Browsing by Author "Achel, D.G."
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Item Crystal structure and in vitro antimicrobial activity studies of Robustic acid and other Alpinumisoflavones isolated from Millettia thonningii(Zeitschrift fur Kristallographie - Crystalline Materials, 2019-04) Harrison, J.J.E.K.; Ayine-Tora, M.D.; Appiagyei, B.; Mills-Robertson, F.C.; Asomaning, W.A.; Achel, D.G.; Ishida, H.; Kingsford-Adaboh, R.We report a systematic study of the antibacterial inhibitory potential of isoflavone natural products isolated from the seeds extracts of Millettia thonningii. In an effort to gain bond topological information which may have consequences for the observed bioactivities, the crystal structure of robustic acid was solved and refined using the independent atom as well as the invariom model, and the structures were compared. Robustic acid contains a fused tricyclic unit with a benzopyran moiety, with a phenylene ring substitution on the coumarin ring similar to the alpinumisoflavones isolated from this plant. At a minimum inhibitory concentration of ~1 mg/mL, alpinumisoflavone and robustic acid were found to be cytotoxic to Staphylococcus aureus (ATCC 25923) showing a zone of inhibition (ZOI) of ~9 mm. On the other hand, at ~2 mg/mL, these compounds were found to be bacteriostatic to a hospital isolate of Salmonella typhi with about 7 mm ZOI. Taken together, these compounds offer potential new avenues for targeting both Gram positive and negative bacteria and could be useful as chemical probes for understanding these pathogens in an effort to overcome drug resistance.Item Ethnopharmacological use of herbal remedies for the treatment of malaria in the Dangme West District of Ghana(Journal of Ethnopharmacology, 2010-04) Asase, A.; Akwetey, G.A.; Achel, D.G.Aim of study: Malaria is one of the most important diseases in the world. Because of the devastating nature of the disease there is an urgent need to develop new drugs or vaccines for the treatment, prevention and management of the disease. The objective of the present study was to collect and document information on herbal remedies traditionally used for the treatment of malaria in the Dangme West District of Ghana. Methods: Data was collected from 67 indigenous households in ten communities in the district using a validated questionnaire. Results: In total, 30 species of plants belonging to 28 genera in 20 families were reported to be used in the preparation of the herbal remedies. Mature leaves were the most (55%) common plant part used and 73.3% of the herbal remedies involved a single plant. Most of the herbal remedies were prepared by boiling and administered orally. The majority (47%) of the species of plants used were collected from their compounds or home gardens. Conclusions: Knowledge about malaria and treatment practices exists in the study area. Herbal remedies were commonly used by people for the treatment of malaria because they were cost-effective. They are also more accessible. Many of the species of plants used have been documented for the treatment of malaria as well as investigated for their phytochemical and antimalarial and/or antiplasmodial activity confirming the results of previous studies as well as rationalization of their traditional use. Five species of plants used in the study area, namely, Bambusa vulgaris Schrad. ex J.C. Wendl. (Poaceae), Deinbollia pinnata Schum &Thonn. (Sapindaceae), Elaeis guineensis Jacq. (Arecaceae), Greenwayodendron sp. (Annonaceae) and Solanum torvum Sw (Solanaceae), are documented for the first time for their use in the treatment of malaria. " The result of this study provides the basis for further pharmacological studies on the herbal remedies used" © 2010 Elsevier Ireland Ltd.Item Extraction, Purification And Partial Characterization Of The Sweet Modifying Glycoprotein, Miraculin From Richardella Dulcifica(University of Ghana, 1996-04) Achel, D.G.; Acquaah, R.A.; Armah, G.E.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Biochemistry, Cell and Molecular BiologyIn the present study miraculin, a non-nutritive taste modifier from the tropical plant, Richardella dulcifica has been purified to homogeneity. It was extracted from the pulp of the fruits in 0.5M NaCl and purified at ordinary temperatures by a three step chromatographic process namely; Hydrophobic interaction chromatography, (HIC), Ion exchange chromatography, (IEC), and Gel filtration chromatography (GFC) respectively. The relative molecular weight (Mr) of purified miraculin was about 43, 000 and 100 fig/ml of the lyophilized product provoked sweetness with lemon. N-terminal amino acid analysis revealed two forms of miraculin, the major form being more than 70 % of the total miraculin population. Protease activity was detected and measured in the pulp of fresh and aged fruits. The activity .and specific protease activity in the pulp of freshly picked berries were 0.0756 units/mg pulp and 0.2414 units/mg protein respectively. Corresponding values for the aged (at least six months old) berries were 0.0369 unit/mg pulp and 0.1342 unit/mg protein. The difference was significant (p s 0.05) . Total protein content measured for the fresh and aged berries were 31.3% + 1.9% and 27.4% + 0.3% (w/w) respectively. The difference was not significant (p <; 0.05), in addition only approximately 10 % (w/w) of the fruits contained the active principle, miraculin. A predictive model: Z = 0.027348 - 0.015177^ - 0.003364/tpH + 0.000128pH + 0.029960/i2 where Z is the solubility, was developed to explain the effect of ionic strength (/x) and pH on the solubility of miraculin. The model had an R2 Of 66.12%. Analysis of variance (ANOVA) showed ionic strength to be the most influential variable in the model. The protein had the maximum solubility at low pH and low ionic strength, with the minimum solubility recorded at high pH and high ionic strength. A thermal denaturation investigation, established that water-glycerol mixtures substantially increased the melting temperature of the purified product.Item Induced mutations for improved lycopene, total antioxidant properties and other quality factors in wild tomato (Solanum pimpinellifoliumL)(Advance Journal of Food Science and Technology, 2012) Quartey, E.K.; Amoatey, H.K.; Achel, D.G.; Klu, G.Y.P.; Mba, R.A.The objective of the study was to determine biochemical changes in (5) gamma radiation induced variant lines of wild tomato after mutation induction. Five gamma radiation-induced variant lines of wild tomato (Solanum pimpinellifolium L.), selected in the M3 generation following mutagenic treatment of seeds using three doses (150, 300 and 450 Gy, respectively) of gamma radiation from a Co-60 gamma source, were analysed for their lycopene content, total antioxidant properties, total and soluble solids as well as pH. Fruits of variant line BV-21 (deep red fruits) recorded higher lycopene contents of 146.1 mg/kg on fresh weight basis and 156.7 mg/kg on dry weight basis compared to 136 and 152 mg/kg, respectively for the control. They also recorded higher total antioxidant properties compared to the control. Fruits of variant line BV-40 (yellow fruits) recorded higher total solids of 17.9% and the lowest pH value of 4.17 compared to 12.8% and 4.36 for fruits from unirradiated plants. The highest amounts of total soluble solids (7%) were contained in fruits harvested from variant lines BV-27 (light red fruits) and BV-23 (deep red fruits) as against 5.6% for fruits from control plants. The study indicates that wild tomato has immense nutritional properties which can be further improved through mutation breeding. © Maxwell Scientific Organization, 2012.Item Investigation of Selected Trace and Heavy Metals in Two Tropical Fish Species from the Coastal Waters of Ghana(International Journal of Science and Technology 3: 40-47, 2013) Nyarko, E.; Foli, B.A.K.; Achel, D.G.; Botwe, B.O.; Adom, T.; Fianko, J.R.; Osae, S.D.Cadmium (Cd), copper, (Cu), Iron (Fe), lead (Pb), and zinc (Zn) burdens were determined by atomic absorption spectrophotometry (AAS) in two tropical fish species (Chloroscombrus chrysurus and Sardinella maderensis) from the western coast of Ghana. Fish samples were collected during three designated Sampling Periods (January 2008 to March 2008 - Periods 1; September 2008 to November 2008 - Period 2; and February 2009 to March 2009 - Period 3) at three sites (Half-Assini, Aboadze and Elmina). Trace elements and heavy metal concentrations in both species followed the order Fe>Zn>Cu while Cd and Pb were below detection limits. High levels of Fe were detected in the fish samples with concentration ranges of 13.05-376.4 μg/g dw. Levels of Cu generally recorded during Period 1 were above FAO maximum recommended limits of 30 μg/g in fish while Zn burdens were below FAO recommended limit of 40 μg/g. S. maderensis and C. chrysurus, can be considered safe for human consumption with respect to Cd, Pb and Zn contaminations. However, Cu will require further monitoring to protect public health. Hazard quotients and hazard indices computed indicate that metal exposure from consumption of the two fish species will not result in any appreciable health risk. Levels of Cu and Zn recorded may however pose threats to physiological functioning of fish since levels were high enough to cause sublethal effects to fish. Metal burdens studied provide background information prior to the commercial exploitation of oil in Ghana’s marine waters.Item National inventory of authorized diagnostic imaging equipment in Ghana: data as of September 2020(PAMJ, 2022) Bour, B.K.; Sosu, E.K.; Hasford, F.; Gyekye, P.K.; Achel, D.G.; Faanu, A.; Amoako, J.K.; Pitcher, R.D.Introduction: to address the challenge of inadequate and non-equitable distribution of diagnostic imaging equipment, countries are encouraged to evaluate the distribution of installed systems and undertake adequate monitoring to ensure equitability. Ghana´s medical imaging resources have been analyzed in this study and evaluated against the status in other countries. Methods: data on registered medical imaging equipment were retrieved from the database of the Nuclear Regulatory Authority and analyzed. The equipment/population ratio was mapped out graphically for the 16 regions of Ghana. Comparison of the equipment/population ratio was made with the situation in other countries. Results: six hundred and seventy four diagnostic imaging equipment units from 266 medical imaging facilities (2.5 units/facility), comprising computed tomography (CT), general X-ray, dental X-ray, single-photon emission computed tomography (SPECT) gamma camera, fluoroscopy, mammography and magnetic resonance imaging (MRI) were surveyed nationally. None of the imaging systems measured above the Organization for Economic Co-operation and Development (OECD) average imaging units per million population (u/mp). The overall equipment/population ratio estimated nationally was 21.4 u/mp. Majority of the imaging systems were general X-ray, installed in the Greater Accra and Ashanti regions. The regional estimates of equipment/population ratios were Greater Accra (49.6 u/mp), Ashanti (22.4 u/mp), Western (21.4 u/mp), Eastern (20.6 u/mp), Bono East (20.0 u/mp), Bono (19.2 u/mp), Volta (17.9 u/mp), Upper West (16.7 u/mp), Oti (12.5 u/mp), Central (11.9 u/mp), Northern (8.9 u/mp), Ahafo (8.9 u/mp), Upper East (6.9 u/mp), Western North (6.7 u/mp), Savannah (5.5 u/mp) and North-East (1.7 u/mp). Conclusion: medical imaging equipment shortfall exist across all imaging modalities in Ghana. A wide inter-regional disparity in the distribution of medical imaging equipment exists contrary to WHO´s recommendation for equitable distribution. A concerted national plan will be needed to address the disparity.Item A review of the medicinal properties and applications of pycnanthus angolensis (WELW) warb(Pharmacologyonline, 2012) Achel, D.G.; Alcaraz, M.; Adabo, K.R.; Nyarko, A.K.; Gomda, Y.Pycnanthus angolensis (also known as African/false nutmeg) is native to the forest zones of West Central Africa. Its use in folklore for the cure of diseases is well documented. Data collected from several references from various research groups in the literature confirm its wide spread use in folk medicine. Among the ailments purported to be cured or controlled by extracts of the plant include diabetes, cognitive disorders, cancer, osteoarthritis, to assuage inflammation, fight microbial infection and for wound healing. Extensive investigative work conducted on the plant exposing its rich phytochemical profile probably provides clue to its value as an important medicinal plant. Over 50 phytochemicals have been isolated from the plant some of which are potential new drug leads. The current review presents the ethnobotanical uses of Pycnanthus angolensis through some evaluated biological activities of various extracts on different models to the numerous chemical compounds isolated from the plant. It concludes by succinctly touching on the current and future perspectives of the plant.