Pluchea indica (L.) Less. is a shrub of the family Compositae and is widespread along the western coast in Taiwan. Previous studies indicated that the components of Pluchea indica have potent anti-inflammatory, anti-ulcer and antimicrobial activities. In the present study, the effects of aqueous extract of roots and leaves from P. indica on the cancer cell lines were investigated. Various experimental approaches including cell growth curves, MTT assay, MTS assay, focus formation assay and cell migration assay were performed on the aqueous extract-treated cancer cells. Our results demonstrate the aqueous extract of P. indica induced anti-proliferation activity on GBM8401 and HeLa cancer cell lines.

Made available in DSpace on 2016-06-02T19:31:42Z (GMT). No. of bitstreams: 1 2411.pdf: 1852790 bytes, checksum: 59e732f774f4acfec1f2c3148f4d6104 (MD5) Previous issue date: 2009-03-26 / Pittosporum undulatum Vent., an Australian tree implicated in supression of tree recruiment in many ecosystems, is found invading secondary Araucaria forests in subtropical Brazil. The first chapter of this study aimed to investigate the role of allelopathy in the invasive proccess, accessing germination and growth of Bauhinia forficata Link. in presence of secondary metabolites from cheesewood leaves. Leachates in concentrations of 20%, 15%, 10% and 5% (w/v), extracts from dry material (10%; 7,5%; 5% and 2,5%) and coumarin solutions (2,5 mM; 1,25 mM; 0,625 mM and 0,3125 mM) were prepared. Petri-dishes germination bioassays, with countings done at each 12 hours, allowed to determinate both germinabilty and germination rate; polyethylene glicol (PEG 6000) solutions were used to evaluate osmotic effects. For seedlings growth, the three highest concentrations of each solution were tested and after seven days root and shoot lenght were measured. While germinability was only sensitive to extracts from dry material, the germination rate showed a dose-dependent curve for all solutions. In seedlings, roots were the most sensitive structure and severe morfo-anatomic anomalies were observed. The main purpose of the second chapter was to investigate the use of Pittosporum undulatum Vent. (cheesewood) leaves as a possible sustainable alternative for barnyard grass control. Leachates in concentrations of 20%; 15%; 10%; 5% and 2,5% (w/v), aqueous extracts from powdered leachated and non- eachated leaves (10%; 7,5%; 5%; 2,5% and 1,25%), coumarin solutions (2,5 mM; 1,25 mM; 0,625 mM and 0,3125 mM) and Roundup Original® according to label informations were prepared. Polyethylene glycol were also used. Both germinability and germination rate were determined by germination biossays, with countings done at each 12 hours. In growth experiments, seedlings were exposed for seven days, when root and shoot length were measured. All solutions, with exception of coumarins, caused only small inhibitory effects on germination. In relation to the growth, all treatments but control caused necrose, absence of hairs and dose-dependent lenght reduction in radicles. Hipocotiles were affected by phenolic compound, extracts from non-leachated leaves and gliphosate. Although the allelopathic effects, ecophisiological aspects relative to Pittosporum undulatum still need to be cleared before its leaves can be used as a herbicide. / A árvore australiana Pittosporum undulatum Vent. (Pittosporaceae) é encontrada diminuindo o recrutamento de espécies nativas em formações secundárias de Floresta Ombrófila Mista no sul do Brasil. O objetivo do primeiro capítulo desse estudo foi verificar a ação alelopática da espécie no processo invasivo, investigando a sensibilidade de sementes e plântulas de Bauhinia forficata Link. (pata-de-vaca) à compostos foliares de pau-incenso. Foram preparados extratos aquosos lixiviados nas concentrações de 20%, 15%, 10% e 5% (m/v), extratos aquosos obtidos do pó de folhas lixiviadas (10%; 7,5%; 5% e 2,5% ) e soluções de cumarina a 2,5 mM; 1,25 mM; 0,625 mM e 0,3125 mM. Bioensaios em placas de Petri, com contagens realizadas a cada 12 horas, permitiram determinar a germinabilidade e velocidade de germinação; soluções de polietileno glicol (PEG 6000) foram preparadas para analisar os efeitos osmóticos. Nos bioensaios de crescimento, utilizaram-se as três concentrações mais elevadas de cada solução, sendo, após sete dias, medidos o comprimento radicular e de parte aérea. Enquanto a germinabilidade mostrou-se sensível apenas aos extratos de pó de folhas, a velocidade de germinação apresentou resposta dose-dependente para todas as soluções testadas. Quanto ao crescimento, a radícula foi a estrutura mais sensível aos efeitos alelopáticos, sendo observadas alterações morfo-anatômicas. No segundo capitulo, objetivou-se investigar o uso de material foliar de pau-incenso como alternativa ao manejo do capim-arroz, uma gramínea resistente a herbicidas que traz problemas a plantações de arroz e à biodiversidade de planícies úmidas em todo o mundo. Foram preparados extratos aquosos foliares lixiviados nas concentrações de 20%; 15%; 10%; 5% e 2,5% (m/v), extratos aquosos obtidos do pó de folhas lixiviadas e não-lixiviadas (10%; 7,5%; 5%; 2,5% e 1,25%), soluções de cumarina a 5mM; 2,5 mM; 1,25 mM; 0,625 mM e 0,3125 mM e solução de Roundup® Original seguindo as recomendações do fabricante. Soluções de PEG também foram utilizadas. Para bioensaios de germinação, as contagens foram realizadas a cada 12 horas, sendo determinadas as porcentagens e velocidades germinativas; para o crescimento, plântulas de sete dias submetidas aos compostos tiveram medidos seus comprimentos de radícula e parte aérea. A germinação, apesar de fortemente inibida pela cumarina, foi pouco sensível às demais soluções. Quanto ao crescimento, as radículas analisadas apresentaram necrose, ausência de pêlos e redução dose-dependente do comprimento para todos os tratamentos com exceção do controle. Os hipocótilos foram afetados pelo composto fenólico, glifosato e extratos aquosos de folhas não-lixiviadas. Apesar da ação alelopática, aspectos ecofisiológicos relativos ao pau-incenso ainda devem ser esclarecidos para que suas folhas possam ser usadas como herbicida.

Infectious diseases are the world’s leading cause of premature deaths in humans and animals. The resistance to antibiotics and the emergence of new infectious diseases has increased the need for additional effective antimicrobial products. Despite numerous publications investigating antimicrobial activity of plant extracts it appears that no effective single product antimicrobial has yet been developed from plants. In many cases, however crude plant extracts have excellent activity and may provide useful products. Plants are frequently selected based on traditional use. Traditional healers usually use aqueous extracts of plants which in our experience generally have very low activities and it may be one of the reasons why no new products were developed from plants. Another approach to select plants for research is to use the taxonomic approach based on the premises that: (1) there is a correlation between active chemical compounds and antimicrobial activity; and (2) species in a family or order may have similar activities if the chemical precursors are inherited from a common ancestor. Future screening programmes could then concentrate on close relatives of species within these promising families and orders. The main aim of this study was to randomly screen leaf extracts of several hundred southern African tree species against important microbial pathogens to determine which taxa have the highest activity and may yield useful products to treat infections in human and animal health markets. A wide selection of plant species improved the possibility of finding promising extracts and has the advantage that active compounds may be discovered from plants that are not used traditionally. To ensure sustainable use only leaves of trees were examined. A spin off of this study would also indicate the susceptibility of different organisms, correlate the antimicrobial activities of the different organisms and determine what minimum inhibitory concentration (MIC) represents a good activity based on investigating many extracts against many microbes. The antimicrobial activity was determined by using a sensitive serial dilution microplate method. Acetone extracts were tested against two Gram-positive bacteria, two Gram-negative bacteria and two fungi, i.e. Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Cryptococcus neoformans. Small and mostly insignificant differences were found between the susceptibility of the microbial pathogens to the extracts. E. faecalis was the most sensitive bacterium and C. neoformans the most sensitive fungal organism. The strongest correlations in activities among the pathogens were between C. albicans and C. neoformans, and among the pathogen classes between Gram-positive and Gram-negative bacteria. The tree extracts analysed in the present study had a wide range of activities against the different pathogens. Twenty six per cent of the extracts inhibited the pathogens at MIC levels of 0.16 mg/ml. This clearly shows that 0.16 mg/ml is not low enough to discriminate between promising species. Some of the extracts inhibited the growth of more than one pathogen while other extracts had selective activities and could be the most promising to follow up. The study identified families and orders with either statistically significantly higher or lower antimicrobial activities. Among the large families, Combretaceae and Fabaceae had high mean activities against all test pathogens. The families Anacardiaceae and Moraceae had high activities against both Gram-positive and Gram-negative bacteria whereas the families Proteaceae and Meliaceae had higher antifungal activities. Among the large orders, Fabales had relatively high activities against all the pathogen classes. Considering that plants in related taxa often contain similar compounds and therefore similar activities, future studies could analyse more representative species in the promising taxa. Many tree species, genera, families and orders, including well-known and lesser known medicinal taxa in southern Africa, were identified with promising activities. To evaluate the potential use of these results, additional cytotoxicity, phytochemical and pharmacological studies should be carried out. The study, although still exploratory, underlined the potential of southern African tree extracts as sources of antimicrobial products. Application of these results within the Phytomedicine Programme has led to patents and products that were as good as commercial products in animal and field trials. We hope that our results will provided a starting point for discovering new products with useful activities. / Thesis (PhD)--University of Pretoria, 2014. / gm2014 / Paraclinical Sciences / Unrestricted

Tyrimų objektas – dirvinis garstukas (Sinapis arvensis L.), dirvinė čiužutė (Thlaspi arvense L.), smalkinis tvertikas (Erysimum cheiranthoides L.), trikertė žvaginė (Capsella bursa-pastoris (L.) Medik.). Tyrimų tikslas ir metodai – nustatyti ir palyginti bastutinių šeimos piktžolių alelopatinę įtaką žemės ūkio augalams. Bendrasis fenolinių junginių kiekis buvo nustatytas pagal (Ragaee et al., 2006) metodiką. Praskiedimo būdu paruoštos vandeninės ištraukos: 1:6250, 1:1250, 1:250 ir 1:50 koncentracijų (Гродзинский, 1965; Lazauskas, 1990). Žieminių ir vasarinių rapsų sėklos bei žieminių kviečių ir vasarinių miežių grūdai buvo daiginami keturias paras ant filtrinio popieriaus, sudrėkinto paruoštų koncentracijų vandeninėmis ištraukomis, Petri lėkštelėse, klimatinėje kameroje RUMED 1301, 22 oC temperatūroje ir esant 65 proc. oro drėgniui. Buvo apskaičiuotas sudygusių žemės ūkio augalų kiekis procentais, išmatuotas jų daigų aukštis ir šaknų ilgis. Tyrimų rezultatai – didžiausias bendrasis fenolinių junginių kiekis nustatytas dirvinio garstuko ir smalkinio tvertiko lapuose (atitinkamai 1,70 ± 0,15 mg g-1 ir 1,81 ± 0,03 mg g-1 žaliosios masės), o trikertės žvaginės ir dirvinės čiužutės – žiedynuose (atitinkamai 1,56 ± 0,02 ir 1,70 ± 0,31 mg g-1). Mažiausiai fenolinių junginių kaupiasi piktžolių šaknyse. Žieminių ir vasarinių rapsų sėklų dygimas ir pradinis augimas labiausiai buvo slopinamas dirvinio garstuko vandeninėse ištraukose, lyginant su kitų piktžolių rūšių vandeninėmis... [toliau žr. visą tekstą] / Research object – charlock mustard (Sinapis arvensis L.), field penny cress (Thlaspi arvense L.), treacle mustard (Erysimum cheiranthoides L.), shepherd’s purse (Capsella bursa-pastoris L.). The aim and methods of investigations – The total phenols content was research in accordance with the methodology (Ragaee et al., 2006 ). Treatments of investigations: Factor A – weed species of Brassicaceae family: 1) charlock mustard (Sinapis arvensis L.), 2) field penny cress (Thlaspi arvense L.), 3) treacle mustard (Erysimum cheiranthoides L.), 4) shepherd’s purse (Capsella bursa-pastoris L.). Factor B – concentrations of aqueous extracts: 1) distilled water, 2) 1: 6250 (ratio of aqueous extracts weed biomass and water), 3) 1: 1250, 4) 1: 250, 5) 1:50, 6) 1:10. The seeds of winter and spring oilseed rape, winter wheat and spring barley was grown for four days on filter paper moistened with the prepared aqueous extracts in Petri dishes, in a climate chamber. Research results – The significant highest content of total phenols was in the leaves of charlock mustard and treacle mustard (respectively 1.70 ± 0.15 mg g-1 and 1.81 ± 0.03 mg g-1 of green mass), in the flowers of shepherd’s purse and field pennycress (respectively 1.56 ± 0.02 and 1.70 ± 0.31 mg g-1). The significant least content of total phenols accumulated in the roots of weeds. The germination and early seedling growth of winter and spring oilseed rape were most inhibited in the aqueous extracts of charlock mustard, compared... [to full text]

Cordia trichotoma (Vell.) Arráb. ex Steud., known as louro-pardo, belongs to the Boraginaceae family and is widely distributed in Brazil. In Rio Grande do Sul (RS), is found in the Alto Uruguai and Depressão Central. This is a large species, reaching 35 meters in height. It is appreciated for the quality of its wood, which has scenic value, and can be employed in the recovery of degraded areas; its leaves have medicinal value, which are used to prepare teas. These, in turn, are used to treat kidney diseases, rheumatism, arthritis and rickets. The Allium cepa test is used as a bioindicator of genotoxic and antiproliferative capacity of aqueous extracts (teas) prepared with different plant materials such as leaves, flowers, fruit and bark. This study aimed to evaluate the antiproliferative potential of infusions of four populations of C. trichotoma on the cell cycle of A. cepa, as well as to analyze the phenolic compounds in infusions. The leaves and fruits of louro-pardo, used in the assembly of the experiments, were collected in three municipalities in the RS. For experiment 1, teas (infusions ) leaves were used , and for the experiment 2, the fruits were used. Six groups of four onion bulbs rooting in water were used, which consisted of six treatments and four replications for each of the populations of C. trichotoma in both experiments. The treatments were: T1 - negative control in distilled water ; T2- infusion of 5 g.L-1 ; T3- infusion of 20 g.L-1 ; T4- infusion of 5 g.L-1 ; T5- infusion of 20 g.L-1 ; T6- positive control in glyphosate 2% . After treatments, the roots of A. cepa were fixed, conserved and then slides prepared by squashing technique, stained with 2% acetic orcein. Therefore, it were subsequently analyzed under a microscope 40x. It were counted 500 cells by bulb, totaling 2000 cells for each treatment and for each of the populations. The mitotic index was calculated as well as the verification of possible irregularities in the cell cycle. Phenolic compounds were determined by the technique of high performance liquid chromatography (HPLC). The results showed a statistically significant difference for the increased inhibition of cell division as the concentration of infusions of louro-pardo in both experiments, no genotoxicity was observed in extracts. Compounds that appeared in larger quantities were caffeic acid, rosmarinic acid and ellagic acid. C. trichotoma infusions prepared in different concentrations exhibit antiproliferative potential and have no genotoxic activity on the cell cycle of A. cepa. The results obtained in the area of genotoxicity as well as the phenolic found in C. trichotoma infusions constitute new information for this species. / Cordia trichotoma (Vell.) Arráb. ex Steud., conhecida como louro-pardo, pertence à família Boraginaceae e é de ampla distribuição geográfica no Brasil. No Rio Grande do Sul (RS), é encontrada nas regiões do Alto Uruguai e Depressão Central. Trata-se de uma espécie de grande porte, podendo chegar a 35 metros de altura. É apreciada pela qualidade de sua madeira, a qual possui valor paisagístico, e pode ser empregada na recuperação de áreas degradadas; suas folhas têm valor medicinal, as quais são utilizadas para o preparo de chás. Estes, por sua vez, são empregados no tratamento de doenças renais, reumatismo, artrite e raquitismo. O teste de Allium cepa é utilizado como bioindicador da capacidade antiproliferativa e genotóxica de extratos aquosos (chás) preparados com materiais vegetais diversos como folhas, flores, frutos e cascas. Este estudo teve como objetivos verificar o potencial antiproliferativo das infusões de quatro populações de C. trichotoma sobre o ciclo celular de A. cepa, bem como analisar os compostos fenólicos presentes nas infusões. As folhas e frutos de louro-pardo, utilizados na montagem dos experimentos, foram coletados em três municípios do RS. Para o experimento 1, foram usados chás (infusões) das folhas, e para o experimento 2, utilizaram-se os frutos. Foram usados seis grupos de quatro bulbos de cebola enraizando em água, os quais constituíram seis tratamentos com quatro repetições para cada uma das populações de C. trichotoma, em ambos os experimentos. Os tratamentos foram: T1- controle negativo em água destilada; T2- infusão de 5 g.L-1; T3- infusão de 20 g.L-1; T4- infusão de 5 g.L-1; T5- infusão de 20 g.L-1; T6- controle positivo em glifosato 2%. Após os tratamentos, as raízes de A. cepa foram fixadas, conservadas e então preparadas lâminas pela técnica de esmagamento, coradas com orceína acética 2%. Posteriormente, foram analisadas no microscópio com aumento de 40x. Foi realizada a contagem de 500 células por bulbo, totalizando 2000 células para cada um dos tratamentos e para cada uma das populações. Foi realizado o cálculo do índice mitótico, bem como a verificação de possíveis irregularidades no ciclo celular. Os compostos fenólicos foram determinados por meio da técnica de cromatografia líquida de alta eficiência (CLAE). Os resultados mostraram diferença estatística significativa para o aumento da inibição da divisão celular conforme o aumento da concentração das infusões de louro-pardo em ambos os experimentos, não tendo sido observada genotoxicidade nos extratos. Os compostos que apareceram em maior quantidade foram o ácido cafeico, o ácido rosmarínico e o ácido elágico. As infusões de C. trichotoma preparadas nas diferentes concentrações apresentam potencial antiproliferativo e não possuem atividade genotóxica sobre o ciclo celular de A. cepa. Os resultados obtidos na área de genotoxicidade, bem como os fenólicos encontrados nas infusões de C. trichotoma configuram informações inéditas para esta espécie.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Rosmarinus officinalis L., popularly known as rosemary, is a medicinal and aromatic species used in the cosmetics and food processing industries, with interest for the herbal industry. This study aimed to determine the biomass production and volatile oil during the growth of rosemary plants cultivated under different salinity (nutritious solution concentrations) and different nitrogen (N) concentrations, and to evaluate the effect of the extracts and volatile oil of the species on the Allium cepa L. cell cycle and genetic material, as well as knowing the phenolic compounds present in the extracts and the chemical composition of volatile oil. The work was divided into two stages: the first aimed evaluating the production of biomass and volatile oil during the rosemary plants growth cultivated under different nutritious solution concentrations, as well as the effect of oil and extracts on the A. cepa cell cycle and genetic material, besides determining the chemical composition of the oil and the phenolic compounds present in the extracts; the second stage aimed evaluating biomass and volatile oil production during the rosemary plants growth cultivated under different N concentrations, as well as the effect of oil and the extracts on the A. cepa cell cycle and genetic material, and determining the chemical composition of the oil and the phenolic compounds present in the extracts as well. The rosemary leaves were collected and analyzed for dry matter, volatile oil extraction and preparation of aqueous extracts by infusion at 5, 20, and 50 g.L-1 concentrations for plants cultivated under different salinities, and 5 and 50 g.L-1 concentrations for plants cultivated at different N concentrations. The volatile oil was analyzed by Gas Chromatography to knowledge of its constitution, and the aqueous extracts were analyzed by High Performance Liquid Chromatography for phenolic compounds determination. The oil and extracts effect was evaluated on the A. cepa cell cycle and genetic material. The completely randomized design was used, and the biomass production and volatile oil yield data were subjected to analysis of variance with polynomial regression and the remaining data were compared by the Scott-Knott test at the 5% level of probability. The nutritious solution concentration, the N concentration and the plant age interfere into the biomass production, and consequently into the rosemary volatile oil yield. However, do not alter the oil and extracts effect on the A. cepa cell cycle and genetic material. The volatile oil and extracts inhibited cell division in all concentrations, and this effect is dose-dependent. In addition, extracts did not show genotoxicity, in spite of oil concentration of 10% being genotoxic. The majority compounds camphor, 1.8 cineole, α-pinene, β-myrcene and verbenone, beyond of β-pinene compounds only controlling the oil crop plants in the concentrations of 8:05, 13:05 and 15:55 mmol.L-1. The phenolic compounds present in the extracts were rosmarinic acid, chlorogenic acid, caffeic acid, carnosic acid, kaempferol, quercetin and rutin. / Rosmarinus officinalis L., popularmente conhecida como alecrim, é uma espécie medicinal e aromática utilizada na indústria de cosméticos e agroalimentícia, com interesse para a indústria de fitoterápicos. Objetivou-se determinar a produção de fitomassa, óleo volátil, composição química do óleo e compostos fenólicos presentes nos extratos, durante o crescimento de plantas de alecrim cultivadas com diferentes salinidades (concentrações de solução nutritiva) e diferentes doses de nitrogênio (N), além de avaliar o efeito dos extratos e óleo volátil da espécie sobre o ciclo celular e material genético de Allium cepa L.. Foram coletadas as folhas de alecrim para determinação da fitomassa, extração de óleo volátil e preparo de extratos aquosos por infusão. Avaliou-se a produção de fitomassa e óleo volátil durante o crescimento de plantas de alecrim cultivadas com diferentes salinidades (1.0, 2.0, 3.0, 4.0 e 5.0 dS.m-1) e em diferentes doses de N (5.55, 8.05, 10.55, 13.05 e 15.55 mmol.L-1), além de avaliar o efeito do óleo (3 e 10%) e dos extratos (nas concentrações de 5, 20, e 50 g L-1 para as plantas cultivadas em diferentes salinidades e nas concentrações de 5 e 50 g L-1 a partir das plantas cultivadas em diferentes doses de N), sobre o ciclo celular e material genético de A. cepa. O óleo volátil foi submetido à análise por Cromatografia Gasosa para conhecimento de sua constituição, e os extratos aquosos à análise por Cromatografia Líquida de Alta Eficiência para a determinação dos compostos fenólicos. As plantas cultivadas em diferentes salinidades foram coletadas aos 100 e aos 160 dias após o plantio (DAP) e as cultivadas em diferentes doses de N aos 90, 180, 270 e 365 DAP. Foi utilizado o delineamento experimental inteiramente casualizado, os dados de produção de fitomassa e rendimento de óleo volátil foram submetidos à análise de variância com regressão polinomial e os demais dados foram comparados pelo teste Scott-Knott (p<0,05). A salinidade, a dose de N e a idade fisiológica da planta interferem na produção de fitomassa e consequentemente no rendimento de óleo volátil de alecrim e não alteram o efeito do óleo e dos extratos sobre o ciclo celular e material genético de A. cepa. O óleo volátil e os extratos inibiram a divisão celular em todas as concentrações estudadas e esse efeito é dose dependente, mas sem apresentar genotoxicidade, exceto na concentração de 10% quando o óleo foi genotóxico. Os compostos majoritários do óleo foram cânfora, 1.8 cienol, α-pineno, β-myrceno e verbenona, além dos compostos β-pineno majoritários apenas no óleo de plantas cultivadas nas concentrações de 8.05, 13.05 e 15.55 mmol.L-1. Os compostos fenólicos presentes nos extratos foram ácido rosmarínico, ácido clorogênico, ácido cafeico, ácido carnósico, canferol, quercetina e rutina.

Made available in DSpace on 2016-06-02T19:29:31Z (GMT). No. of bitstreams: 1 3411.pdf: 2299382 bytes, checksum: 44ff227a0e9cd4657b1aca56caa5179c (MD5) Previous issue date: 2010-12-20 / Universidade Federal de Sao Carlos / The plants release primary and secondary metabolites in the environment that may influence the development of adjacent vegetation, this interference phenomenon is called allelopathy. It is recognized as an important ecological process because it interferes with the structure, distribution, composition and dynamics of plant communities. Studies on allelopathic interactions may be useful in the search for natural phytotoxins are produced by plants or microorganisms to be used as natural herbicides, more specific and less harmful to the environment. According to floristic survey conducted by IBGE, Myrtaceae family is one of the major in the cerrado ecosystem. This study attempted to clarify the following issues: species of Myrtaceae family present in the cerrado (Brazilian savanna) exhibit allelopathic potential? There is a similar allelopathic response within genera? Among the active species, which is most promising for starting a bioprospecting? Some of these species has potential as a herbicide for use in agroforestry or organic production of food? To answer these questions were conducted experiments of seed germination and seedling growth of target species cultivated and weedy, and chemical extraction of active compounds in leaves of Myrcia tomentosa. The leaves of Blepharocalyx salicifolius, Campomanesia pubescens, Eugenia bimarginata, Eugenia klotzschiana, Eugenia myrcianthes, Eugenia punicifolia, Myrcia bella, Myrcia lingua, Myrcia multiflora, Myrcia splendens, Myrcia tomentosa, Psidium australe, Psidium cinereum, Psidium laruotteanum and Psidium rufum were collected , cleaned, crushed and stored in plastic bags until use. In the first stage, were carried out the germination and growth bioassays using aqueous extracts of leaf in a concentration of 10% (w / v). We selected three target species, Lactuca sativa and Solanum lycopersicum, both eudicotyledonous and a monocotyledonous Allium cepa. The extracts were applied to all Myrtaceae species compared with the control (distilled water). In the second phase, bioassays were carried out using aqueous extracts of leaves at concentrations of 5 and 10% (w / v). We selected as target species three weeds Euphorbia heterophylla, Echinochloa crus-galli and Ipomoea grandifolia. The leaf extracts of B. salicifolius, M. multiflora, M. splendens and M. tomentosa were compared to negative control (distilled water) and positive (herbicide Oxyfluorfen). In the third stage were carried out biotests germination, growth, and coleoptile of wheat (Triticum aestivum) to direct chemical extraction of active compounds of M. tomentosa. The extractions were carried out using dried leaves powdered and organic solvents of different polarity, the extracts were fractionated using chromatographic column and purified by HPLC. The isolated and purified compounds were identified in RMN13C and RMN1H, by comparison of spectra. The results showed that aqueous extracts of twelve out of fifteen donor species evaluated showed allelopathic activity and each species showed a distinct behavior regarding the allelopathic activity, no grouping by taxonomic proximity. Evaluating the four species most active on weeds species, was detected the potential and efficiency of the extracts, since these were more toxic to weeds species than the herbicide. The leaf extracts of M. tomentosa stood out for demonstrating high activity even at low concentrations, so was chemical extraction from powdered of leaves of M. tomentosa were isolated two compounds from the ethyl acetate extract: juglanin and avicularin, the difference between ix both is the presence of one hydroxyl attached to carbon 3' in avicularin molecule, this difference has an phytotoxic effect more pronounced in the juglanin. This paper is the first report of the presence of the flavonoids kaempferol (juglanin) and quercetin (avicularin) in species of Myrtaceae of cerrado (Brazilian savanna) and gave foundation for future studies on bioprospecting of the M. tomentosa, which did not find any reports of allelopathic studies, fractionation and identification of chemical compounds. / Os vegetais liberam metabolitos primarios e secundarios no ambiente que podem influenciar no desenvolvimento da vegetacao adjacente, este fenomeno de interferencia e denominado alelopatia. E reconhecida como um processo ecologico importante, pois interfere na estrutura, distribuicao, composicao e dinamica de comunidades vegetais. Estudos sobre interacoes alelopaticas podem ser uteis na busca por fitotoxinas naturais, produzidas por plantas ou microrganismos a serem empregados como herbicidas naturais, mais especificos e menos prejudiciais ao ambiente. De acordo com inventario floristico realizado pelo IBGE a familia Myrtaceae e uma das principais em riqueza e diversidade no ecossistema de cerrado. Assim, este trabalho tentou esclarecer as seguintes questoes: especies da familia Myrtaceae presentes no cerrado apresentam potencial alelopatico? Existe semelhanca na resposta alelopatica dentro dos generos? Dentre as especies ativas, qual a mais promissora para se iniciar uma bioprospeccao? Alguma dessas especies apresenta potencial para utilizacao como herbicida em sistemas agroflorestais ou de producao organica de alimentos? Para responder essas perguntas foram realizados bioensaios de germinacao de diasporos e crescimento de plantulas, de especies alvo cultivadas e infestantes de cultura, e extracao quimica de compostos ativos em folhas de Myrcia tomentosa. As folhas maduras de Blepharocalyx salicifolius, Campomanesia pubescens, Eugenia bimarginata, Eugenia klotzschiana, Eugenia myrcianthes, Eugenia punicifolia, Myrcia bella, Myrcia lingua, Myrcia multiflora, Myrcia splendens, Myrcia tomentosa, Psidium australe, Psidium cinereum, Psidium laruotteanum e Psidium rufum foram coletadas, higienizadas, trituradas e armazenadas em embalagens plasticas ate a utilizacao. Na primeira etapa, os bioensaios de germinacao e crescimento, foram efetuados utilizando-se extratos aquosos de po de folhas em concentracao de 10% (p/v). Como especies receptoras foram selecionadas duas eudicotiledoneas Lactuca sativa e Solanum lycopersicum e, uma monocotiledonea Allium cepa, nas quais foram aplicados os extratos de todas as especies de Myrtaceae comparadas ao controle (agua destilada). Na segunda etapa, os bioensaios foram efetuados utilizando-se extratos aquosos de po de folhas em concentracao de 5 e 10% (p/v). Como especies receptoras foram selecionadas as infestantes de cultura Euphorbia heterophylla, Echinochloa crus-galli e Ipomoea grandifolia, nas quais foram aplicados os extratos de folhas de B. salicifolius, M. multiflora, M. splendens e M. tomentosa, comparadas ao controle negativo (agua destilada) e ao positivo (herbicida Oxifluorfem). Na terceira etapa, foram efetuados biotestes de germinacao, crescimento e de coleoptilo de trigo para direcionar a extracao quimica de compostos ativos de M. tomentosa. Para tanto as extracoes foram feitas empregando-se o po de folhas e os solventes organicos de diferentes polaridades. Os extratos foram fracionados em coluna cromatografica e purificados em CLAE. Os compostos isolados e purificados foram identificados em RMN13C e RMN1H, por comparacao de espectros. Os resultados mostraram que extratos aquosos de doze das quinze especies doadoras avaliadas apresentaram atividade alelopatica e cada especie demonstrou comportamento distinto em relacao a atividade alelopatica, nao houve agrupamento por proximidade taxonomica. Avaliando as quatro especies mais ativas sobre especies invasoras, constatou-se o potencial e a eficiencia dos extratos, uma vez que estes foram mais fitotoxicos as especies invasoras que o herbicida. O extrato foliar de M. tomentosa destacou-se por demonstrar elevada atividade mesmo em baixa concentracao, assim foi realizada a extracao quimica do po folhas desta especie. Foram isolados dois compostos do extrato acetato de etila: juglanina e avicularina, o que as diferencia e a hidroxila ligada ao carbono 3 na molecula de avicularina, esta diferenca produziu efeito fitotoxico mais acentuado da molecula de vii juglanina. O presente trabalho relatou pela primeira vez a presenca dos flavonoides kaempferol (juglanina) e quercetina (avicularina) em uma especie de Myrtaceae do cerrado e deu embasamento para futuros estudos relativos a bioprospeccao da especie Myrcia tomentosa, da qual nao se encontrou nenhum relato de estudos alelopaticos, fracionamento e identificacao de compostos quimicos.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology / The present study includes the use of a green synthetic method to prepare copper and silver nanoparticles using chitosan, aqueous extracts of Camellia sinensis, Combretum molle and Melia azedarach linn leaves. This study aims to investigate the influence of capping and precursor concentration on the properties of silver nanoparticles with emphasis on the medicinal plants chosen. The effect of capping agent on the properties of copper nanoparticles is also investigated. The phytochemical properties of plant extracts and the antimicrobial activity of the synthesized particles were also studied; this was achieved by using microdilution bioassay. Decoction method was used to extract secondary metabolites from plant leaves. Preliminary phytochemical screening carried out on the aqueous extracts of the plant leaves showed the presence of tannins, proteins, flavonoids, phenols, and carbohydrates. The total phenolic and flavonoids content of the aqueous extract was determined using spectroscopic methods. The highest phenolic content was found in the aqueous extract of Combretum molle (135 mg/g), and the highest flavonoid content was found in the aqueous extract of Camellia sinensis (0.4 mg/g). Characterization was done by a combination of spectroscopic, microscopy and XRD techniques. Both the size and shape of the synthesized silver nanoparticles were dependent on the identity of the capping molecule, precursor and capping agent concentration as depicted from their TEM and XRD results. Silver nanoparticles were found to be predominantly spherical. The capping agent concentration was also found to influence the degree of agglomeration, with an increase in capping agent concentration giving lesser agglomeration. FTIR spectral analysis showed that silver nanoparticles interact with bioactive compounds found in the plants through the hydroxyl functional group. Other shapes including diamond were observed for the effect of precursor concentration. The XRD micrographs revealed a face-centered cubic geometry and the phase remained the same with an increase in precursor concentration. The synthesized silver nanoparticles were all blue shifted compared to the bulk material. The TEM results revealed that copper nanoparticles with different sizes and shapes were successfully synthesized. All the prepared copper and silver nanoparticles showed satisfactory antifungal and antibacterial activity against Candida albicans, Cryptococcus neoformans, Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumonia and Pseudomonas aeruginosa. The capping molecules used in this study also showed some antibacterial and antifungal activity against the selected strains. However nanoparticles performed better than these capping molecules. Both silver and copper nanoparticles were found to be more active against gram-negative bacteria compared to gram-positive bacteria. Amongst all the prepared silver nanoparticles Combretum molle capped nanoparticles were found to be the most active nanoparticles. Also with copper nanoparticles, it was found that Combretum molle capped nanoparticles were the most active nanoparticles. Between the two metal nanoparticles, silver nanoparticles showed high antibacterial and antifungal activity compared to copper nanoparticles. The antioxidant activity of silver nanoparticles was assessed using 2.2-diphenyl-1-picrylhydrazyl. Silver nanoparticles were found to have some antioxidant activity. However, the capping molecules were found to be more active than the synthesized nanoparticles. This observation is attributed to the presence of some bioactive compounds in the plant extracts.