Department of Chemistry
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Item SYNTHESIS OF Cu–Mn–S TERNARY METAL CHALCOGENIDE QUANTUM DOTS AS POTENTIAL HIGH-PERFORMANCE OPTICAL NANOSENSORS(Covenant University, Ota, 2026-07) LASISI, Bolatito Lateefat; Covenant University, DissertationThe detection of environmentally relevant pollutants and biomedical biomarkers by traditional analytical techniques is often time-consuming, invasive, and insufficiently sensitive, underscoring the need for advanced optical nanosensor materials. In this study, the synthesis and characterisation of ternary metal chalcogenide quantum dots (TMC-QDs) of Cu-Mn-S were carried out as candidate materials for advanced optical nanosensors in environmental and biomedical applications. Eight Cu-Mn-S QDs (TMC-1 to TMC-8) were successfully synthesised via the modified solvothermal method. CuCl2, Mn(CH3COO)2, and thiourea were employed as precursors and sulfur source, respectively, in a 1:1 deionised water/ethylene glycol solvent, with two stoichiometries (CuMn2S2 and CuMn1.7S2), three varied temperatures (180 to 190 °C), and two reaction times (10 and 12 hrs). The synthesised QDs were characterised. The UV-Vis absorption measurements revealed a controllable wavelength range from 205 nm to 556 nm and visible-region excitonic absorption, indicating the optical activity of the CuS sub-phase in the samples at low temperatures. The XRD pattern of the resultant particles showed crystalline QDs with particle sizes ranging from 14.97 to 16.19 nm. The product is found to be of a single hexagonal CuS covellite phase except for TMC-6 and TMC-7, which are binary composites of hexagonal CuS covellite and cubic MnS alabandite. FTIR confirmed the presence of both phases, with CuS and MnS stretching. Thus, this work established, for the first time, the synthesis of ternary metal chalcogenide Cu-Mn-S QDs with controlled structural and optical properties. The ternary system conditions for phase segregation of a dual CuS covellite and α-MnS alabandite composite were also found to depend on reaction temperature and time, rather than just the stoichiometric ratio.Item VIRTUAL SCREENING OF PHTHALIMIDE-BASED INHIBITORS TO OVERCOME PROSTATE CANCER RESISTANT DRUGS(Covenant University, Ota, 2026-07) Ojo, Abigail Victory; Covenant University DissertationDespite the successes of traditional androgen-deprivation therapy, the emergence of therapeutic resistance has become one of the main hurdles to PC management, and efforts have been made to develop novel molecules that inhibit the activity of persistent AR pathways. The aim of this work is to use a comprehensive in silico virtual screening approach to identify and assess phthalimide derivatives as potential inhibitors of the mutated androgen receptor protein (PDB ID: 1GS4). To find drug-like molecules, the initial library of 1508 phthalimide derivatives was retrieved from the PubChem database and structurally filtered using Lipinski's Rule of Five and an e-pharmacophore hypothesis phase module (Schrodinger) to remove non-drug-like molecules, resulting in 54 molecules. Using the high-throughput, extra-precision molecular docking and Molecular Mechanics-Generalized Born Surface Area free energy calculations, 13 compounds with binding affinities better than the clinical standard (Bicalutamide) were identified. Of these, 5-(1,3-dioxoisoindol-4-yl)-pentanenitrile was selected as the initial lead owing to its ADMET and excellent electronic properties, as determined by DFT calculations. The lead structure was then optimized to address toxicological issues associated with the CN and CO groups, yielding six new structural analogues of the lead compound. The best thermodynamic stability and binding were observed for Lead Analog A (4-heptyl-3-methoxyisoindolin-1-one), with a docking score of −10.742 kcal/mol. Critical pharmacokinetic profiling and toxicity studies demonstrated that this next-generation derivative not only has a greatly diminished risk of hepatotoxicity and mutagenic potential, but also exhibits high membrane permeability and blood-brain barrier penetration. Altogether, these computational results support a synergy between the optimized phthalimide scaffold and its observed potency, revealing a viable targeted therapeutic for prostate cancer that can overcome resistance.Item IN SILICO IDENTIFICATION OF POTENTIAL Plasmodium falciparum ACETYL-COA SYNTHETASE (PfACS) INHIBITORS USING DRUG REPURPOSING APPROACH(Covenant University, Ota, 2026-06) Akinwale, Oluwapelumi Lois; Covenant University DissertationThe persistent rise in malaria-related deaths among children and pregnant women underscores the ongoing global health challenge posed by this disease. Although preventive activities and first-line treatment options (which include artemisinin-based combination therapies) have been extensively used, the swift development of drug-resistant Plasmodium falciparum isolates has left malaria control efforts severely impaired. Drug repurposing provides an economical alternative to traditional drug discovery approaches by uncovering novel therapeutic uses for existing drugs with well-characterized safety profiles. This study focuses on Plasmodium falciparum acetyl-CoA synthetase (PfACS), an essential enzyme involved in acetate metabolism and histone acetylation, as a potential antimalarial drug target. Its structural divergence from human isoforms increases its likelihood of selective inhibition, with the lowest potential to induce toxicity in the host. A multistage computational drug repurposing workflow was employed to identify FDA-approved inhibitors of PfACS. Structural analysis identified the crystal structure of Coccidioides immitis acetyl-CoA synthetase (PDB: 7KQ6) as the most suitable template for PfACS modeling. The AlphaFold2-predicted PfACS structure was also validated. A library of 12,718 DrugBank compounds was sequentially selected using Lipinski’s Rule of Five and the Ersilia eos80ch machine-learning antiplasmodial activity model, yielding a dataset of 377 biologically enriched compounds. Molecular docking, binding free-energy estimation (MM/GBSA), pharmacophoric interaction analysis, and density functional theory (DFT) calculations and Molecular Dynamics (MD) Simulation were subsequently performed. Four lead compounds (Hit 01–04) demonstrated favorable binding affinity, interaction similarity with the reference inhibitor MMV693183, and supportive electronic reactivity profiles, with promising potential as PfACS inhibitors and antimalarial agents.Item COMBUSTION PERFORMANCE OF PALM KERNEL SHELL BIOCHAR BRIQUETTE MODIFIED WITH ACID-LEACHED NEEM LEAF ASH(Covenant University, Ota, 2026) ADEYEYE, PEACE IFEOLUWA; Covenant University, DissertationWood fuel contributes significantly to air pollution and deforestation. Agro-waste briquetting as solid fuel has emerged to reduce the burden on forest resources, but its adoption is hindered by poor combustion performance and high pollutant emissions. This study developed biomass briquettes from Palm Kernel Shell (PKS) biochar modified with Acid-Leached Neem Leaf Ash (ALNLA) and rendered beef tallow. This is to target improved combustion efficiency and reduced harmful emissions, for household cookstove applications. Neem leaves were calcined at 750°C and then leached with 2M HCl at 45°C for 2 hours, thereby achieving a leachability percentage of 91.24% and producing a silica-enriched residue (SiO₂ = 57.86 wt%; Fe₂O₃ = 8.20 wt%; CaO = 7.52 wt%). PKS biochar was produced by slow pyrolysis at 550°C. Six briquette formulations (B1–B6) were prepared and characterized using XRF, FT-IR, XRD, TGA, and proximate analysis. Water boiling test (WBT), and measurement of burn duration, combustion temperature and some Toxic Air Pollutants (TAP) (CO, SO₂, NO₂ and particulate matter) emission, heating value and fixed carbon, were carried out. All formulations outperformed commercial charcoal in burn duration by factors of 1.97 – 4.02%. Formulation B6 (90% biochar, 1.0% ALNLA, 10% starch) achieved the longest burn duration (378 minutes), highest combustion temperature (1109°C), and lowest stabilized TAP emissions. Formulation B5 recorded the highest estimated higher heating value (5.78 MJ/kg) and fixed carbon (15.59%). These results demonstrate the viability of acid-leached neem leaf ash as a low-cost, waste-derived modifier for producing cleaner-burning briquettes suited to Sub-Saharan African household energy needs.Item Complexes of SCN and dithiol ligands for solvothermal green synthesis of high indexed binary PbS and SnS semiconductor nanoparticles(Journal of the Indian Chemical Society Volume 102, Issue 6,, 2025-06) Adekoya, Joseph Adeyemi; Oyeku, Pelumi Olusola; Edidiong, Sunday Sam; Adeniyi, Adeleke Ayoola; Almalki, Abdulraheem S. A; Mersal, Gaber A.M.; Ibrahim, Mohamed M.; Revaprasadu, NeerishItem COVID lockdowns significantly affect statewide atmospheric fine aerosols in India after excluding long-term pollution patterns and time-lag effect(Atmospheric Environment Volume 343, 2025-02-15) Etchie, Tunde O.; Etchie, Ayotunde T.; Pinker, Rachel T.; Kumar, Prashant; Swaminathan, NedunchezhianAtmospheric fine particulate matter (PM2.5 , near-surface concentrations when size is ≤ 2.5 μm) affects global climate and human health. India alone accounts for a quarter of the global PM2.5-related health burden. Studies in India, mostly in urban areas, have reported significant declines in PM2.5 concentrations because of COVID-19 lockdown. These studies did not consider the long-term PM2.5 patterns and time-lag effect (inter yearly variations in PM2.5 concentrations carried forward from one period to another due to interannual shifts in meteorological conditions). Since the studies focused primarily on urban areas, not covering rural/remote areas where pollution may rise during lockdown, it is still unclear what impact lockdown had on statewide pollution levels in (AODf India. Here, we examine whether significant changes in fine-mode aerosol optical depth : columnar PM2.5 ) occurred statewide across India because of lockdown after excluding the confounding variables. We found a substantial decrease in AODf in a few (28%) states/territories. The declines were significant (ANCOVA; α = 0.05) in some Northeastern states/territories: Sikkim (29%), Arunachal Pradesh (24%), Nagaland (5%), Mizoram (4%) and Uttarakhand (3%). However, in most states/territories, AODf increased significantly because of lockdown. The lockdown-associated hardship caused more people to rely on polluting cooking fuels, thereby increasing residential emissions, particularly in rural areas. At city-level, we found significant reductions in near-surface PM2.5 concentrations due to lockdown. These declines were comparable or greater than previously reported. Also, there were significant reductions in AODf (PM2.5 concentrations) at state (city) levels resulting from previous environmental intervention measures. If not accounted, previous environmental intervention measures can significantly bias lockdown effect estimates in India.Item Structure-based Design of Coumarin Moieties as Sustainable Inhibitors of Diabetes Mellitus Type 2(2025) Opebiyi, O. T.; Oduselu, G.O.; Ogunnupebi, T. A.; Elebiju, O. F.; Adekoya, Joseph Adeyemi; Ajani, O. O.The search for novel and more potent antidiabetic agents globally is due to the increase in insulin resistance, and more type 2 diabetes patients become susceptible to secondary compilations. Many pharmacologically active compounds are organic, mostly heterocyclic compounds, accounting for about 85% of Food and Drug Administration (FDA)-approved drugs. An example of a heterocyclic compound is coumarin, a benzopyrone group containing oxygen heteroatoms. Coumarin has been reported to possess several pharmacological properties, and combining coumarin with other compounds has made coumarin more potent. Computer-aided techniques have helped improve the design of potential drug candidates. Using computer-aided techniques, coumarin moieties were investigated for antidiabetic activities for future drug design. Coumarin template was used to search for ligand library on PubChem, an open chemistry database at the National Institutes of Health (NIH); 1653 compounds were downloaded with acarbose and metformin in SDF format, 1632 compounds, acarbose and metformin were successfully prepared, and then docked against human pancreatic alpha-amylase (Protein Data Bank- PDB ID: 4GQR) with Autodock vina. The qualitative structural assessment of the best hits from this molecular docking of a ligand library, acarbose and metformin was done. The functional groups present in this best hits, acarbose and metformin were used to generate 15 novel coumarin derivatives. The designed compounds were also docked against 4GQR, and their chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies were conducted. It was observed that 11 of the designed compounds had the lowest binding affinity than the co-crystalized ligand of 4GQR. The best hits compounds from the docking studies were 2g, 2f, 1a and 3e, and the ADMET studies predicted that compounds 1a, 3b, 3c and 3a had better pharmacokinetic and toxicity profiles. This promising result suggests that the designed compounds, particularly 1a, 3b, 3c and 3a, have the potential to be further optimized, synthesized and developed as potent antidiabetic agents, offering a hopeful future for diabetes treatment.Item Advances in nanoparticles as drug delivery systems: A review(Scientific African, 2025) Akomolafe, Oluwatobi Abayomi; Akinsiku, Anuoluwa AbimbolaThe use of nanoparticles in the pharmaceutical sector as drug carriers is rapidly growing, with many benefits over conventional drug delivery procedures. These nanoscale carriers are composed of biodegradable biocompatible materials, delivering therapeutic agents to the target with precise control and mitigating unwanted side effects. Despite numerous reports, many research gaps remain; thus, opportunities to improve the specificity and effectiveness of nanoparticle-based drug delivery for various illnesses, such as cancer, cardiovascular disease, infectious diseases, and central nervous system (CNS) disorders, are identified. The advances in nanoparticle-based drug delivery and their tremendous potential for revolutionising how drugs are delivered to treat disease are discussed. This review provides an overview of the various types of nanoparticles, including lipid-based, polymeric, natural polymers, and inorganic nanoparticles, which are being developed with their unique physical and chemical characteristics. It also reveals the strategies employed to enhance the targeting efficacy and stability of these nanoscale carriers in nanomedicine. The advantages, mechanisms, future direction, and drawbacks of each nanoparticle-based drug delivery system in target therapy and personalised medicine are well reviewed. Thus, addressing the identified gaps will be crucial for the clinical translation of nanoparticle-based therapeutics.Item Antimicrobial and cytotoxicity evaluation of Annona muricata-based silver-cobalt nanoparticles on WEHI 164 cell line(Results in Chemistry, 2025) Akinsiku, Anuoluwa Abimbola; Odaudu, Ruth Opiotu; Ejilude, OluwaseunThe harsh chemicals in conventionally fabricated metal nanoparticles have limited their applications for biomedical purposes. As part of green and sustainable chemistry in this study, an aqueous extract of indigenous Annona muricata was a reductant in preparing silver‑cobalt nanoparticles (Ag Co NPs) for therapeutic appli cation. The reaction progress and rate of formation of nanoparticles were monitored with a UV–visible spec trophotometer. The functional groups, structural morphology, and elemental composition of the Ag Co NPs were confirmed using FTIR, SEM, TEM, and EDX techniques, respectively. This study evaluated the cytotoxicity potential of 21.38± 8.0 nm Ag–– Co NPs on the WEHI 164 cell line for the first time, using an MTT assay and the antimicrobial potential of Ag Co NPs against six microorganisms. The characteristic wavelength of absorption was observed between 400 and 450 nm. The antimicrobial test showed evident growth inhibition by Ag Co NPs on P. aeruginosa, Candida albicans and Aspergillus niger. The in vitro cytotoxicity evaluation on the WEHI 164 cell line indicated that the Ag–– Co NPs were cytotoxic at an IC 50 dosage of 84 concentration-dependent. Hence, the Annona muricata synthesised Ag μ g/mL, and the cytotoxic potential was Co NPs are potential pharmaceutical drug candidates.Item Improving cycling performance and high rate capability of LiNi0.5 Mn0.3 Co0.2 O2 cathode materials by sol-gel combustion synthesis(Journal of Physics and Chemistry of Solids, Volume 196, 2025-01) Ehi-Eromosele, Cyril O.; Liu, Xinying; Mathe, Mkhulu K.The layered LiNi0.5 Mn0.2 Co0.2 O2 (NMC532) material displays capacity loss and poor rate performance even though it is a widely used cathode in commercial Li-ion batteries (LIBs). In this work, the structural and electrochemical performance of the NMC532 cathode were optimized using the fuel-to-oxidizer ratio assisted sol-gel combustion synthesis (SCS). It was shown that the fuel-to-oxidizer ratio markedly influenced the exothermicity of the combustion reaction which affected the crystal structure, morphology, and electrochemical performance of the final NCM532 materials. The fuel lean (FL) composition produced NMC532 cathode materials with the biggest crystallite and particle sizes, less cation mixing degree and better layered structure compared with the fuel stoichiometric (FS) and fuel rich (FR) compositions. The FL cell presented an initial discharge capacity of 180 mAh g−1 and the highest capacity retention of 92.2 % when it was cycled at 0.1 C between 2.5 and 4.4 V. Also, the FL cell displayed exceptional rate capability with the average capacities reaching 180, 178, 175, and 173 mAh/g at current densities of 1 C, 3 C, 5 C, and 10 C, respectively between 3.0 and 4.6 V. The EIS tests and dQ/dV plots showed that the FL cell both had the least impedance and polarization. The superior electrochemical performance of the FL material was ascribed to its optimized structural properties. Furthermore, the electrochemical results also show the influence of voltage window and current density on the performance of the NMC532 cathode materials.