Synthesis and biological evaluation of some hybrid 2-quinolinone derivatives containing cinnamic acid as anti-breast cancer drugs

ABSTRACT. A new series of hybrid 2-quinolinone derivatives were synthesized by using 7-hydroxy-4-methyl-1-amino-quinolin-2-one (2) and cinnamic acid. Hybrid halogenated 2-quinolinone derivatives (3-(7-hydroxy-4-methyl-3,6,8-tribromo-2-oxo-2H-quinolin-1-ylamino)-3-phenyl acrylic acid (4) and 3-(7-acetoxy-4-methyl-3,6,8-tribromo-2-oxo-1H-quinolin-1-ylamino)-3-phenyl acrylic acid (7)) were prepared via the halogenation of 3-(7-hydroxy-4-methyl-2-oxo-2H-quinolin-1-ylamino)-3-phenyl acrylic acid (3) with bromine to give compound 4 with acetic anhydride led to the formation of hydride halogenated 2-quinolinone derivative (7). All the synthesized hybrid 2-quinolinone and hybrid halogenated 2-quinolinone derivatives were tested for their cytotoxicity against MCF-7 cell line. DNA flow cytometric analysis of compounds 3 showed cell cycle arrest at G2/M phase with concomitant increase of cells in apoptotic phase. Dual annexin-V/propidium iodide staining assay of compound 3 revealed that, the selected molecule increases the apoptosis of MCF-7 cells more than control.                     KEY WORDS: Quinolinone, Hybrid, Cinnamic acid, Apoptosis, MCF-7 cells   Bull. Chem. Soc. Ethiop. 2021, 35(3), 551-564. DOI: https://dx.doi.org/10.4314/bcse.v35i3.

Synthesis of novel nitrogen heterocycles bearing biological active carboxamide moiety as potential antitumor agents

ABSTRACT. In the present study, synthesis of a simple series of nitrogen heterocycles containing N-(p-bromophenyl) carboxamide moiety, such as benzimidazole, benzoxazine, oxadiazole and triazole compounds, by using 4-bromo aniline and diethyl oxalate as a key starting material has been described. Five nitrogen heterocycles compounds moiety were evaluated for their anticancer activity against MCF-7 cell line. The results revealed that compound 8 (N-(4-bromophenyl)-5-thioxo-1,3,4-oxadiazole-2-carboxamide) was the most potent cytotoxic activity. Cell cycle analysis demonstrated that compound 8 induce cell cycle arrest at G1 phase with apoptosis inducing activity marked by increase in G0 phase.                     KEY WORDS: Synthesis, Nitrogen heterocycles, Carboxamide, Antitumor agents   Bull. Chem. Soc. Ethiop. 2021, 35(2), 449-459. DOI: https://dx.doi.org/10.4314/bcse.v35i2.1

Exploring engineering students' epistemic beliefs and motivation: A case of a South African university

This study seeks to investigate how chemical engineering students from South African low-income communities locate knowledge structures. The study used an existing Engineering Related Beliefs Questionnaire (ERBQ) to evaluate beliefs of 268 chemical engineering students. The questionnaire collects additional information by allowing open-ended responses on each item to increase reliability of the questionnaire. Findings suggest that more than 60 per cent of students believe that engineering knowledge cannot be argued, and that learning takes place only when the lecturer transmits knowledge. Engineering educators may consider a humanizing pedagogy, which create opportunities for students from low-income communities to be liberated and reduce the dependency culture. Application of this pedagogy may assist students to achieve life long learning whilst developing necessary soft skills like independent thinking and innovation

Toward Understanding Personalities Working on Computer: A Preliminary Study Focusing on Collusion/Plagiarism

Ample research has been carried out in the area of collusion, plagiarism and e-learning. Collusion is a form of active cheating where two or more parties secretly or illegally corporate. Collusion is at the root of common knowledge plagiarism. While plagiarism requires two or more entities to compare, collusion can be determined in isolation. It is also possible that collusion do not lead to positive plagiarism checks. It is therefore the aims of this preliminary study to: (i) identify the factors responsible for collusion in e-learning (ii) determine the prominent factor that is representative of collusion and (iii) through user behaviour including, but not limited to, application switching time, determine collusion. We claim that user computer activities and application processes can help understand user behaviour during assessment task. It is on this premise that we develop a machine learning model to predict collusion through user behaviour during assessment tas

Effect of paint-bake like treatment on mechanical properties of Mg-Zn-Ca alloy

Magnesium alloys are promising materials for the fabrication of automotive components due to their lightweight which could help car manufacturers reduce the amount of emissions generated per automobile and to meet present and future regulations of owning more environmentally friendly vehicles. However, the low strength of magnesium alloys compared to aluminium and steel have limited its usage and has necessitated the search for more potent strengtheningmechanism, like precipitation strengthening, to widen the application of magnesium alloys in the automotive industries. Precipitation hardening response of a Mg-4wt%Zn-0.3 wt%Ca(ZX40) alloy in an ageing process at 180oC temperature typical of those used during paint baking cycle in automotive industries were studied using optical microscopy, Scanning electron microscopy (SEM), micro - hardness and thermoelectric power machine (TEP). Prior to the ageing process, one alloy was subjected to a 30 minutes solution heat treatment while the other sample was without solution heat treatment. Although, an initial decrease in hardness and strength of the alloy was observed due to solution treatment prior to ageing. The overall results showed that the mechanical (strength and hardness) and microstructure (fracture surface and precipitate formation) properties were enhanced in the 30 minutes solution treated sample s, which further emphasizes the need for solution treatment for better properties in an alloy. Keywords: Paint baking, Magnesium alloys, Precipitation strengthening, scanning electron microscop

Public Health Expenditure and Economic Growth in Nigeria: Testing of Wagner's Hypothesis

The idea supporting the relationship between public expenditure and economic growth is that an increase in public spending is an inevitable consequence of economic growth. This propelled Wagner to hypothesize a connection between economic growth and public expenditure. However, arguments on the impact of public health expenditure on economic growth remain inconclusive. This study re-examined the connection between public health expenditure and economic growth in Nigeria within the context of Wagner’s theory of ever-increasing State activities. The study found evidence of a long-run relationship between public health expenditure and economic growth. The granger-causality test results, indicate neither uni-directional nor bi-directional relationship between public health expenditure and GDP. But health expenditure as a share of total government expenditure and population has a uni-directional causal relationship with real GDP. Thus, public expenditure pushes public health expenditure. It was concluded that though there is no causal relationship between public health expenditure and GDP, public health expenditure and GDP still have evidence of a long-run connection. Therefore, health insurance should be expanded to cover more people to mobilize more resources for the health sector. These may engender the required impact of health care expenditure on economic growth in Nigeri

Crevice Corrosion Behavior of Nickel-Based Alloy 718 in both Aerated and De-Aerated Chloride Environment

In this study, anodic potentiodynamic polarization techniques were used to study the crevice corrosion behaviour of Nickel alloy 718 (with and without a crevice former) in both aerated and de-aerated solution of 3.5wt% sodium chloride solution. Surface observation of the specimens after each experiment was done with the optical microscope. The results showed that crevice corrosion were initiated at potentials as low as 520mVSCE, while the surface observation on the specimen with a crevice former revealed that the crevice corrosion attack was restricted under the crevice gap and at the border areas of the crevice former but did not occur at the surfaces outside the shielded areas. Conversely, the specimen without a crevice former showed evidence of waterline corrosion. These results can be attributed to the development of differential oxygen concentration in the specimen depending on the exposure of the parts to dissolved oxygen. This study has developed a more comprehensive understanding of the crevice corrosion initiation mechanism and behaviour of Nickel-based Alloy 718 under applied crevice torques, chloride environment and exact potentials, thereby leading to better prevention and control of localized corrosion in this alloy

Optimization of protocols for DNA extraction and RAPD analysis in West African fonio (Digitaria exilis and Digitaria iburua ) germplasm characterization

Fonio is an important indigenous grain crop of West Africa, but the extent of genetic diversity in fonio, its origin and phylogeny are not well understood. DNA markers allow precise characterization of plant germplasm accessions, but there is no literature report of their use in fonio. This paper reports theresult of protocol optimization research for DNA isolation and RAPD analyses in fonio. High quality DNA was successfully isolated and RAPD was effectively used to study genetic similarity among fonio accessions. This result might stimulate the application of DNA markers to investigate the origin and phylogeny of fonio in Africa

Weed Control Efficacy and Arbuscular Mycorrhizal (AM) Colonization of Upland Rice Varieties as Affected by Population Densities

Field  experiments were  conducted in 2011 and 2012 at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (Latitude 7 20`N and Longitude 3 23`E) in the Forest/ Savanna Transition Agro- ecological zone of South Western Nigeria  to determine the weed control efficacy and AM colonization  of upland rice varieties   at different population densities. The experiment was a 3x3 factorial arranged in a Randomized Complete Block Design (RCBD) and replicated three times. The three plant population used included 333, 333; 250, 000 and 166, 666 plants per hectare obtained by planting at 20cm x 15cm, 20cm x 20cm and 20cm x 30 cm respectively, while the three rice varieties used were ITA 150, NERICA 2 and OFADA. The results obtained from the study showed that plant population at 333, 333 plants per hectare significantly (p < 0.05) reduced weed population, number of tillers per hill and yield of rice varieties. Moreover, the local rice variety, OFADA was observed to be significantly (p < 0.05) taller than the other varieties, reduced weed biomass and consequently gave better yield advantage over the other tested varieties (ITA 150 and NERICA 2).   Panicle length and days to 50% flowering were significantly (p<0.05) longer in OFADA and NERICA 2.  Planting density did not affect AM root colonization but significant differences were observed among the rice varieties with respect to spore abundance. Keywords: rice, arbuscular mycorrhizal, plant population, varietie

The non-technical skills needed by graduates of technical colleges in metalwork technology

This study centered on the views of the professionals about the non-technical skills considered crucial as recruitment prerequisite among graduates of metalwork technology from technical and vocational institutions in Nigeria. It will also examine the possibility of integrating these skills into the curriculum. The study made use of the survey research design. One research question guided the study. The population for the study comprised metalwork technology professionals in Ogun State, Southwestern Nigeria. A 36-item questionnaire was the instrument used for data collection. The instrument was validated by experts from the University of Lagos (UNILAG). The reliability of the instrument was determined using Cronbach Alpha and the reliability index which stood at 0.79. The data collected were analysed using mean statistic and standard deviation. The study revealed that professionals placed great importance on communication skills, problem-solving skills, teamwork skills and self-management qualities among others, as important recruitment prerequisite among graduates of metalwork technology from technical and vocational institutions in Nigeria. The study concludes with the suggestions that non-technical skills should be integrated into the curriculum particularly in the field of metalwork technology in technical colleges. Students should be familiar with the employers’ recruitment criteria while they are still in schools in order to equip them with the necessary skills needed for employment