ABSTRACT The objective of this research was to identify the existence of root exudation of organic acid in Lotus corniculatus germplasms subjected to toxic aluminum (Al) levels and investigate the effect of this mechanism on the Al content in the root tissue and in morphological parameters of plant development. Two experiments were performed in nutrient solution to evaluate the Al accumulation and exudation of organic acids, using cultivars INIA Draco and São Gabriel and genotypes UFRGS and UF-T2. The plants were cultivated in Al-free solution, which was applied on the 45th day in half of the pots of each genotype. Root exudation was highly correlated with the reduced accumulation of Al in the root tissue (r2 = 0.75 at 72 h). Genotype UF-T2, selected for Al tolerance, extruded 80% more oxalic acid in the presence of Al compared with the other germplasms, indicating that this mechanism is involved with Al tolerance in L. corniculatus. This experiment showed strong evidence that L. corniculatus exhibits Type I tolerance, in which anionic channels are rapidly activated by Al exposure. Exudation of oxalic acid is likely a crucial mechanism that allows the maintenance of L. corniculatus growth when exposed to toxic Al conditions, and this characteristic should be used to identify tolerant genotypes in the future.

Abstract Trifolium pratense L., Fabaceae, is a rich source of isoflavones and has become the focus of several studies related to its phytoestrogenic activity. The aim of this study was to establish germination and cell cultures protocol for T. pratense and quantify isoflavones content in cell cultures, in vitro cultured and wild plants harvested in two different seasons. Murashige Skoog medium supplemented with naphthalene acetic acid and kinetin was able to produce the highest formation of friable calli. Calli cultures were analyzed qualitatively after 60 days of culture, and in vitro plants after 30, 45 and 60 days of cultivation. The chemical analysis was performed by ultra performance liquid chromatography, using the linearity curves of daidzein, genistein, formononetin and biochanin A as standards. The concentrations of isoflavones detected in wild plants were different in the two harvest periods and contrasted in content when compared to the in vitro plants. Cell cultures exhibited diverse profiles and concentration of isoflavones, none of which presented the isoflavonoid biochanin A. Pectinase was used to promote reduction of clumps and ended up altering the characteristics of secondary metabolites production in some cultures. Formononetin showed higher concentration in wild red clover samples (15.407 mg g-1), and in the in vitro grown plants the highest concentration was daidzein (17.591 mg g-1) at 60 days. The methods used for this research were effective, and the red clover plants of the analyzed variety can be cultivated in vitro aiming the commercial productivity by having contents greater than or equal to the wild plants in the periods studied, even without the use of elicitors during the cultivation.

In recent years alkaloids from the genus Hippeastrum have been shown to exhibit a broad spectrum of biological activities, including antiparasitic, antiproliferative, apoptosis-induced, psychopharmacological, acetylcholinesterase-inhibitory, among others. This work presents a brief chemical and biological review of the alkaloids found in the genus Hippeastrum.

En los últimos años, los alcaloides aislados del género Hippeastrum han mostrado un amplio espectro de actividades incluyendo, entre otras, la antiparasitaria, antiproliferativas, inductoras de apoptosis, psicofarmacológicas y como inhibidores de la acetilcolinesterasa. En este trabajo se presenta una breve revisión química y biológica de los alcaloides del género Hippeastrum.

Natural products have been, historically, very important for Brazil. Coffee, sugar and soy were some examples that prove this economical significance. A project that involves phytoproducts should be guide by three main axis: agriculture management for the plants; pharmaceutical; support the national industry and academy. In Brazil, pharmaceutical products contribute negatively to the commerce balance showing an enormous technological dependence in this economical sector. The consolidation of the phytoproduct's chain in Brazil could contribute for the development of the pharmaceutical sector in order to help all domains in natural products area.

Amaryllidaceae family is an important source of bioactive molecules and considering the taxonomic relationships, it is relevant to investigate the genus Hippeastrum. Thus, the aim of this work was to determine antioxidant and anticholinesterasic activities of Hippeastrum morelianum, Hippeastrum psittacinum and Hippeastrum santacatarina. Both antioxidant and acetylcholinesterasic activities of extracts were determinated by bioautography as 10 mg/mL and 0.1 mg/mL, respectively. The antioxidant activity of alkaloid lycorine, determinated spectrophotometrically with DPPH, indicated an IC50 value of 0.326 mM.

Culturas de calos e de células em suspensão foram estabelecidas a partir de folhas jovens de Pilocarous pennatifolius em meio Murashige & Skoog (MS) suplementado com 5 mg/L de ácido 2,4-diclorofenoxiacético e 1 mg/L de cinetina. O teor de pilocarpina nas culturas e suspensões celulares foi quantitativamente comparado por CLAE.

Callus and cell suspension cultures were established from young leaves of Pilocarpus pennatifolius on Murashige & Skoog (MS) medium supplemented with 5.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg/L kinetine. The pilocarpine contents of callus and cell suspension cultures were quantitatively compared by HPLC.

Com o objetivo de descrever a variabilidade genética e química da planta medicinal chapéu de couro (Echinodorus grandiflorus Mich. e outras espécies) existente no Rio Grande do Sul, foram coletadas plantas em 16 diferentes localidades e transplantadas para uma área experimental na Universidade Federal de Pelotas, em Pelotas-RS. As plantas foram cultivadas em planossolo alagado no inverno e com irrigação suplementar quando houve umidade insuficiente no solo. A adubação das plantas foi calcáreo, cinza de casca de arroz e vermicomposto. As folhas e sementes foram colhidas na primavera e verão. Foi procedida a descrição dos ecotipos, através dos parâmetros fenológicos: início da brotação, vigor da brotação, florescimento, antese, maturação das sementes e, agronômicos: resistência ao frio e à insolação, competição com plantas daninhas e peso da matéria seca foliar, bem como uma análise dos compostos químicos majoritários nas folhas. As avaliações permitiram concluir que: 1- a espécie predominante no Rio Grande do Sul é a Echinodorus grandiflorus; 2 - os ecotipos de Cruz Alta e de São Gabriel são recomendados para cultivo como precocidade e produção de matéria seca; 3 - os ecotipos de Arroio Grande e Jaguarão são recomendados para cultivo pela composição química mais numerosa.

The aim of this research work was to describe the genetic and chemical variability of the medicinal specie "chapéu de couro" (Echinodorus grandiflorus and other species), which is found in Rio Grande do Sul State, Brazil. The plants had been collected at sixteen different sites and planted again in an experimental area at the Federal University of Pelotas (UFPel), in the town of Pelotas-RS. The plants have grown in waterlands, by keeping them underwater during the winter and adding water when the soil was dry. The plants have been fed up with lime, ash of rice waste and vermcomposite. The leaves and the seeds have been collected during spring and summer. The phenology of the different material has been observed to proceed the botanical and physiological description of ecotypes, through field parameters and in the experimental area. The chemical composition of the major chemical substances in the leaves of both native and non native plants was also analyzed. The evaluation led to conclude that: 1- the vailing specie in Rio Grande do Sul State is Echinodorus grandiflorus; 2 - the ecotypes from Cruz Alta and São Gabriel are prefered for cropping due to their early and dry matter production; 3 - the ecotypes from Arroio Grande and Jaguarão are prefered for cropping due to your rich chemical composition.