http://41.74.91.244:8080/handle/123456789/760 2026-04-05T19:30:46Z http://41.74.91.244:8080/handle/123456789/5145 GC-MS profiling and biological evaluation of ethyl acetate extract of the bark of morinda lucida benth Amenano, J. This study investigates the allelopathic effects of Morinda lucida stem bark extract on seed germination, alongside its antimicrobial and antioxidant properties, as well as the Gas Chromatography-Mass Spectrometry (GC-MS) profiling of compounds found in the extract. The objectives included assessing antimicrobial activities against various microbial strains, evaluating antioxidant capacities using 1,1-diphenylpicrylhydrazyl (DPPH) and 2,2'-Azinobis-3-Ethylbenzothiazolin-6-sulfonic acid (ABTS) assays, conducting anti-germination bioassays, and profiling phytochemical compounds via Gas Chromatography-Mass Spectrometry (GC-MS). The antimicrobial evaluation, employing agar well diffusion and broth micro-dilution methods, revealed that the extract demonstrated bactericidal activity against Salmonella typhi, Staphylococcus aureus, and Escherichia coli, with minimum inhibitory consentrations (MICs) of 10 mg/mL and an MBC/MIC ratio of 2. Phytophthora megakarya had an Minimum Inhibitory Concentration (MIC) of 0.313 mg/mL and an MFC/MIC ratio of 2, indicating strong susceptibility and a fungicidal effect, meaning all the organisms were killed at this lower concentration. Antioxidant assays demonstrated a concentration-dependent raise in free radical scavenging, confirming potent antioxidant activity comparable to Vitamin C that was used as control. Phytotoxicity tests on Lactuca sativa seeds demonstrated a dose-dependent suppression of root and shoot development. At the highest concentration (TR3, 78.4 μg/μL), shoot and root lengths was decrease by 80 % and 85 %, respectively. GC-MS profiling identified 24 bioactive compounds, with Ergosta-4,22-dien-3-one being the most abundant (14.2 %). These findings indicate that Morinda lucida stem bark extract possesses strong antimicrobial, antioxidant, and allelopathic properties. The results provide a foundation for further exploration of its potential applications as a natural herbicide or in therapeutic contexts. A dissertation in the Department of Chemistry Education, Faculty of Science Education, submitted to the School of Graduate Studies in partial fulfillment of the requirements for the award of the degree of Master of Philosophy (Chemistry Education) in the University of Education, Winneba JUNE, 2024 2024-06-01T00:00:00Z http://41.74.91.244:8080/handle/123456789/5140 Extraction, biological evaluation and GC-MS characterization of ethyl acetate extract of the stem bark of newbouldia laevis Agbetum, C.A. The increasing resistance to conventional antibiotics and the demand for effective natural remedies have prompted the exploration of medicinal plants for bioactive compounds. This study aimed to extract and characterize secondary metabolites from the stem bark of Newbouldia laevis and evaluate their antimicrobial and antioxidant activities. The stem bark was collected from Dambai-Zongo in the Oti Region of Ghana and extracted using ethyl acetate via maceration. The crude extract was subjected to Gas Chromatography-Mass Spectrometry (GC-MS) analysis, which identified various compounds, including fatty acids (linoleic acid, octadecanoic acid), sterols (stigmasterol, stigmast-5-en-3-ol), triterpenoids (olean-12-en-3-ol), and esters. The antimicrobial activities of the extract were evaluated using the Kirby-Bauer agar diffusion method and broth microdilution assays against bacterial strains such as Staphylococcus aureus, Escherichia coli, and Salmonella typhi, as well as fungal strains like Candida albicans. The extract demonstrated significant antimicrobial activity, particularly against S. aureus, with zones of inhibition ranging from 8.33 to 19.33 mm. Minimum Inhibitory Concentrations (MICs) ranged from 0.078 to 25 mg/mL, confirming the extract’s bactericidal and fungicidal effects. Antioxidant activity was assessed using DPPH and ABTS scavenging assays. The extract exhibited notable free radical scavenging potential, with IC50 values of 0.322 mg/mL and 0.329 mg/mL, respectively, comparable to the standard vitamin C. These findings validate the traditional use of Newbouldia laevis in treating microbial infections and oxidative stress-related conditions. The presence of bioactive compounds highlights their potential for pharmaceutical applications, particularly in developing natural antibiotics and antioxidants. Further studies are recommended to evaluate the pharmacokinetics, toxicity, and clinical efficacy of the identified compounds to facilitate their development into therapeutic agents. A thesis in the Department of Chemistry Education, Faculty of Science Education, submitted to the School of Graduate Studies in partial fulfilment of the requirements for the award of the degree of Master of Philosophy (Chemistry Education) in the University of Education, Winneba SEPTEMBER, 2025 2025-09-01T00:00:00Z http://41.74.91.244:8080/handle/123456789/5080 Senior High School chemistry teachers’ professional competence, attitudes and practices in Organising practical work in the Greater Accra Region, Ghana Anim, W. Teachers’ competence and attitudes are essential to enhance the quality of the teaching profession. This study employed a descriptive research design to explore the senior high school chemistry teacher’s professional competence, attitudes and practices in organising practical work in the Greater Accra Region. A simple random technique was used to select 170 chemistry teachers from 34 randomly chosen senior high schools for the study. A close-ended questionnaire and an observation checklist were used to collect quantitative and qualitative data, respectively. The study finds out that majority of chemistry teachers had a high competency level but exhibited poor practices in organising practical work due to negative attitudes toward organising practical work. The teachers gave clear explanation and demonstrated experiments before practical work, defined problems in simple language, handled all instruments and glassware, used internet to gather information for students and prepared reagents for laboratory practical. Qualitatively, the teachers never supervised students during practical lessons. As a result, students hardly followed rules and regulations and performed practical work without a manual. Besides, practical tasks were not selected from Ghana Education Service approved textbooks. Generally, the attitudes of the teachers were not good enough to translate their high professional competence into actual practice during practical work. It was recommended among others that, Chemistry teachers in senior high schools in Greater Accra Region of Ghana should organised chemistry practical work often, offer guidance and supervise students during practical activities and develop positive attitudes toward practical activities. A thesis in the Department of Integrated Science Education, Faculty of Science Education, submitted to the School of Graduate Studies in partial fulfilment of the requirements for the award of the degree of Master of Philosophy (Science Education) in the University of Education, Winneba FEBRUARY, 2025 2025-01-01T00:00:00Z http://41.74.91.244:8080/handle/123456789/5078 Senior high students’ academic performance in stoichiometry the use of interactive simulations Apeh, D.O. The study investigated the use of interactive simulation intervention on students’ academic performance in stoichiometry. The study used action research as the research design. The sample size for the study was 28 students comprising form 2 science students at Keta Senior High Technical School. A pre-test was administered to all the students followed by a semi-structured interview to know their prior conceptions about chemical stoichiometry. A questionnaire was used to determine the factors influencing students' poor stoichiometry performance. The results of students show that a lot of factors contributed to their poor performance in stoichiometry, some of which include low level of interest in the subject of study. After that, the interactive simulation was used to investigate the effect of students’ performance before and after incorporating the interactive simulation intervention on students’ performance in stoichiometry. To determine whether there was a significant difference in the academic performance of the students, the pre-test and post-test were analyzed using the paired sample t-test. There was a statistically significant difference in the academic performance of the pupils, as indicated by the paired sample t-test, which revealed that the t-statistics (6.42) was higher than the t-critical (2.060). This indicates that the interactive simulation intervention had a bigger impact on the students and that they fared better on the posttest than the pre-test. A questionnaire was again administered to examine student’s perceptions about the use of interactive simulation intervention and the results were positive indicating students enjoyed the interactive simulation intervention which had a positive influence on their academic performance. thesis in the Department of Chemistry Education, Faculty of Science Education, submitted to the School of Graduate Studies in partial fulfillment of the requirements for the award of the degree of Master of Philosophy (Chemistry Education) in the University of Education, Winneba AUGUST, 2025 2025-08-01T00:00:00Z