Several studies have been conducted to discover new antimicrobial agents from plants to be used in pharmaceuticals, cosmetics and in the food industry. The lack of standardized methods for the evaluation of plant extracts with antimicrobial potential complicates the comparison of results. Taking into consideration the need to establish a method with consistent results to evaluate the antimicrobial activity of plant extracts, this study aimed to evaluate the antimicrobial activity of extracts of some plants from the Myrtaceae family on different micro-organisms based on a comparative assay with three methods that are commonly used for the assess antimicrobials. The methods used were broth microdilution, and agar diffusion by disc and well. The evaluated extracts were those of Psidium guajava, Myrciaria cauliflora, and Syzygium cumini for Grampositive and negative bacteria and yeast. In general, inhibition extracts promoted by the agar diffusion test by well was higher than the values obtained by disc, regardless of the plant extracts tested. However, the inhibitory activity of all micro-organisms was only possible to be determined with the microdilution broth method, which also presented the more reproducible results, and proved to be the most economic and reliable way to evaluate the antimicrobial activity of plant extracts in contrast with other methods. KEYWORDS:Myrtaceae; agar diffusion; disc diffusion; microdilution. RESUMO:Vários estudos estão sendo conduzidos para a descoberta de novos agentes antimicrobianos provenientes de plantas, para que possam ser utilizados em produtos farmacêuticos, cosméticos e na indústria alimentícia. A ausência de padronização de métodos utilizados para a avaliação de extratos vegetais com potencial antimicrobiano dificulta a comparação de resultados. Considerando a necessidade de estabelecer um método com resultados consistentes para avaliar a atividade antimicrobiana dos extratos vegetais, este trabalho propôs-se a avaliar a atividade antimicrobiana e determinar a concentração mínima inibitória de extratos de plantas da família Myrtaceae sobre diferentes micro-organismos, utilizando três méto-dos para avaliação de antimicrobianos. Os métodos empregados foram microdiluição em caldo e difusão em ágar por disco e poço. Foram avaliados os extratos de Psidium guajava, Myrciaria cauliflora e Syzygium cumini sobre bactérias Gram-positivas, negativas e levedura. Em geral, a inibição promovida pelos extratos no teste de difusão em ágar por poço foi maior do que os valores obtidos por disco, independentemente do extrato vegetal testado. Contudo, a atividade inibitória de todos os micro-organismos só pôde ser determinada com o método de microdiluição em caldo, que também apresentou os resultados mais reprodutíveis, e mostrou-se o mais econômico e confiável para se avaliar a atividade antimicrobiana de extratos vegetais quando comparado aos outros métodos. PALAVRAS-CHAVE:Myrtaceae; difusão em ágar; disco-difusão; microdiluição.Comparação de métodos para avaliação da atividade a...

Two new monoterpene indole alkaloids, named croceaines A (1) and B (2), were isolated from the leaves of Palicourea crocea. The structures of 1 and 2 were elucidated by means of spectroscopic methods.

Resumo -O objetivo deste trabalho foi avaliar o efeito do extrato de tabaco no controle do besouro cascudinho [Alphitobius diaperinus (Coleoptera: Tenebrionidae)] de aviário. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro tempos de contato (2½, 5, 7½ e 10 min) e quatro concentrações do extrato de tabaco (0, 25, 50 e 75% de diluição). O tempo de contato e as diluições do extrato foram independentes; entretanto, o tempo de contato exerceu maior influência na mortalidade do inseto. O extrato de tabaco tem potencial inseticida no manejo de aviários, mas testes de toxicidade devem ser realizados com as aves.Termos para indexação: Alphitobius diaperinus, Nicotiana tabacum, avicultura, inseticida natural. Tobacco extract in the control of the mealworm beetle in aviariesAbstract -The objective of this work was to evaluate the effect of tobacco extract on the control of the mealworm beetle [Alphitobius diaperinus (Coleoptera: Tenebrionidae)] in aviaries. The experiment was carried out in a completely randomized design, using four contact times (2½, 5, 7½, and 10 min) and four tobacco extract concentrations (0, 25, 50, and 75% dilution). The contact time and the dilution of the extract were independent; however, contact time had greater effect on insect mortality. The tobacco extract has insecticide potential in the management of aviaries, but toxicity tests should be performed on the birds.

The expression of chemical compounds by individual plants of the same species in different locations may be affected by abiotic factors resulting in differences in the production of allelopathic compounds. The objective of this study was to compare the phytochemical profiles of plant species from two different forest formations in the state of Paraná, Brazil. The forest formations were Seasonal Semideciduous Forest (SSF) and Lowland Ombrophilous Dense Forest (LODF), and the five study species were Jacaranda micrantha, Cecropia pachystachya, Mimosa bimucronata, Schinus terebinthifolius and Cedrela fissilis. Secondary metabolites were extracted by exhaustive extraction with methanol, and the crude extract was fractionated using column chromatography. The fractions were used to calculate the retention factor of the main compounds using thin layer chromatography and phytochemical tests. The classes of compounds identified were practically the same among the analyzed species, however, at different levels of concentration. The type of tannins found in S. terebinthifolius differed between the two forest formations.

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RESUMO:Pediculose é uma infestação causada pelo parasita Pediculus humanus capitis De Geer, conhecido popularmente como piolho. A doença é considerada um problema ABSTRACT:Pediculosis is an infestation caused by the parasite Pediculus humanus capitis de Geer, popularly known as lice. The disease is considered a serious public health problem.Although there are several popular treatments for the infestation, few scientic studies have proven their efcacy. The use of vegetal species with anti pediculosis insecticide activity, besides being accessible to low income population, also constitutes an efcient