Browsing by Author "Ayine-Tora, D.M."
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Item Design, Synthesis, and Evaluation of Biological Activity of Ferrocene-Ispinesib Hybrids: Impact of a Ferrocenyl Group on the Antiproliferative and Kinesin Spindle Protein Inhibitory Activity(Chemistry—A European Journal, 2023) Kowalczyk, K.; Błauż, A.; Ayine-Tora, D.M.; Hartinger, C.G.; et al.With the aim to combine more than one biologically-active component in a single molecule, derivatives of ispinesib and its (S) analogue were prepared that featured ferrocenyl moieties or bulky organic substituents. Inspired by the strong kinesin spindle protein (KSP) inhibitory activity of ispinesib, the compounds were investigated for their antiproliferative activity. Among these compounds, several derivatives demonstrated significantly higher antiproliferative activity than ispinesib with nanomolar IC50 values against cell lines. Further evaluation indicated that the antiproliferative activity is not directly correlated with their KSP inhibitory activity while docking suggested that several of the derivatives may bind in a manner similar to ispinesib. In order to investigate the mode of action further, cell cycle analysis and reactive oxygen species formation were investigated. The improved antiproliferative activity of the most active compounds may be assigned to synergic effects of various factors such as KSP inhibitory activity due to the ispinesib core and ability to generate ROS and induce mitotic arrest.Item Identification of novel Atg3-Atg8 inhibitors using virtual screening for autophagy modulation(Bioorganic Chemistry, 2021) Leung, E.; Ayine-Tora, D.M.; Santos-Ledo, A.; Korolchuk, V.I.A collection of 9050 natural products, their derivatives, and mimetics, was virtually screened against the human Atg3-Atg8 (Atg - autophagy) binding scaffold. By blocking this interaction, the lipidation of Atg8 does not occur and the formation of autophagosomes is inhibited. Forty-three (43) potential ligands were tested using enhanced Green Fluorescent Protein (eGFP) tagged LC3, the human ortholog of Atg8, in MCF7 breast cancer cells. Three hits showed single digit μM IC50 values with AT110, an isoflavone derivative, being the best at 1.2 ± 0.6 μM. Molecular modelling against Atg8 in conjunction with structural activity relationship (SAR) strongly supports the binding to this target. Testing in a panel of cancer cell lines showed little cytotoxic effect as compared to chloroquine. However, same concentration of AT110 was shown to be toxic to young zebrafish embryos. This can be explained in terms of the autophagy process being very active in the zebrafish embryos rendering them susceptible to AT110 whereas in the cancer cells tested the autophagy is not usually active. Nevertheless, AT110 blocks autophagy flux in the zebrafish confirming that the ligand is modulating autophagy. A small molecule non-cytotoxic autophagy inhibitor would open the door for adjunct therapies to bolster many established anticancer drugs, reducing their efficacious concentration thus limiting undesirable site effects. In addition, since many cancer types rely on the autophagy mechanism to survive a therapeutic regime, recurrence can potentially be reduced. The discovery of AT110 is an important step in establishing such an adjunct therapy.Item Purpose This study aims to examine the effects of cyberbullying on the academic lives of Ghanaian university students. It also establishes whether cyberbullying victims, perpetrators, victim-perpetrators and bystanders differed in their thoughts on the effects of cyberbullying on students’ academic lives. Design/methodology/approach This study is anchored on Bandura’s theory of triadic reciprocal determinism and Abraham Maslow’s theory of needs. This study uses a cross-sectional survey design and quantitative approach to collect the data from 1,374 students from three public universities. The authors use descriptive statistics and ANOVA techniques to analyse the data. Findings The results show that the effects of cyberbullying on academic life are difficulty concentrating on studies, difficulty studying in groups and difficulty assessing important academic information online. There is also a statistically significant difference among cyberbullying victims, perpetrators, victim-perpetrators and bystanders in their thoughts on the effects of cyberbullying on students’ academic lives.(Journal of Molecular Structure, 2024) Abbasi, M.A.; Siddiqui, S.S.; Ayine-Tora, D.M.; et al.In the research delineate herein, an innovative sequence of new series of multi-functional target molecules (9a-i) having indole-N-phenyltriazole bi-heterocyclic hybrids unified with N-arylated butanamides was synthesized as alkaline phosphatase inhibitor. The structural validation of all the formulated compounds was accomplished through IR, EI-MS, 1 H NMR, 13C NMR and CHN analysis data. The in vitro enzyme inhibitory investigation revealed the efficacy of these bi-heterocyclic derivatives, 9a–i, as potent inhibitors of alkaline phosphatase relative to the standard used. The compound 9h was found to be the most active compound (IC50 = 0.062 ± 0.017 μM), and its inhibitory activity is about 10 times higher than potassium dihydrogen phosphate (KH2PO4) (IC50 = 5.251 ± 0.468 μM). The kinetics mechanism was attributed by evaluating the Lineweaver–Burk plots, which revealed that compound 9h inhibited the alkaline phosphatase non-competitively to form an enzyme –inhibitor complex. The inhibition constant Ki determined from Dixon plots for this compound was 0.045 μM. The computational study was in full agreement with the experimental records and these ligands exhibited good interactions and binding energy values. These molecules also demonstrated mild cytotoxicity toward red blood cell membranes when analyzed through hemolysis. So, based on the presented results, these molecules, being the promising inhibitors of alkaline phosphatase, might be deliberated as suitable medicinal scaffolds to render normal calcification of bones and teeth.Item Synthesis and Biological Properties of Ferrocenyl and Organic Methotrexate Derivatives(ACS Omega, 2024) Rózga, K.; Błauz, A.; Ayine-Tora, D.M.; et al.Synthesis and biological activity of two series of modified side chain methotrexate (MTX) derivatives are presented, one with a ferrocenyl moiety inserted between the pteroyl and glutamate portions of the molecule and the other with glutamate substituted for short chain amino acids. Ferrocenyl derivatives of MTX turned out to be rather moderate inhibitors of dihydrofolate reductase (DHFR) although molecular modeling suggested more effective interactions between these compounds and the target enzyme. More interestingly, ferrocene-decorated MTX derivatives were able to impede the proliferation of four murine and human cell lines as well as their methotrexate-resistant counterparts, overcoming the multidrug resistance (MDR) barrier. They were also able to directly interact with Abcc1, an MDR protein. Of the amino acid pteroyl conjugates, the γ-aminobutyric acid derivative was an efficient inhibitor of DHFR but had no effect on cell proliferation in the concentration range studied while a taurine conjugate was a poor DHFR inhibitor but able to affect cell viability. We postulate that modification of the methotrexate side chain may be an efficient strategy to overcome efflux-dependent methotrexate resistance.