111 research outputs found

    Theoretical and experimental investigation of thiourea derivatives: synthesis, crystal structure, in-silico and in-vitro biological evaluation

    Get PDF
    ABSTRACT. In this study, five different thiourea derivatives were synthesized from aryl amines according to the reported method. 1-Benzoyl-3-(4-methoxyphenyl)thiourea (2) was confirmed with single crystal XRD analysis while 1-benzoyl-3-phenylthiourea (1), 1-benzoyl-3-(4-hydroxyphenyl)thiourea (3), 1-benzoyl-3-(2-nitrophenyl) thiourea (4) and 1-benzoyl-3-p-tolylthiourea (5) were elucidated with FTIR and NMR techniques. The geometry optimization of the targeted molecules was accomplished with density functional theory applying B3LYP function. The experimental (XRD) and calculated (DFT) bond angles and bond lengths were compared. The frontier molecular orbitals and molecular electrostatic potential were computed to determine the charge density distribution and possible sites for electrophilic and nucleophilic reactions of the crystalline compound. The synthesized compounds were evaluated as an anti-radical scavenger and enzyme (esterases and protease) inhibitor using in-vitro models. The results confirmed that the synthesized molecules have good anti-oxidant property while a moderate enzyme inhibiting activity. Docking study was conducted with acetylcholine and butyrylcholine esterase which suggested that molecules under study have a potential to inhibit these esterases and protease enzymes. On the basis of in-vitro studies, it is concluded that compound 2 is most active against all tested assays.                     KEY WORDS: Thiourea, 2,2-Diphenyl-1-picrylhydrazyl, Enzyme inhibition, Density functional theory, Docking studies   Bull. Chem. Soc. Ethiop. 2021, 35(3), 587-600. DOI: https://dx.doi.org/10.4314/bcse.v35i3.1

    Comparative Analysis of Barriers for Renewable Energy Technologies Diffusion in Finland and Poland

    No full text
    Renewable Energy Technologies (RETs) are critical for the energy transition towards environmentally friendly solutions. There are many international regulations enhancing climate change mitigation. However, on a national level, disruptive technologies often struggle with many various barriers. There is ample evidence supporting the claim that innovative energy technologies require the whole ecosystem to support their diffusion. In fact, it is often a case that the change starts at the regional level. Therefore, some country-specific limitations are worth investigating. In this study, we examine various barriers of renewable energy technologies diffusion in the case of two European countries: Finland and Poland in the first phase. It served to perform a comparative analysis in a second stage, revealing the similarities and differences between them. An analysis provides insightful knowledge about the current constraints of widespread and effective renewable energy technologies diffusion. As a conclusion, the directions and possibilities for improvement are suggested.©2020 Springer Nature Switzerland AG. This is an author’s accepted manuscript of a book part in an article published in: Kantola J., Nazir S., Salminen V. (eds) Advances in Human Factors, Business Management and Leadership. Springer, Cham. The final authenticated version is available online at https://doi.org/10.1007/978-3-030-50791-6_34fi=vertaisarvioitu|en=peerReviewed

    Antimicrobial activities of some medicinal essential oils

    Get PDF
    S u m m a r y in this study, the antimicrobial properties of essential oils obtained from Coriandrum sativum, Foeniculum vulgare Miller, Salvia triloba, Laurus nobilis L., Citrus limon and Origanum smyrnaeum L. were investigated. A total of eight microbial organisms belonging to six species of bacteria, namely Salmonella typhimurium, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli and Enterobacter aerogenes, as well as two fungi, Candida albicans and Aspergillus niger, were studied using a disc-diffusion and agar dilution (minimal inhibition concentration) method. the antimicrobial activity of essential oils obtained from the six plants turned out to be more effective in the case of bacteria than against fungi. the antimicrobial activity against Gram-positive bacteria was more pronounced than against Gram-negative ones. All the investigated plants are known as having healing properties and are used to treat various diseases. the essential oils obtained from L. nobilis and O. smyrnaeum showed the highest antifungal activity against C. albicans and A. niger, while the essential oils obtained from F. vulgare showed the highest antimicrobial activity against P. aeruginosa and E. coli. On the other hand, the essential oils obtained from O. smyrnaeum showed stronger antibacterial activity in the case of E. aerogenes and S. aureus, but were not equally effective against E. coli. the other crude essential oils showed varied levels of antibacterial and antifungal activity. the minimal inhibition concentrations (Mic) of the essential oils obtained from O. smyrnaeum and of those obtained from L. nobilis ranged from 1.17 to 4.71 mg/ml, and 2.4 to 19.2 mg/ml, respectively

    A review on the current state of the art for the production of advanced liquid biofuels

    No full text

    Phenylethanoid glycosides in Plantago media L. organs obtained in in vitro cultures

    No full text
    Micropropagation of Plantago media L. and the presence of phenolic compounds in organs of multiplied plants were investigated for the first time. Multiplication of plant material was achieved in shoot-tip cultures and via direct organogenesis on Murashige and Skoog (MS) medium with four variants of plant growth regulators (M1–M4). The best multiplication coefficient – 9.2 was obtained in seedling shoot-tip cultures on MS medium M3 with BA 0.2 mg/L and IAA 1.0 mg/L. Methanol extracts prepared separately from shoots and roots of in vitro- derived plantlets were found to contain typical of the genus Plantago L. phenylethanoid glycosides as the only phenolics. Acteoside and plantamajoside were the major compounds – both known to possess a wide range of promising biological activities applicable for medicinal (therapeutic) and cosmetic uses. Martynoside, as a trace constituent, was also found for the first time in the studied species. The quantitative screening of the extracts by TLC video densitometric method showed a higher content of acteoside in shoots (range 62.43–93.03 mg/g, dry weight) and plantamajoside in roots (range 22.45–44.08 mg/g); the highest recorded values – 93.03 mg/g and 44.08 mg/g, respectively, were found in the organs obtained on MS medium M4 with BA 2.0 mg/L

    Waste to biodiesel: A preliminary assessment for Saudi Arabia

    Get PDF
    This study presents a preliminary assessment of biodiesel production from waste sources available in the Kingdom of Saudi Arabia (KSA) for energy generation and solution for waste disposal issues. A case study was developed under three different scenarios: (S1) KSA population only in 2017, (S2) KSA population and pilgrims in 2017, and (S3) KSA population and pilgrims by 2030 using the fat fraction of the municipal solid waste. It was estimated that S1, S2, and S3 scenarios could produce around 1.08, 1.10 and 1.41 million tons of biodiesel with the energy potential of 43423, 43949 and 56493 TJ respectively. Furthermore, annual savings of US $55.89, 56.56 and 72.71 million can be generated from landfill diversion of food waste and added to the country's economy. However, there are challenges in commercialization of waste to biodiesel facilities in KSA, including waste collection and separation, impurities, reactor design and biodiesel quality

    Editorial

    Get PDF

    Microbial electrochemical technologies with the perspective of harnessing bioenergy: Maneuvering towards upscaling

    No full text
    Microbial electrochemical technologies have gained much attention in the recent years during which basic research has been carried out to provide proof of concept by utilizing microorganisms for generating bioenergy in an electro redox active environment. However, these bio-electrocatalyzed systems pose significant challenges towards up-scaling and practical applications. Various parameters viz., electrodes, materials, configuration, biocatalyst, reaction kinetics, fabrication and operational costs, resistance for electron transfer etc. will critically govern the performance of microbial catalyzed electrochemical systems. Majorly, the surface area of electrode materials, biofilm coverage on the electrode surface, enrichment of electrochemically active electrode respiring bacteria and reduction reactions at cathode will aid in increasing the reaction kinetics towards the upscaling of microbial electrochemical technologies. Enrichment of electroactive microbial community on anode electrode can be promoted with electrode pretreatment, controlled anode potential or electrical current, external resistance, optimal operation temperature, chemical additions and bioaugmentation . Inhibition of the growth of methanogens also increases the columbic efficiency, an essential parameter that determines the efficacy of bioelectricity generation. Considering the practical implementation of these microbial electrochemical technologies, the current review addresses the challenges and strategies to improve the performance of bio-electrocatalyzed systems with respect to the operational, physico-chemical and biological factors towards scale up. Besides, the feasibility for long term operation, the scope for future research along with the operational and maintenance costs are discussed to provide a broad spectrum on the role of the system components for the implementation of these bio-electrochemical technologies for practical utility

    Carbon dioxide rich microbubble acceleration of biogas production in anaerobic digestion

    Get PDF
    This paper addresses the use of anaerobic bacteria to convert carbon dioxide to biomethane as part of the biodegradation process of organic waste. The current study utilises gaslift bioreactors with microbubbles generated by fluidic oscillation to strip the methane produced in the gaslift bioreactor. Removal of methane makes its formation thermodynamically more favourable. In addition, intermittent sparging of microbubbles can prevent thermal stratification, maintain uniformity of the pH and increase the intimate contact between the feed and microbial culture with lower energy requirements than traditional mixing. A gaslift bioreactor with microbubble sparging has been implemented experimentally, using a range of carrier gas, culminating in pure carbon dioxide, in the anaerobic digestion process. The results obtained from the experiments show that the methane production rate is approximately doubled with pure carbon dioxide as the carrier gas for intermittent microbubble sparging
    corecore