Some Biochemical properties of polyphenoloxidase from spearmint (Mentha arvensis)

Polifenoloxidase (PPO, EC 1.14.18.1) extraída de folhas de Mentha arvensis foi isolada por precipitação com (NH4)2SO4 e diálise extensiva. Seu pH e temperatura ótimos variaram com o substrato. A PPO apresentou atividade com vários difenóis. Valores de Km foram 0,825; 0,928 e 7,41 mM para ácido caféico, 4-metilcatecol e catecol, respectivamente. Na inativação térmica, 50% da enzima foi inativada após 60 e 15 segundos a 70 e 75ºC, respectivamente. A medida de atividade residual mostrou um efeito estabilizante de sacarose a várias temperaturas e uma energia de ativação (Ea) para inativação aumentando com a concentração de sacarose de 0 a 40% (p/p). Valores de energias de ativação de 78,13; 80,37; 82,79 and 81,00 kJ/Mol foram encontradas para 0, 15, 30 e 40% de sacarose, respectivamente. A PPO foi inibida pelos ácidos ascórbico, benzóico, cinamico, ferulico, p-cumárico, protocatéquico, além de metabisulfito de sódio, resorcinol e pirogalol. Os valores de Ki mostram que o ácido ascórbico foi o mais efetivo inibidor. O tipo de inibição foi determinado para cada inibidor.

Diurnal effects on mentha canadensis oil concentration and composition at two different harvests

Japanese cornmint, also known as menthol mint (Mentiza canadensis L. syn M. arvensis L.), is an essential oil crop cultivated in several countries in Asia and South America. The plant is currently the only commercially viable source for natural menthol as a result of the high concentration of menthol in the oil compared with other crops. The hypothesis of this study was that harvesting at regular intervals within a 24-hour period would have an effect on essential oil concentration and composition of Japanese cornmint grown at high altitude in northern Wyoming. Flowering plants were harvested every 2 hours on 7 to 8 Aug. and on 14 to 15 Aug. and the essential oil was extracted by steam distillation and analyzed by gas chromatography mass spectroscopy (GC-MS). The effects of harvest date (Harvest 1 and Harvest 2) and harvest time (12 times within a 24-hour period) were significant on oil concentration and yield of menthol, but only harvest date was significant on the concentration of menthol in the oil. The interaction effect of harvest date and harvest time was significant on water content and on the concentrations of menthol and menthofuran in the oil and on the yield of limonene, menthol, and menthofuran. Overall, the oil concentration in grams per 100 g dried material for the two harvests (1.26 and 1.45, respectively), the concentration of menthol in the oil (67.2% and 72.9%, respectively), and menthol yield (1066 to 849 mg/100 g dried biomass) were higher in plants at Harvest 2 as compared with plants at Harvest 1. The oil concentration was higher in plants harvested at 1100 HR or at 1300 am and lowest in the plants harvested at 1500 BR. Menthol yield was the highest in plants harvested at 1300 HR and lowest in the plants harvested at 0700 HR, 1900 am, or at 0300 HR. This study demonstrated that harvesting time within a 24-hour period and harvest date (maturity of the crop) may affect essential oil concentration and composition of Japanese cornmint grown at high altitude in northern Wyoming.

Antimicrobial activity of essential oils from plants used in Brazilian popular medicine

Essential oils from, Salvia officinalis L. (SO), Mentha sylvestris L. (MS), Casearia sylvestris Sw. (CS), Mentha piperita L. (MP), Ocimum micrantum Willd. (OM) and Mentha arvensis L. (MA), plants used in Brazilian popular medicine were extracted using method I, as described in the Brazilian Pharmacopoeia, in order to obtain the phytochemical profile and to evaluate their antimicrobial activity against the following microorganisms: Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Serratia marcescens, Candida albicans and Aspergilus oryzae. Test was made by means of the disk-plaque diffusion test in liquid medium using 1% essential oil. In the disk-plaque diffusion test, all the essential oils exhibited activity against B. subtilis, but OM showed the greatest inhibition zone and was the only one to show activity against S. aureus. Samples of SO, MS, MP, OM and MA were active against M. luteus, E. coli and S. marcescens, while A. oryzae was sensitive to MS, MP, OM and MA. No sample, however, was active against C. albicans. In the liquid medium test, significant results were observed for OM and MA, which inhibited the growth of all microorganisms for 24 hours, and OM continued active against E. coli and A. oryzae until the last reading.

Caracterização histoquimica de folhas de mentas infectadas por Puccinia menthae e Erysiphe biocellata

Pós-graduação em Agronomia (Horticultura) - FCA

Controle de Guignardia citricarpa e Penicillium digitatum em laranja com óleos essenciais e agentes de biocontrole

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Translocação orgânica, produtividade e rendimento de óleo essencial de Mentha piperita L. cultivada em solução nutritiva com variação dos níveis de N, P, K e Mg

O estudo objetivou avaliar translocação orgânica, índices fisiológicos da análise de crescimento e rendimento do óleo essencial de Mentha piperita L. cultivada em solução nutritiva com variação dos níveis de N, P, K e Mg. Assim, foram avaliados os quatro tratamentos contendo 50% N, P, K, 25% Mg; 50% N, P, K, Mg; 65%N, 50%P, 25%K, 100% Mg e 100% N, P, K, Mg. A translocação orgânica foi avaliada por meio da determinação da razão de massa foliar (RMF) e da distribuição de massa seca para os diferentes órgãos. Os índices fisiológicos razão de área foliar (RAF), área foliar específica (AFE), taxa assimilatória líquida (TAL) e taxa de crescimento relativo (TCR) derivadas que compõem a análise de crescimento foram estimados pelo programa ANACRES, após ajuste exponencial quadrático da área foliar e massa seca de lâminas foliares e total da planta em relação ao tempo. O rendimento do óleo essencial, em porcentagem, foi calculado após extração da parte aérea por hidrodestilação. As plantas submetidas ao tratamento com nível completo de nutrientes (100%N/P/K/Mg) exportaram com menor eficiência o material orgânico a partir da folha e a RMF mostrou queda mais lenta, devido à retenção desse material por mais tempo no local de sua produção. Além disso, não apresentaram melhor produtividade e as curvas da TAL e TCR mostraram quedas mais lentas. As plantas submetidas ao tratamento com 65%N/50%P/25%K/100%Mg revelaram adequada exportação de matéria orgânica da folha para caule e pecíolos, conforme demonstra a RMF e a distribuição de massa seca para esses órgãos. Revelaram ainda a RAF mais elevada no inicio do desenvolvimento e mais baixa aos 94 DAT, indicando sombreamento das folhas como resultado de seu crescimento. A AFE dessas plantas mostrou menor variação durante o ciclo, refletindo espessura mais constante de suas folhas. A TAL e a TCR apresentaram curvas decrescentes, com quedas bem acentuadas em relação às demais plantas. Todos esses índices indicam melhor produtividade das plantas submetidas ao tratamento 65%N/50%P/25%K/100%Mg, que também apresentaram rendimento de óleo essencial, em média, maior durante o ciclo. Conclui-se que a redução de 35% de N, 50% de P, 75% de K (65%N/50%P/25%K/100%Mg) é indicada para o cultivo e extração de óleo essencial de M. piperita.

Development of mint (Mentha piperita L.) grown on biosolids: evaluation of productivity and essential oil content

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Growth and development of Mentha piperita L. in nutrient solution as affected by rates of potassium

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolic Profile of Offspring from Diabetic Wistar Rats Treated with Mentha piperita (Peppermint)

This study aimed at evaluating glycemia and lipid profile of offspring from diabetic Wistar rats treated with Mentha piperita (peppermint) juice. Male offspring from nondiabetic dams (control group: 10 animals treated with water and 10 treated with peppermint juice) and from dams with streptozotocin-induced severe diabetes (diabetic group: 10 animals treated with water and 10 treated with peppermint juice) were used. They were treated during 30 days, and, after the treatment period, levels of glycemia, triglycerides, total cholesterol, and fractions were analyzed in the adult phase. The offspring from diabetic dams treated with peppermint showed significantly reduced levels of glucose, cholesterol, LDL-c, and triglycerides and significant increase in HDL-c levels. The use of the M. piperita juice has potential as culturally appropriate strategy to aid in the prevention of DM, dyslipidemia, and its complications.

Anthelmintic activity of Cymbopogon martinii, Cymbopogon schoenanthus and Mentha piperita essential oils evaluated in four different in vitro tests

Anthelmintic resistance is a worldwide concern in small ruminant industry and new plant-derived compounds are being studied for their potential use against gastrointestinal nematodes. Mentha piperita, Cymbopogon martinii and Cymbopogon schoenanthus essential oils were evaluated against developmental stages of trichostrongylids from sheep naturally infected (95% Haemonchus contortus and 5% Trichostrogylus spp.) through the egg hatch assay (EHA), larval development assay (LDA), larval feeding inhibition assay (LFIA), and the larval exsheathment assay (LEA). The major constituent of the essential oils, quantified by gas chromatography for M. piperita oil was menthol (42.5%), while for C. martinii and C. schoenanthus the main component was geraniol (81.4% and 62.5%, respectively). In all in vitro tests C. schoenanthus essential oil had the best activity against ovine trichostrongylids followed by C. martini, while M. piperita presented the least activity. Cymbopogon schoenanthus essential oil had LC(50) value of 0.045 mg/ml in EHA, 0.063 mg/ml in LDA, 0.009 mg/ml in LFIA, and 24.66 mg/ml in LEA. The anthelmintic activity of essential oils followed the same pattern in all in vitro tests, suggesting C. schoenanthus essential oil could be an interesting candidate for nematode control, although in vivo studies are necessary to validate the anthelmintic properties of this oil. (C) 2011 Elsevier B.V. All rights reserved.

Estudos de microscopia óptica e de microscopia eletrônica de varredura em folhas de Mentha spicata e de Mentha spicata x suaveolens (Lamiaceae)

O presente trabalho tem como objetivo realizar um estudo de anatomia foliar por meio de microscopia óptica e de microscopia eletrônica de varredura em Mentha spicata L. e Mentha spicata X suaveolens, caracterizando histologicamente a lâmina foliar. Secções transversais e paradérmicas da região mediana do limbo foliar mostraram a presença de epiderme unisseriada, coberta por uma fina camada de cutícula, apresentando tricomas glandulares do tipo capitado e peltado e não glandulares unisseriados multicelulares, não ramificados. O mesofilo de ambas as espécies é dorsiventral, com parênquima paliçádico uniestratificado, com células alongadas e rico em inclusões citoplasmáticas. O parênquima lacunoso é formado por três a quatro camadas de células irregulares. Os tricomas capitados presentes são classificados como do tipo I, e apresentam-se com uma célula basal, uma célula peduncular e uma grande célula apical, cujo formato varia de circular a piriforme. Os tricomas peltados consistem de uma célula basal, uma célula peduncular curta, larga e unicelular, com paredes externas cutinizadas e uma cabeça grande multicelular com 12 células secretoras, distribuídas radialmente em dois círculos concêntricos, o central com 4 células e o externo com 8 células, as quais acumulam o produto da secreção em uma cavidade entre a cutícula e as células secretoras; o pé do tricoma glandular está inserido em 11 células epidérmicas. Há predominância de tricomas capitados em relação aos tricomas peltados em ambas as espécies de Mentha.

Yield and composition of the essential oil of Mentha piperita L. (Lamiaceae) grown with biosolid

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização histológica de folhas de Mentha pulegium x spicata (Lamiaceae)

The glandular hairs of Mentha pulegium x spicata (Lamiaceae) were studied by light microscopy and scanning electron microscopy, Three morphologically distinct types of trichomes are described: two of them are glandulars (peltate and capitate) and one is non-glandular hair (tector). Capitate trichome is of Type I, and consists of a foot cell, a stalk and a unicellular head with elongated format and two lateral depressions, showing the thinnest cuticle. The peltate trichome consists of a foot cell, a stalk cell and a radial cluster of secretory cells, cover by cuticle. The tector trichomes can be simple and forked -format, both multicellular, in which there are ornamentations on cell cuticle. The leaf cross sections, analysed in light microscopy, showed mesophyll organized for unistratification palisade parenchyma and lacurary parenchyma with four to five cell stratum. It was observed the presence of cristal mass agglomerate in mesophyll cells and in epidermical cells.

Caracterização biométrica e química da folha de Mentha pulegium x spicata (Lamiaceae)

The hybrid Mentha pulegium x spicata, also well-known as poejo de praia, it is a perennial, low plant, with fields, violet stem and opposite leaves, with lance format and sawed board, presenting characteristic smell. The objective of the present work was accomplish a study of the leaf anatomy, including a biometric study of tissue and quantitative analysis of secretory trichomes/mm2 and of stomata/mm2 in both faces of the epidermis, besides a chemical analysis of the essential oil. Histological permanent laminas were made for anatomical analysis of the leaf surface and also sheets of the impression to foliate for the count of the trichomes number and stomatas. The chemical studies were made through the extraction of the essential oil by hydrodistillation and analyzed in GC-MS. The capitate and peltates trichomes are present on both sides of the leaf, even so they prevail in the abaxial surface. The variance analysis show that there are significant differences for the number of capitate trichomes and tectores between the adaxial and abaxial surfaces, but they are not significant for the peltate trichoma. The analyzed of essential oil shows the presence of a majority component, trans piperitone epoxide, being it responsible for more than 80% of the relative composition in the essential oil.