Research Articles (Chemistry)

Permanent URI for this collectionhttp://hdl.handle.net/2263/1724

This collection contains some of the full text peer-reviewed/ refereed articles published by researchers from the Department of Chemistry

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Now showing 1 - 20 of 776

Sustainable synthesis strategies of metal-organic frameworks (MOFs) using unconventional precursors : advances and challenges
Hassan, Ibrahim; Debiagi, Paulo; Iqbal, Shahid; Langmi, Henrietta Wakuna; Xi, Ziyun; Xu, Mengxia; Musyoka, Nicholas M. (Elsevier, 2026-09)
Metal-Organic Frameworks (MOFs) are a new type of porous material with large surface areas, configurable porosity, and with potential for a wide range of applications due to their chemical and structural tunability. They are also observed to have diverse applications in gas storage, catalysis, and environmental remediation, among others. However, in traditional MOF synthesis processes, the requirements for high-purity metal salts and conventionally derived organic linkers are often expensive, environmentally unsustainable, and hence hinder MOF commercialisation efforts. Recent progress in MOF synthesis using unconventional precursors is changing the narrative. This review article focuses on recent advances and challenges for the use of naturally occurring inorganic minerals, biomass-derived linkers, and industrial metal-rich waste materials as unconventional feedstocks for MOF synthesis. The study categorises these alternative materials based on their chemical makeup and suitability, while also examining their impact on the structure and function of MOFs. The review's findings suggest that employing unconventional precursors is a viable technique for producing MOFs in an inexpensive and sustainable manner. The study further emphasises the need for more research into the environmental implications of large-scale use, precursor reactivity, and structural integrity. The proposed approach of using alternative or unconventional precursors presents new opportunities for integrating MOF synthesis strategies with circular economy approaches.
Kinetics, thermodynamics, and mechanistic understanding of adsorptive removal of Congo red using oxidized carbon nanoplatelets
Mudzamiri, Gamuchirai; Mombeshora, Edwin Tonderai (Wiley, 2026-05)
The illicit use of synthetic dyes, which are harmful to humankind's health and aquatic ecosystems, highlights the urgent need for efficient adsorbents in wastewater treatment. This work investigates the adsorption performance, kinetics, and thermodynamics of anionic Congo red (CR) dye removal, using oxidized carbon nanoplatelets (OCNPs). Optimal adsorption was achieved at pH 2.25, 25°C, initial CR concentration of 30 mg L−1, adsorbent dose of 10 g L−1, after 1 h. Fourier transformation infra-red spectroscopy (FTIR) analysis before and after adsorption suggested a predominantly physisorption mechanism, and this trait enhances reusability, thus indirectly supporting the practical applicability of OCNPs. The adsorption data follow the pseudo-second-order kinetic model (R2 = 0.9998), suggesting adsorption rates governed by adsorption capacity. The negative Gibbs energy at all temperatures and enthalpy changes confirm spontaneous and exothermic processes, respectively, whereas a positive entropy change indicates increased energy dispersal at the solid–liquid interface. Notably, OCNPs achieved high decontamination efficiency under both acidic and basic conditions, demonstrating strong affinity toward CR molecules. These findings position oxidation-tailored OCNPs as effective and low-cost adsorbents with oxidation-induced surface chemistry for the remediation of anionic dye-contaminated wastewater at low adsorbent doses and operational at room temperature. The material demonstrated high adsorption performance without the need for composite formation across a wide pH range or additional functionalization. Furthermore, its surface properties can be systematically controlled with oxygen content/species, providing a straightforward route to tailor adsorption behavior. This approach also reduces production complexity and cost, particularly given the potential derivation of the precursor from renewable biomass sources.
Differential metabolomic effects of progestagen-based estrus synchronisation in South African Dohne Merino ewes
Shingange, Rimbilana N'wa-Nghondzweni; Visser, Carina; Wooding, Madelien; Webb, E.C. (Edward Cottington) (Springer, 2026-07-10)
This study represents one of the first to comprehensively profile the homeostatic cervicovaginal metabolome of South African Dohne Merino ewes using liquid chromatography high resolution mass spectrophotometry (LC-HRMS) and compare that metabolome immediately after estrus synchronisation using progestagen intravaginal pessaries. As the use of assisted reproductive technologies gains traction in various livestock production systems, characterising their effects using novel omics approaches is crucial to physiology, welfare and production. An ewe has well-developed metabolomic cascades that are homeorhetically responsive to the stress caused by assisted reproductive treatments in order to maintain homeostasis. The cervicovaginal fluid of sixty ewes was sampled by transvaginal FLOQSwabs before pessary insertion as well as immediately post-pessary removal. These swabs, along with field, solvent and swab blanks, underwent extraction in acetonitrile and drying under nitrogen prior to reconstitution. Using one-way ANOVA with Tukey's HSD post-hoc analysis and PERMANOVA, this study found no significant metabolomic features prior to treatment (P > 0.05). However, after pessary removal, 32 features were reported to be different between the CIDR-, sponge-treated and control group (P < 0.005 and False Discovery Rate < 0.05). Features were identified at four levels including at verification with pure chemical standards. Progesterone was found to be highest in the CIDR-treated group (P < 5.0 × 10- 48) while linolenic acid, an immune modulator, was highest in the sponge-treated group (P < 5.0 × 10- 3). These findings present a novel understanding of the metabolomic fluctuations that occur within the cervicovaginal microenvironment in response to progestagen synchronisation protocols, which are a routine part of management in the production systems of sheep and various other species of livestock. These stark metabolomic differences highlight endocrine and immune changes that are triggered by the CIDR or sponge and warrant further characterisation of the physiological and welfare implications of these technologies.
Investigations into alternative analytical approaches for N-nitrosamine contamination in drinking water
Tyhali, Akhona; Forbes, Patricia B.C. (South African Chemical Institute, 2025)
Nitrosamines (NAs) are probable human carcinogens and their occurrence in drinking water is predominantly attributed to chloramination and chlorination disinfection in the presence of amine species. Although methods have been reported for NAs in drinking water with very low detection limits, the equipment required may not be readily available. The use of alternative instrumentation, namely UPLC-QToFMS and GC-ToFMS was thus investigated. Upon analysis of NAs by UPLC-QToFMS, the same number of peaks (6 or 7) were detected for both atmospheric-pressure chemical ionization (APCI) and electrospray ionization (ESI) for the nine NAs (NDMA, NMEA, NPyr, NDEA, NPip, NMor, NDPA, NDBA, and NDPhA) that were analyzed by UPLC-QToFMS at concentrations >5 μg/mL, but APCI performed better than ESI at lower concentrations (0.5 and 1.0 μg/mL). Importantly, NAs were found to degrade over time with eight out of the nine NAs showing a decrease in peak area response of > 60% after five days when the stability of NA standards was determined by GC-ToFMS. Consequently, the detection of NAs at trace levels becomes even more challenging due to their inherent instability.
Defect passivation in CsPbBr3 perovskite using phenethylammonium bromide
Thubane, Sandile Job; Nombona, Nolwazi; Diale, M. (Mmantsae Moche) (Wiley, 2026-01)
Please read abstract in the article.
Occurrence, distribution, and risk assessment of selected pharmaceuticals in municipal biosolids from the four wastewater treatment plants in Gauteng Province, South Africa
Ngoetjana, Matome Peter; Tesfamariam, Eyob Habte; Brown, Sally; Wooding, Madelien (Nature Research, 2025-11-24)
The presence of pharmaceutical residues in municipal biosolids is an emerging environmental concern due to their potential accumulation in agricultural soils following land application. While parent compounds like sulfamethoxazole and carbamazepine are frequently studied, data on their transformation products in biosolids remain limited. This study assessed the occurrence, distribution, and environmental risks of sulfamethoxazole, carbamazepine, and two of their selected metabolites in biosolids collected from four wastewater treatment plants (WWTPs) in Gauteng Province, South Africa. A single biosolid sampling campaign was conducted across the four WWTPs, each characterized by varying operational parameters. Sulfamethoxazole and its two metabolites were not detected in any of the samples. In contrast, carbamazepine and its metabolites—carbamazepine-10,11-epoxide and carbamazepine diol—were detected, with maximum concentrations of 150.67, 601.95, and 89.18 ng/g dry weight, respectively. Carbamazepine and carbamazepine-10,11-epoxide occurred in all samples, while carbamazepine diol appeared in 50% of the samples. The concentration patterns varied across WWTPs and were significantly correlated with biosolid pH, organic carbon content, and oxidation-reduction potential. Risk quotient analysis indicated that the predicted soil concentrations of carbamazepine (0.50 ng/g dry weight) pose negligible ecological risk (RQ = 0.003). However, due to a lack of ecotoxicological data, environmental risks associated with carbamazepine-10,11-epoxide and carbamazepine diol could not be fully assessed. Overall, the findings highlight the persistence of carbamazepine and its metabolites in biosolids and underscore the importance of optimizing sludge treatment processes and generating toxicity data for pharmaceutical metabolites to support safe land application practices.
CRISPR-Cas9 gene drive and conventional approaches for malaria control : a review of progress, challenges, and future prospects
Robinson, Ayibanuah F.; Okafor, Esther O.; Oduselu, Gbolahan O.; Opebiyi, Oluwabukayo T.; October, Natasha; Ajani, Olayinka O. (Elsevier, 2026-09)
Malaria remains a global health challenge, having a steadily increasing incidence as well as death rate, particularly in sub-Saharan Africa. Modern methods of tackling malaria, which primarily include long-lasting insecticide-treated nets (LLINs), indoor residual spraying (IRS), and antimalarial drugs, are faced with a serious threat emanating from drug and insecticide/pesticide resistance, thereby undermining eradication efforts. This work extensively reviewed the current literature on conventional means of controlling malaria to unveil the impediments to their use and the urgent need for a permanent solution through innovative strategies. It also provided a detailed evaluation of gene drive technology based on the CRISPR-Cas9 system as a crucial complementary tool for malaria control. Additionally, this present study carefully evaluated the ethical issues related to this technology, as well as the ecological concerns regarding the production and release of gene drive modified organisms. The CRISPR-Cas9 system employs a sequence-specific endonuclease mechanism to generate targeted double-strand DNA breaks, forming the basis for precise gene editing and drive development, and utilises two fundamental strategies for vector control: population suppression, primarily aimed at reducing the mosquito population, and population replacement, which aims to spread genes that make mosquitoes refractory to the Plasmodium parasite. HIGHLIGHTS • CRISPR-Cas9 gene drive technology represents a cutting-edge approach capable of achieving mosquito population suppression and population modification, ultimately eliminating malaria tr transmission. • Homing suppression drives targeting conserved genes, such as the double sex, can achieve complete cage population elimination while minimizing functional resistance allele formation. • A major biological barrier to field deployment of gene drive technology is the formation of functional resistance alleles and fitness cost. • In any field release of gene drive mosquitoes, the ecological risk assessment, ethical governance framework, and community involvement remain an indispensable prerequisite.
Stimuli-responsive aluminium-fumarate MOFs from recycled aluminium : phase evolution, thermochromism and gas sorption
Ndamyabera, Christophe Adrien; Joubert, Serena Elizabeth; Langmi, Henrietta Wakuna (South African Chemical Institute, 2026-06)
Please read abstract in the article.
Supramolecular architecture modulated by positional isomerism : synthesis, structure, and fluorescence properties of ionic systems containing 1,8-Naphthalimide derivatives and tetrahalometallate anions
Beebeejaun-Boodoo, B.M. Parveen; Kleine, Tatjana (American Chemical Society, 2026-05-13)
Please read abstract in the article.
Assessing the cytotoxic effects of Group IX metal N-heterocyclic carbene complexes of iridium and rhodium on B16-F10 melanoma and non-cancerous RAW 264.7 cells
Van Vuuren, Estefan; Nadasen, Carolyn Courtney; Malan, F.P. (Frederick); Hlophe, Yvette Nkondo; Serem, June Cheptoo; Landman, Marile (Elsevier, 2026-09-15)
The development of highly effective and selective anticancer agents remains a central challenge in oncological research. Herein, we report a systematic evaluation of the anticancer activity of a series of rhodium- and iridium-based NHC (N-heterocyclic carbene) complexes (complexes 1, 3, 5–7), including the novel complex 3, as well as two imidazole-containing complexes (2 and 4). Their cytotoxic profiles were investigated against B16-F10 melanoma cells and benchmarked against non-cancerous RAW 264.7 macrophage cells to assess cancer selectivity. Cytotoxicity of complexes 1–7 was quantified using the crystal violet assay following exposure to 0.01 mM and 0.1 mM concentrations over 24, 48, and 72 h. Half-maximal inhibitory concentrations (IC50) were determined to establish comparative selectivity and potency indices. Mechanistic insight was further obtained through morphological assessment of treated cells at IC50 values using polarised light optical differential interference contrast (PlasDIC) microscopy. At 0.1 mM, all complexes induced a pronounced reduction in B16-F10 cell viability, with complexes 2 and 3 emerging as the most potent, achieving >90% inhibition after 72 h. Notably, early time-point IC50 values (24 h) revealed marked cytotoxicity in melanoma cells (complex 2: 0.04 mM; complex 3: 0.05 mM), while eliciting minimal effects in RAW 264.7 macrophages, indicating selective anti-cancer activity. Morphological analysis of B16-F10 cells demonstrated features consistent with both apoptosis (membrane blebbing, apoptotic bodies, nuclear fragmentation) and necrosis (cell swelling, debris). Cell cycle analysis demonstrated a general increase in the S phase in B16-F10 cells, indicative of replication stress or cell cycle arrest, whereas no significant changes were observed in RAW 264.7 cells. Collectively, complexes 2, 3, and 5, display a compelling combination of potency and selectivity towards B16-F10 melanoma cells, with reduced cytotoxicity towards non-cancerous RAW 264.7 cells. These results support the continued development of NHC-based metal complexes as promising selective anticancer agents and warrant further mechanistic and in vivo investigation. HIGHLIGHTS • Range of Rh and Ir metal complexes tested against B16F10 melanoma cells and non-cancerous RAW 264.7 macrophage cells with moderate activity (0.04–0.09 mM IC50) and high selectivity. • Morphological analysis of B16-F10 cells revealed both apoptotic (membrane blebbing, apoptotic bodies, nuclear fragmentation) and necrotic (cell swelling, debris) features. • Cell cycle analysis showed a general increase in S phase in B16-F10 cells and showed no significant changes in RAW 264.7 cells.
The role of teaching experience in shaping university lecturers’ enacted TSPCK in electrochemistry
Rakhunwana, Langanani; Mundy, Christine Elizabeth; Mavhunga, Elizabeth (Taylor and Francis, 2026-04-13)
In higher education, lecturers shape learning through various teaching methods, which rely on pedagogical expertise, especially for difficult topics such as electrochemistry. Therefore, it becomes important to investigate whether pedagogical expertise develops with teaching experience and how that experience influences lecturers’ teaching practices. This study compared an experienced and a novice lecturer by analysing their teaching practices using the enacted topic-specific pedagogical content knowledge (enacted TSPCK) model. The study followed an exploratory qualitative case study design. Data were collected through lecture observations, audio-recordings of lectures and post-lecture interviews. The analysis involved deductive coding of lecture observations, audio-recordings and teaching materials to identify instances where two or more TSPCK components interacted; these instances were referred to as TSPCK episodes. Post-lecture interviews were then analysed to substantiate and contextualise the findings from the classroom data. The TSPCK episodes were classified into three categories reflecting increasing levels of advancement: simple, proficient and sophisticated. The experienced lecturer demonstrated a greater number of sophisticated TSPCK episodes, indicating more advanced enacted TSPCK. Interviews further revealed that the experienced lecturer’s use of representations, analogies and real-life examples was closely linked to teaching experience. An analysis of the frequency of occurrence of TSPCK components within the exhibited episodes for each lecturer was also conducted. Results revealed that the novice lecturer’s episodes showed a more even distribution of TSPCK components compared with the experienced lecturer. The implications of these findings are discussed, including the possible relationship between teaching experience and the quality of enacted TSPCK episodes overall.
Synthetic strategies for dihydrochalcones
Selepe, Mamoalosi A.; Madibana, Lorraine T.; Mthembu, Siyanda T.; Sonopo, Molahlehi S. (ARKAT USA, 2026)
Dihydrochalcones are open chain derivatives of flavanones characterised by the presence of the benzylacetophenone skeleton. They have been reported to exhibit many important biological activities, which make them attractive targets for chemical synthesis. Several synthetic strategies have been developed for the dihydrochalcones. The most widely employed synthetic method involves selective reduction of the double bonds of chalcones. Other methods that have been developed for the synthesis of dihydrochalcones include transition metal-catalysed coupling reactions as well as light-catalysed reactions. This review discusses the synthetic strategies for the dihydrochalcones.
Revisiting chemorganizers : supporting electrolysis learning in contemporary first-year chemistry classrooms
Rakhunwana, Langanani; Mundy, Christine Elizabeth (American Chemical Society, 2026-01-07)
Electrolysis remains one of the most conceptually difficult areas in chemistry. Despite the availability of modern technology and visualization tools, students continue to face challenges in connecting observable phenomena with underlying electrochemical concepts. Therefore, there is a need to revisit earlier developed tools and evaluate their usefulness in contemporary learning environments. This study revisits chemorganizers, instructional tools introduced in the early 2000s, and investigates their effectiveness in supporting student learning in electrolysis. Guided by Cognitive Load Theory, the study aimed to minimize extraneous cognitive load and promote deeper learning. A mixed-methods approach was adopted and implemented with two student cohorts (2023 and 2024) through a tutorial-based intervention. Both cohorts’ samples could be naturally divided into two groups due to the timing of the lectures: a well-prepared group (who experienced electrolysis lectures prior to engaging with the chemorganizers) and an under-prepared group (no prior exposure to electrolysis content in lectures). The intervention was centered on the use of chemorganizers. A tutorial worksheet and a content knowledge test, used as both pre- and post-tests, were included to support and assess the implementation. Statistical analysis showed significant performance improvement for both groups across both cohorts from the pre- to post-test. Furthermore, while the well-prepared group initially outperformed the under-prepared group in the pretest, the performance gap closed in the post-test. The chemorganizers may have closed the knowledge gap between the sample groups. An online survey was later distributed to capture student perceptions on the usefulness of the chemorganizers. Students reported that chemorganizers improved their understanding, supported problem-solving, and were easy to navigate. Critiques focused mainly on the implementation. Overall, the findings suggest that chemorganizers remain relevant and effective in supporting learning in topics within contemporary first-year chemistry classrooms.
Editorial for special issue "Coal fly ash as a resource : advances in characterization, utilization and sustainable solutions"
Doucet, Frédéric J. (MDPI, 2026-04-08)
Coal fly ash (CFA), the fine particulate by-product of coal combustion in thermal power plants, has traditionally been regarded as an environmental liability. Its large volumes, heterogeneous composition, and potential for trace metal release have posed persistent challenges related to disposal, land use, and long-term environmental management. Increasingly, however, this perception is shifting. Rather than being viewed solely as waste, CFA is now recognized as a secondary resource rich in reactive mineral phases and valuable elements suitable for industrial and environmental applications. This evolving perspective aligns closely with the principle of the circular economy, in which materials once destined for disposal are redirected into productive value chains, thereby reducing environmental burdens while conserving primary raw materials. Within this context, the present Special Issue was conceived to consolidate recent advances that deepen our understanding of CFA properties while showcasing innovative strategies for its beneficiation, functionalization, and utilization across diverse sectors. Emphasis has been placed on rigorous characterization, novel processing routes, and practical demonstrations of application pathways capable of transforming CFA into high-value products. Between 2024 and 2026, five contributions were assembled that collectively fulfill these objectives. Although differing in technical focus and application domain, all studies share a common theme: the systematic integration of detailed physicochemical and mineralogical characterization with targeted performance outcomes. Together, they demonstrate how fundamental understanding enables the rational and sustainable design of value-added uses for CFA.
Catena-poly [[bis [tris (4-methoxyphenyl) phosphine-κP] silver (I)] -μ-thiocyanato-κ2N:S]
Malan, F.P. (Frederick); Potgieter, Kariska; Meijboom, Reinout (International Union of Crystallography, 2025-09)
The coordination polymer, [Ag(NCS)(C21H21O3P)2]n or {[Ag(P(4-OMePh)3)2]-μ-NCS}n, features μ-thiocyanato ligands bridging between neighbouring silver(I) atoms, generating chains along the b-axis direction. Each AgI atom is four-coordinate, with two phosphorus donors from two distinct tris(p-methoxyphenyl)phosphine ligands, and two atoms from the thiocyanato ligands in severely distorted tetrahedral shape. The Ag—P [2.4331 (6) and 2.4625 (5) Å], Ag—N [2.339 (2) Å] and Ag—S [2.6760 (6) Å] bond lengths all appear within the expected ranges, with corresponding P—Ag—P and S—Ag—N angles of 129.610 (19) and 86.75 (6)°. In the crystal, the polymeric chains pack into layers parallel to (001) separated by the aryl groups of the phosphine ligands.
Bis [(2-methoxyphenyl) diphenylphosphane-κP] (nitrito-κ2O,O') silver (I)
Malan, F.P. (Frederick); Potgieter, Kariska; Meijboom, Reinout (International Union of Crystallography, 2025-03)
The synthesis and single-crystal structure description of a silver(I) diphenyl-2-methoxyphenylphosphine nitrite complex is described. The molecular structure of the title AgI complex, [Ag(NO2)(C19H17OP)2], is described, where a distorted tetrahedral coordination environment for the AgI atom is apparent within a O2P2 donor set as the nitrito anion coordinates in a bidentate mode. A fairly large angle for P—Ag—P [129.126 (16)°] is noted. The O—Ag—O chelate angle is = 50.38 (6)° and the P—Ag—O angles lie in the range 99.51 (5) to 118.45 (6)°. In the crystal, C—H⋯O interactions are evident.
(Nitrito-κ2O:O′)bis[tris(4-fluorophenyl)phosphine-κP]silver(I)
Malan, F.P. (Frederick); Potgieter, Kariska; Meijboom, Reinout (International Union of Crystallography, 2025-04)
The molecular structure of the title AgI complex, [Ag(NO2)(C18H12F3P)2], features a distorted tetrahedral geometry about the central AgI atom, with a total range of bond angles spanning from 49.80 (5) to 114.92 (1)°. The distortion arises primarily due to the small bite angle [49.80 (5)°] of the nitrito ligand. The compound crystallizes with one molecule in the asymmetric unit, in the space group P21/n, with Z = 4 and Z′ = 1.
Flavonol-mediated modulation of angiogenesis-related microRNAs in breast cancer : a narrative synthesis of current evidence and knowledge gaps
Ramali, Dakalo Portia; Maphoso, Tania Mmapule; Mulaudzi, Thanyani Victor; Ambele, Melvin Anyasi; Maharaj, Vinesh J.; Mabeta, Peaceful Lucy; Damane, Botle Precious (Taylor and Francis, 2026-05-08)
Angiogenesis is essential for breast cancer progression and metastasis; however, the clinical impact of vascular endothelial growth factor (VEGF)-targeted therapies remains limited due to adaptive resistance and activation of compensatory angiogenic pathways. Angiogenesis-regulating microRNAs (angiomiRs) act as upstream modulators of both VEGF-dependent and VEGF-independent signaling networks contributing to vascular plasticity, immune evasion, and therapeutic escape. Dietary flavonols such as kaempferol, myricetin, and quercetin have demonstrated anti-angiogenic activity in preclinical models, yet their mechanistic interaction with angiomiR-mediated regulation in breast cancer remains poorly characterized. This narrative review critically evaluates evidence identified through structured searches of Google Scholar, PubMed, Scopus, and Web of Science (2010–2026). We synthesize mechanistic and translational findings linking flavonols to microRNA-associated regulation of hypoxia signaling, endothelial activation, extracellular vesicle communication, and vascular normalization. Available evidence indicates that flavonols may influence angiogenic pathways both directly, by inhibiting key signaling cascades, and indirectly, through modulation of non-coding RNA networks. Despite these insights, experimental validation of specific flavonol-angiomiR interactions in breast cancer remains limited. AngiomiR modulation by flavonols, therefore, represents a mechanistically grounded but predominantly preclinical concept that warrants further translational investigation to clarify its therapeutic relevance and potential applications within precision oncology in breast cancer. PLAIN LANGUAGE SUMMARY : Blood vessels are essential for supplying breast cancer tumors with nutrients and oxygen. Tumors often rely on a molecule called vascular endothelial growth factor (VEGF) to form new blood vessels. For this reason, treatments that block VEGF have been developed to slow tumor growth. However, these treatments can lose effectiveness over time because cancer cells can find alternative ways to keep their blood supply. Blood vessel formation is controlled by signals within cells. MicroRNAs (miRNAs) are very small molecules that help turn genes on or off, influencing how blood vessels develop and how tumors respond to treatment. Flavonols are naturally occurring compounds found in certain fruits and vegetables. Some studies suggest that flavonols can affect blood vessel growth, possibly by influencing miRNAs involved in this process. Although early findings are promising, most evidence comes from laboratory and preclinical studies. Further research is needed to determine whether targeting these pathways could lead to safe and effective treatment strategies for patients with breast cancer.
Experimental and molecular-level insights into thermal conductivity of cobalt hydroxychloride nanofluids
Ntumba, P.T.; Khamlic, s.; Sone, Bertrand T.; Fester, V. (Elsevier, 2025-05-17)
Please read abstract in the article.
Structural and antimicrobial studies on a tricarbonyl rhenium(i) complex with the 6,7-dimethyl-2-(pyridin-2-yl)quinoxaline ligand
Sithole, Sibusiso A.; Mansour, Ahmed M.; Malan, F.P. (Frederick); Manikandan, Gurusamy; Katerere, David R.; Shehab, Ola R.; Manicum, Amanda-Lee E. (Royal Society of Chemistry, 2026-01-26)
A new tricarbonyl rhenium(I) complex featuring 6,7-dimethyl-2-(pyridin-2-yl)quinoxaline (1) was synthesized and characterized using spectroscopic and crystallographic techniques, supported by density functional theory (DFT) calculations. Ligand 1 acts as a bidentate N,N′-donor, coordinating through the pyridyl and quinoxaline nitrogen atoms to form a fac-[ReCl(CO)3(1)] (2) complex. Single-crystal X-ray diffraction analysis revealed an octahedral geometry around the Re(I) centre, with the three carbonyl ligands adopting a facial arrangement. Hirshfeld surface analysis indicated that weak C–H⋯Cl interactions play a significant role in crystal packing stabilization. DFT and time-dependent DFT (TDDFT) calculations confirmed the observed experimental geometry and provided insights into the metal–ligand bonding, charge distribution, and electronic transitions. The combined results highlight the structural and electronic features that contribute to the stability and potential bioactivity of this rhenium(I) tricarbonyl complex. The antimicrobial assay indicated that the rhenium metal complex (2) was superior to the ligand (1) in activity against six different microbial species, but inferior to the standard antimicrobial agents.

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