nÃo hà / The general objective of this work is to analyze the productive potential of the castor oil in the state of Cearà from a technical, social and economic approach. To obtaining the results, the research followed the following steps: initially, a study took place to tabulate and describe primary data collected through the application of 118 questionnaires to the growers and 120 to the not growers of the castor oil plant in the districts of Boa Viagem, CanindÃ, Itatira, Pedra Branca, QuixadÃ, Quixeramobim, QuiterianÃplois and TauÃ. Secondly, a binary probit regression was made to verify whether the farmer is a castor oil plant grower or not. Thirdly, a multiple lineal regression of the equation of castor oil plant offer in the State of Cearà was made concerning the period from 1980 to 2007 and this was possible due to secondary data collected in IBGE and IPECE. The analysis of the data allowed to identify the profile of the growers of castor oil plant and of the techniques used in the production. Thus, one can conclude that the farmer's propensity to plant castor oil plant is being influenced by the area, agricultural income, family total income, financing, participation in association and in the credibility of the program. Finally, it was verified that the castor oil plant offer is strongly related with the planted area and with its own price, being necessary investments in technologies and fairer prices. / Este trabalho tem como objetivo geral analisar o potencial produtivo da mamona no estado do Cearà a partir de uma abordagem tÃcnica e socioeconÃmica. Para a obtenÃÃo dos resultados, a pesquisa seguiu as seguintes etapas: inicialmente realizou-se um estudo tabular e descritivo de dados primÃrios coletados atravÃs da aplicaÃÃo de 118 questionÃrios aos produtores e 120 para os nÃo produtores de mamona dos municÃpios de Boa Viagem, CanindÃ, Itatira, Pedra Branca, QuixadÃ, Quixeramobim, QuiterianÃplois e TauÃ. Na segunda parte do estudo, foi realizada uma regressÃo binÃria probit, sobre a chance de o agricultor plantar mamona e, por Ãltimo, realizou-se uma regressÃo linear multipla da equaÃÃo de oferta de mamona no Estado do Cearà no perÃodo de 1980 a 2007, usando dados secundÃrios coletados no IBGE e IPECE. A anÃlise dos dados permitiu identificar o perfil dos produtores de mamona e das tÃcnicas usadas na produÃÃo. Conclui-se entÃo, que a propensÃo do agricultor a plantar mamona està sendo influenciada pela Ãrea, renda agrÃcola, renda total, financiamento, participaÃÃo em associaÃÃo e na credibilidade do programa. Por fim, identificou-se que a oferta de mamona està fortemente relacionada com a Ãrea plantada e com o seu prÃprio preÃo, fazendo-se necessÃrios investimentos em tecnologias e preÃos mais justos.

Thesis (M.Sc. (Microbiology)) -- University of Limpopo, 2015 / Antioxidants play an important role in living organisms to control level of free radicals and other reactive molecules in the body to reduce oxidative damage. Synthetic antioxidant compounds are used in food industries as food additives to boost our immune systems. These compounds are associated with a number of critical side effects including liver damage and carcinogenesis. Scientists are also concerned about microorganisms that have developed resistant genes against current antibiotics used in hospitals. The aim of the study was to isolate and characterize bioactive compounds from Ricinus communis leaves with activity against Staphylococcus aureus (ATCC 29213), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853). Consequently, medicinal plants are studied and considered for their efficacy and safety, because they possess bioactive compounds with various biological activities. Leaves of R. communis were collected at the University of Limpopo, Turfloop campus in Limpopo province, South Africa. The leaves were dried and milled to a fine powder. A number of trial extraction methods were employed using various solvents of different polarities on a fine powder leaves to identify the best extraction method. Plant extracts were analyzed by thin layer chromatography (TLC) developed in four mobile phases. To detect separated phytochemical compounds, TLC plates were sprayed with vanillin- sulphuric acid in methanol and heated at 110oC for optimal colour development. Qualitative antioxidant activity was determined by using 2, 2–diphenyl-1-picrylhydrazyl (DPPH) assay on TLC plates. Quantitative antioxidant activity was determined by measuring percentages scavenging activity of DPPH and 2, 2’-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) free radical molecules by plant extracts. Antibacterial activity of all extracts was quantified by a serial microbroth dilution method while bioautography was used in qualitative analysis of the active compounds. Cytotoxicity effect of R. communis extracts was evaluated using tetrazolium-based calorimetric assay on human Caucasian skin fibroblast (Bud-8) cell line. Anti-inflammatory activity was assessed using phagoburst kit on Raw 264.7 macrophages cell line. Pure compounds were subjected to nuclear magnetic resonance spectroscopy for 1H, 13C and DEPT experiments to elucidate structures of compounds. 2 During extraction process, methanol was the best extractant, extracting greater amount of extracts than any of the other solvents. Serial exhaustive extraction method was selected as the best extraction method for extracting compounds from ground plant materials. In quantitative antioxidant assays, chloroform and methanol extracts had highest percentage scavenging activity against DPPH free radicals compared to other extracts and vitamin C. Methanol extract had the highest percentage scavenging activity of ABTS free radicals and minimum percentage scavenging activity was in hexane extract. Acetone, ethyl acetate and ethanol extracts showed strong antioxidant activity against DPPH free radicals in qualitative antioxidant assay on TLC plates. In quantitative antibacterial assay, crude extracts showed lowest minimum inhibitory concentration value of 0.13 mg/ml against all tested organisms and the highest was 1.05 mg/ml. Hexane extracts revealed potent antibacterial activity against all tested microorganisms on bioautograms. Hexane and acetone extracts also revealed anti-inflammatory activity and have ability to reduce oxidative stress. In cytotoxicity effect of plant extracts, Methanol extracts had lethal concentration for 50% of the cells (Lc50) of 784 μg/ml on Human Caucasian skin fibroblast (Bud-8) cell line while hexane extracts had Lc50 of 629 μg/ml. Plant extracts with high Lc50 are low toxic to normal cell line and preferable to work with for drug development. Bioassay-guided fractionations results in successful isolation of three antioxidant and two antibacterial compounds from R. communis using column chromatography. Isolated compounds were tested for their biological activities using qualitative DPPH assay on TLC plates for antioxidant activity and bioautography for antibacterial activity. Antioxidant compounds showed strong antioxidant activity after spraying with DPPH in methanol and antibacterial compounds showed less activity compared to the crude extracts. The study suggests the use of crude extracts to fight against pathogenic microorganisms compared to pure compounds. Compound 4 was successful identified as the mixture of stigmasterol and β-sitosterol. The present study recommends the use of R. communis leaves as the potential source of antioxidant, antibacterial and anti-inflammatory compounds. The study serves as a scientific proof for use of this plant in traditional medicine for treatment of various ailments.