https://repositorio.unimontes.br/handle/1/810 Sun, 26 Apr 2026 05:13:02 GMT 2026-04-26T05:13:02Z https://repositorio.unimontes.br/handle/1/2552 Título: análise fitoquímica e atividade antibacteriana “in vitro” de extratos de plantas do cerrado Autor(es): Maia, Caroline Nogueira Abstract: Ethanolic and methanolic extracts of 10 plants collected from the Cerrado of the North of State of Minas Gerais (Brazil) were submitted to antibacterial test against the bacteria Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923) e Pseudomonas aeruginosa (ATCC 27853) using the disc diffusion method. The botanical species which presented antibacterial activity, Anacardium humile A. St. Hil, Psidium giuneense SW. and Myracrodruon urundeuva Allemao, had their ethanolic extracts tested in 15 stems of the species Staphylococcus aureus that were obtained from the patients area at the Hospital Universitário Clemente de Faria and from clinical laboratories in Montes Claros and standard stem ATCC 25923. Inhibitory activity was determined and the interaction between the extracts and the main groups of secondary compounds present in these plants was surveyed. Through the study of the antibacterial activity in bacterial stems of Staphylococcus aureus, the extract of Myracrodruon urundeuva Allemao has started its inhibitory action at a 30 mg/mL concentration, while the extracts of Anacardium humile A. St. Hil. and Psidium guineense SW. started their activity at a 60 mg/mL concentration. A synergic interaction between the vegetable extracts was observed when they were combined by pairs at variable percentages. Tannins and flavonoids were detected in the phytochemical analysis of the species; such substances may be responsible for the observed antibacterial action. From these results, other studies should be carried out with the plants Anacardium humile A. St. Hil., Psidium giuneense SW. and Myracrodruon urundeuva Allemao; they have showed a considerable therapeutic potential. Fri, 22 Feb 2008 00:00:00 GMT https://repositorio.unimontes.br/handle/1/2552 2008-02-22T00:00:00Z https://repositorio.unimontes.br/handle/1/2543 Título: Consequências da alteração do hábitat para a dispersão e predação de sementes de Cavanillesia arborea (Malvaceae) em florestas tropicais secas Autor(es): Silva, Herbert Souza e Abstract: We compared these processes in pasturelands and preserved old-growth forests in the Mata Seca State Park and its surroundings. To describe the seed shadows, 15 isolated individuals of C. arborea were marked in each habitat type and seed density was determined up to a 30 m radius from each parental plant. To compare seed predation and germination between pasture and forests, five seeds were offered at 5, 10 and 15m from another 15 individuals marked at each habitat. Habitat alteration affected seed shadows and the dispersal distance was longer at the open vegetation of pasturelands (11.35 m forest vs. 14.21 m pasture). Seed predation was significantly higher in forests (59.05%) than in pastures (9.52%), but mortality by other factors showed the reversed pattern (22.3% vs, 90.2%). Temporal patterns of seed predation, mortality by other factors and germination also differed between habitats. Seed predation started late in pastures, probably because grass growth with the first rains provides foraging protection for predators from their natural enemies. On the other hand, seed mortality by other factors increased drastically in the same period, making most seeds produced in pastures unavailable for ground predators. As a whole, all seeds offered in pasturelands died after four months of experiment, whereas 16.1% of seeds were saplings in forest at the same date. Given the high rates of deforestation of Brazilian tropical dry forests, the absence of recruitment in pasturelands is a serious threat to the viability of C. arborea populations Sun, 01 Jan 2012 00:00:00 GMT https://repositorio.unimontes.br/handle/1/2543 2012-01-01T00:00:00Z https://repositorio.unimontes.br/handle/1/2542 Título: Sazonalidade no acúmulo de frutanos em órgãos subterrâneos de gomphrena marginata seub. (AMARANTHACEAE) em área de campo rupestre Autor(es): Silva, Fernanda Gomes da Abstract: The climatic seasonality is one of the main features of Cerrado and as a consequence, the vegetation of this biome has developed several adaptations. Gomphrena marginata Seub. is a herbaceous of ‘campos rupestres’ that has thick underground structure and occurs in a region marked by climatic seasonality. In this context, this study aims to evaluate the occurrence and the seasonality of accumulation of carbohydrates like fructans in underground organs of G. marginata and their relationship with soil water availability and hydric relations of plants. Sample of G. marginata were collected monthly from August 2010 to July 2011 in the ‘campos rupestres’ of Environmental Preservation Area "Complexo Paisagístico Serra Resplandecente " in the city of Itacambira-Minas Gerais State (16°59'47"S, 43°20 '01"W). To this end, monthly quantitative analysis of the levels of total fructose, fructo-polysaccharides, fructo-oligosaccharides, reducing sugars and free proline were carried out in underground organs of G. marginata. It was made qualitative analysis of carbohydrates by Thin Layer Chromatography (TLC) and High Performance Anion Exchange Chromatography with Pulsed Amperometric Detection (HPAEC/PAD). Regarding the hydric aspects, it was established soil humidity, the relative content of water (TCW) and osmotic potential from underground organs cell sap. In addition, rainfall data (mm), relative humidity (RH) and average air temperature were obtained from the website of the Institute of Agricultural Sciences of UFMG. Data were analyzed using simple correlation (Pearson) and all the environmental parameters of hydric and biochemical relations. It was used the "t" Student test for assessing the significance of the correlations in 5% level of probability. During the rainy season (September 2010 to March 2011) it was observed an increase of reducing sugars content while there was a decrease in the content of fructo-polysaccharides. Such changes were also detected in the analysis by TLC and HPAEC / PAD. From August to December it was observed high amount of free fructose and sucrose indicating the occurrence of depolymerization of the fructo-polysaccharides chain. In field it was observed that the flowering period of this species occurred predominantly from September to November 2010. Probably reserve carbohydrates (fructo-polysaccharides) were depolymerized and translocated to the shoot of the plant which was in intense development. During the dry period it was found correlations between the reducing sugar content, parameters RH and soil humidity. In this period there was an intense accumulation of fructo-polysaccharides. This accumulation can be associated with translocation of photoassimilates to the underground system before leaf senescence and abscission which was observed especially in the months of June and July 2010. The species G. marginata probably has strategies to avoid loss of water as the control of stomatal movement and / or acceleration of leaf senescence and abscission. The proline content showed significant positive correlations with the TCW. However, due to the low concentration observed its performance in the osmoregulation is questionable, although it is not ruled out the possibility of being a flag. It was concluded that the accumulation of fructans in the underground organs in G.marginata is seasonal. The depolymerization of fructo-polysaccharides occurs during the rainy season which coincides with the period of plants flowering. On the other hand, during the dry period occurs and accumulation of long chain fructans Sun, 01 Jan 2012 00:00:00 GMT https://repositorio.unimontes.br/handle/1/2542 2012-01-01T00:00:00Z https://repositorio.unimontes.br/handle/1/2541 Título: Diversidade e produção de ácido abscísico por fungos endofíticos associados a Goniorrhachis marginata Taub. E Cavanillesia arborea K. Shum Autor(es): Penna, Patrícia Mendonça Moreira Abstract: The endophytic fungi are microorganisms that settle the inner part of the plant tissues in at least one phase of their development and establish a relationship that apparently is not harmful to the hosts. The interaction with endophytic fungi is present in most of the plant species and has influence in their biological mechanisms as the production of secondary metabolites and the defense against herbivores and pathogens. There are some perspectives that the endophytic fungi can occur widely in rain forests due to the high diversity of plant species and to the several kinds of vegetation present in these places. This paper aimed to evaluate the endophytic fungi diversity associated with Goniorrhachis marginata and Cavanillesia arborea and their abscisic acid production (ABA) throughout the foliage cycle of the two species of trees. The endophytic fungi were isolated from leaves of 10 individuals of both species and grouped into morphospecies. The ABA production by the fungi was detected by liquid chromatography (HPLC). From the leaf material collected from C arborea and G. marginata it was obtained the total of 179 isolated endophytic fungi grouped into 31 morphospecies. The abundance of endophytic fungi isolated was significantly higherin mature leaves over young leaves for both tree species, corroborating with other studies. The fungi community of C.arborea differed from the fungi community isolated from G. marginata. The same was observed in relation to the fungi community isolated from young and mature leaves of the two tree species, demonstrating that there was an influence of temporal variation in these communities. Regarding the ABA production, from the 33 morphospecies characterized in this study, 15 produced this phytohormone. The production of ABA by the endophytic fungi may be related to a colonization strategy used by the analyzed fungi, as it has already been demonstrated in other studies, with the ABA increasing concentrations, the leaves become more susceptible to infection and perennial colonization Sun, 01 Jan 2012 00:00:00 GMT https://repositorio.unimontes.br/handle/1/2541 2012-01-01T00:00:00Z