Essential oil variability in Eugenia dysenterica fruits.

Essential oils (EOs) of Eugenia dysenterica fruits from seven populations were assessed using GC/MS and chemometric analysis. Variations in EOs between populations and three operational chemical units (OCUs), combined with foliar Mn2+ as an environmental variable, indicate that 86.8% of variation in oils was explained by these predictors. Variance partitioning shows that the largest pure contribution was attributed to foliar Mn2+ (13.1%), followed by OCU (11.4%). Populational origin contributed with lowest variance (6.6%).

Chemical composition and chemotaxonomy of Nasutitermes spp. defensive secretion from Brazilian Cerrado for the differentiation of species.

Nasutitermes spp. soldier defensive secretion has a toxic and repellent effect against predators. Chemical profile characterization of this secretion is an interesting tool to differentiate similar termite species. This study aimed to determine defensive secretion composition of Nasutitermes spp. soldier and to apply chemotaxonomy tool for the unambiguous species identification. Fifteen volatile compounds were identified by gas chromatography-mass spectrometry. Multivariate analysis classified populations into three groups. Principal component (PCA), axis 1, was able to separate two groups: group I, colonies 1 and 2 (Nasutitermes corniger) and group II, colony 3 (Nasutitermes ephratae). Therefore, determination of defensive chemical secretion profile proved to be very useful in termite chemotaxonomy, since it was able to differentiate morphologically similar specimens.

Chemovariations in Hypenia essential oils under infrageneric and phenological influences.

The essential oils (EOs) of six Hypenia species that are endemic in the central Brazilian Cerrado were assessed by GC/MS and chemometric analysis. EO variations according to two taxonomic sections, combined with two phenophases (vegetative and reproductive), showed that 23.2% of total variance was explained by such predictors. Variation partitioning showed that the largest pure contribution was attributed to section (43.7%), followed by phenophase (39.3%), with 17% of joint influence. A multivariate regression tree (MRT) indicated that 13 EO constituents may be potential chemomarkers for distinguishing sections and two developmental stages in the genus.

Variability of polyphenols and volatiles during fruit development of three pitanga (Eugenia uniflora L.) biotypes.

Changes in volatile constituents and phenolic compounds were investigated during fruit development of three pitanga biotypes. Constituents were submitted to multivariate analysis and fruit samples were differentiated by selina-1,3,7(11)-trien-8-one (38.2 ±â€¯2.9%) and its epoxide (26.4 ±â€¯7.2%) for the red-orange biotype; by curzerene (15.04 ±â€¯2.1%) and atractylone (8.47 ±â€¯2.1%) for the red biotype; and by spathulenol (3.7 ±â€¯0.8%) and germacrone (54.7 ±â€¯3.1%) for the purple biotype. Hydrolysable tannins such as mono-O-galloyl-d-glucose, 1,2,6-tri-O-galloyl-ß-d-glucose, tellimagrandin II, and eugeniflorin D2 were identified, as well as oenothein B as the major compound (32.43 ±â€¯7.1 mg/g dry fruit). During pitanga's maturation, anthocyanin content increased, while flavonoid and tannin contents decreased. Higher contents of the majority of phenolic compounds occurred in the red-orange biotype. Biosynthesis of phenolic compounds was influenced by biotype and degree of maturation, whereas chemovariation in essential oil constituents was mainly due to biotypes, thus confirming essential oil chemotypes of E. uniflora.

Seasonal changes of fructans in dimorphic roots of Ichthyothere terminalis (Spreng.) Blake (Asteraceae) growing in Cerrado.

Cerrado is a floristically rich savanna in Brazil, whose vegetation consists of a physiognomic mosaic, influenced by rainfall seasonality. In the dry season rainfall is substantially lower and reduces soil water supply, mainly for herbs and subshrubs. Climatic seasonal variations may well define phenological shifts and induce fluctuations of plant reserve pools. Some Cerrado native species have thickened underground organs that bear buds and store reserves, as adaptive features to enable plant survival following environmental stresses. Asteraceae species accumulate fructans in storage organs, which are not only reserve, but also protecting compounds against the effects of cold and drought. Ichthyothere terminalis is one Asteraceae species abundant in cerrado rupestre, with underground organs consisting of thickened orthogravitropic and diagravitropic roots. The objectives of this study were to analyze how abiotic environmental factors and plant phenology influence fructan dynamics in field grown plants, and verify if fructan metabolism differs in both root types for one year. I. terminalis accumulates inulin-type fructans in 10-40% of the dry mass in both root types. Fructan dynamics have similar patterns described for other Asteraceae species, exhibiting a proportional increase of polysaccharides with the senescence of the aerial organs. Multivariate analyzes showed that, as rainfall decreased, environmental factors had a stronger influence on metabolite levels than phenological shifts in both root types. Only slight differences were found in fructan dynamics between orthogravitropic and diagravitropic roots, suggesting they may have similar fructan metabolism regulation. However, these small differences may reflect distinct microclimatic conditions in both root types and also represent the influence of sink strength.

Polyphenol and Ellagitannin Constituents of Jabuticaba (Myrciaria cauliflora) and Chemical Variability at Different Stages of Fruit Development.

A new ellagitannin named cauliflorin (1), seven known hydrolyzable tannins (2-8), and six known phenolics (9-14) were isolated from jabuticaba. Compounds 2-8 had not been previously isolated from M. cauliflora fruits. The jabuticaba fruit was analyzed at four developmental stages for ellagitannins 1, 3, 7, and 8, phenolic acids 11 and 12, anthocyanins, organic acids, and sugars via HPLC-UV-DAD and NMRq. The content of ellagitannins and organic acids declined during fruit development, whereas at full ripeness sugar and anthocyanin levels underwent a sharp increase and were mainly constituted by fructose and cyanidin-3-O-glucose, respectively. Ellagitannins' profile varied considerably among fruit tissues, with pedunculagin (3), castalagin (7), and vescalagin (8) mostly concentrated in jabuticaba seeds, whereas cauliflorin (1) and anthocyanins accumulated in the peels. Changes in jabuticaba's phenolic compound contents were mostly influenced by fruit part (peel, pulp, and seed) rather than by degree of ripeness.

Essential Oil Composition, Antimicrobial and Pharmacological Activities of Lippia sidoides Cham. (Verbenaceae) From São Gonçalo do Abaeté, Minas Gerais, Brazil.

BACKGROUND: Lippia sidoides (Verbenaceae) is used in Brazilian folk medicine as an antiseptic, and it is usually applied topically on skin, mucous membranes, mouth, and throat, or used for vaginal washings. OBJECTIVES: To analyze the chemical composition of the essential oil from L. sidoides collected in São Gonçalo do Abaeté, Minas Gerais and grown in Hidrolândia, Goiás; to evaluate the antimicrobial activity of the essential oil, crude ethanol extract, and hexane, dichloromethane, ethyl-acetate, and aqueous fractions (AFs); to study the antinociceptive, anti-inflammatory, and central nervous system activities of the crude ethanol extract. MATERIALS AND METHODS: The essential oils were obtained by hydro-distillation using a Clevenger-type apparatus and analyzed by GC/MS. The antimicrobial activity in vitro was performed by broth microdilution method. The pharmacological tests were performed using female Swiss albino mice. RESULTS: The major components of the essential oil were isoborneol (14.66%), bornyl acetate (11.86%), α-humulene (11.23%), α-fenchene (9.32%), and 1.8-cineole (7.05%), supporting the existence of two chemotypes of this species. The hexane fraction (HF) had good antifungal activity against Cryptococcus sp. ATCC D (MIC = 31.25 µg/mL) and Cryptococcus gatti L48 (MIC = 62.5 µg/mL). In the pharmacological tests, the crude ethanol extract presented antinociceptive and anti-inflammatory activities. CONCLUSION: Given that the ethanol extract of L. sidoides is included in the Formulary of Phytotherapeutic Agents of the Brazilian Pharmacopeia as an anti-inflammatory for oral cavities, the present work provides scientific evidence to back this use and highlight the importance of selecting the appropriate chemotype on the basis of the expected biological response. SUMMARY: The major components of the essential oil of L. sidoides were isoborneol bornyl acetate, α-humulene, α-fenchene, and 1.8-cineole. The HF had good antifungal activity against Cryptococcus sp. ATCC D and C. gatti L4.The crude ethanol extract of L. sidoides presented antinociceptive and anti-inflammatory activities.The present work provides scientific evidence of the importance of selecting the appropriate chemotype on the basis of the expected biological response. Abbreviations used: UFG: Universidade Federal de Goiás; HF: hexane fraction; DF: dichloromethane fraction; EAF: ethyl acetate fraction; AF: aqueous fraction; MeOH: methanol; MIC: minimum inhibitory concentration; ATCC: American Type Culture Collection; MH: Müller Hinton; DMSO: dimethyl sulfoxide; RPMI: Roswell Park Memorial Institute; NaCl: sodium chloride; µL: microliters; mL: milliliters; µg: microgram; kg: kilogram; h: hour; min: minute; cm: centimeter; COBEA: Brazilian College of Animal Experiments; p.o.:, oral; i.p.: intraperitoneal; s.c.: subcutaneous; SEM: standard error of the mean; RI: retention indices.

Unveiling chemical defense in the rice stalk stink bug against the entomopathogenic fungus Metarhizium anisopliae.

Eggs, nymphs (1st-5th instar) and adults of Tibraca limbativentris were challenged by conidial suspensions of its major fungal pathogen Metarhizium anisopliae in order to assess their susceptibility. The role of chemical defensive compounds from exocrine secretions produced by both nymphs and adults were examined for their participation on M. anisopliae infection. Although insect susceptibility to M. anisopliae followed a dose-dependent manner, adults followed by older nymphs displayed the highest resistance. Eggs were highly susceptible showing >96% fungal infection. Crude extracts isolated from metathoracic scent gland and dorsal abdominal glands of adults and nymphs, respectively, showed fungistatic effects by impairing spore germination, vegetative growth and sporulation. Gas chromatography-mass spectrometry analysis of these extracts revealed that the major components were short-chain hydrocarbons (C10-13) and unsaturated aldehydes. In vitro tests with the corresponding synthetic standards indicated compounds with greater antifungal activity including (E)-2-hexenal, (E)-2-octenal, and (E)-2-decenal, with the latter being the most deleterious to fungal fitness. We demonstrated that differential susceptibility of the rice stalk stink bug to M. anisopliae infection is age-specific and partly mediated by fungistatic properties of aldehydes, which are produced by scent glands of both nymphs and adults.

Genotoxicity and cytotoxicity evaluation of oenothein B and its protective effect against mitomycin C-induced mutagenic action.

The natural product oenothein B (OeB), a dimeric macrocyclic ellagitannin, has a wide range of biological activities, such as antioxidant, anti-inflammatory, anti-viral, antifungal, and antitumor. However, investigations concerning its genotoxicity have not been carried out. This study assessed the cytotoxicity, genotoxicity, and protective effects of oenothein B using in vitro SOS-Inductest and in vivo mouse bone marrow micronucleus (MN) assay through oral and intraperitonial routes. In both assays oenothein B did not produce genotoxic effects in any of doses tested; in contrast, cytotoxic effect in cells was detected only in mice groups treated by both routes and exposed for 24 and 48h. Antigenotoxic and anticytotoxic activities of oenothein B were evaluated using both assays in combination with mitomycin C (MMC), a bioreductive alkylating agent. In the MN assay, a significant reduction was observed in MN frequency in all groups co-treated with MMC and OeB compared to those which received only MMC. Anticytotoxicity was observed in mice groups exposed to OeB and MMC for 24 and 48h. In the SOS-Inductest, oenothein B failed to show antigenotoxic and anticytotoxic effects; thus, it undoubtedly showed an in vivo protective activity against primary DNA damage induced by mitomycin C.

Composição química e atividade antimicrobiana dos óleos essenciais das folhas e flores de Callistemon viminalis (sol. ex Gaertn.) G. Don ex. Loudon (Myrtaceae) / Chemical composition and antimicrobial activity of essential oils of leaves and flowers of Callistemon viminalis (sol. ex Gaertn.) G. Don ex. Loudon (Myrtaceae)

O presente trabalho teve como objetivo determinar a composição química e avaliar a atividade antimicrobiana dos óleos essenciais obtidos das folhas (frescas e secas) e flores da Callistemon viminalis. Os óleos essenciais foram analisados por CG/EM. A concentração inibitória mínima (CIM) foi determinada utilizando o método de microdiluição em caldo frente a bactérias Gram-positivas e Gram-negativas. De um total de 96,72%, 98,70% dos compostos identificados nos óleos essenciais foram monoterpenos. O 1,8-cineol foi o componente majoritário no óleo essencial das folhas frescas (70,43%), folhas secas (71,71%) e flores (42,39%), seguido do tricicleno com 12,97% nas folhas frescas, 8,20% nas folhas secas e 28,08% nas flores. A CIM para todos os micro-organismos testados foi ≥ a 2.000 μg/mL. Esse estudo é o primeiro relato sobre a composição química e atividade antimicrobiana do óleo essencial das flores de C. viminalis.

The aim of this study was to determine the chemical composition and the antimicrobial activity of essential oils of Callistemon viminalis leaves (fresh and dried) and flowers. The essential oils were analyzed by GC/MS and the minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria was determined by the broth microdilution method. Between 96.72% and 98.70% of the compounds identified in the essential oils were monoterpenes. 1,8-Cineole was the major component in the essential oils of fresh leaves (70.43%), dried leaves (71.71%) and flowers (42.39%), followed by tricyclene: 12.97% in the fresh leaves, 8.20% in the dried leaves and 28.08% in the flowers. The MIC for all microorganisms tested was ≥ 2,000 μg/mL, for all the essential oil samples. This study is the first report on the chemical composition and antimicrobial activity of essential oil from the flowers of C. viminalis.

Composição química e atividade antimicrobiana do óleo essencial e anatomia foliar e caulinar de Citrus limettioides Tanaka (Rutaceae) / Chemical Composition and Antimicrobial Activity of Essential Oil and Anatomy of Citrus limettioides Tanaka(Rutaceae) Leaves and Stem

Citrus limettioides (Rutaceae) é utilizada popularmente para tratamento da sinusite, e também como antitérmica e hipotensora. Este trabalho teve como objetivos: identificar os constituintes dos óleos essenciais da folha e da casca dos frutos de C. limettioides; avaliar a atividade antimicrobiana dos óleos essenciais da folha e da casca dos frutos e realizar o estudo anatômico da folha e caule jovem. Os óleos essenciais foram obtidos por hidrodestilação em aparelho de Clevenger modificado e analisados por CG-EM. A concentração inibitória mínima (CIM) foi determinada utilizando o método de microdiluição em caldo frente a bactérias Gram-positivas, Gram-negativas e fungos. Para o estudo anatômico foram realizados cortes histológicos a mão livre e as secções foram coradas com azul de Alcian/safranina, reagente de Steinmetz, lugol e analisados em microscopia de luz. O linalol foi o componente majoritário no óleo essencial das folhas (36,88 a 45,15%) e o limoneno no óleo da casca dos frutos (70,60 a 75,18%). O óleo essencial das folhas apresentou CIM de 2000 μg/mL frente às bactérias e nenhuma atividade frente aos fungos. O óleo essencial da casca dos frutos não apresentou atividade antimicrobiana. A folha é hipoestomática, predominando os estômatos anomocíticos; o mesofilo é dorsiventral com parênquima paliçádico bisseriado e parênquima lacunoso com 11 camadas de células. Cavidades secretoras foram observadas no mesofilo da folha, no pecíolo e no caule, enquanto cristais prismáticos foram identificados em todas as estruturas da folha e do caule. Os dados obtidos no estudo microscópico podem auxiliar na identificação taxonômica desta planta e na avaliação da autenticidade da droga vegetal.

Citrus limettioides (Rutaceae), a sweet lime, is popularly used to treat sinusitis, and as an antipyretic and hypotensive agent.the aim of this study was to identify the constituents of the essential oils from the leaf and fruit peel of C. limettioides, test the antimicrobial activity of these essential oils and perform an anatomical study of the leaf and young stem. Essential oils were isolated by steam distillation in a modified Clevenger apparatus and analyzed by GC-MS. the minimum inhibitory concentrations (MIC) against Gram-positive and Gram-negative bacteria and fungi were determined by broth microdilution.Anatomical studies were performed on freehand histological sections, which were stained with Alcian blue / safranin, Steinmetz reagent and lugol and analyzed by light microscopy. Linalol was the major component in the leaf essential oil (36.88 to 45.15%) and limonene in the fruit peel essential oil (70.60 to 75.18%).the essential oil from leaves showed antimicrobial activity against bacteria (MIC 2000 μg/mL) and no activity against fungi.the essential oil from the fruit peel showed no antimicrobial activity. the leaf is hypostomatic with predominance of anomocytic stomata, the mesophyll is dorsiventral with biseriate palisade and 11 layers of spongy parenchyma cells.Secretory cavities were observed among the mesophyll cells of the leaf, petiole and stem, whilst prismatic crystals were identified in all structures of leaf and stem. the anatomical data obtained in the microscopic study may help in the taxonomic identification of this plant and to verify the authenticity of the drug plant.

Transcriptional profile of Paracoccidioides induced by oenothein B, a potential antifungal agent from the Brazilian Cerrado plant Eugenia uniflora.

BACKGROUND: The compound oenothein B (OenB), which is isolated from the leaves of Eugenia uniflora, a Brazilian Cerrado plant, interferes with Paracoccidioides yeast cell morphology and inhibits 1,3-ß-D-glucan synthase (PbFKS1) transcript accumulation, which is involved in cell wall synthesis. In this work we examined the gene expression changes in Paracoccidioides yeast cells following OenB treatment in order to investigate the adaptive cellular responses to drug stress. RESULTS: We constructed differential gene expression libraries using Representational Difference Analysis (RDA) of Paracoccidioides yeast cells treated with OenB for 90 and 180 min. Treatment for 90 min resulted in the identification of 463 up-regulated expressed sequences tags (ESTs) and 104 down-regulated ESTs. For the 180 min treatment 301 up-regulated ESTs and 143 down-regulated were identified. Genes involved in the cell wall biosynthesis, such as GLN1, KRE6 and FKS1, were found to be regulated by OenB. Infection experiments in macrophages corroborated the in vitro results. Fluorescence microscopy showed increased levels of chitin in cells treated with OenB. The carbohydrate polymer content of the cell wall of the fungus was also evaluated, and the results corroborated with the transcriptional data. Several other genes, such as those involved in a variety of important cellular processes (i.e., membrane maintenance, stress and virulence) were found to be up-regulated in response to OenB treatment. CONCLUSIONS: The exposure of Paracoccidioides to OenB resulted in a complex altered gene expression profile. Some of the changes may represent specific adaptive responses to this compound in this important pathogenic fungus.

Chemical Constituents of Essential Oil from Lippia sidoides Cham. (Verbenaceae) Leaves Cultivated in Hidrolândia, Goiás, Brazil.

Several studies involving the family Verbenaceae, occurring in the Brazilian Cerrado, have emphasized the popular use of many aromatic species. We highlight the use of Lippia sidoides Cham., known as "alecrim pimenta," native to northeastern Brazil and northern Minas Gerais. Leaves of this species were collected in antropized Brazilian Cerrado area, in Hidrolândia, Goiás, and their essential oils were extracted by hydrodistillation in a Clevenger-type apparatus and thereafter analyzed GC/MS. Among the compounds identified in this study were the most abundant oxygenated monoterpenes, followed by sesquiterpenes hydrocarbons. The oxygenated monoterpene 1,8-cineole was the major constituent followed by isoborneol and bornyl acetate. The chemical composition of essential oil described in this paper differs from that described in the literature for L. sidoides found in its native environment, where the major constituents are thymol and carvacrol.

Molecular analysis and dimorphism of azole-susceptible and resistant Candida albicans isolates / Análise molecular e dimorfismo de isolados de Candida albicans suscetíveis e resistentes aos azólicos

INTRODUCTION: Candida albicans is responsible for superficial or systemic infections known as candidiasis, which may be found in infected tissue as unicellular budding yeasts, hyphae, or pseudohyphae. In this study, the effects of both fluconazole and itraconazole antifungal agents on the hyphal formation and genotypic characterization of C. albicans isolates classified as either susceptible or resistant were investigated. METHODS: The hyphal production of five C. albicans isolates under the action of antifungal agents was investigated by culturing yeast on growth medium and on hyphal induction medium. The genotypic characterization was carried out for 13 isolates of C. albicans using the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) method. RESULTS: The dimorphism analysis showed that the hyphal formation was higher in resistant than in the susceptible isolates to both azoles. The RAPD-PCR method identified the formation of two different groups. In group A, four resistant and two susceptible isolates were clustered, and in group B, one resistant and six susceptible isolates were clustered. CONCLUSIONS: Considering that hyphal formation was higher in resistant isolates in the presence of azole drugs, we confirmed that the hyphal production is closely related to susceptibility to azoles. These drugs may affect the morphogenesis of C. albicans depending on their susceptibility to these drugs. In relation to RAPD-PCR, most resistant isolates classified in group A and susceptible isolates in group B demonstrated that this method presented a similar standard between the two groups, suggesting that by this technique, a strong correlation between genotypes and fluconazole-resistant samples may be found.

INTRODUÇÃO: Candida albicans é responsável por infecções superficiais ou sistêmicas conhecidas como candidíase, encontrada em tecidos infectados na forma de leveduras brotantes unicelulares, hifas ou pseudohifas. Neste estudo, os efeitos de agentes antifúngicos como o fluconazol e o itraconazol sobre a formação de hifas e caracterização genotípica de isolados de C. albicans suscetíveis ou resistentes foram investigados. MÉTODOS: A produção de hifas de cinco isolados de C. albicans, sob a ação de antifúngicos foi investigada pelo cultivo da levedura em meios de crescimento e de indução de hifas. A caracterização genotípica foi realizada para 13 isolados de C. albicans pelo método de RAPD-PCR. RESULTADOS: A análise do dimorfismo mostrou que a formação de hifas foi maior nos isolados resistentes do que nos suscetíveis aos antifúngicos. O método de RAPD-PCR identificou a formação de dois diferentes grupos. No grupo A, foram agrupados quatro isolados resistentes e dois suscetíveis e no grupo B um resistente e seis suscetíveis. CONCLUSÕES: Considerando que a formação hifal foi maior em isolados resistentes na presença de azólicos, concluimos que a produção hifal está muito relacionada a suscetibilidade a estes fámacos. Estes antifúngicos podem alterar a morfologia de C. albicans em dependência da sua suscetibilidade. No método de RAPD-PCR, o encontro da maioria dos isolados resistentes classificados como pertencentes ao grupo A e suscetíveis ao grupo B demonstrou que este método apresentou um padrão semelhante entre os dois grupos, sugerindo que por este método pode ser detectado uma estreita correlação entre genótipos e amostras resistentes ao fluconazol.

Influence of environmental factors on the concentration of phenolic compounds in leaves of Lafoensia pacari

Lafoensia pacari A. St.-Hil., Lythraceae, a plant from the Cerrado known as pacari or dedaleiro, is widely used as an antipyretic, wound healing, anti-inflammatory, antidiarrheal and in the treatment of gastritis and cancer. Notable among the metabolite groups identified in leaves of L. pacari are the polyphenols, such as tannins and flavonoids, related to the pharmacological activities of pacari. Studies on the influence of environmental factors over production of major groups of secondary metabolites in pacari are important because they contribute data for its cultivation and harvest, and establish quantitative parameters of secondary metabolites in the plant drug. The objective of this study was to evaluate the influence of environmental factors on concentrations of phenolic metabolites in the leaves of L. pacari. Compounds quantified in the leaves were: total phenols, tannins by protein precipitation, hydrolysable tannins, total flavonoids, ellagic acid and mineral nutrients, while soil fertility was also analyzed, all over a period of one year. The data were analyzed using multivariate analysis, and the results suggest that metabolite concentrations in the leaves of this plant are influenced by seasonal factors, in particular the temperature and foliar micronutrients (Cu, Fe, Mn, Zn).

Molecular analysis and dimorphism of azole-susceptible and resistant Candida albicans isolates.

INTRODUCTION: Candida albicans is responsible for superficial or systemic infections known as candidiasis, which may be found in infected tissue as unicellular budding yeasts, hyphae, or pseudohyphae. In this study, the effects of both fluconazole and itraconazole antifungal agents on the hyphal formation and genotypic characterization of C. albicans isolates classified as either susceptible or resistant were investigated. METHODS: The hyphal production of five C. albicans isolates under the action of antifungal agents was investigated by culturing yeast on growth medium and on hyphal induction medium. The genotypic characterization was carried out for 13 isolates of C. albicans using the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) method. RESULTS: The dimorphism analysis showed that the hyphal formation was higher in resistant than in the susceptible isolates to both azoles. The RAPD-PCR method identified the formation of two different groups. In group A, four resistant and two susceptible isolates were clustered, and in group B, one resistant and six susceptible isolates were clustered. CONCLUSIONS: Considering that hyphal formation was higher in resistant isolates in the presence of azole drugs, we confirmed that the hyphal production is closely related to susceptibility to azoles. These drugs may affect the morphogenesis of C. albicans depending on their susceptibility to these drugs. In relation to RAPD-PCR, most resistant isolates classified in group A and susceptible isolates in group B demonstrated that this method presented a similar standard between the two groups, suggesting that by this technique, a strong correlation between genotypes and fluconazole-resistant samples may be found.

Potential synergistic effect of Melia azedarach fruit extract and Beauveria bassiana in the control of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in cattle infestations.

The use of a concentrate emulsion of Melia azedarach green fruits and a suspension of the fungus Beauveria bassiana was evaluated in the control of Rhipicephalus microplus on artificially infested cattle. The evaluation was conducted following the protocol established by the Brazilian Agriculture Ministry. Five groups of 4 or 5 animals were allocated to one of the following treatments: emulsion concentrate of M. azedarach at 0.25% (T AZED 0.25%), emulsion concentrate of M. azedarach at 0.5% (T AZED 0.5%), B. bassiana at 2.4 × 10(8) conidia (T BASS), association of the concentrate of M. azedarach at 0.25% with B. bassiana at 2.4 × 10(8) conidia (T AZED 0.25%+BASS), and control (untreated). The association of the two compounds provided better results than any one isolated treatment, indicating compatibility or perhaps a synergy between M. azedarach and B. bassiana. This treatment resulted in fewer engorged females (129 ± 70) than in the control group (233 ± 82), showing high performance against all developmental stages of the tick. Results revealed an apparent synergistic effect of M. azedarach and B. bassiana in the control of R. microplus that should be further investigated.

Repellent activity of plant-derived compounds against Amblyomma cajennense (Acari: Ixodidae) nymphs.

Repellence responses of Amblyomma cajennense nymphs to callicarpenal, intermedeol, Hyptis suaveolens essential oil, extract of Melia azedarach, Cymbopogon nardus, Spiranthera odoratissima, Chenopodium ambrosioides, Ageratum conyzoides, Mentha pulegium, Ruta graveolens, and Memora nodosa were studied. Among these the extract of C. nardus stood out because of the long-lasting repellence, maintaining, in the highest concentration, 35h of protection against 90% of the nymphs. The essential oil of H. suaveolens and the extracts of C. ambrosioides and A. conyzoides showed good repellence index (66%) when applied in high concentrations. However, greater protection could be obtained at higher concentrations but with a shorter repellence time. Callicarpenal, intermedeol, extract of M. Pulegium, and M. nodosa leaves showed moderate repellence in high concentrations. Extracts from M. azedarach, R. graveolens, S. odoratissima, and M. nodosa roots showed little or no repellent effect. These results show that some plant extracts may represent a promising alternative in the control of infestations by A. cajennense.