Abstract INTRODUCTION: Bioprospection of plant products is used to discover new insecticides. METHODS: The larvicidal activity of ethanolic extract and triterpene (tingenone B) from the bark of Maytenus guianensis and their effect on pupation and emergence were evaluated against Aedes aegypti. RESULTS: Crude extract LC50 was 11.3 ppm and caused ejection of the larvae intestine; tingenone B LC50 was 14.8 ppm. Pupation was reduced by 20% and 10%, respectively; however, the emergence was not affected. CONCLUSIONS: The crude bark extract exhibited a higher larvicidal effect against the vector.

Abstract INTRODUCTION This aim of this study was to evaluate the antibacterial activity of fractions and isolates of Maytenus guianensis, a plant species used in Amazonian folk medicine. METHODS A disk diffusion technique was used to investigate the antibacterial potential. RESULTS The hexanic fractions and tingenone B isolate showed inhibitory effects against Staphylococcus aureus and Streptococcus pneumoniae. CONCLUSIONS These results indicate the antibacterial potential of this species and will enable future studies to identify novel therapeutic alternatives from this species.

Abstract INTRODUCTION This study assessed the activity of compounds from Piper tuberculatum against Plasmodium falciparum and Leishmania guyanensis. METHODS The effects of compounds from P. tuberculatum fruits on P. falciparum and L. guyanensis promastigote growth in vitro were determined. Hemolytic action and cytotoxicity in HepG2 and J774 cells were measured. RESULTS Three compounds showed strong antiplasmodial activity and one compound showed strong antileishmanial activity. Two compounds were non-toxic to HepG2 cells and all were toxic to J774 cells. The compounds showed no hemolytic activity. CONCLUSIONS The tested compounds from P. tuberculatum exhibited antiparasitic and cytotoxic effects.

RESUMO Estratégias de controle do carrapato dos bovinos, Rhipicephalus microplus, fundamentam-se na utilização de pesticidas. Os principais grupos químicos utilizados atualmente mostram-se ineficazes devido ao surgimento de populações resistentes. A pesquisa de novas moléculas com eficiência acaricida é uma necessidade para manutenção da produtividade dos rebanhos bovinos estabelecidos em regiões de clima tropical. Avaliamos a atividade de Piper tuberculatum para o controle de fêmeas ingurgitadas e larvas de R. microplus através de bioensaios de imersão de adultos e de pacotes de larvas. As concentrações avaliadas foram de 50; 25; 12,50; 6,25; 3,12 e 1,56 mg mL-1 de extrato etanólico de folha, talo e fruto de P. tuberculatum. As concentrações letais para 50% dos indivíduos (CL50) após 24 horas de exposição de larvas de R. microplus foram 3,62; 3,99 e 5,30 mg mL-1 para os extratos etanólicos de fruto, talo e folha, respectivamente. Para fêmeas ingurgitadas, a maior eficácia resultou da concentração de 50 mg mL-1 de extrato de fruto (71.57%). O principal efeito dos extratos etanólicos de P. tuberculatum foi sobre a eclodibilidade, com uma redução de 55.63% para extratos de fruto e folha. P. tuberculatum mostra-se promissora como fonte de moléculas candidatas a uso em pesticidas, em formulações destinadas ao controle das infestações de R. microplus.

ABSTRACT The strategies to control the cattle tick, Rhipicephalus microplus are based mainly on the use of synthetic pesticides. However, the emergence, establishment, and development of resistance of ticks is rendering the main chemical groups ineffective. Finding new molecules to effectively control infestations by R. microplus is necessary to maintain the productivity of cattle herds, particularly of taurine breeds established in equatorial and tropical regions of the world. Ethanol extracts from the leaves, stems, and fruits of Piper tuberculatum were evaluated in bioassays at concentrations of 50, 25, 12.50, 6.25, 3.12 and 1.56 mg mL-1. The concentrations lethal to 50% of the individuals (LC50) of tick larvae after 24 hours of exposure were 3.62, 3.99 and 5.30 mg mL-1 for fruit, stem and leaf extracts, respectively. Against the engorged females, the highest efficacy rates were obtained at the concentration of 50 mg mL-1, corresponding to 71.57%, 68.38% and 37.03% of the fruit, leaf and stem extracts, respectively. The main effect of the ethanol extracts was on the egg hatching rate of ticks, with a reduction of 55.63% for the fruit and leaf extracts, and 20.82% for the stem extract. The results show that P. tuberculatum is a promising source of molecules for use as active ingredients in pesticide formulations for R. microplus control.

Abstract INTRODUCTION Maytenus guianensis is a member of the Celastraceae family that is used in traditional medicine, particularly for its anti-parasitic and anti-cancer effects. To explore the ethnopharmacological potential of this plant, the present study was designed to screen the in vitro antileishmanial activities of extracts and compounds isolated from M. guianensis. METHODS Maytenus guianensis stems and leaves were extracted in acetone, followed by the preparation of eluates and isolation of secondary metabolites using chromatography on a glass column with silica gel as the fixed phase. The chemical components were identified using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance of hydrogen-1 and carbon-13, mass spectroscopy, and infrared spectroscopy. The anti-Leishmania amazonensis activities of these eluates and compounds were evaluated by direct promastigote counting and viability assays. RESULTS It was found that the hexane bark eluate produced the strongest anti-L. amazonensis effect, with 90-100% inhibition of the promastigote form. The isolated metabolite that produced the best result was tingenone B, followed by a compound formed by the union of tingenone and tingenone B (80-90% inhibition). CONCLUSIONS Maytenus guianensis shows anti-parasite activity that warrants further investigation to determine the mechanisms underlying this antileishmanial effect and to evaluate the pharmacological potential of these eluates and isolated secondary metabolites, while minimizing any adverse effects.

Abstract The species Maytenus guyanensis Klotzsch ex Reissek, Celastraceae, present a wide variety of possible pharmacological activities and its roots and stems are used by popular medicine in the western Amazon rainforest. Few studies have demonstrated the genotoxic safety of the popular use of this species, and owing to this, the present study aimed to perform an analysis of the acute genotoxicity in vivo of the aqueous extract of M. guyanensis. Male and female mice from Mus musculus species, of weights ranging from 20 to 40 g, organized in eight groups with different treatments were used. The aqueous extracts of the bark of M. guyanensis were administered orally by gavage with 0.1 ml of the test substance per 10 g of the animal, followed by performance of comet assay in peripheral blood, PCE/NCE correlation and occurrence of micronuclei in the bone marrow. It was found that the aqueous extract of M. guyanensis, with ten times higher concentration than those used in ethnopharmacology, did not present genotoxic effect and, moreover, it has antigenotoxic action in mice treated acutely. Further studies regarding bioaccumulation and chronic effects of this species are suggested, in order to improve the understanding of its mechanism of action, ensuring the efficacy and safety of its utilization and developing phytotherapics and drugs.

Copaifera spp. is a common tree species found in the tropical region of Latin America, popularly known as copaiba or pau-d'alho. Oil-resin from different Copaifera species and its components present several biological activities such as antimicrobial, anti-inflammatory, antioxidant and insecticidal, including larvicidal activity against mosquitoes. Thus, bark and leaf ethanolic extracts, oil-resin, essential oil and alepterolic acid from Copaifera multijuga Hayne, Fabaceae, were tested as larvicides against the main malaria vector in the north of Brazil, Anopheles darlingi and also Aedes aegypti, the dengue vector. A. darlingi larval mortality was significantly higher than A. aegypti for most tested compounds. Bark and leaf extracts resulted in lower Lethal Concentrations (LC50) values for A. darlingi, 3 and 13 ppm, respectively, while the essential oil provided the lowest LC50 value for A. aegypti, 18 ppm. Despite of that, the lowest LC values were from the alepterolic acid for both species, i.e. 0.9 and 0.7 ppm for A. darlingi and A. aegypti, respectively.

Este trabalho relata o estudo químico de duas plantas medicinais da Amazônia: Philodendron scabrum K. krause (Araceae) e Vatairea guianensis Aubl. (Fabaceae). As composições dos óleos essenciais dos cipós de P. scabrum e dos frutos de V. guianensis, respectivamente, foram analisadas em CG-DIC e CG-EM. Os constituintes majoritários dos cipós de P. scabrum foram óxido de cariofileno (19,42%), α-copaeno (16,08%) e β-bisaboleno (10,01%); e nos frutos de V. guianensis foram o ácido (9Z)-octadecenoico (24,95%) e o ácido docosahexaenoico (24,17%). β-sitosterol e o alquilresorcinol 1-hexadecanoil-2,6-dihidroxibenzeno foram isolados do extrato etanólico dos cipós de P. scabrum; e do extrato etanólico dos frutos de V. guianensis, foram isoladas as antraquinonas crisofanol e fisciona. As determinações estruturais foram baseadas em dados de RMN de ¹H e 13C. RMN, uni e bidimensional e comparação com dados da literatura.

This work describes the chemical study of two medicinal plants of the Amazon Philodendron scabrum K. Krause (Araceae) and Vatairea guianensis Aubl. (Fabaceae). Essential oils composition from stems of Philodendron scabrum K. Krause (Araceae) and fruits of Vatairea guianensis Aubl. (Fabaceae), respectively were analyzed in GC-FID and GC-MS. The major constituents from stems of P. scarabum were caryophyllene oxide (22.42%), α-copaene (16.08%) and β-bisabolene (12.01%) and from fruits of V. guianensis were (9Z)-octadecenoic acid (24.95%) and docosahexenoic acid (24.17%). β-sitosterol and alkylresorcinol 1-hexadecanoyl-2,6-dihydroxybenzene were isolated from ethanolic extracts from stems of P. scabrum and from ethanolic extracts from fruits of V. guianensis, the athraquinones chrysophanol and physcion were isolated. The structure of isolated compounds we determinate wered based on data from ¹H and 13C NMR, including two dimensional analyses and comparison with literature data.

Este trabalho teve como objetivo avaliar o potencial inseticida do extrato acetônico das folhas de Piper hispidum Kunth sobre Hypothenemus hampei (Ferrari, 1867) em aplicação tópica, superfície contaminada e efeito de repelência. Adotou-se as diluições de 25,0; 5,0; 0,1; 0,02; 0,004 e 0,0008 mg mL-1 para exposição em superfície contaminada e aplicação tópica. No teste de repelência, utilizou-se a diluição 0,5 mg mL-1 do extrato. As avaliações foram realizadas nas 48 horas após a exposição ao extrato. Na exposição em superfície contaminada, obteve-se 100% de mortalidade, na diluição 25,0 mg mL-1, e de 50 a 80% nas diluições 0,004 a 5,0 mg mL-1, enquanto 0,0008 mg mL-1 e o controle resultaram em apenas 5% de mortalidade. Na aplicação tópica, atingiu-se 60 a 65% de mortalidade, com as diluições de 0,1 a 25,0 mg mL-1. As diluições de 0,2 a 0,0008 mg mL-1 não diferiram do controle. Os índices de repelência foram inferiores ao valor mínimo preconizado na literatura para se considerar uma substância como repelente. Este estudo evidencia a atividade inseticida do extrato de folhas de P. hispidum sobre H. hampei, o que sugere seu potencial no controle deste inseto.

The objective of this work was to evaluate the insecticidal and repellent potential of the acetonic leaf extract of Piper hispidum Kunth on Hypothenemus hampei (Ferrari, 1867) insects by topical application, contaminated surface and repellent effect. Dilutions of 25.0; 5.0; 0.1; 0.02; 0.004 and 0.0008 mg mL-1 were used for exposition in contaminated surface and topical application. In the repellence test 0.5 mg mL-1 of this extract were used. Evaluations occurred during 48 hours after exposure to the extract. In the exposition in contaminated surface 100% of mortality were observed in the dilution of 25.0 mg mL-1 and 50 to 80% in dilutions of 5.0 to 0.004 mg mL-1, while 0.0008 mg mL-1 and the control resulted in only 5% of mortality. In the topic application 60 to 65% of mortality were observed with dilutions of 25.0 to 0.1 mg mL-1. Dilutions of 0.0008 to 0.2 mg mL-1 did not differ from the control. The repellence index was lower than the minimum value praised in literature to consider a substance as repellent. These results pointed out to the high potential of P. hispidum extract for the control of H. hampei.

Os óleos essenciais dos frutos e talos finos de Piper tuberculatum e das raízes de P. hispidum, coletados no estado de Rondônia, foram obtidos por hidrodestilação e analisados por GC e GC-MS. Foram identificados como constituintes majoritários, nos óleos dos frutos e talos finos de P. tuberculatum, o óxido de cariofileno (32,1%) e (26,6%) e o (E)-cariofileno (17,7%) e (12,3%), respectivamente. No óleo essencial das raízes de P. hispidum, foram identificados, como constituintes majoritários, o dilapiol (57,5%), a elemicina (24,5%) e o apiol (10,2%). Do extrato etanólico dos frutos de P. tuberculatum, foram isolados os esteróides β-sitosterol e estigmasterol, as amidas piplartina e dihidropiplartina e um derivado do ácido cinâmico, o ácido 3,4,5-trimetoxi-dihidrocinâmico.

The essential oils of the fruits and fine stems of Piper tuberculatum and of the roots of P. hispidum, collected in the state of Rondônia, had been gotten by hydrodistillation and analyzed by GC and GC-MS. Caryophyllene oxide - 32,1% in fruits and 26,6% in fine stem, and (E)-caryophyllene - 17,7% in fruits and 12,3% in fine stems, were identified as the major constituents in such parts of P. tuberculatum. In the essential oil of the roots of P. hispidum, dillapiol (57,5%), elemicine (24,5%) and apiole (10,2%) were identified as the most abundant constituents. From the ethanolic extract of the fruits of P. tuberculatum, the steroids β-sitosterol and stigmasterol, the amides piplartine and dihidropiplartine and the derivative of the cinâmico acid 3,4,5-trimethoxy-dihidrocinâmic acid were isolated.

Chemical investigation of Z. ekmanii resulted in the isolation of skimmianine, dictamnine, tembamide, sesamin, lupeol and beta-sitosterol. The structures were established by spectroscopic analyses. This is the first report on the phytochemical study of the roots and leaves of Z. ekmanii.