used to relieve rheumatic pain, flatulence and the seeds are employed as purgatives. The aim of the present study was to isolate chemical constituents of the n-butanol fraction (BF) of D. elata and to find out, by capillary electrophoresis (CE), percentage of rutin present in this BF. Three quercetin glycosides and one kaempferol rutinoside were isolated from the BF of aerial parts of D. elata; namely, Quercetin 3-O-rutinoside-7-O-glucoside (1), Quercetin 3,7-diglucoside (2), Quercetin 3-O-rutinoside (RUT) (3) and Kaempferol 3-O-rutinoside (4). Rutin, an active constituent has been reported to possess good pharmacological as well as therapeutic potentials. A sensitive and rapid procedure for quantitative determination of RUT by capillary electrophoresis was developed and its content was found to be 7.349 mg/gm, relative to n-butanol fraction and 18.373 mg%, relative to the dry powde...
The Food and Drug Administration (FDA) has approved duvelisib (DUV) for managing follicular lymph... more The Food and Drug Administration (FDA) has approved duvelisib (DUV) for managing follicular lymphoma, small lymphocytic lymphoma, and relapsed or refractory chronic lymphocytic leukemia. Seliciclib (SEL) is a candidate drug for these cancers, neurodegenerative disorders, renal diseases, several viral infections, and chronic inflammation disorders. This work describes the development and validation of a 96-microwell-based spectrophotometric method (MW-SPM) and a high-performance liquid chromatography with fluorescence detection method (HPLC-FD) for the quantitation of DUV and SEL in their bulk forms and capsules. The MW-SPM is based on the formation of colored charge transfer complexes (CTCs) as products for the reactions of DUV and SEL, as n-electron donors, with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), as a π-electron acceptor. The absorption intensity of the CTCs was measured by using an absorbance plate reader at 450 nm. The stoichiometric ratios of DUV:DDQ and SEL:DDQ we...
Six in vitro phase I metabolites, three in vitro phase II metabolites, seven reactive intermediat... more Six in vitro phase I metabolites, three in vitro phase II metabolites, seven reactive intermediates (four GSH conjugates and three cyano adducts), six in vivo phase I and three in vivo phase II metabolites of ZFB were detected by LC-IT-MS.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The molecular charge transfer reactions of quinine (Q) with 2,3-dichloro-5,6-dicyano-p-benzoquino... more The molecular charge transfer reactions of quinine (Q) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a π-acceptor to form charge transfer (CT) complexes have been studied. The CT complexes were characterized by infrared spectra, NMR, mass spectrometry, conductometry and spectrometry. The Q-DDQ and Q-TCNQ charge transfer complexes were monitored at 480 and 843 nm, respectively. The results confirm the formation of CT complexes. The molar ratio of Q:DDQ and Q: TCNQ assessed using Job’s method was 1:1, which agrees with the results obtained by the Benesi-Hildebrand equation. The stability of the formed CT complexes was assessed by measuring different spectroscopic parameters such as oscillator strength, transition dipole moment, ionization potential, the energy of CT complex, resonance energy, dissociation energy and standard free energy change. The DFT geometry optimization of quinine, DDQ and TCNQ, its charge transfer complex, and U...
The study aims to develop simple, sensitive, and selective methods for detecting methylphenidate ... more The study aims to develop simple, sensitive, and selective methods for detecting methylphenidate in its bulk, dosage form and human urine. Sensing materials include β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), and 4-tertbutylcalix[8]arene as ionophores or electroactive materials have been used for construction of sensors 1, 2, and 3, respectively; Potassium tetrakis (4-chlorophenyl)borate (KTpClPB) as an ion additive was used and dioctyl phthalate as a plasticizer. The sensors displayed a fast, stable response over a wide concentration range of methylphenidate (8 × 10−6 M to 1 × 10−3 M) with 10−6 M detection limit over the pH range of 4–8. The developed sensors displayed a Near-Nernstian cationic response for methylphenidate at 59.5, 51.37, and 56.5 mV/decade for sensors β-CD, γ-CD, or 4-tertbutylcalix[8]arene respectively. Validation of the proposed sensors is supported by high accuracy, precision, stability, fast response, and long lifetimes, as well as selectivity for methylphen...
Background: Duloxetine (DL) is a selective serotonin and norepinephrine reuptake inhibitor. The d... more Background: Duloxetine (DL) is a selective serotonin and norepinephrine reuptake inhibitor. The drug is used in the treatment of major depression, anxiety, pain related to diabetic peripheral neuropathy and stress urinary incontinence. Objective: This study described, for the first time, the development and validation of a highly selective and sensitive microemulsion liquid chromatography-fluorescence (MELC-FL) method with low environmental pollution and without extraction steps for the simultaneous quantification of DL, and its two main metabolites; 5-hydroxy-6-methoxy duloxetine (5-HDL) and 4-hydroxy duloxetine glucuronide (4- HDLG) in plasma. Methods: The studied analytes and methyl paraben (an internal standard) were detected using excitation and emission wavelengths of 280 and 340 nm, respectively. The analysis was performed on Water Symmetry C18 analytical column (100 Å, 150 mm x 3.9 mm, 5 µm) by directly injecting the plasma after appropriate dilution with microemulsion mobil...
The FT-IR and FT-Raman spectra of 4-[(4-acetylphenyl)amino]-2- -methylidene-4-oxobutanoic acid we... more The FT-IR and FT-Raman spectra of 4-[(4-acetylphenyl)amino]-2- -methylidene-4-oxobutanoic acid were recorded. The vibrational wave numbers were computed by DFT quantum chemical calculations and the vibrational assignments were realized using the potential energy distribution. The theoretically predicted geometrical parameters were in agreement with the XRD data. Determination and visualization of molecule sites prone to electrophilic attacks were performed by mapping the average local ionization energies (ALIE) to the electron density surface. Furthermore, determination of possible reactive centres of title molecule was realized by calculation of the Fukui functions. Intramolecular non-covalent interactions were also determined and visualized. In addition, prediction of molecule sites possibly prone to autoxidation was performed by calculation of the bond dissociation energies (BDE), while the stability of the title molecule in water was assessed by calculation of radial distributio...
ABSTRACT Two stability-indicating chromatographic methods are reported for the determination of m... more ABSTRACT Two stability-indicating chromatographic methods are reported for the determination of methyl gallate in crude extracts of Bauhinia retusa. Separation by high performance thin layer chromatography was conducted on silica gel aluminum sheets using 9.5:0.5:0.2 (v/v/v) chloroform:methanol:acetic acid at 280 nm. The results from the 2–40 µg/band were used to prepare a linear calibration graph. The limits of detection and quantitation were 0.5 and 1.5 µg/band, respectively. The reverse phase high performance liquid chromatographic isolation of methyl gallate was performed at ambient temperature with an injection volume of 10 μL. The mobile phase consisted of 40:60 (v/v) methanol:0.1% ortho-phosphoric acid. The separation was performed at 1 mL/min using a detection wavelength of 280 nm. The calibration graph for methyl gallate was rectilinear from 0.02–40 µg/mL with limits of detection and quantitation of 0.004 and 0.010 µg/mL, respectively. For both methods, intra-day and inter-day precision were evaluated and the relative standard deviation was less than 2%, indicating good precision. The robustness was evaluated by making small and deliberate changes to appropriate parameters and the calculated relative standard deviation was less than 2%.The chromatographic methods were employed to determine methyl gallate in crude Bauhinia retusa extracts.
Increasing numbers of patients who recover from COVID-19 report lasting symptoms, such as fatigue... more Increasing numbers of patients who recover from COVID-19 report lasting symptoms, such as fatigue, muscle weakness, dementia, and insomnia, known collectively as post-acute COVID syndrome or long COVID. These lasting symptoms have been examined in different studies and found to influence multiple organs, sometimes resulting in life-threating conditions. In this review, these symptoms are discussed in connection to the COVID-19 and long-COVID-19 immune changes, highlighting oral and psychiatric health, as this work focuses on the gut microbiota’s link to long-COVID-19 manifestations in the liver, heart, kidney, brain, and spleen. A model of this is presented to show the biological and clinical implications of gut microbiota in SARS-CoV-2 infection and how they could possibly affect the therapeutic aspects of the disease. Probiotics can support the body’s systems in fighting viral infections. This review focuses on current knowledge about the use of probiotics as adjuvant therapies fo...
Background: Erlotinib (ERL) and gefitinib (GEF) are extensively metabolized by CYP450 enzymes. As... more Background: Erlotinib (ERL) and gefitinib (GEF) are extensively metabolized by CYP450 enzymes. Aspartame (ASP), an artificial sweetener, induces CYP2E1 and CYP3A2 enzymes in the brain and could increase liver enzymes. In this work, the influence of ASP on the pharmacokinetics (PK) of ERL and GEF in Wistar rats was evaluated. Methods: The PKs of ERL and GEF were evaluated after receiving 175 mg/kg or 1000 mg/kg of ASP for four weeks using UPLC-MS/MS. Levels of liver enzymes after four weeks of ASP consumption were also evaluated. Results: ASP 175 mg/kg was able to significantly alter levels of Cmax (36% increase for ERL, 38% decrease for GEF), AUC0–72 (205% increase for ERL, 41% increase for GEF), and AUC0–∞ (112% increase for ERL, 14% increase for GEF). Moreover, ASP 175 mg/kg decreased the apparent oral clearance ERL and GEF by 58% and 13%, respectively. ASP 1000 mg/kg increased Cmax of ERL by 159% and decreased GEF’s Cmax by and 73%. Both AUC0–72 and AUC0–∞ were increased by ASP 1...
Delonix elata (L.) Gamble (Fabaceae) is an important, traditionally used plant in Saudi Arabia. I... more Delonix elata (L.) Gamble (Fabaceae) is an important, traditionally used plant in Saudi Arabia. It is used to relieve rheumatic pain, flatulence and the seeds are employed as purgatives. The aim of the present study was to isolate chemical constituents of the n-butanol fraction (BF) of D. elata and to find out, by capillary electrophoresis (CE), percentage of rutin present in this BF. Three quercetin glycosides and one kaempferol rutinoside were isolated from the BF of aerial parts of D. elata; namely, Quercetin 3-O-rutinoside-7-O-glucoside (1), Quercetin 3,7-diglucoside (2), Quercetin 3-O-rutinoside (RUT) (3) and Kaempferol 3-O-rutinoside (4). Rutin, an active constituent has been reported to possess good pharmacological as well as therapeutic potentials. A sensitive and rapid procedure for quantitative determination of RUT by capillary electrophoresis was developed and its content was found to be 7.349 mg/gm, relative to n-butanol fraction and 18.373 mg%, relative to the dry powde...
The Food and Drug Administration (FDA) has approved duvelisib (DUV) for managing follicular lymph... more The Food and Drug Administration (FDA) has approved duvelisib (DUV) for managing follicular lymphoma, small lymphocytic lymphoma, and relapsed or refractory chronic lymphocytic leukemia. Seliciclib (SEL) is a candidate drug for these cancers, neurodegenerative disorders, renal diseases, several viral infections, and chronic inflammation disorders. This work describes the development and validation of a 96-microwell-based spectrophotometric method (MW-SPM) and a high-performance liquid chromatography with fluorescence detection method (HPLC-FD) for the quantitation of DUV and SEL in their bulk forms and capsules. The MW-SPM is based on the formation of colored charge transfer complexes (CTCs) as products for the reactions of DUV and SEL, as n-electron donors, with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), as a π-electron acceptor. The absorption intensity of the CTCs was measured by using an absorbance plate reader at 450 nm. The stoichiometric ratios of DUV:DDQ and SEL:DDQ we...
Six in vitro phase I metabolites, three in vitro phase II metabolites, seven reactive intermediat... more Six in vitro phase I metabolites, three in vitro phase II metabolites, seven reactive intermediates (four GSH conjugates and three cyano adducts), six in vivo phase I and three in vivo phase II metabolites of ZFB were detected by LC-IT-MS.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The molecular charge transfer reactions of quinine (Q) with 2,3-dichloro-5,6-dicyano-p-benzoquino... more The molecular charge transfer reactions of quinine (Q) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a π-acceptor to form charge transfer (CT) complexes have been studied. The CT complexes were characterized by infrared spectra, NMR, mass spectrometry, conductometry and spectrometry. The Q-DDQ and Q-TCNQ charge transfer complexes were monitored at 480 and 843 nm, respectively. The results confirm the formation of CT complexes. The molar ratio of Q:DDQ and Q: TCNQ assessed using Job’s method was 1:1, which agrees with the results obtained by the Benesi-Hildebrand equation. The stability of the formed CT complexes was assessed by measuring different spectroscopic parameters such as oscillator strength, transition dipole moment, ionization potential, the energy of CT complex, resonance energy, dissociation energy and standard free energy change. The DFT geometry optimization of quinine, DDQ and TCNQ, its charge transfer complex, and U...
The study aims to develop simple, sensitive, and selective methods for detecting methylphenidate ... more The study aims to develop simple, sensitive, and selective methods for detecting methylphenidate in its bulk, dosage form and human urine. Sensing materials include β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), and 4-tertbutylcalix[8]arene as ionophores or electroactive materials have been used for construction of sensors 1, 2, and 3, respectively; Potassium tetrakis (4-chlorophenyl)borate (KTpClPB) as an ion additive was used and dioctyl phthalate as a plasticizer. The sensors displayed a fast, stable response over a wide concentration range of methylphenidate (8 × 10−6 M to 1 × 10−3 M) with 10−6 M detection limit over the pH range of 4–8. The developed sensors displayed a Near-Nernstian cationic response for methylphenidate at 59.5, 51.37, and 56.5 mV/decade for sensors β-CD, γ-CD, or 4-tertbutylcalix[8]arene respectively. Validation of the proposed sensors is supported by high accuracy, precision, stability, fast response, and long lifetimes, as well as selectivity for methylphen...
Background: Duloxetine (DL) is a selective serotonin and norepinephrine reuptake inhibitor. The d... more Background: Duloxetine (DL) is a selective serotonin and norepinephrine reuptake inhibitor. The drug is used in the treatment of major depression, anxiety, pain related to diabetic peripheral neuropathy and stress urinary incontinence. Objective: This study described, for the first time, the development and validation of a highly selective and sensitive microemulsion liquid chromatography-fluorescence (MELC-FL) method with low environmental pollution and without extraction steps for the simultaneous quantification of DL, and its two main metabolites; 5-hydroxy-6-methoxy duloxetine (5-HDL) and 4-hydroxy duloxetine glucuronide (4- HDLG) in plasma. Methods: The studied analytes and methyl paraben (an internal standard) were detected using excitation and emission wavelengths of 280 and 340 nm, respectively. The analysis was performed on Water Symmetry C18 analytical column (100 Å, 150 mm x 3.9 mm, 5 µm) by directly injecting the plasma after appropriate dilution with microemulsion mobil...
The FT-IR and FT-Raman spectra of 4-[(4-acetylphenyl)amino]-2- -methylidene-4-oxobutanoic acid we... more The FT-IR and FT-Raman spectra of 4-[(4-acetylphenyl)amino]-2- -methylidene-4-oxobutanoic acid were recorded. The vibrational wave numbers were computed by DFT quantum chemical calculations and the vibrational assignments were realized using the potential energy distribution. The theoretically predicted geometrical parameters were in agreement with the XRD data. Determination and visualization of molecule sites prone to electrophilic attacks were performed by mapping the average local ionization energies (ALIE) to the electron density surface. Furthermore, determination of possible reactive centres of title molecule was realized by calculation of the Fukui functions. Intramolecular non-covalent interactions were also determined and visualized. In addition, prediction of molecule sites possibly prone to autoxidation was performed by calculation of the bond dissociation energies (BDE), while the stability of the title molecule in water was assessed by calculation of radial distributio...
ABSTRACT Two stability-indicating chromatographic methods are reported for the determination of m... more ABSTRACT Two stability-indicating chromatographic methods are reported for the determination of methyl gallate in crude extracts of Bauhinia retusa. Separation by high performance thin layer chromatography was conducted on silica gel aluminum sheets using 9.5:0.5:0.2 (v/v/v) chloroform:methanol:acetic acid at 280 nm. The results from the 2–40 µg/band were used to prepare a linear calibration graph. The limits of detection and quantitation were 0.5 and 1.5 µg/band, respectively. The reverse phase high performance liquid chromatographic isolation of methyl gallate was performed at ambient temperature with an injection volume of 10 μL. The mobile phase consisted of 40:60 (v/v) methanol:0.1% ortho-phosphoric acid. The separation was performed at 1 mL/min using a detection wavelength of 280 nm. The calibration graph for methyl gallate was rectilinear from 0.02–40 µg/mL with limits of detection and quantitation of 0.004 and 0.010 µg/mL, respectively. For both methods, intra-day and inter-day precision were evaluated and the relative standard deviation was less than 2%, indicating good precision. The robustness was evaluated by making small and deliberate changes to appropriate parameters and the calculated relative standard deviation was less than 2%.The chromatographic methods were employed to determine methyl gallate in crude Bauhinia retusa extracts.
Uploads