Papers by Chisom Egedeuzu
Catalysts
Silicatein-α (Silα), a hydrolytic enzyme derived from siliceous marine sponges, is one of the few... more Silicatein-α (Silα), a hydrolytic enzyme derived from siliceous marine sponges, is one of the few enzymes in nature capable of catalysing the metathesis of silicon–oxygen bonds. It is therefore of interest as a possible biocatalyst for the synthesis of organosiloxanes. To further investigate the substrate scope of this enzyme, a series of condensation reactions with a variety of phenols and aliphatic alcohols were carried out. In general, it was observed that Silα demonstrated a preference for phenols, though the conversions were relatively modest in most cases. In the two pairs of chiral alcohols that were investigated, it was found that the enzyme displayed a preference for the silylation of the S-enantiomers. Additionally, the enzyme’s tolerance to a range of solvents was tested. Silα had the highest level of substrate conversion in the nonpolar solvents n-octane and toluene, although the inclusion of up to 20% of 1,4-dioxane was tolerated. These results suggest that Silα is a po...
Resources and Environment, 2013
The study assessed lead and nickel levels in leaves of roadside trees in Umuahia urban. Leaves we... more The study assessed lead and nickel levels in leaves of roadside trees in Umuahia urban. Leaves were collected during the dry season from five dominant trees, (Anarcadium occidentale, Azidirachta indica, Citrus sinesis, Magnifera indica and Psidium guajara) along a high traffic route (SS1) and a low traffic route (SS2). Mean concentration of Pb at SS1 and SS2 was 12.09mg/kg and 0.05mg/ kg respectively. Mean Ni values at SS1 and SS2 were 2.26mg/ kg and 0.09mg/kg respectively. Significant differences were observed for Pb and Ni concentrations of roadside leaves between the two locations. This suggests that traffic volu me may influence the levels of Pb and Ni and possibly other automobile derived heavy metals and pollutants. With increasing urbanization, the concentrations of these metals might increase and possibly create health hazards. The study further emphases the important roles vegetation can play in monitoring and mitigating air pollution.
International Journal of Medicinal Plants and Natural Products, 2018
Medicinal plants are sources of herbal and synthetic drugs, a lot of medicine if not all, have bi... more Medicinal plants are sources of herbal and synthetic drugs, a lot of medicine if not all, have bioactive constitutes which are responsible for biological and pharmacological activities they exhibit. Most of the activities can be attributed to secondary metabolites (phytochemical constituents) that are bioactive and present in the plant. Secondary metabolites are organic compounds that are not directly involved in the normal growth development and reproduction of the plant [1] and through to result from the evolutionary defense put up by plants [2]. Examples include alkaloids, tannins, terpenoids, flavonoids, saponins, phenolics, coumarins, glycosides and steroids. They are of paramount importance in the treatment of diseases for man. South Eastern Nigeria is endowed with many of such vegetative plants and they are used as food and in herbal medicine to cure diseases and heal injuries; this implies that treatment of diseases in this region is not limited to synthetic drugs, as most people still depend on botanical preparations as medicine. These are always available in form of infusions, decoctions, macerations and concoctions. Most of these people even believe that herbal preparations are more effective than conventional synthetic drugs but are more effective than conventional synthetic drugs but are skeptical about is use since there is no clear cut dosage hence making it a major constraint Ageratum conyzoides is among the medicinal plants that have effect against disease and may contain those biologically active compounds, which are effective against ailments. It belongs to the family and tribe of Asteraceae and Eupatoriae respectively. The plant is native to
Journal of Natural Sciences Research, 2014
This study analyzed the effects of heavy metals concentrations of Pb, Cd, Zn, Cr , Ni, Co in the ... more This study analyzed the effects of heavy metals concentrations of Pb, Cd, Zn, Cr , Ni, Co in the Amaogwugwu River Drainage basin from its headstream, midstream up to the downstream and in both surface and groundwater and the water is used for may purpose including water supply, fishing and agriculture mainly irrigation. Based on above pH average water in the study area can be interpreted as slightly alkaline and still within permissible limits of all the three standards/guidelines. EC with above average also shows that all the water their value falls within the three guidelines. Samples from both surface and groundwater in the studied area have ranges and means of: Co ranges from 0.11-21.24 ppb and average of 2.26 ppb , Ni ranges from 0.26-37.01 ppb and average of 7.37 ppb , Cu ranges from 0.17-640.93 ppb and average of 37.62 ppb, Zn ranges from 15-408 ppb and average of 115.03 ppb, As ranges from 0.09-2.3 1ppb and average of 0.62 ppb ,Pb ranges from 0.16-834.38 ppb and average of 29.82 ppb , Cr ranges from 0.16-5557.35 ppb and average of 419.58 ppb ,Cd ranges from 0.04-1.64 ppb and average of 0.21 ppb. EC. It is therefore recommended that concentrations level in crops grown with these waters needs to be investigated. Again it is confirmed that probably this may be one of the reasons for the drop in fish catch from midstream up to the downstream especially in area like Umuagwu which is known for its fishing, Okpuala and even Ngbagoro in Umuahia North local government of Abia state.
Biomolecules, 2020
Silicatein-α is a hydrolase found in siliceous sea sponges with a unique ability to condense and ... more Silicatein-α is a hydrolase found in siliceous sea sponges with a unique ability to condense and hydrolyse silicon–oxygen bonds. The enzyme is thus of interest from the perspective of its unusual enzymology, and for potential applications in the sustainable synthesis of siloxane-containing compounds. However, research into this enzyme has previously been hindered by the tendency of silicatein-α towards aggregation and insolubility. Herein, we report the development of an improved method for the production of a trigger factor-silicatein fusion protein by switching the previous hexahistidine tag for a Strep-II tag, resulting in 244-fold improvement in protein yield compared to previous methods. Light scattering and thermal denaturation analyses show that under the best storage conditions, although oligomerisation is never entirely abolished, these nanoscale aggregates of the Strep-tagged protein exhibit improved colloidal stability and solubility. Enzymatic assays show that the Strep-...
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Papers by Chisom Egedeuzu