Thesis (M.S.)--University of Wisconsin--Madison, 1964. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 52-60.

D.Phil. / The genus Crotalaria (tribe Crotalarieae, Fabaceae) includes 700 species with its main centre of species diversity in Africa and Madagascar and secondary radiations to other parts of the world (including North and South America, India, South-East Asia and Australia). Molecular systematics has recently provided profound new insights into generic relationships in the Crotalarieae, thereby creating the opportunity to re-evaluate the taxonomic and functional significance of flower and fruit structure in the tribe, with emphasis on the large genus Crotalaria. A representative sample of flowers from 211 species was dissected to record morphological character states and fruit transverse sections of 142 species was cut to record anatomical variation across the tribe. These data were supplemented from the literature to allow for generalizations. Six structural-functional flower types were identified: (1) pump; (2) gullet; (3) hugging; (4) saddle; (5) tunnel; and (6) brush. The saddle and tunnel types are here described for the first time. Crotalaria is the only genus within the tribe that has the brush type; specialized flowers characterized by a rostrate keel, highly dimorphic anthers, stylar trichomes and four types of elaborate callosities on the standard petal: (1) ridge callosities – vertical swellings on the blade and claw; (2) disc callosities – subcircular swellings on the blade; (3) columnar callosities – cylindrical protruding appendages on the blade; and (4) lamelliform callosities – plate-like protruding appendages on the blade. Trends toward specialization are apparent across the phylogeny as a whole suite of specialized floral characters and are homoplastic as a result of convergence.

Orientador: Ladaslav Sodek / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-23T07:48:30Z (GMT). No. of bitstreams: 1 Goncalves_KatiaViviane_M.pdf: 2523264 bytes, checksum: 6d12338edf721f6a804d16a963fad313 (MD5) Previous issue date: 1997 / Resumo: Foi implementado um sistema in vitro para o crescimento de cotilédones imaturos de Crotalaria juncea L. Com a finalidade de estudar o metabolismo do nitrogênio, cotilédones com 39 dias após a antese cresceram por 8 dias em meio líquido de cultivo contendo diferentes fontes nitrogenadas. As atividades das enzimas asparaginase, glutamina sintetase, glutamato sintase e glutamato desidrogenase foram maiores quando asparagina foi utilizada como fonte de nitrogênio. O uso de glutamina proporcionou os melhores níveis de crescimento e deposição de proteínas de reserva. Asparagipa, entre as fontes testadas, foi a segunda melhor para a promoção do crescimento dos cotilédones. A menor eficiência da asparagina não pode ser explicada por deficiência na atividade de glutamina sintetase, limitação de asparaginase ou insuficiência de glutamato para a reação de glutamina sintetase / Abstract: An in vitro system for the growth of Crotalaria juncea L. was implemented. In order to study the metabolism of nitrogen, cotyledons collected 39 days after anthesis were grown for 8 days in a liquid culture medium containing different nitrogen sources. It was observed that the activities of the enzimes asparaginase, glutamine synthetase, glutamate syntase and glutamate dehydrogenase were greater when asparagine was used as a nitrogen source. Among the tested sources, glutamine provided the greatest growth rates and deposition of storage proteins, followed by asparagine. It was concluded that the lower efficiency obtained with asparagines can not be explained by a deficiency of the glutamine sinthetase activity, asparaginase limitation or glutamate insufficiency in the glutamine sinthetase reaction / Mestrado / Mestre em Ciências Biológicas

Orientador : Ana Maria Goulart de Azevedo Tozzi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-01T09:14:54Z (GMT). No. of bitstreams: 1 Filliettaz_AndreaMartinelli_M.pdf: 8109606 bytes, checksum: 9f6a0f25dd203c0c848baac66a9950b4 (MD5) Previous issue date: 2002 / Resumo: Um estudo taxonômico das espécies de Crotalaria sect. Calycinae no Brasil é apresentado. São fornecidas a atualização nomenclatural e a avaliação da sinonímia da maioria dos táxons, bem como a descrição, ilustração e atualização da distribuição geográfica e hábitat das espécies. É proposta uma chave de identificação para os táxons. A composição e circunscrição morfológica da seção Calycinae é ampliada pela aceitação de novos estados de caráter referentes ao hábito, estípulas e pétalas. Cratalaria sect. Calycinae está representada no Brasil por 14 espécies nativas (C. paulina, C. vespertilio, C. otoptera,C. tweediana, C. flavicoma, C. balansae, C. hilariana, C. grandiflora, C. martiana, C. velutina, C. stipularia, C. pilosa, C. subdecurrens e C. breviflora), uma subespécie .(C. martiana subsp. moh/enbrackiJ) e uma espécie introduzida (C. juncea), originária da índia. São propostas a sinonimização de cinco espécies e de três variedades, a transferência de G. paraguayensis da sinonímia de C. martiana subsp. martiana para C. martiana subsp. mohlenbrackii e o restabelecimento de C. subdecurrens da sinonímia de C. breviflora varo pohliana. A seção Calycinae distribui-se principalmente no centro-sudeste do Brasil, sendo possível o reconhecimento de quatro padrões de distribuição: ampla, restrita, endêmica e disjunta. Os ambientes preferenciais das espécies são os cerrados, campos e campos rupestres. A altitude parece atuar como um importante fator na distribuição geográfica e irradiação das espécies. Novas referências de ocorrências são registradas para 15 estados brasileiros, mais o Distrito Federal. O termo "estípulas decorrentes" é substituído por "alas internodais", freqüentemente utilizado na descrição de espécies de Crotalaria , uma vez que o último descreve mais precisamente a origem da estrutura. Palavras-chave: Taxonomia, Leguminosae, Papilionoideae, Crotalaria, Crotalaria sect. Calycinae / Abstract: A taxonomic study of Brazilian Crotalaria sect. Calycinae species is presented. Nomenclature updating and synonymy evaluation for most of the taxa are provided, as well as the description, iIIustration and updated geographic distribution and habitat data are included. An analytical key for taxa identification is proposed. The composition and circumscription of Calycinae section is extended based on the acknowledgment of new habit, stipules and petals character states. Crotalaria sect. Calycinae is represented by 14 native species (C. paulina, C. vespertilio, C. otoptera, C. tweediana, C. flavicoma, C. balansae, C. hilariana, C. grandiflora, C. martiana, C. velutina, C. stipularia, C. pilosa, C. subdecurrens and C. breviflora), one subspecies (C. martiana subsp. mohlenbreckil) and one introduced species (C. juncea). The synonymy of five species and three varieties, the transference of C. paraguayensis from synonymy of C. martiana subsp. martiana to C. martiana subsp. mohlenbrockii, and the reestablishment of e. subdecurrens to the specific rank are proposed. Calycinae section spreads mainly the center-southeast area of Brazil, and four distribution patterns can be recognized: wide, restricted, endemic and disjunct. The preferential habitats of the species are cerrados, campos and campos rupestres. The altitude seems to represent an important factor for the specific geographic distribution and irradiation. New references of occurrences have been registered for 15 Brazilian states plus Distrito Federal. The expression "internodal wings" is applied in substitution to "decurrent stipules", usually considered in Crotalaria species description, since the former describes more accurately the structure ontogeny. Key words: Taxonomy, Leguminosae, Papilionoideae, Crotalaria, Crotalaria sect. Calycinae / Mestrado / Mestre em Biologia Vegetal

Orientador: Marlene A. Schiavanato / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-02T12:43:25Z (GMT). No. of bitstreams: 1 Mendonca_EleniraHenriqueMiranda_D.pdf: 4083060 bytes, checksum: d8a412147cb11bb86dd39a6db2096ec1 (MD5) Previous issue date: 2002 / Resumo: Crotalaria juncea L. é uma legurninosa amplamente utilizada como adubo verde. O objetivo deste trabalho foi verificar o efeito do N-NH/ sobre o crescimento da planta, produção de compostos nitrogenados e atividade das enzimas envolvidas na assimilação do Nnessa espécie. Foram avaliadas as respostas de plantas, inoculadas (I) ou não (NI) com Rhizobium, à presença (+N) ou ausência (-N) de NH/. Os experimentos foram conduzidos em casa de vegetação, em vasos contendo vermiculita, os quais foram irrigados com solução nutritiva contendo (NH/)2S04 de modo a fornecer 20 mgN/planta/semana ou com solução nutritiva sem N. Todas as avaliações foram realizadas em plantas com 60 dias de idade. A FBN não foi afetada pelo NH/, visto que na presença deste íon a atividade N2ase não foi inibida e houve aumento de :MF e MS de parte aérea, raízes e nódulos. A atividade específica da GS foi maior em folhas que em raízes, em todos os tratamentos. As folhas de plantas NI/+N apresentaram maior atividade de GS e GDH que as de plantas I/+N. Em folhas, raízes e nódulos de plantas inoculadas (+N ou -N), a atividade específica de GS foi semelhante; no entanto, no caso de GDH, a atividade foi maior em folhas e raízes de plantas I/-N e em nódulos de plantas I/+N. Independente do tratamento, em folhas, a atividade específica da GOGAT NADH foi quase nula e a forma predominante da enzima foi aquela dependente de ferredoxina (GOGAT-Fd). Em geral, folhas de plantas +N apresentaram maiores concentrações de pigmentos (clorofila total e carotenóides), N total e ALT. Plantas -N, totalmente dependentes da fixação de N2, exibiram seiva do xilema com maiores teores de AL T que plantas dos outros tratamentos, enquanto que plantas +N apresentaram nódulos com maior concentração de AL T. Em geral, não foram observadas diferenças entre os tratamentos, quanto ao conteúdo de NH/ nas diferentes partes da planta. Os teores de URE encontrados foram minimos, confirmando que o transporte de compostos nitrogenados em seiva de C. juncea se dá na forma de AL T e do íon NH/ / Abstract: Crotalaria juncea L. is a legume widely used as green manure. The objective of this work was to obtain basic information on the influence of the N-NH/ in the growth and production of nitrogen compounds and enzymes involved in nitrogen assimilation in this species. The responses of plants, inoculated (I) or not (NI) with Rhizobium to the presence (+N) or absence (- N) of NH/ were evaluated. The experiments were carried out in a greenhouse, in pots with vermiculite irrigated with nutrient solution containing (NH/)zSO4 in order to supply 20 mg of N/plant.week or with nutrient solution deprived of N. AlI the evaluations were carried out with 60 day old plants. Biological nitrogen fixation was not affected by _ +, since in the presence of this ion nitrogenase activity was not inhibited and shoots, roots and nodules ftesh and dry mass increased. GS activity was higher in leaves than in roots, in alI the treatments. Leaves ofNIl+N plants presented higher GS and GDH activities than ofI/+N plants. GS activity ofleaves, roots and nodules ofinoculated plants (+N or - N) was similar. However, GDH specific activity was higher in I/-N plants leaves and roots and in I/+N plant nodules. Independent of the treatment, GOGAT -NADH activity in leaves was almost null and the predominant form of the enzyme was that dependent of ferredoxin (GOGAT-Fd). In general, +N plant leaves presented higher pigment (total chlorophyl and carotenoids), total N and amino acids concentration. -N plants, that are fully dependent on Nz fixation, showed xylem sap with bigger amino acid contents than plants of other treatments, while +N plants presented nodules with bigger amino acid concentration. In general, differences between the treatments were not observed, as regards the ammonia content in the differents parts of the planto The levels of ureides found were minimum, confirming that the transport of nitrogen compounds in xylem sap of C. juncea is based on amino acids and ammoma / Doutorado / Doutor em Biologia Vegetal

Orientador: Ricardo Antunes de Azevedo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-03T21:30:01Z (GMT). No. of bitstreams: 1 Pereira_GuilhermeJoseGoncalves_D.pdf: 1076114 bytes, checksum: a6b5c1c85b9d597d9f61d04b0e962d8c (MD5) Previous issue date: 2004 / Doutorado

Orientador: Benedito Oliveira Filho / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-26T00:30:03Z (GMT). No. of bitstreams: 1 Rego_EvandroJoseLima_D.pdf: 2631101 bytes, checksum: 36faf195b04a371b72d3cedc478ca815 (MD5) Previous issue date: 2000 / Doutorado

Pyrrolizidine alkaloids (PAs) are one of the most significant groups of plant toxins in the world and are an important cause of poisoning in livestock, resulting in significant financial and production losses each year (Kellerman et al. 1996). Pyrrolizidine alkaloids may also enter the human food chain as contaminants of grains, via animal products such as milk, eggs and honey or may be consumed as constituents of herbal medicines (ANZFA 2001). Not all PAs are toxic. Pyrrolizidine alkaloids affecting human health are the esters of 1,2-unsaturated hydroxymethyl dehydropyrrolizidines (DHP). Before it can be converted to DHP, PAs need to have certain essential features, which include an unsaturated 3-pyrrole ring, one or two hydroxyl groups attached to the ring, one or two ester groups and a branched acid moiety (Mattocks 1986). These compounds can be metabolized in the liver to nucleophillic pyrroles which cause damage to hepatocytes (Winter and Segall 1989). Although the involvement of PAs in the development of hepatic veno-occlusive disease is well established (Bras et al. 1961), there is still uncertainty concerning the consequences of long-term, low-dose exposure in humans. Exposure to PAs through the use of herbal remedies may also be a contributing factor to the high rates of liver cancer and cirrhosis seen in Africa (Steenkamp et al. 2000). Crotalaria spp. are known to contain toxic PAs and various incidences of human poisoning through contaminated grains have been recorded in the scientific literature (IPCS 1989). Legislation controlling the allowable levels of toxic seeds in grains in South Africa is generally much stricter than in many other grain producing countries. The Soybean and Sunflower Forum recently commissioned a study (Eloff et al. 2003) to review published and unpublished information on toxic seed that could affect human health in South Africa and to make recommendations accordingly. Crotalaria sphaerocarpa is one of the problem plants discussed in the review and is apparently the only species which regularly contaminate grain in certain areas in South Africa. There is uncertainty at present about the number of these seeds that should be allowed in grains and the threat that this may pose to human health. Based on the review a provisional recommended level of 10 seeds of C. sphaerocarpa per 10 kg of grain was proposed as an approximated safe level in the report. As emphasized by the authors (Eloff et al. 2003), this absolute level is based on assumptions that must still be tested. As a follow-up on the report, a sensitive LC-MS/MS method for the determination of toxic PAs in plants was developed in this study. The characteristic fragments produced by 1,2-unsaturated necine bases under specific MS/MS conditions were used to discriminate between the toxic and non-toxic PAs. The concentration of these PAs were then determined using multi-reaction-mode experiments. Quantitative results were calculated against a retrorsine calibration curve and expressed as µg retrorsine equivalents per gram plant material. Various extraction methods described in the literature were investigated. A final liquid-liquid extraction method was used to extract unsaturated PAs from small amounts (about one gram) of milled plant samples. Recoveries from spiked lucerne samples were 98% for retrorsine and 105% for monocrotaline. To determine the applicability of the LC-MS/MS method the unsaturated PA content of C. laburnifolia and C. dura were investigated. Crotalaria laburnifolia, which is regarded as non-toxic, contained low concentrations (< 20 µg.g-1) of unsaturated PAs. Crotalaria dura, on the other hand, is known to be toxic to livestock and the concentration of unsaturated PAs was significantly higher (585 µg.g-1). The toxic PA content of Senecio inaequidens was also determined after an incident of livestock poisoning. The plant material contained very high concentrations of retrorsine (11.5 mg.g-1) and senecionine (0.5 mg.g-1) which were also present in the rumen content collected post-motally. These results confirmed the suspected toxicity of S. inaequidens. The LC-MS/MS method was also used to follow variations in unsaturated PA content in C. sphaerocarpa plants during the growing season. Pyrrolizidine alkaloids were present in the roots of the growing plants as N-oxides and also found in the mature aerial parts, where it was present mainly as the basic alkaloids. The method was used to determine the concentration of unsaturated PAs, in various C. sphaerocarpa seeds from different locations, in order to calculate the allowable level of C sphaerocarpa seed in maize. Of all the seed samples analyzed, the highest unsaturated PA concentration found was 150 µg.g-1. The allowable level of seed was calculated using this result and was found to be 656 seeds per 10 kg maize, based on the Australian and New Zealand Food Authority level of 0.1 µg.kg-1.day-1. If these results are confirmed with systematic statistical samples of C. sphaerocarpa seed from different grain production areas, the allowable level could be increased substantially. This may have an economic benefit to grain producers. / Thesis (PhD (Paraclinical Science))--University of Pretoria, 2006. / Paraclinical Sciences / PhD / unrestricted

O conhecimento de plantas tóxicas tem apresentado um grande papel para a sociedade. Seus estudos são importantes desde que são responsáveis por diferentes enfermidades, e até mesmo mortes por envenenamento, assim como por tornar possível o conhecimento de moléculas bioativas, as quais muitas delas se tornaram importantes na terapêutica atual. Vários são os exemplos de fármacos que estão no mercado, provenientes da observação humana de sinais de intoxicação após a ingestão de plantas capazes de metabolizar essas estruturas. Portanto, o estudo de plantas tóxicas está intimamente relacionado com a saúde de homens e de animais. Todavia, estão envolvidas também em aspectos econômicos, se for considerado os milhões de ruminantes que morrem a cada ano pelas suas ingestões. O envenenamento do gado, ocasionado por essas espécies é um sério problema, principalmente no Brasil, onde aproximadamente um milhão de animais morre por ano, devido à ingestão dessas plantas. Após avaliação de diversas plantas, consideradas tóxicas ou potencialmente tóxicas para o gado, observouse a presença de poucos estudos referentes à composição dos metabólitos secundários para várias espécies. Este trabalho apresentou como objetivos realizar um screening químico das espécies tóxicas Riedeliella graciliflora, Indigofera truxillensis e Crotalaria micans, além das espécies pertencentes a gêneros tóxicos Senna pendula, Senna splendida, Senna aculeata e Ipomoea chiliantha, envolvendo estudos farmacognósticos, além de análises espectroscópicas (RMN de 1H) e observação do perfil químico em CLAE-UV-DAD, CG-EM. Tal screening permitiu selecionar as espécies para a realização de estudo químico mais detalhado. Também foram propostas as avaliações da atividade citotóxica dos extratos e frações, a partir de ensaios utilizando Artemia salina, e das atividades antimicrobianas, antitumorais, anti-alérgica e tripanocida. Quanto aos ensaios de citotoxicidade dos extratos para Artemia salina, apesar destes não se apresentarem muito ativos, observou-se maior toxicidade de Crotalaria micans, Senna splendida e Indigofera truxillensis, nas quais todos os microcrustáceos apresentaram comprometimento da motilidade ou morte nas concentrações 500 e 1000 ?g/ml. No estudo químico de I. chiliantha foram identificados triterpenos, alcoóis, ácidos e ésteres graxos, derivados fenilpropanoides, flavonoide, além de calisteginas, as quais são alcaloides nortropânicos, e uma resina glicosídica ainda não descrita na literatura. As calisteginas são inibidoras de glicosidases, sendo tal atividade atribuída à toxicidade apresentada pelas espécies do gênero Ipomoea, ao gado. Já as resinas glicosídicas têm apresentado efeito catártico drástico, além de citotoxicidade, podendo contribuir para a toxicidade das espécies do gênero. No estudo químico de R. graciliflora, foram identificados triterpenos, esteroides, ácidos graxos, tocoferol, flavonoides C-glicosídeos e O-glicosídeos, benzenoide, além de quatro isoflavanas, sendo três inéditas na literatura e a outra inédita como produto natural. A fração diclorometânica de R. graciliflora, a partir da qual foram isolados os isoflavanóis descritos, apresentou-se muito ativa contra as linhagens celulares tumorais SP-295, HCT-8 e MDA-MB-435. No estudo químico de I. truxillensis, foram identificados triterpeno, esteroides, ácidos e ésteres graxos, benzenoides, flavonoides O-glicosídeos, e o alcaloide indoxil-?-glicopiranosídeo, ao qual ii têm sido atribuído ser o responsável por toxicidade urêmica, em ratos, devido ao seu produto de biotransformação, indoxil (3-hidroxindol) sulfato, ser uma toxina urêmica. Devido os sintomas de intoxicação apresentados pelo gado que ingeriram esta planta estarem relacionados à toxicidade nos rins, a presença deste alcaloide parece ter um importante papel em sua toxicidade. No estudo químico de S. splendida e S. pendula, foram identificados ácidos e ésteres graxos, tocoferóis, triterpeno, esteroides, flavonóis e antraquinona. Nenhuma destas substâncias parece estar relacionada à toxicidez. Quanto aos ensaios de atividade citotóxica frente às linhagens celulares tumorais, o extrato bruto de C. micans apresentou atividade moderada frente à linhagem celular SF-295. Quanto aos ensaios antimicrobianos, nenhum dos extratos brutos apresentou-se ativo. Porém, as frações de S. splendida provenientes das partições apresentaram atividade contra as bactérias Klebsiela pneumoniae/13883 e Proteus mirabilis/29906. Quanto aos ensaios para avaliação da atividade anti-alérgica, os derivados fenilpropanoides isolados de I. chiliantha apresentaram-se ativos. Quanto aos ensaios para avaliação da atividade tripanocida, apresentaram atividade o extrato etanólico bruto de R. graciliflora e a fração em acetato de etila de S. splendida. / Knowledge about toxic plants has played a fundamental role in our society. Investigation of such plants is important, because they are responsible for a wide range of malaise and even death by poisoning. Moreover, gaining insight into active biomolecules is paramount, since many of these compounds have become extremely relevant in current therapeutics. There are various examples of commercially available drugs originated from the human observation of signs of intoxication following ingestion of plants capable of metabolizing these structures. Therefore, the study of toxic plants is closely related to human and animal health. Economic issues are also involved, if one considers the millions of ruminants that die every year due to toxic plant ingestion. Cattle poisoning owing to these species is a serious matter, especially in Brazil, where approximately a million animals die due to poisoning by ingested plants every year. After evaluation of several plants deemed toxic or potentially toxic to cattle, we have observed that there are few works on the composition of secondary metabolites from these species. Therefore, the present investigation aimed at the chemical screening of the toxic species Riedeliella graciliflora, Indigofera truxillensis, and Crotalaria micans, and of species belonging to the toxic genera Senna pendula, Senna splendida, Senna aculeate, and Ipomoea chiliantha, by means of pharmacodiagnostic studies , spectroscopic analysis (1H NMR), and examination of the chemical profile by HPLC-UV-DAD, GC-MS. Such screening allowed for selection of the species to be used in a more detailed chemical study. Assessment of the cytotoxic activity of the extracts and fractions was proposed on the basis of assays employing Artemia salina and evaluating its antimicrobial, antitumor, anti-allergic, and trypanocidal activities. Although the extracts from Artemia salina did not exhibit pronounced cytotoxicity, larger toxicity was detected for Crotalaria micans, Senna splendida, and Indigofera truxillensis, in the presence of which all the crustraceans presented reduced motility or death at concentrations of 500 and 1000 ?g/ml. The chemical investigation of I. chiliantha enabled identification of triterpenes, alcohols, fatty acids and esters, phenylpropanoid derivatives, flavonoids, as well as calystegines, which are nortropane alkaloids, and a resin glycosidic not yet described in the literature. Calystegines are inhibitors of glycosidases, and this action is attributed to the toxicity displayed by species of the genus Ipomoea against cattle. As for resins glycosidic, besides cytotoxicity they also present a drastic cathartic effect, thereby contributing to the toxicity inherent to the species of this genus. The chemical study of R. graciliflora allowed for identification of triterpenes, steroids, fatty acids, tocopherol, flavonoids, C-glycosides and O-glycosides, benzenoids, in addition to four isoflavans, three of which have not been reported in the literature yet and one of which is novel as natural product. The dichloromethane fraction of R. graciliflora, from which the described isoflavanols were isolated, was very active against the tumor cell strains SP-295, HCT-8, and MDA-MB- 435. The chemical investigation of I. truxillensis revealed the existence of triterpene, steroids, fatty acids and esters, benzenoids, flavonoid O-glycosides, and the alkaloid indoxyl-?-glucopiranoside, to which uremic toxicity in rats has been attributed. This is because of its biotransformation product indoxyl (3-hydroxindol) sulfate, which is known to be a uremic toxin. Because the intoxication symptoms detected in the cattle that have ingest this plant are related to kidney toxicity, the presence of this alkaloid seems to play iv an important part in the toxicity of this species. The chemical screening of S. splendida and S. pendula demonstrated the existence of fatty acid and esters, flavonols, and anthraquinone. None of these compounds seem to be related to toxicity. As for the assays regarding the cytotoxic activity against tumor cell strains, the crude extract of C. micans was moderately active against the cell strain SF-295. With respect to the antimicrobial assays, none of the crude extracts displayed activity. Nevertheless, S. splendida fractions originated from partitions presented activity against the bacteria Klebsiela pneumoniae/13883 and Proteus mirabilis/29906. Concerning the assays evaluating the anti-allergic action, the phenylpropanoid derivatives isolated from I. chiliantha exhibited interesting properties. When it comes to the trypanocidal activity, the crude ethanolic extract from R. graciliflora and the acetyl acetate fraction of S. splendida were active.

O conhecimento de plantas tóxicas tem apresentado um grande papel para a sociedade. Seus estudos são importantes desde que são responsáveis por diferentes enfermidades, e até mesmo mortes por envenenamento, assim como por tornar possível o conhecimento de moléculas bioativas, as quais muitas delas se tornaram importantes na terapêutica atual. Vários são os exemplos de fármacos que estão no mercado, provenientes da observação humana de sinais de intoxicação após a ingestão de plantas capazes de metabolizar essas estruturas. Portanto, o estudo de plantas tóxicas está intimamente relacionado com a saúde de homens e de animais. Todavia, estão envolvidas também em aspectos econômicos, se for considerado os milhões de ruminantes que morrem a cada ano pelas suas ingestões. O envenenamento do gado, ocasionado por essas espécies é um sério problema, principalmente no Brasil, onde aproximadamente um milhão de animais morre por ano, devido à ingestão dessas plantas. Após avaliação de diversas plantas, consideradas tóxicas ou potencialmente tóxicas para o gado, observouse a presença de poucos estudos referentes à composição dos metabólitos secundários para várias espécies. Este trabalho apresentou como objetivos realizar um screening químico das espécies tóxicas Riedeliella graciliflora, Indigofera truxillensis e Crotalaria micans, além das espécies pertencentes a gêneros tóxicos Senna pendula, Senna splendida, Senna aculeata e Ipomoea chiliantha, envolvendo estudos farmacognósticos, além de análises espectroscópicas (RMN de 1H) e observação do perfil químico em CLAE-UV-DAD, CG-EM. Tal screening permitiu selecionar as espécies para a realização de estudo químico mais detalhado. Também foram propostas as avaliações da atividade citotóxica dos extratos e frações, a partir de ensaios utilizando Artemia salina, e das atividades antimicrobianas, antitumorais, anti-alérgica e tripanocida. Quanto aos ensaios de citotoxicidade dos extratos para Artemia salina, apesar destes não se apresentarem muito ativos, observou-se maior toxicidade de Crotalaria micans, Senna splendida e Indigofera truxillensis, nas quais todos os microcrustáceos apresentaram comprometimento da motilidade ou morte nas concentrações 500 e 1000 ?g/ml. No estudo químico de I. chiliantha foram identificados triterpenos, alcoóis, ácidos e ésteres graxos, derivados fenilpropanoides, flavonoide, além de calisteginas, as quais são alcaloides nortropânicos, e uma resina glicosídica ainda não descrita na literatura. As calisteginas são inibidoras de glicosidases, sendo tal atividade atribuída à toxicidade apresentada pelas espécies do gênero Ipomoea, ao gado. Já as resinas glicosídicas têm apresentado efeito catártico drástico, além de citotoxicidade, podendo contribuir para a toxicidade das espécies do gênero. No estudo químico de R. graciliflora, foram identificados triterpenos, esteroides, ácidos graxos, tocoferol, flavonoides C-glicosídeos e O-glicosídeos, benzenoide, além de quatro isoflavanas, sendo três inéditas na literatura e a outra inédita como produto natural. A fração diclorometânica de R. graciliflora, a partir da qual foram isolados os isoflavanóis descritos, apresentou-se muito ativa contra as linhagens celulares tumorais SP-295, HCT-8 e MDA-MB-435. No estudo químico de I. truxillensis, foram identificados triterpeno, esteroides, ácidos e ésteres graxos, benzenoides, flavonoides O-glicosídeos, e o alcaloide indoxil-?-glicopiranosídeo, ao qual ii têm sido atribuído ser o responsável por toxicidade urêmica, em ratos, devido ao seu produto de biotransformação, indoxil (3-hidroxindol) sulfato, ser uma toxina urêmica. Devido os sintomas de intoxicação apresentados pelo gado que ingeriram esta planta estarem relacionados à toxicidade nos rins, a presença deste alcaloide parece ter um importante papel em sua toxicidade. No estudo químico de S. splendida e S. pendula, foram identificados ácidos e ésteres graxos, tocoferóis, triterpeno, esteroides, flavonóis e antraquinona. Nenhuma destas substâncias parece estar relacionada à toxicidez. Quanto aos ensaios de atividade citotóxica frente às linhagens celulares tumorais, o extrato bruto de C. micans apresentou atividade moderada frente à linhagem celular SF-295. Quanto aos ensaios antimicrobianos, nenhum dos extratos brutos apresentou-se ativo. Porém, as frações de S. splendida provenientes das partições apresentaram atividade contra as bactérias Klebsiela pneumoniae/13883 e Proteus mirabilis/29906. Quanto aos ensaios para avaliação da atividade anti-alérgica, os derivados fenilpropanoides isolados de I. chiliantha apresentaram-se ativos. Quanto aos ensaios para avaliação da atividade tripanocida, apresentaram atividade o extrato etanólico bruto de R. graciliflora e a fração em acetato de etila de S. splendida. / Knowledge about toxic plants has played a fundamental role in our society. Investigation of such plants is important, because they are responsible for a wide range of malaise and even death by poisoning. Moreover, gaining insight into active biomolecules is paramount, since many of these compounds have become extremely relevant in current therapeutics. There are various examples of commercially available drugs originated from the human observation of signs of intoxication following ingestion of plants capable of metabolizing these structures. Therefore, the study of toxic plants is closely related to human and animal health. Economic issues are also involved, if one considers the millions of ruminants that die every year due to toxic plant ingestion. Cattle poisoning owing to these species is a serious matter, especially in Brazil, where approximately a million animals die due to poisoning by ingested plants every year. After evaluation of several plants deemed toxic or potentially toxic to cattle, we have observed that there are few works on the composition of secondary metabolites from these species. Therefore, the present investigation aimed at the chemical screening of the toxic species Riedeliella graciliflora, Indigofera truxillensis, and Crotalaria micans, and of species belonging to the toxic genera Senna pendula, Senna splendida, Senna aculeate, and Ipomoea chiliantha, by means of pharmacodiagnostic studies , spectroscopic analysis (1H NMR), and examination of the chemical profile by HPLC-UV-DAD, GC-MS. Such screening allowed for selection of the species to be used in a more detailed chemical study. Assessment of the cytotoxic activity of the extracts and fractions was proposed on the basis of assays employing Artemia salina and evaluating its antimicrobial, antitumor, anti-allergic, and trypanocidal activities. Although the extracts from Artemia salina did not exhibit pronounced cytotoxicity, larger toxicity was detected for Crotalaria micans, Senna splendida, and Indigofera truxillensis, in the presence of which all the crustraceans presented reduced motility or death at concentrations of 500 and 1000 ?g/ml. The chemical investigation of I. chiliantha enabled identification of triterpenes, alcohols, fatty acids and esters, phenylpropanoid derivatives, flavonoids, as well as calystegines, which are nortropane alkaloids, and a resin glycosidic not yet described in the literature. Calystegines are inhibitors of glycosidases, and this action is attributed to the toxicity displayed by species of the genus Ipomoea against cattle. As for resins glycosidic, besides cytotoxicity they also present a drastic cathartic effect, thereby contributing to the toxicity inherent to the species of this genus. The chemical study of R. graciliflora allowed for identification of triterpenes, steroids, fatty acids, tocopherol, flavonoids, C-glycosides and O-glycosides, benzenoids, in addition to four isoflavans, three of which have not been reported in the literature yet and one of which is novel as natural product. The dichloromethane fraction of R. graciliflora, from which the described isoflavanols were isolated, was very active against the tumor cell strains SP-295, HCT-8, and MDA-MB- 435. The chemical investigation of I. truxillensis revealed the existence of triterpene, steroids, fatty acids and esters, benzenoids, flavonoid O-glycosides, and the alkaloid indoxyl-?-glucopiranoside, to which uremic toxicity in rats has been attributed. This is because of its biotransformation product indoxyl (3-hydroxindol) sulfate, which is known to be a uremic toxin. Because the intoxication symptoms detected in the cattle that have ingest this plant are related to kidney toxicity, the presence of this alkaloid seems to play iv an important part in the toxicity of this species. The chemical screening of S. splendida and S. pendula demonstrated the existence of fatty acid and esters, flavonols, and anthraquinone. None of these compounds seem to be related to toxicity. As for the assays regarding the cytotoxic activity against tumor cell strains, the crude extract of C. micans was moderately active against the cell strain SF-295. With respect to the antimicrobial assays, none of the crude extracts displayed activity. Nevertheless, S. splendida fractions originated from partitions presented activity against the bacteria Klebsiela pneumoniae/13883 and Proteus mirabilis/29906. Concerning the assays evaluating the anti-allergic action, the phenylpropanoid derivatives isolated from I. chiliantha exhibited interesting properties. When it comes to the trypanocidal activity, the crude ethanolic extract from R. graciliflora and the acetyl acetate fraction of S. splendida were active.