12 results on '"Muhammad Nawaz Tahir"'
Search Results
2. Highly dispersed palladium nanoparticles decorated on nitrogen doped graphene for enhanced photoelectrochemical water splitting
- Author
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Mohammed Rafi Shaik, Maha Al-Othman, Mufsir Kuniyil, Abdulrahman Al-Warthan, Mohammad Rafe Hatshan, Mohamed E. Assal, Muhammad Nawaz Tahir, and Mujeeb Khan
- Subjects
Metallic NPs ,Nitrogen doped graphene ,Nanocomposite ,Electrocatalysts ,Hydrogen evaluation ,Chemistry ,QD1-999 - Abstract
Among various clear energy generation processes, electrocatalytic water splitting or hydrogen evolution reaction (HER) has been considered as an efficient method for the sustainable production of hydrogen (H2) fuel. But, significant efforts are still required to develop cheap, effective and stable electrocatalysts for water splitting to achieve the economical production of H2. In the quest of finding cheap electrocatalysts, herein, we demonstrate the preparation of palladium (Pd) nanoparticles decorated nitrogen (N) doped highly reduced graphene oxide (NDG-Pd) based electrocatalysts. The nitrogen (N) doped highly reduced graphene oxide (NDG) was produced by using graphene oxide as precursor, which was reduced and doped with nitrogen, simultaneously in one-step hydrothermal method. Subsequently, Pd nanoparticles were decorated on the surface of NDG using a facile ultrasonic method to produce NDG-Pd. In order to restrict the amount of precious metal to reduce the cost of catalysts, very small percentage of Pd, such as, 1 and 3 % was utilized during the preparation of electrocatalysts. The as-prepared electrocatalysts were successfully characterized by using different methods such as, XRD, XPS, EDX, BET, SEM and TEM. Results confirmed the formation of slightly agglomerated, smaller size of Pd NPs on the surface of NDG with an average particle size of ∼ 6 nm. The as prepared nanocomposites NDG, NDG-Pd1% and NDG-Pd3% were used to prepare electrodes and their electrocatalytic activity was evaluated towards the production of H2 through water splitting. The results of electrochemical performance of as-prepared electrodes within the voltage range have revealed that among different samples prepared, the NDG did not show any current, whereas NDG-Pd3% showed a good potential for HER with current density ≈24 mA/cm2 at very low potential i.e. −0.2 V vs RHE.
- Published
- 2024
- Full Text
- View/download PDF
3. Design, characterization and enhanced bioavailability of hydroxypropylcellulose-naproxen conjugates
- Author
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Muhammad Ajaz Hussain, Iqra Shad, Iram Malik, Fasiha Amjad, Muhammad Nawaz Tahir, Nisar Ullah, Muhammad Ashraf, and Muhammad Sher
- Subjects
Esterification ,Hydroxypropylcellulose ,Naproxen ,Pharmacokinetics ,Prodrug ,Chemistry ,QD1-999 - Abstract
Polysaccharides are beneficially used as drug carriers via prodrug formation and offer a mechanism for better effectiveness and delivery of the drug. The unique geometry of hydroxypropylcellulose (HPC), a polysaccharide, allows the attachment of drug molecules with a higher degree of substitution because the hydroxyls groups are projected outside the HPC chains. Therefore HPC-Naproxen conjugates, i.e., macromolecular prodrugs, were synthesized using a powerful acylation reagent carbonyldiimadazole (CDI) in N,N' dimethylacetamide (DMAc) solvent. The reactions were carried out at 80 °C under stirring for 24 h and inert environment. This reaction strategy appeared efficient to obtain a high degree of drug substitution (DS = 0.88–1.40) on the polymer parent chain as calculated by UV–visible spectrophotometry after hydrolysis of the samples. The method provides high efficacy as product yields were high (77–81%). Macromolecular prodrugs (MPDs) with different DS of naproxen designed were found soluble in organic solvents.
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- 2020
- Full Text
- View/download PDF
4. Flurbiprofen conjugates based on hydroxyethylcellulose: Synthesis, characterization, pharmaceutical and pharmacological applications
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Khawar Abbas, Muhammad Ajaz Hussain, Syed Nasir Abbas Bukhari, Muhammad Amin, Muhammad Nawaz Tahir, and Sheshanath V. Bhosale
- Subjects
Chemistry ,QD1-999 - Abstract
Present study deals with fabrication of macromolecular prodrugs (MPDs) of flurbiprofen (FLB) with hydroxyethylcellulose (HEC). FLB was activated using p-toluenesulfonyl chloride and reacted with pre-dissolved HEC to yield HEC-FLB conjugates 1–3. Resultant prodrugs showed moderate to high degree of substitution (DS: 0.40–1.74) and assembled into nanoparticles of 220–550 nm at water/DMSO interface. Pharmacokinetic studies of HEC-FLB conjugate revealed a tmax of 4.0 h indicating delayed release of FLB while t1/2 of 10.63 h indicated sustained release characteristics of the conjugate in rabbit model. Pharmacological studies revealed that HEC-FLB conjugates had immunomodulatory potential as results showed 34 and 36% inhibition of Interleukin-6 and tumor necrosis factor-α, respectively. A 79% inhibition of paw edema indicated anti-inflammatory properties of the conjugates. Cell viability studies indicated safety of the conjugates to L929 cell lines up to 24 h in the range of 2–10 mM. Moreover, thermal analysis indicated greater stability of MPDs than FLB. Keywords: Hydroxyethylcellulose, Flurbiprofen, Prodrug, Immunomodulatory assay, Anti-inflammatory activity
- Published
- 2020
- Full Text
- View/download PDF
5. Sodium hyroxyethylcellulose adipate: An efficient and reusable sorbent for cadmium uptake from spiked high-hardness ground water
- Author
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Muhammad Ajaz Hussain, Shahana Zaman, Azhar Abbas, Muhammad Nawaz Tahir, Muhammad Amin, Syed Zajif Hussain, and Irshad Hussain
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Chemistry ,QD1-999 - Abstract
Herein, we report on the evaluation of chemically modified hyrdroxyethylcellulose for its sorption efficacy to remove Cd(II) from spiked high-hardness ground water (GW) and distilled water (DW) solutions. Hyrdroxyethylcellulose was chemically modified using adipic anhydride in the presence of DMAP as a catalyst under homogeneous reaction conditions. Hyrdroxyethylcellulose adipate (HEC-Adip) obtained was then converted to its sodium salt as HEC-Adip-Na after treating with saturated solution of NaHCO3. Structures were thoroughly characterized using FTIR, SEM, EDS and solid-state CP/MAS 13C NMR. The surface charge of the sorbent was monitored by pHZPC (pH of zero point charge). The sorption data fitted well to Langmuir isotherm and pseudo-second order kinetic model. Maximum sorption capacity of Cd(II) was calculated to be 114.94 mg g−1 and 112.35 mg g−1 from DW and GW, respectively. Thermodynamic parameters, i.e., ΔH°, ΔS° and ΔG°, were also calculated and showed negative values indicating spontaneous and exothermic nature of sorption process. In addition, the synthesized sorbent is more suitable for repeated use because it shows negligible decrease in its sorption capacity for the uptake of Cd(II) from aqueous solution after five regeneration cycles. Keywords: Hydroxyethylcellulose, Sodium hydroxyethylcellulose adipate, Metal uptake, Cadmium, Kinetics
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- 2020
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6. Capparis decidua Edgew (Forssk.): A comprehensive review of its traditional uses, phytochemistry, pharmacology and nutrapharmaceutical potential
- Author
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Sonaina Nazar, Muhammad A. Hussain, Ameer Khan, Gulzar Muhammad, and Muhammad Nawaz Tahir
- Subjects
Chemistry ,QD1-999 - Abstract
Capparis decidua, a medicinal plant of family Capparaceae grows abundantly in wild arid regions of Asia, Africa and Saudi Arabia. The plant has found wide folk medicinal applications along with its nutritional value. C. decidua possessed many pharmacological attributes such as antidiabetic, anthelmintic, antibacterial, antifungal, analgesic, anti-nociceptive, antirheumatic, hypolipidemic, antiatherosclerotic, anti-tumor, antigiardial, antioxidant, anti-inflammatory, hepatoprotective, and anticonvulsant activities. These marvellous bioactivities of the caper plant can be attributed to the presence of a wide range of phytochemicals including alkaloids (capparisinine, capparisine, stachydrine, isocodonocarpine), phenolics, flavonoids, sterols and fatty acids. This review focuses on detailed phytochemistry, folk medicinal uses and pharmacological attributes of this multipurpose plant. Moreover, we also covered the importance of plant as a source of functional food and nutrapharmaceuticals. Keywords: Capparis decidua, Medicinal applications, Biofuels, Bioactivities, Phytochemistry
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- 2020
- Full Text
- View/download PDF
7. Synthesis of new cadmium(II) complexes of Schiff bases as alkaline phosphatase inhibitors and their antimicrobial activity
- Author
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Rana Muhammad Irfan, Muhammad Ashraf Shaheen, Muhammad Saleem, Muhammad Nawaz Tahir, Khurram Shahzad Munawar, Saeed Ahmad, Syeda Laila Rubab, Tehreem Tahir, Katarzyna Kotwica-Mojzych, and Mariusz Mojzych
- Subjects
Schiff bases ,Cadmium complexes ,Alkaline phosphatase inhibition ,Antimicrobial studies ,Chemistry ,QD1-999 - Abstract
The present investigation deals with the synthesis, characterization and pharmacological evaluation of four cadmium complexes (1–4) with Schiff bases (1L-4L) derived from the substituted amines and aryl aldehydes. Amantadine is reacted with different aryl aldehydes (salicylaldehyde, 3-ethoxysalicylaldehyde and 4-(diethylamino) salicylaldehyde) to prepare Schiff base ligands 1L-3L, while 4L was prepared using 4-methylaniline. The complexes were characterized by elemental analysis, spectroscopic techniques and thermal analysis, and the structure of one of the ligands, 3L was determined by X-ray crystallography. The spectroscopic data indicate that the ligands coordinate with Cd(II) in a bidentate fashion to give octahedral geometry. Single crystal XRD analysis shows that 3L is orthorhombic with the space group P212121. The ligands and their Cd(II) complexes were evaluated for antimicrobial activities, while the complexes were also investigated for inhibition effects towards an enzyme, alkaline phosphatase. The anti-microbial screening results showed that cadmium complex 1 exhibited significant antibacterial potential, particularly against Staphylococcus aureus with respect to the corresponding ligand suggesting that the complexes are more effective than their ligands for antimicrobial activity. In case of alkaline phosphatase inhibition screening, the synthesized cadmium complex 1 was found to maximally inhibit the activity of alkaline phosphatase in comparison to rest of three complexes.
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- 2021
- Full Text
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8. Green synthesis of Pd@graphene nanocomposite: Catalyst for the selective oxidation of alco
- Author
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Abdulhadi H. Al-Marri, Merajuddin Khan, Mohammed Rafi Shaik, Nils Mohri, Syed Farooq Adil, Mufsir Kuniyil, Hamad Z. Alkhathlan, Abdulrahman Al-Warthan, Wolfgang Tremel, Muhammad Nawaz Tahir, Mujeeb Khan, and Mohammed Rafiq H. Siddiqui
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Graphene ,Palladium NPs ,Natural products ,Green chemistry ,Catalysis ,Aromatic alcohols oxidation ,Chemistry ,QD1-999 - Abstract
Due to their excellent physicochemical properties and synergistic effect, graphene metallic NPs based nanocomposites have gained significant attention in various technological fields including catalysis. Here we demonstrate a single pot, facile and environmental friendly synthesis of catalytically active palladium(Pd)@graphene nanocomposites (SP-HRG-Pd) by the simultaneous reduction of graphene oxide (GRO) and PdCl2 using Salvadora persica L. (miswak) root extract (RE) as bioreductant. The synthesis of SP-HRG-Pd was confirmed by various spectroscopic and microscopic techniques, including ultraviolet–visible (UV–vis), Fourier-transform infrared (FT-IR), Raman and X-ray photoelectron (XPS) spectroscopy, X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The polyphenolic (flavonoids) and terpenoids rich contents of the miswak RE not only facilitated the reduction of graphene oxide and PdCl2 but also ensured the homogeneous binding of the Pd NPs on graphene, and through stabilization of the surface of SP-HRG-Pd nanocomposites. This also led to the enhanced dispersibility of as synthesized nanocomposites in aqueous solutions. The as-prepared SP-HRG-Pd nanocomposites also demonstrated excellent catalytic activity toward the selective oxidation of aromatic alcohols. Furthermore, in order to study the effect of calcination temperature and concentration of Pd NPs on the catalytic activities of nanocomposites, different samples of SP-HRG-Pd nanocomposites containing different amounts of Pd using various concentrations of Pd precursor were prepared and calcined at various temperatures.
- Published
- 2016
- Full Text
- View/download PDF
9. Design, characterization and enhanced bioavailability of hydroxypropylcellulose-naproxen conjugates
- Author
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Fasiha Amjad, Muhammad Ashraf, Iqra Shad, Iram Malik, Muhammad Nawaz Tahir, Muhammad Sher, Muhammad Ajaz Hussain, and Nisar Ullah
- Subjects
Naproxen ,General Chemical Engineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Drug Substitution ,Dimethylacetamide ,Acylation ,lcsh:Chemistry ,chemistry.chemical_compound ,medicine ,Pharmacokinetics ,Prodrug ,Esterification ,General Chemistry ,021001 nanoscience & nanotechnology ,Combinatorial chemistry ,Hydroxypropylcellulose ,0104 chemical sciences ,Solvent ,chemistry ,lcsh:QD1-999 ,Reagent ,0210 nano-technology ,Drug carrier ,medicine.drug - Abstract
Polysaccharides are beneficially used as drug carriers via prodrug formation and offer a mechanism for better effectiveness and delivery of the drug. The unique geometry of hydroxypropylcellulose (HPC), a polysaccharide, allows the attachment of drug molecules with a higher degree of substitution because the hydroxyls groups are projected outside the HPC chains. Therefore HPC-Naproxen conjugates, i.e., macromolecular prodrugs, were synthesized using a powerful acylation reagent carbonyldiimadazole (CDI) in N,N' dimethylacetamide (DMAc) solvent. The reactions were carried out at 80 °C under stirring for 24 h and inert environment. This reaction strategy appeared efficient to obtain a high degree of drug substitution (DS = 0.88–1.40) on the polymer parent chain as calculated by UV–visible spectrophotometry after hydrolysis of the samples. The method provides high efficacy as product yields were high (77–81%). Macromolecular prodrugs (MPDs) with different DS of naproxen designed were found soluble in organic solvents.
- Published
- 2020
10. Capparis decidua Edgew (Forssk.): A comprehensive review of its traditional uses, phytochemistry, pharmacology and nutrapharmaceutical potential
- Author
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Gulzar Muhammad, Muhammad Ajaz Hussain, Sonaina Nazar, Muhammad Nawaz Tahir, and Ameer Khan
- Subjects
Antifungal ,Phytochemistry ,biology ,Traditional medicine ,Chemistry ,medicine.drug_class ,General Chemical Engineering ,fungi ,food and beverages ,Capparaceae ,General Chemistry ,biology.organism_classification ,lcsh:Chemistry ,Functional food ,lcsh:QD1-999 ,medicine ,Capparis decidua - Abstract
Capparis decidua, a medicinal plant of family Capparaceae grows abundantly in wild arid regions of Asia, Africa and Saudi Arabia. The plant has found wide folk medicinal applications along with its nutritional value. C. decidua possessed many pharmacological attributes such as antidiabetic, anthelmintic, antibacterial, antifungal, analgesic, anti-nociceptive, antirheumatic, hypolipidemic, antiatherosclerotic, anti-tumor, antigiardial, antioxidant, anti-inflammatory, hepatoprotective, and anticonvulsant activities. These marvellous bioactivities of the caper plant can be attributed to the presence of a wide range of phytochemicals including alkaloids (capparisinine, capparisine, stachydrine, isocodonocarpine), phenolics, flavonoids, sterols and fatty acids. This review focuses on detailed phytochemistry, folk medicinal uses and pharmacological attributes of this multipurpose plant. Moreover, we also covered the importance of plant as a source of functional food and nutrapharmaceuticals. Keywords: Capparis decidua, Medicinal applications, Biofuels, Bioactivities, Phytochemistry
- Published
- 2020
11. Green synthesis of Pd@graphene nanocomposite: Catalyst for the selective oxidation of alcohols
- Author
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Muhammad Nawaz Tahir, Wolfgang Tremel, Mohammed Rafiq H. Siddiqui, Hamad Z. Alkhathlan, Syed Farooq Adil, Mohammed Rafi Shaik, Merajuddin Khan, Abdulrahman Al-Warthan, Nils Mohri, Mufsir Kuniyil, Mujeeb Khan, and Abdulhadi H. Al-Marri
- Subjects
Chemistry(all) ,Aromatic alcohols oxidation ,General Chemical Engineering ,Inorganic chemistry ,Oxide ,chemistry.chemical_element ,Palladium NPs ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,law.invention ,lcsh:Chemistry ,chemistry.chemical_compound ,X-ray photoelectron spectroscopy ,law ,Calcination ,Natural products ,Nanocomposite ,Graphene ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,lcsh:QD1-999 ,Green chemistry ,chemistry ,Alcohol oxidation ,Chemical Engineering(all) ,0210 nano-technology ,Palladium ,Nuclear chemistry - Abstract
Due to their excellent physicochemical properties and synergistic effect, graphene metallic NPs based nanocomposites have gained significant attention in various technological fields including catalysis. Here we demonstrate a single pot, facile and environmental friendly synthesis of catalytically active palladium(Pd)@graphene nanocomposites (SP-HRG-Pd) by the simultaneous reduction of graphene oxide (GRO) and PdCl 2 using Salvadora persica L. (miswak) root extract (RE) as bioreductant. The synthesis of SP-HRG-Pd was confirmed by various spectroscopic and microscopic techniques, including ultraviolet–visible (UV–vis), Fourier-transform infrared (FT-IR), Raman and X-ray photoelectron (XPS) spectroscopy, X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The polyphenolic (flavonoids) and terpenoids rich contents of the miswak RE not only facilitated the reduction of graphene oxide and PdCl 2 but also ensured the homogeneous binding of the Pd NPs on graphene, and through stabilization of the surface of SP-HRG-Pd nanocomposites. This also led to the enhanced dispersibility of as synthesized nanocomposites in aqueous solutions. The as-prepared SP-HRG-Pd nanocomposites also demonstrated excellent catalytic activity toward the selective oxidation of aromatic alcohols. Furthermore, in order to study the effect of calcination temperature and concentration of Pd NPs on the catalytic activities of nanocomposites, different samples of SP-HRG-Pd nanocomposites containing different amounts of Pd using various concentrations of Pd precursor were prepared and calcined at various temperatures.
- Published
- 2016
- Full Text
- View/download PDF
12. Fabrication, characterization, thermal stability and nanoassemblies of novel pullulan-aspirin conjugates
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Muhammad Nawaz Tahir, Khawar Abbas, Bilal Ahmad Lodhi, Saima Iqbal, Wolfgang Tremel, Muhammad Ali, Muhammad Sher, and Muhammad Ajaz Hussain
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Thermal properties ,Chemistry(all) ,General Chemical Engineering ,Carboxylic acid ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,lcsh:Chemistry ,chemistry.chemical_compound ,Biopolymers ,Amphiphile ,Organic chemistry ,Thermal stability ,chemistry.chemical_classification ,Aspirin ,Esterification ,Pullulan ,General Chemistry ,Prodrug ,021001 nanoscience & nanotechnology ,Combinatorial chemistry ,0104 chemical sciences ,chemistry ,lcsh:QD1-999 ,Covalent bond ,Reagent ,engineering ,Chemical Engineering(all) ,Nanoparticles ,Biopolymer ,0210 nano-technology ,Pullulan-aspirin conjugates - Abstract
Present study deals with homogeneous and one-pot synthesis of novel macromolecular prodrugs (MPDs) of aspirin onto naturally occurring hydrophilic biopolymer pullulan. Pullulan-aspirin conjugates were synthesized by using green carboxylic acid activating reagent 1,1′-carbonyldiimidazole (CDI). The aspirin was first reacted with CDI to prepare aspirin-imidazolide at RT for 24 h which in situ reacted with pre-dissolved pullulan and the reaction preceded further for 24 h at 80 °C under nitrogen. Degree of substitution (DS 0.32–0.40) of aspirin onto pullulan was calculated from 1H NMR spectroscopy. Spectroscopic techniques confirmed the high covalent drug loading and purity. Thermal analysis has revealed that new MPDs of aspirin are thermally more stable than pure aspirin. The activation energy, order and frequency factor of the degradation reactions were calculated using Broido, Friedman and Chang models. The amphiphilic pullulan-aspirin conjugates self-assembled in nanoparticles without further structural modifications at solvent interface in the range of 500–680 nm as examined by transmission electron microscopy. These novel pullulan-aspirin conjugates with masked COOH functional group could be potentially safe prodrugs for the stomach.
- Published
- 2017
Catalog
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