Production and Characterization of k-Carrageenan Films Incorporating Cymbopogon winterianus Essential Oil as New Food Packaging Materials.

The global production of synthetic plastics from petroleum-based raw ingredients exceeds 150 million metric tons. The environment is threatened by tons of plastic waste, thus endangering wildlife and the public's health. These consequences increased the interest in biodegradable polymers as potential substitutes for traditional packaging materials. This study aimed to produce and characterize k-carrageenan films incorporating Cymbopogon winterianus essential oil, in which citronellal was determined to be the major compound (41.12%). This essential oil presented remarkable antioxidant activity, as measured through DPPH (IC50 = 0.06 ± 0.01%, v/v; AAI = 85.60 ± 13.42) and ß-carotene bleaching (IC50 = 3.16 ± 0.48%, v/v) methods. The essential oil also showed antibacterial properties against Listeria monocytogenes LMG 16779 (diameter of inhibition zone = 31.67 ± 5.16 mm and MIC = 8 µL/mL), which were also observed when incorporated in the k-carrageenan films. Moreover, scanning electron microscopy showed the reduction of the biofilms of this bacterium, and even its inactivation, due to visible destruction and loss of integrity when the biofilms were created directly on the developed k-carrageenan films. This study also revealed the quorum sensing inhibition potential of Cymbopogon winterianus essential oil (diameter of violacein production inhibition = 10.93 ± 0.81 mm), where it could impede intercellular communication and, hence, lower violacein synthesis. The produced k-carrageenan films were transparent (>90%) and slightly hydrophobic (water contact angle > 90°). This work demonstrated the viability of using Cymbopogon winterianus essential oil to produce k-carrageenan bioactive films as new food packaging materials. Future work should focus on the scale-up production of these films.

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification / Toxicidade e atividade larvicida sobre Aedes aegypti de óleo essencial de citronella submetido à esterificação enzimática

The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-¹ were obtained for the essential oil and 4.36 μg mL-¹ for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-¹ for the essential oil of citronella and 86.30 μg mL-¹ for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 μg mL-¹ para o óleo essencial e 4,36 μg mL-¹ para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 μg mL-¹ para o óleo essencial de citronela e 86,30 μg mL-¹ para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification

Abstract The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 g mL-1 were obtained for the essential oil and 4.36 g mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 g mL-1 for the essential oil of citronella and 86.30 g mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

Resumo O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 g mL-1 para o óleo essencial e 4,36 g mL-1 para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 g mL-1 para o óleo essencial de citronela e 86,30 g mL-1 para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification / Toxicidade e atividade larvicida sobre Aedes aegypti de óleo essencial de citronella submetido à esterificação enzimática

Abstract The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-1 were obtained for the essential oil and 4.36 μg mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-1 for the essential oil of citronella and 86.30 μg mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

Resumo O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 μg mL-1 para o óleo essencial e 4,36 μg mL-1 para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 μg mL-1 para o óleo essencial de citronela e 86,30 μg mL-1 para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy coupled with chemometric analysis for detection and quantification of adulteration in lavender and citronella essential oils.

INTRODUCTION: The growing consumer interest in "naturals" led to an increased application of essential oils (EOs). The market outbreak induced the intensification of EO adulterations, which could affect their quality. OBJECTIVES: Nowadays, little is known about the illegal practice of adulteration of EOs with vegetable oils. Therefore, the application of mid-infrared spectroscopy coupled with chemometrics was proposed for the detection of EO counterfeits. MATERIALS AND METHODS: Two EOs, three seed oils, and their mixtures were selected to build the adulteration model. EO-adulterant mixtures for model calibration and validation were analyzed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The spectral data were analyzed with principal component analysis (PCA) and partial least-squares (PLS) regression. RESULTS: PCA allowed the discrimination of the EO and adulterant percentages by explaining 97.47% of the total spectral variance with two principal components. A PLS regression model was generated with three factors explaining 97.73% and 99.69% of the total variance in X and Y, respectively. The root mean square error of calibration and the root mean square error of cross-validation were 0.918 and 1.049, respectively. The root mean square error of prediction value obtained from the external validation set was 1.588 and the coefficients of determination R2 CAL and R2 CV were 0.997 and 0.996, respectively. CONCLUSIONS: The results highlighted the robustness of the developed method in quantifying counterfeits in the range from 0 to 50% of adulterants, disregarding the type of EO and adulterant employed. The present work offers a research advance and makes an important impact in phytochemistry, revealing an easily applicable method for EO quality assessment.

Biological properties of functional flavoring produced by enzymatic esterification of citronellol and geraniol present in Cymbopogon winterianus essential oil.

The chemical composition and biological properties of citronella essential oil were modified by enzymatic esterification reaction of the major monoterpenic alcohols with cinnamic acid. The almost complete conversion of geraniol and citronellol present in the citronella (Cymbopogon winterianus) essential oil, into geranyl (99%) and citronellyl (98%) cinnamates was obtained after 48 hours of reaction using a molar ratio of 3:1 (cinnamic acid/alcohol), lipase concentration (Novozym 435) of 15% (w/w) and 70 °C. The esterified oil showed higher antimicrobial activity against Staphylococcus aureus bacteria resistant to oxacillin and penicillin and also greater larvicidal activity against Aedes aegypti larvae compared to unesterified oil. The results concerning the evaluation of toxicity against Artemia salina and cytotoxicity against monkey kidney epithelial cells also showed the superiority of the esterified oil.

Fungicidal potential of essential oils in control of Fusarium spp. and Sclerotinia sclerotiorum / Potencial fungicida de óleos essenciais no controle de Fusarium spp. e Sclerotinia sclerotiorum

The use of highly toxic pesticides to control soil pathogens, such as Fusarium spp. and Sclerotinia sclerotiorum has generated concern, due to the irreversible impacts caused on the environment, in addition to selecting resistant isolates. In this way, essential oils appear as an efficient alternative in control of diseases. Facing the problem of soil pathogens control and high antimicrobial fungicide that essential oils present, this work aimed to evaluate the in vitro fungicidal potential of essential oils in control of Fusarium spp. and S. sclerotiorum. A completely randomized design, factorial scheme 2×4×8 was used, with two isolates (Fusarium spp. and S. sclerotiorum), four essential oils (Aloysia citriodora, Cymbopogon winterianus, Lippia alba and Ocimum americanum), eight essential oil concentrations (0.0; 0.2; 0.4; 0.6; 0.8; 1.0; 1.2 and 1.4 ?L·mL-1), and ten replicates. The essential oils inhibited mycelial growth of the fungi in different concentrations, being their potential justified by the presence of antifungal chemical compounds. Essential oils of A. citriodora, C. winterianus, L. alba and O. americanum present high fungicidal potential, being viable alternatives for formulation of commercial products, boosting the pesticides industry.(AU)

O uso de pesticidas com alta toxicidade para controlar patógenos do solo, como Fusarium spp. e Sclerotinia sclerotiorum, tem gerado preocupação, devido aos impactos irreversíveis causados no meio ambiente, além de selecionar isolados resistentes. Dessa forma, os óleos essenciais surgem como uma alternativa eficiente no controle de doenças. Diante da problemática de controle de patógenos do solo e alto potencial antimicrobiano que os óleos essenciais possuem, este trabalho teve como objetivo avaliar o potencial fungicida de óleos essenciais no controle de Fusarium spp. e S. sclerotiorum, in vitro. Utilizou-se um delineamento inteiramente randomizado, esquema fatorial 2×4×8, com dois isolados (Fusarium spp. e S. sclerotiorum), quatro óleos essenciais (Aloysia citriodora, Cymbopogon winterianus, Lippia alba e Ocimum americanum) e oito concentrações de óleo essencial (0,0; 0,2; 0,4; 0,6; 0,8; 1,0; 1,2 e 1,4 ?L·mL-1), com dez repetições. Os óleos essenciais inibiram o crescimento micelial dos fungos em diferentes concentrações, sendo seu potencial justificado pela presença de compostos químicos antifúngicos. Os óleos essenciais de A. citriodora, C. winterianus, L. alba e O. americanum apresentam alto potencial fungicida, sendo alternativas viáveis para formulação de produtos comerciais, impulsionando a indústria de agrotóxicos.(AU)

Sono hydrodistillation for isolation of citronella oil: A symbiotic effect of sonication and hydrodistillation towards energy efficiency and environment friendliness.

Environmental benign approach for extraction of essential oil was made. An essential oil rich in citronellol, linalool and citronellal was extracted from the leaves of Cymbopogon winterianus using a clean hybrid extraction technique, sono hydrodistillation. Sono hydrodistillation combines ultrasonic waves along with conventional hydrodistillation process to have symbiotic outcomes in terms of process improvement. Significant process parameters such as size of the plant material, extraction time, power, ultrasound amplitude, pulse interval and solid loading were investigated independently to study the effect on yield of oil and composition of oil. The water residue remained after extraction of volatile oil was analyzed using Folin-Ciocalteu method to determine the total phenolic content (TPC) which would help in assessing the residue as a useful by-product. Substantial reduction in time was observed with the inclusion of ultrasound compared to conventional hydrodistillation. Further, to optimize the extraction conditions, observe interactive effects of various parameters and develop mathematical model, response surface methodology was employed. The maximum yield of oil was found to be 4.118% (w/w) at 21 min extraction time, 5 g solid loading, 250 mL water volume, 500 W heating mantle power, 70% ultrasonic amplitude and 10:50 pulse interval. Total phenolic content was 13.84 mg GAE/g DM. The citronella oil was found to be composed of 27.47% of linalool, 11.52% of citronellal, 34.25% citronellol and 11.15% of elemol. Extraction time, solid loading and pulse interval had the significant influence on the yield of oil and total phenolic contents. Microscopic analysis has assisted in envisaging the probable mechanism indicating the role of sonication for rapid extraction. This novel technique was compared with the conventional hydrodistillation to ascertain the impact towards process intensification. Sono hydrodistillation was found to be a greener and cleaner process as energy consumption has been reduced by 40% while carbon footprint has shrunken by 47%.

Atividade fungicida do óleo essencial de Cymbopogon winterianus jowit (Citronela) contra Fusarium solani / Fungicide activity of essential oil Cymbopogon winterianus jowit (Citronella) against Fusarium solani

O declínio é a principal doença da goiabeira causada pelo parasitismo de Meloidogyne enterolobii e pelo fungo Fusarium solani, tem sido responsável pela erradicação de muitos pomares em âmbito nacional, o que resulta em elevada perda econômica aos produtores. Devido à crescente pressão da sociedade por produtos naturais e com o aumento da importância dos óleos essenciais no manejo de doenças de plantas, o objetivo deste trabalho foi identificar os principais componentes e avaliar o efeito fungitóxico do óleo essencial de Cymbopogon winterianus (citronela) sobre três isolados de Fusarium solani (UENF/CF163, UENF/CF241 e UENF/CF295). O óleo essencial foi obtido por hidrodestilação, utilizando o aparelho tipo Clevenger. Os compostos foram identificados por cromatografia gasosa e cromatografia gasosa com detector de massas do óleo essencial. Para avaliar o efeito dos óleos essenciais no crescimento micelial, esporulação e germinação de esporos do fungo, foram utilizadas alíquotas de 5, 10, 15, 20, 25 e 30 µL do óleo essencial que foram distribuídas na superfície do meio de cultura BDA contido em placas de Petri antes da repicagem do fungo. O delineamento experimental foi inteiramente casualizado num esquema fatorial 1 x 6 + 1, (um óleo, seis alíquotas e uma testemunha adicional), com 5 repetições. Os principais componentes encontrados no óleo de C. winterianus foram o geranial (28,62%), citronelol (23,62%) e neral (17,10%). A menor alíquota do óleo essencial de citronela (5µL) inibiu em mais de 90% a germinação de esporos dos isolados UENF/CF241 e UENF/CF295 e reduziu a produção de esporos em mais de 95% nos três isolados, indicando que esse óleo possui uma boa atividade fungitoxica para esses isolados.

The decline is the main disease of guava caused by parasitism of Meloidogyne enterolobii and the fungus Fusarium solani, has been responsible for the eradication of many orchards nationwide, resulting in high economic loss to producers. Due to increasing pressure from society for more natural products and to increase the importance of essential oils in the management of plant diseases, the aim of this study was to determine the chemical composition and evaluate the antifungal effect of the essential oil of Cymbopogon winterianus (citronella) on three isolates of Fusarium solani (UENF/CF 163, and UENF/CF241 UENF/CF295). The essential oil was obtained by hydrodistillation using the Clevenger type apparatus. The compounds were identified by gas chromatography and gas chromatography with mass detector essential oil. To evaluate the effect of essential oils on mycelial growth, sporulation and germination of spores of the fungus were used aliquots of 5, 10, 15, 20, 25 and 30 µl essential oil which were distributed on the surface of PDA culture medium contained in Petri dishes before subculturing the fungus. The experimental design was completely randomized with a 1 x 6 + 1, (an oil, six aliquots and an additional control) with 5 repetitions. The major components found in the oil of C. winterianus were geranial (28.62%), citronellol (23.62%) and neral (17.10%). The lowest essential oil of citronella (5µL) inhibited more than 90% spore germination of isolates UENF/CF241 and UENF/CF295 and reduced the production of spores in over 95% in three isolates.

Influence of essential oil fractionation by vacuum distillation on acaricidal activity against the cattle tick

The aim of this work was to study the influence of essential oil fractionation on acaricidal activity against the cattle tick Rhipicephalus (Boophilus) microplus. The citronella (Cymbopogon winterianus J.) and pepper tree (Schinus molle L.) essential oils were fractionated by vacuum distillation yielding fractions that were analyzed by the GC/MS. Laboratory tests were carried out to determine the effect of the total essential oil and fractions on larvae of the cattle tick R. (B.) microplus. The fractions 04 and 05 of the C. winterianus essential oil were the most active showing LC50 values of 1.20 and 1.34 μL/mL, respectively. The LC50 of the total oil was 3.30 μL/mL while the effect of the fractions 01, 02 and 03 was less pronounced, with LC50 values of 4.37, 4.24 and 3.49 μL/mL, respectively. The fraction 03 of the S. molle essential oil was the most active showing LC50 value of 8.80 μL/mL while the fractions 01 and 02 did not show toxic effects on the larvae.

Solvent-Free Production of Bioflavors by Enzymatic Esterification of Citronella (Cymbopogon winterianus) Essential Oil.

Enzymatic esterification of citronella essential oil towards the production of geranyl and citronellyl esters may present great scientific and technological interest due to the well-known drawbacks of the chemical-catalyzed route. In this context, this work reports the maximization of geranyl and citronellyl esters production by esterification of oleic and propionic acids in a solvent-free system using a commercial immobilized lipase as catalyst. Results of the reactions showed that the strategy adopted for the experimental design proved to be useful in evaluating the effects of the studied variables on the reaction conversion using Novozym 435 as catalyst. The operating conditions that maximized the production of each ester were determined, leading, in a general way, to conversions of about 90% for all systems. New experimental data on enzymatic esterification of crude citronella essential oil for geranyl and citronellyl esters production in solvent-free system are reported in this work.

Viabilidade de sementes de feijão caupi após o tratamento com óleo essencial de citronela (Cymbopogon winterianus Jowitt) / Viability of Vigna unguiculata bean seeds treated with essential oil of Java grass (Cymbopogon winterianus Jowitt)

O tratamento de sementes com óleos essenciais é um método alternativo que auxilia o manejo integrado de pragas. O objetivo deste trabalho foi avaliar a influência do tratamento de sementes de feijão Vigna unguiculata (L.) Walp. com o óleo essencial de citronela (Cymbopogon winterianus Jowitt). Foi avaliado o efeito do óleo essencial de C. winterianus sobre V. unguiculata nas dosagens 20 µL, 15 µL, 10 µL, 5 µL e testemunha. A qualidade fisiológica das sementes foi determinada pela porcentagem de emergência, velocidade de emergência e índice de velocidade de emergência. A análise dos dados foi realizada no delineamento inteiramente casualizado, disposto em esquema fatorial 5 x 2 com cinco repetições. As sementes fumigadas apresentaram diferenças estatísticas entre os parâmetros avaliados em relação à testemunha. O óleo essencial de citronela revelou potencialidade alelopática sobre a germinação de sementes de feijão que variou de acordo com a concentração do óleo.

Seed treatment with essential oils is an alternative method tool in integrated pest management. The objective of this study was to evaluate the effect of treating Vigna unguiculata (L.) Walp. bean seeds with essential oil of Java grass (Cymbopogon winterianus Jowitt). The effect of C. winterianus essential oil on P. vulgaris was evaluated at levels of 20 µL, 15 µL, 10 µL, 5 µL and control. The physiologic quality of the seeds was determined by percentage emergence, speed emergence and speed emergence index. The data analysis was carried out using an entirely randomized design, in a 5 x 2 factorial scheme with five repetitions. The fumigated bean seeds showed the statistics differences among the analyzed parameters when was compared with the no treated check. The essential oil of Java grass revealed allelopathic potentiality on bean seed germination which varied according to the oil concentration.

Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans

Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59 percent), geraniol (18,81 percent) and citronellol (11,74 percent). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin.

Effects of Cymbopogon winterianus Jowitt ex Bor essential oil on the growth and morphogenesis of Trichophyton mentagrophytes / Efeitos do óleo essencial de Cymbopogon winterianus Jowitt ex Bor no crescimento e na morfogênese de Trichophyton mentagrophytes

Trichophyton mentagrophytes is a fungus causative agent of dermatophytosis, affecting humans worldwide. This has driven the search for products for the treatment of these infections. Accordingly, the aim of this study was to investigate the antifungal activity of the Cymbopogon winterianus essential oil against T. mentagrophytes. The antifungal tests consisted of antifungal screening, determination of MIC and MFC, analysis of the essential oil's effects on mycelial growth, germination of fungal spores, fungal viability, morphogenesis, cell wall (test with sorbitol) and cell membrane (cell leakage test) of T. mentagrophytes. Upon screening, the oil inhibited all strains, with zones of growth inhibition of 24-28 mm in diameter. The MIC was 312 μg/mL and CFM was 2500 μg/mL for almost all the strains tested. There were morphological changes in the conidia group, form and pigmentation of hyphae. The antifungal action of the product does not involve the cell wall and its action may involve the fungal plasma membrane. It is concluded that C. winterianus essential oil constitutes a potential antifungal product, especially for the treatment of dermatophytosis.

Trichophyton mentagrophytes é um fungo causador de dermatofitoses, afetando humanos em todo o mundo. Isto direciona a busca de produtos para o tratamento destas infecções. Assim, este estudo teve por objetivo investigar a atividade antifúngica do óleo essencial de Cymbopogon winterianus contra T. mentagrophytes. Os ensaios antifúngicos foram constituídos do screening antifúngico, da determinação CIM e CFM, da análise dos efeitos do óleo essencial no crescimento micelial, na germinação dos esporos, na viabilidade fúngica, na morfogênese, na parede celular (ensaio com sorbitol) e na membrana celular (ensaio de lise celular) de T. mentagrophytes. No screening, o óleo inibiu todas as cepas, com zonas de inibição de crescimento de 24-28 mm de diâmetro. A CIM foi de 312 μg/mL e a CFM foi de 2500 μg/mL para quase todas as cepas testadas. O óleo essencial inibiu o desenvolvimento micelial, a germinação dos esporos e a viabilidade fúngica. Houve alterações morfológicas no agrupamento dos conídios, na forma e pigmentação das hifas. A ação antifúngica do produto não envolve a parede celular e parece estar envolvida com a membrana celular fúngica. Pode-se concluir que o óleo essencial de C. winterianus se apresenta como um potencial produto antifúngico, especialmente para o tratamento das dermatofitoses.

Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans.

Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59%), geraniol (18,81%) and citronellol (11,74%). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin.

Influence of season, harvest time and drying on Java citronella (Cymbopogon winterianus Jowitt) volatile oil

Java citronella (Cymbopogon winterianus Jowitt) is member of the Poaceae family. Java citronella volatile oil has been reported to be among the volatile oils, showing repellent, antimycotic, and acaricide activities. It has been known that agronomical factors have a great effect on both the quality and quantity of essential metabolites. For this reason, it is necessary to determine optimum levels of agronomical factors affecting plant growth and production. Harvest time and drying are very important agronomical factors. This study has been conducted in the Research farm of the " Universidade Federal de Sergipe" , Agronomical Engineering Department along 2002-2003 on the base of factorial experiment in randomized complete block design with three replications. Java citronella was cultivated in a 60 x 60 cm space. Early, midday, and late harvest at 9:00 h, 12:00 h, and 15:00 h were conducted on four different seasons. Fresh and dried leaves were used on the experiments. In order to study the effects of harvest time and drying, yields of dry and fresh herbage (kg/ha), moisture content ( percent), volatile oil content ( percent) and yield (L/ha), and chemical composition of the volatile oil were measured. Seasonal changes had significant effect on yield of fresh herbage, yield and volatile oil content. Maximum volatile oil yields were observed at 9:00 during summer, winter, and spring. Volatile oil content was influenced by season and drying, but not influenced by harvest time.

Citronela de Java (Cymbopogon winterianus Jowitt) pertence à família Poaceae. Óleo volátil de citronela de Java apresenta atividade repelente, antimicrobiana e acaricida. Sabe-se que fatores agronômicos têm grande efeito sobre a qualidade e quantidade de metabólitos essenciais. Por isso é importante a determinação dos níveis ótimos dos fatores agronômicos que afetem o crescimento e a produção. Horário de colheita e secagem são fatores agronômicos muito importantes. O presente estudo foi conduzido na Fazenda Experimental do Departamento de Engenharia Agronômica da Universidade Federal de Sergipe, no período de 2002-2003, usando o delineamento de blocos casualizados e um experimento em esquema fatorial com três repetições. O capim citronela foi cultivado usando espaçamento de 60 cm entre linhas e 60 cm entre plantas. Realizaram-se colheitas de manhã, meio dia e à tarde, às 9:00 h, 12:00 h e 15:00 h, nas quatro estações do ano. Usaram-se folhas frescas e secas no experimento. Para estudar os efeitos do horário de colheita e secagem avaliaram-se as seguintes características: rendimento de biomassa seca e fresca (kg/ha), umidade ( por cento), teor ( por cento) e rendimento (L/ha) de óleo essencial, e a composição química do óleo essencial. Mudanças sazonais apresentaram efeito significativo sobre o rendimento de biomassa fresca e seca, e teor e rendimento de óleo. Rendimentos máximos de óleo essencial foram observados às 9:00 h durante o verão, inverno e primavera. O teor de óleo essencial foi influenciado pela estação doa ano e secagem, mas não foi influenciado pelo horário de colheita.