11 research outputs found
Chemical composition of ten medicinal plant seeds from South-west Nigeria
The phytochemical, proximate and mineral element composition of ten different medicinal plant seeds were assessed and compared. The medicinal plant seeds investigated are Canna bidentata, Ceasalpinia bunduc, Cola millenii, Hunteria umbellata, Hydrocotyle asiata, Megaphrynium macrostarchyum, Perinari excelsa, Rauwolfia vomitoria, Solanum dasyphyllum and Sphenocentrum jollyanum. The result of the phytochemical analysis showed that all the selected plant seeds contain alkaloids and saponin except Megaphrynium macrostarchyu while phenolic group is present in Perinari excelsa only. The moisture content of the samples ranged between (12.51-26.7 %), crude protein (8.65-48.09 %), crude fibre (2.69-12.66%), crude fat (2.65-18.10%), ash content (3.26-11.45 %) and carbohydrate (16.79-59.38%). Mineral element analysis showed that the selected plant seeds contained low levels of potassium (2.14-8.12 mg/L), zinc (1.38-5.53 mg/L), iron (0.22-1.90 mg/L) and manganese (0.14-1.40 mg/L) and high level of calcium (3.25-68.55mg/L). All the selected plant seeds have potential of serving as supplementary sources of antimicrobial drugs and essential nutrients to man and livestock. Keywords: mineral elements, phytochemical, proximate composition, plant seed
Homo- and Heterometallic Complexes of Vanadium and Chromium and their Conversion into Oxide Ceramics
Phytochemical analysis and mineral element composition of ten medicinal plant seeds from South-west Nigeria
Abstract: The phytochemical, proximate and mineral element composition of ten different medicinal plant seeds were assessed and compared. The medicinal plant seeds investigated are Canna bidentata, Ceasalpinia bunduc, Cola millenii, Hunteria umbellata, Hydrocotyle asiata, Megaphrynium macrostarchyum, Perinari excelsa, Rauwolfia vomitoria, Solanum dasyphyllum and Sphenocentrum jollyanum. The result of the phytochemical analysis showed that all the selected plant seeds contain alkaloids and saponin except Megaphrynium macrostarchyu while phenolic group is present in Perinari excelsa only. The moisture content of the samples ranged between (12.51-26.7 %), crude protein (8.65-48.09 %), crude fibre (2.69-12.66%), crude fat (2.65-18.10%), ash content (3.26-11.45 %) and carbohydrate (16.79-59.38%). Mineral element analysis showed that the selected plant seeds contained low levels of potassium (2.14-8.12 mg/L), zinc (1.38-5.53 mg/L), iron (0.22-1.90 mg/L) and manganese (0.14-1.40 mg/L) and high level of calcium (3.25-68.55mg/L). All the selected plant seeds have potential of serving as supplementary sources of antimicrobial drugs and essential nutrients to man and livestock
Phytochemical analysis and mineral element composition of ten medicinal plant seeds from South-west Nigeria
Abstract: The phytochemical, proximate and mineral element composition of ten different medicinal plant seeds were assessed and compared. The medicinal plant seeds investigated are Canna bidentata, Ceasalpinia bunduc, Cola millenii, Hunteria umbellata, Hydrocotyle asiata, Megaphrynium macrostarchyum, Perinari excelsa, Rauwolfia vomitoria, Solanum dasyphyllum and Sphenocentrum jollyanum. The result of the phytochemical analysis showed that all the selected plant seeds contain alkaloids and saponin except Megaphrynium macrostarchyu while phenolic group is present in Perinari excelsa only. The moisture content of the samples ranged between (12.51-26.7 %), crude protein (8.65-48.09 %), crude fibre (2.69-12.66%), crude fat (2.65-18.10%), ash content (3.26-11.45 %) and carbohydrate (16.79-59.38%). Mineral element analysis showed that the selected plant seeds contained low levels of potassium (2.14-8.12 mg/L), zinc (1.38-5.53 mg/L), iron (0.22-1.90 mg/L) and manganese (0.14-1.40 mg/L) and high level of calcium (3.25-68.55mg/L). All the selected plant seeds have potential of serving as supplementary sources of antimicrobial drugs and essential nutrients to man and livestock
Molecularly Engineered Lithium-Chromium Alkoxide for Selective Synthesis of LiCrO2 and Li2CrO4 Nanomaterials
Achieving control over the phase-selective synthesis of mixed metal oxide materials remains a challenge to the synthetic chemist due to diffusion-driven growth, which necessitates the search for new compounds with pre-existent chemical bonds between the phase-forming elements. We report here a simple solvothermal process to fabricate LiCrO2 and Li2CrO4 nanoparticles from bimetallic single-source precursors, demonstrating the distinctive influence of molecular design and calcination conditions on the resulting nanomaterials. The chemical identity of [Li2Cr((OBu)-Bu-t)(4)Cl(THF)(2)] (1) and [LiCr((OBu)-Bu-t)(2)(PyCH=COCF3)(2)(THF)(2)] (2) was unambiguously established in the solid state by single-crystal X-ray diffraction, revealing the formation of a coordination polymeric chain in compound 1, whereas electron paramagnetic resonance spectroscopy (EPR) studies revealed a monomeric structure in solution. TEM analysis of synthesized LiCrO2 nanoparticles showed nearly uniform particles size of approximately 20 nm. The sensitivity of the LiCrO2 phase towards oxidation was investigated by X-ray diffraction, revealing the formation of the stable Li2CrO4 after calcination in air
Reductive transformation of V(III) precursors into vanadium(II) oxide nanowires
Vanadium(II) oxide nanostructures are promising materials for supercapacitors and electrocatalysis because of their excellent electrochemical properties and high surface area. In this study, new homoleptic vanadium(III) complexes with bi-dentate O,N-chelating heteroarylalkenol ligands (DmoxCH=COCF3, PyCH=COCF3 and PyN=COCF3) were synthesized and successfully transformed by reductive conversion into VO nanowires. The chemical identity of V(iii) complexes and their redox behaviour were unambiguously established by single crystal X-ray diffraction studies, cyclic voltammetry, spectrometric studies and DFT calculations. Transformation into the metastable VO phase was verified by powder X-ray diffraction and thermo-gravimetry. Transmission electron microscopy and X-ray photoelectron spectroscopy data confirmed the morphology and chemical composition of VO nanostructures, respectively
Photocatalytic reduction of Cr(VI) using star-shaped Bi2S3 obtained from microwave irradiation of bismuth complex
The reduction of hexavalent chromium specie, Cr(VI), to trivalent chromium, Cr(III), in aqueous solutions using star-shaped nanostructured Bi2S3, prepared via a facile microwave irradiation of bismuth dithiocarbamate complex is reported. The bismuth sulphide were characterized using X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometer (EDX). The study showed that Cr(VI) reduction was dependent on its initial concentration, the pH value of the solution, and the Bi2S3 dosage. Almost all the Cr(VI) in a concentration of 2 ppm and at pH 2 was reduced within 90 min by the addition of 100 mg L-1 of the Bi2S3. The reduction capacity of the nanostructure was attributed to photocatalytic-induced reduction process as well as the high specific surface area. Pseudo-first order kinetics model parameters well described the Cr(VI) reduction experimental data with high correlation factor of 0.998. This study demonstrates that microwave irradiation of precursor complex could offer a quick and facile route to nanostructured photocatalyst, which are good candidate material for the removal of trace chromium in surface water
Electrochemical Gas Sensor Integrated with Vanadium Monoxide Nanowires for Monitoring Low Concentrations of Ammonia Emission
An electrochemical sensor for the detection of extremely low concentration of ammonia (1 part per billion, ppb) was fabricated by integrating vanadium monoxide (VOx; x = 0.8-1.2) nanowires on the platinum electrodes. The nanowire-based sensor responds at room temperature non-linearly to a staircase sequence of ammonia from 1 ppb to 100 ppb. The rise and fall time of the nanowire sensor was found to be 10 s and 9 s, respectively. While the immobilization of VO nanowires increased the electrochemical surface area, the defect rich and ionic nature of the VO surface (V2+O2-) facilitated the chemical interaction and adsorption of polar ammonia molecules as evident in the room temperature response of the VO@Pt amperometric electrochemical sensor. The availability of metal centered d-electrons and the semiconductor nature of vanadium monoxide lowered the interfacial resistance of the nanowire-modified sensor enabling the lower detection limit of ammonia. The sensor seems to respond to CH4, H2S and C3H6 as well although the NH3 response is nearly six-fold compared to these common interfering compounds. The results pave the way for a low-cost alternative paper-based sensor to monitor ammonia emissions primarily from confined animal feeding operations (CAFOs). (c) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited