ABSTRACT TLC has been used in combination with micro-extraction and clean-up methods to provide an alternative cost effective analytical procedure for screening pesticide residues in plant matrices. Thirty-five (35) agrochemicals, which are used in priority crops in Ghana, were used in this study. Ethylacetate extraction in the presence of anhydrous sodium sulphate, followed by gel permeation chromatographic clean up and additional purification on silica gel cartridges provided clean extracts...
ABSTRACT The radiological impact of naturally occurring radioactive materials (NORMs) from the usage of phosphate and organic fertilizers in the New Juaben Municipality of Ghana was investigated. The activity concentrations of 226Ra, 232Th and 40K were measured in seven (7) widely used phosphate and organic fertilizers using gamma spectroscopy. The activity concentrations were found to be 32.10±2.60 Bq/kg, 12.20±1.60 Bq/kg and 3005.50±68.80 Bq/kg respectively. The radioactivity level index...
ABSTRACT The native starches of white and red cocoyam (Colocasia esculenta), white yam (Dioscorea rotundata) and yellow yam (Dioscorea cayenensis), and seeds of pigeon pea (Cajanus cajan), lima bean (Phaseolus lunatus) and jack bean (Canavalia ensiformis) were isolated and modified to obtain their hydroxypropyl and ozone-oxidized derivatives. The nanocrystals of the starches were prepared by mild acid hydrolysis at 40oC with continuous stirring for five (5) days. The native starches were eval...
ABSTRACT In the present study, the stem of Dichapetalum crassifolium was investigated for its phytochemical constituents and their biological properties. The petroleum ether extract yielded friedelan-3-one, friedelan-3β-ol and a mixture of friedelan-3-one and friedelan-3β-ol. The ethyl acetate extract yielded pomolic acid, dichapetalin M and maslinic acid as well as the friedelins and a mixture of β-sitosterol and stigmasterol. No solid was isolated from the methanol extract. These compoun...
ABSTRACT This thesis determined the level of mercury and cadmium in selected biologicalspecies namely tilapia (Tilapia zillit), mudfish (Clarias slIbmargillatlls), prawns (Pellaeus //Iolladall) , crabs (Carcilllls 11laellas) and Molluscs Periwinkle (Gastropod) from the River Pra Estuary using. The samples were taken every fortnight from four sampling sites from Beposo to Shama Beach in the Western Region of Ghana for two months. That is form 10105/06 to 29106/06. During the period a total of...
ABSTRACT Essential Oils (EOs) are volatile secondary metabolites characterised by a strong odour and widely used for pharmacological and industrial applications. There is dearth of information on chemical compositions and bioactivities of EOs of some fruit trees in Nigeria. This study was therefore designed to extract and characterise the EOs from selected fruit trees, screen the EOs for bioactivity as well as to isolate and characterise non-volatile constituents from Theobroma cacao L. pod-...
ABSTRACT Dried, pulverized stem bark and the root bark of Entandrophragma anqolense were separately extracted with methanol. The crude methanolic extract o f the stem and root bark of E. anqolense were subjected to column fractionation and purification . This exercise afforded the Isolation o f methyl angolensate, 2.26% yield from the stem bark and 0.27% yield from the root bark. The effect of the crude methanolic stem bark extract was investigated on indomethacin-induced gastric ulcer in rat...
ABSTRACT Declining male fertility is of global concern and has been linked to the effects of endocrine disruptors on the modulation of oestradiol. These disruptors are also recognised to be toxic to the testes. Selenium and zinc play specific roles in heavy metal detoxification, testosterone metabolism, sperm formation and motility. This study was aimed at identifying the possible contribution of cadmium, lead, selenium and zinc to oestradiol modulation and sperm defects in Nigerian men. One...
ABSTRACT Watermelon fruits and soil samples (depth of 0 – 20 cm) were analysed for pesticide residues. Residues were extracted from 10.0 g of watermelon fruit using a multi-residue method for extracting pesticides from non fatty foods with acetone as the extracting solvent. Soil and okro from a nearby okro farm which were used as control to study the effect of pesticides on non target crops were also analysed. Extract clean up was done using a 10 mm chromatographic column with a 1:1 solvent...
ABSTRACT Dyslipidemia, reduced omega-3 and -6 fatty acids and vitamins are risk factors for cerebrovascular disease associated with dementia. Prognosis differs between Alzheimer’s disease (AD) and Vascular Dementia (VD) but derangements of the fatty acids and their clinical values for making distinction are unclear. In addition, inadequate antioxidant levels have been associated with hyperhomocystenemia in dementia patients. Therefore, levels of lipids, omega-3 and-6 fatty acids, folate, h...
The ground and excited state properties of naphthalene and some of its derivatives have been studied. The molecular orbitals were evaluated using the modified Huckel Molecular Orbital (HMO) theory and the calculated molecular properties such as dipole moments, electronic transition frequencies, have been compared with experimental values. The electronic absorption spectra of some of ktheir band systems and characteristics, solvent polarity effects and hydrogen bonding effects. The�...
ABSTRACT Conjugated polymers which interact with biological systems have attracted interest due to their high conductivity, stability and electronic properties. Substituted polymers of 3-methyl pyrrole-4-carboxylic acid (MPCa ) have been synthesised and used as components of biosensor, while unsubstituted polypyrroles are not effective for such application. However the mechanism of interaction, nature, the relative importance of dynamic and static electron correlation of the polymers are not...
ABSTRACT Untreated industrial effluents discharged into land and surface water are of great environmental concern. Previous studies on physicochemical characteristics of effluents and sediments from discharged points of various industrial sectors in Lagos metropolis are inadequate in scope, duration, chemical treatment options and estimated pollutant discharge load which are of importance in waste water management. This study was designed to investigate the physicochemical characteristics of...
ABSTRACT In the first part of this thesis, a brief survey of the chemistry of veratramine viz. its occurrence, isolation and structural diagnosis is given. This part also includes a review of recent work on the stereochemistry and the synthetic work of other workers on the alkaloid. The main section describes three approaches to the synthesis of the C-Nor-D-homo ring system of the veratrura alkaloids. Howell and Taylor’s acétate diester 6(3-acetoxy-1 p:2adi (methoxy carbonyl methyl)-9P~me...
ABSTRACT This research was conducted to detennine the levels of mercury, cadmium and zinc in the leaves of Xanthosoma sagittifoliwn (kotombre), Marlihot esclIlenta (cassava leaves) and the conn of Colecasia esclIlenta (taro conn) growing in the mining communities of Tarkwa, Prestea, Bankyim and Agona Junction. The Random sampling method was used to collect the samples and the wet digestion method was used to digest the samples for AAS analysis. A statistical analysis of the results of the res...