https://cris.library.msu.ac.zw//handle/11408/301 Tue, 07 Apr 2026 01:46:05 GMT 2026-04-07T01:46:05Z https://cris.library.msu.ac.zw//handle/11408/6625 Title: Copper-based metal-organic framework: synthesis, characterization and evaluation for the hydrogenation of furfural to furfuryl alcohol Authors: Moyo, Pamela S.; Mehlana, Gift; Matsinha Leah C.; Makhubela Banothile C. E. Abstract: A novel Cu-MOF was synthesized at room temperature from commercially available and inexpensive reagents. The pre-catalyst was characterized using X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, inductively coupled plasma-optical emission spectroscopy, Fourier transform-infrared spectroscopy, powder X-ray diffraction, Brunauer-Emmet-Teller (BET) and scanning electron microscopy-energy dispersive X-ray spectroscopy. The Cu-MOF was characterized as microporous material with BET surface area and pore volume of 7.47 m2/g and 0.27 cm3/g, respectively, and is stable in most solvents. The MOF was evaluated as a heterogeneous catalyst for the hydrogenation of furfural to furfuryl alcohol (FA). Cu-MOF exhibited a high conversion of FF (76%) with selectivity towards FA (100%) at 140 °C, 50 bar for 24 h. The MOF was reused four consecutive times with a loss in catalytic performance. The decrease in catalytic activity could be attributed to the formation of inactive Cu(0) as revealed by HR-TEM and XPS studies. The HR-TEM of spent Cu-MOF showed a uniform particle size diameter of 3.5 nm. This work is significant in providing new strategies for the design and fabrication of highly selective MOF catalysts for the FF upgrading. Wed, 01 Jan 2025 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/6625 2025-01-01T00:00:00Z Moyo, Pamela S. Mehlana, Gift Matsinha Leah C. Makhubela Banothile C. E. https://cris.library.msu.ac.zw//handle/11408/6624 Title: Understanding metal–organic framework densification: solvent effects and the growth of Colloidal Primary Nanoparticles in Monolithic ZIF-8 Authors: Pathak, Ayush; Alghamdi, Lana A.; Fernández-Catalá, Javier; Tricarico, Michele; Cazorla-Amorós, Diego; Jin-Chong Tan; Ángel Berenguer-Murcia; Mehlana, Gift; Andrew E. H. Wheatley Abstract: To commercialize metal–organic frameworks (MOFs), it is vital they are made easier to handle. There have been many attempts to synthesize them as pellets, tablets, or granules, though they come with innate drawbacks. Only recently have these been overcome, through the advent of self-shaping densified or monolithic MOFs (monoMOFs), which require minimal post-synthetic modification and avoid poor structural integrity, intractability, and pore collapse or blockage. ZIF-8 (zeolitic imidazolate framework-8) has emerged as a prototypical monoMOF in pure and in situ doped forms. Now its formation in solvent mixtures is studied to better understand the early stages of monolith formation and improve the scope of monoliths for hosting solvent-sensitive guests. Solvent-, temperature- and coagulant-dependent control over reaction kinetics induces variations in morphology that are explained by relating the nucleation and growth rates of primary nanocrystallites to the stability of colloidal dispersions during reaction. This yields mesoporous monoZIF-8 with mean pore size 16 nm, SBET >1400 m2 g−1, bulk density 0.76 g cm−3, and resistance to permanent deformation exceeding previous reports. While the study highlights the powerful manipulation of monoMOF characteristics, a new understanding of the growth and stability of primary nanocrystallites has consequences for colloid synthesis generally. Wed, 01 Jan 2025 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/6624 2025-01-01T00:00:00Z Pathak, Ayush Alghamdi, Lana A. Fernández-Catalá, Javier Tricarico, Michele Cazorla-Amorós, Diego Jin-Chong Tan Ángel Berenguer-Murcia Mehlana, Gift Andrew E. H. Wheatley https://cris.library.msu.ac.zw//handle/11408/6608 Title: Closing the loop in the Carbon Cycle: Enzymatic reactions housed in Metal-Organic Frameworks for CO2 conversion to Methanol Authors: Moyo Praise K.; Mehlana Gift; Tshuma Piwai; Chikukwa Evernice S.; Makhubela Banothile C. E. Abstract: The preparation of value-added chemicals from carbon dioxide (CO2) can act as a way of reducing the greenhouse gas from the atmosphere. Industrially significant C1 chemicals like methanol (CH3OH), formic acid (HCOOH), and formaldehyde (HCHO) can be formed from CO2. One sustainable way of achieving this is by connecting the reactions catalyzed by the enzymes formate dehydrogenase (FDH), formaldehyde dehydrogenase (FALDH), and alcohol dehydrogenase (ADH) into a single cascade reaction where CO2 is hydrogenated to CH3OH. For this to be adaptable for industrial use, the enzymes should be immobilized in materials that are extraordinarily protective of the enzymes, inexpensive, stable, and of ultra-large surface area. Metal–organic frameworks (MOFs) meet these criteria and are expected to usher in the much-awaited dispensation of industrial biocatalysis. Unfortunately, little is known about the molecular behaviour of MOF-immobilized FDH, FALDH, and ADH. It is also yet not known which MOFs are most promising for industrial enzyme-immobilization since the field of reticular chemistry is growing exponentially with millions of hypothetical and synthesized MOF structures reported at present. This review initially discusses the properties of the key enzymes required for CO2 hydrogenation to methanol including available cofactor regeneration strategies. Later, the characterization techniques of enzyme-MOF composites and the successes or lack thereof of enzyme-MOF-mediated CO2 conversion to CH3OH and intermediate products are discussed. We also discuss reported multi-enzyme-MOF systems for CO2 conversion cognizant of the fact that at present, these systems are the only chance of housing cascade-type biochemical reactions where strict substrate channelling and operational conditions are required. Finally, we delve into future perspectives. Wed, 01 Jan 2025 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/6608 2025-01-01T00:00:00Z Moyo Praise K. Mehlana Gift Tshuma Piwai Chikukwa Evernice S. Makhubela Banothile C. E. https://cris.library.msu.ac.zw//handle/11408/6366 Title: Discovery of gamma-secretase inhibitors for breast cancer therapy through chemogenomic methods Authors: Ngceboyakwethu Primrose Zinyama Abstract: Breast cancer recurrence is often treated with hormonal and targeted chemotherapy. To this end, nicastrin, a protein involved in Notch signaling, has been associated with breast cancer recurrence. In this work, binding sites in nicastrin were identified. Binding interactions, and modes, of known nicastrin inhibitors were investigated using structure-based techniques. A binding site, termed the DYIGS binding site, (named after the conserved hydrophilic residues Asp336, Tyr337, Iso338, Gly339, and Ser340 found in the site) was identified. The binding mechanisms, and interactions, of known nicastrin inhibitors were investigated in the identified binding sites. This was done using binding free energy calculations, and per residue decomposition analysis. Residues such as Val138, Gln139. Asp143, Arg105 and Glu174 were discovered to be important in the interactions. The physicochemical properties and scaffold space of nicastrin inhibitors were investigated. Scaffold analysis and machine learning models identified specific connectivity containing a sulfon, sulfonamide, or sulfonamide connected to cyclic structures; and a halide or a halide connected to a benzene ring as being associated with high activity for nicastrin inhibition. Seven nicastrin inhibitors were discovered using this information. A preliminary antitumour bioassay confirmed the activity of six of the seven compounds, which inhibited tumour growth by more than 20%. However, three of these compounds demonstrated acceptable physicochemical and pharmacokinetic properties. The identification of these nicastrin actives opens new avenues for the development of breast cancer treatments. Wed, 18 Oct 2023 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/6366 2023-10-18T00:00:00Z Ngceboyakwethu Primrose Zinyama