13 research outputs found

    Solvent free hydroxylation of the methyl esters of Blighia unijugata seed oil in the presence of cetyltrimethylammonium permanganate

    Get PDF
    Extraction of oil from the seed of Blighia unijugata gave a yield of 50.82 ± 1.20% using hexane in a soxhlet extractor. The iodine and saponification values were 67.60 ± 0.80 g iodine/100 g and 239.20 ± 1.00 mg KOH/g respectively with C18:1 being the dominant fatty acid. Unsaturated methyl esters of Blighia unijugata which had been previously subjected to urea adduct complexation was used to synthesize methyl 9, 10-dihydroxyoctadecanoate via hydroxylation in the presence of cetyltrimethylammonium permanganate (CTAP). The reaction was monitored and confirmed using FTIR and GC-MS. This study has revealed that oxidation reaction of mono unsaturated bonds using CTAP could be achieved under solvent free condition

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

    Get PDF
    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Lubricant properties of the polyol from the seed oil of Lonchocarpus sericeus

    No full text
    Oil was extracted from the seed of the Lonchocarpus sericeus using hexane in a soxhlet extractor. The oil was characterized and used for the synthesis of polyol via epoxy ring opening reaction with 2-ethylhexanol. The structural characterization of the polyol was confirmed using FTIR and 1HNMR. The GC analysis of the oil of L. sericeus revealed C18:3 and C18:1 fatty acid as the dominant fatty acids present in the oil. The polyol had hydroxyl value of 182.10 ± 0.20 mg KOH/g, a copper strip corrosion value of 1A and a flash point of 280.00 ± 1.20oC. The synthesis and lubricant properties exhibited by the polyol suggested that the seed oil of L. sericeus can be chemically modified and employed as a starting material for lubricantproduction

    Synthesis of hydroxylated fatty amide from underutilized seed oil of Khaya senegalensis: a potential green inhibitor of corrosion in aluminum

    No full text
    Abstract Background Corrosion is a serious problem all over the world. Most currently used approach to control corrosion have short comings which necessitates the search for novel materials that are green, cheap, from renewable source, and eco-friendly that can be used to combat this problem of corrosion control. Method Khaya senegalensis fatty hydroxylamide (KSFA) was synthesized from K. senegalensis seed oil via simple reaction route involving esterification, transesterification, hydroxylation, and amidation reaction. KSFA was characterized using Fourier-transform infrared (FTIR), nuclear magnetic resonance (1HNMR), CHN elemental analyzer, particle size distribution (PSD), X-ray diffractometer, zeta potential, thermogravimetric analysis (TG), thermogravimetric-mass spectrometer (TG-MS), and scanning electron micrograph (SEM) coupled with energy dispersion spectroscopy (EDS). Inhibitory effect of KSFA on corrosion of aluminum (Al) in 0.5 M HCl was studied at different concentrations of KSFA and temperatures using weight loss method. Result Result from gas chromatography (GC) revealed oil of K. senegalensis to predominantly contain C18:1 (68.46%) fatty acid. Hydroxyl and amide functional groups present in KSFA were confirmed by FTIR and 1HNMR. TG analysis revealed loss in mass around 80–190, 200–450, and above 450 °C while TG-MS revealed five different masses with m/z values 16, 17, 18, 28, and 44. Corrosion inhibition capacity of KSFA was by surface adsorption, which is spontaneous, and physisorption and described by Langmuir isotherm. The corrosion inhibition efficiency of KSFA increased with increase in its concentration while its corrosion rate reduced with increase in concentration. Conclusion The inhibition efficiency of 90.43% exhibited by KSFA and the fact that KSFA was synthesized via non-hazardous process from a renewable sourced biomass is an indication that KSFA is a potential green and efficient inhibitor of corrosion in aluminum. KSFA is simple to use as an inhibitor and easy to prepare

    Synthesis of tin ferrite-dopped zeolitic imidazolate framework and its application in the photocatalytic degradation of sulfamethoxazole, ciprofloxacin, erythromycin and ampicillin in water

    No full text
    Incomplete removal of antibiotics such as sulfamethoxazole (SMX), ciprofloxacin (CIP), ampicillin (AMP) and erythromycin (ERY) from water is a global challenge. Therefore, tin ferrite incorporated in zeolitic imidazolate framework (SnFe2O4@monoZIF-8) was synthesized as a photocatalyst for complete water photodegradation of SMX, ERY, CIP and AMP. Characterization of SnFe2O4@monoZIF-8 revealed a surface area of 1506.94 m2 g−1 and a direct bandgap of 2.05 eV. SnFe2O4@ZIF-8 exhibited outstanding degradation efficiency with complete removal of SMX, CIP, AMP and 91.00 ± 0.20% of ERY. The regeneration capacity of SnFe2O4@monoZIF-8 is higher than 90%, which reveals it as a promising photocatalyst for water treatment

    Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

    Get PDF
    Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium

    Solvent free hydroxylation of the methyl esters of <it>Blighia unijugata </it>seed oil in the presence of cetyltrimethylammonium permanganate

    No full text
    Abstract Extraction of oil from the seed of Blighia unijugata gave a yield of 50.82 ± 1.20% using hexane in a soxhlet extractor. The iodine and saponification values were 67.60 ± 0.80 g iodine/100 g and 239.20 ± 1.00 mg KOH/g respectively with C18:1 being the dominant fatty acid. Unsaturated methyl esters of Blighia unijugata which had been previously subjected to urea adduct complexation was used to synthesize methyl 9, 10-dihydroxyoctadecanoate via hydroxylation in the presence of cetyltrimethylammonium permanganate (CTAP). The reaction was monitored and confirmed using FTIR and GC-MS. This study has revealed that oxidation reaction of mono unsaturated bonds using CTAP could be achieved under solvent free condition.</p

    Synthesis of amine imprinted manganese ferrite and its application in the removal of free fatty acid from waste vegetable oil

    No full text
    The presence of free fatty acid (FFA) in waste vegetable oil (WVO) is undesired and must be removed. The present study synthesized amine imprinted manganese ferrite (MnFe2O4-DEA) via coprecipitation method and used it for the removal of FFA in WVO. Fourier transformed Infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results confirmed the formation of MnFe2O4-DEA and further analysis by Brunauer-Emmett-Teller (BET) surface area showed the nanoparticles possessed a surface area of 20.64 mÂČ g−1. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) revealed elemental composition and surface morphology. MnFe2O4-DEA showed promising results of FFA separation, recording 99.57% removal rate. The process obeyed langmuir isotherm and can be described by pseudo-second-order kinetic model. The values of Gibb's free energy change (∆Go) decreased with increase in temperature, the entropy change (∆So) was positive while enthalpy change (∆Ho) value suggested an endothermic sorption process. The mechanism for the removal of FFA by MnFe2O4-DEA may have occurred by simple chemical bonding, which could be described as donor-acceptor interaction by quantum chemical analysis
    corecore