Identification of Coumarins and Antimicrobial Potential of Ethanolic Extracts of Dipteryx odorata and Dipteryx punctata.

Dipteryx odorata and Dipteryx punctata are species native to the Amazonian, traded by extractivists to obtain coumarin. We aimed to analyze the presence of coumarin in the ethanolic extracts of leaves, branches and fruits of D. odorata and D. punctata and to evaluate the antimicrobial activity of these extracts against phytopathogenic fungi and bacteria of clinical interest. Chemical analyses were performed by thin layer chromatography (TLC) and by gas chromatography coupled to mass spectrometry (GC-MS). For the antifungal assays, the fungi used were Cercospora longissima, Colletotrichum gloeosporioides, two isolates of Fusarium spp. and Sclerotium rolfsii, and the antibacterial assay was performed using the minimum inhibitory concentration (MIC) test with Burkholderia cepacia, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus bacteria. In D. odorata seed extracts and in D. punctata husks, endocarps, and seeds, we identified 1,2-benzopyrone. D. odorata endocarp extracts and D. punctata seeds provided the greatest decrease in mycelial growth of the evaluated phytopathogens, showing promise as an alternative control. The husk and endocarp extracts of both species had a weak effect on E. coli. This research is the first to compare the different parts of species of the genus Dipteryx and to evaluate the use of husks and endocarps of D. punctata fruits to obtain coumarin. Chemical analyses used to quantify the compounds existing in the extracts, and tests with phytopathogens in vitro and in vivo are currently being carried out.

Control of Colletotrichum gloeosporioides (penz.) Sacc. In yellow passion fruit using Cymbopogon citratus essential oil

The use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. On the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. Essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. The aim of this study was to determine the activity of 28 essential oils from medicinal plants cultivated at CPMA (Medicinal and Aromatic Plants Collection), CPQBA/UNICAMP, against Colletotrichum gloeosporioides (Penz.) Sacc., the anthracnose agent in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg), as well as evaluating their effect in the control of post-harvest decay. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentrations (MIC) determined by the micro-dilution method. According to the results, 15 of the 28 essential oils presented activity against Colletotrichum gloeosporioides, and the following four oils presented MIC values between 0.25 and 0.3 mg/mL: Coriandrum sativum, Cymbopogon citratus, Cymbopogon flexuosus and Lippia alba. The evaluation of Cymbopogon citratus essential oil in the control of post-harvest decay in yellow passion fruit showed that the disease index of the samples treated with the essential oil did not differ (P < 0.05) from that of the samples treated with fungicide. The present study shows the potential of Cymbopogon citratus essential oil in the control of the anthracnose agent in yellow passion fruit.

Control of Colletotrichum gloeosporioides (penz.) Sacc. In yellow passion fruit using Cymbopogon citratus essential oil.

The use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. On the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. Essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. The aim of this study was to determine the activity of 28 essential oils from medicinal plants cultivated at CPMA (Medicinal and Aromatic Plants Collection), CPQBA/UNICAMP, against Colletotrichum gloeosporioides (Penz.) Sacc., the anthracnose agent in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg), as well as evaluating their effect in the control of post-harvest decay. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentrations (MIC) determined by the micro-dilution method. According to the results, 15 of the 28 essential oils presented activity against Colletotrichum gloeosporioides, and the following four oils presented MIC values between 0.25 and 0.3 mg/mL: Coriandrum sativum, Cymbopogon citratus, Cymbopogon flexuosus and Lippia alba. The evaluation of Cymbopogon citratus essential oil in the control of post-harvest decay in yellow passion fruit showed that the disease index of the samples treated with the essential oil did not differ (P ≤ 0.05) from that of the samples treated with fungicide. The present study shows the potential of Cymbopogon citratus essential oil in the control of the anthracnose agent in yellow passion fruit.

Activity of essential oils from Brazilian medicinal plants on Escherichia coli.

Essential oils obtained from leaves of 29 medicinal plants commonly used in Brazil were screened against 13 different Escherichia coli serotypes. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentration (MIC) were determined by microdilution method. Essential oil from Cymbopogon martinii exhibited a broad inhibition spectrum, presenting strong activity (MIC between 100 and 500 microg/mL) against 10 out of 13 Escherichia coli serotypes: three enterotoxigenic, two enteropathogenic, three enteroinvasive and two shiga-toxin producers. C. winterianus inhibited strongly two enterotoxigenic, one enteropathogenic, one enteroinvasive and one shiga-toxin producer serotypes. Aloysia triphylla also shows good potential to kill Escherichia coli with moderate to strong inhibition. Other essential oils showed antimicrobial properties, however with a more restricted action against the serotypes studied. Chemical analysis of Cymbopogon martinii essential oil performed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS) showed the presence of compounds with known antimicrobial activity, including geraniol, geranyl acetate and trans-cariophyllene, which tested separately, indicated geraniol as antimicrobial active compound. The significant antibacterial activity of Cymbopogon martinii oil suggests that they could serve as a source for compounds with therapeutic potential.

Anti-Candida activity of Brazilian medicinal plants.

Essential oils and ethanolic extracts from the leaves and/or roots of 35 medicinal plants commonly used in Brazil were screened for anti-Candida albicans activity. The oils were obtained by water-distillation using a Clevenger-type system. Essential oils from 13 plants showed anti-Candida activity, including Aloysia triphylla, Anthemis nobilis, Cymbopogon martini, Cymbopogon winterianus, Cyperus articulatus, Cyperus rotundus, Lippia alba, Mentha arvensis, Mikania glomerata, Mentha piperita, Mentha sp., Stachys byzantina, and Solidago chilensis. The ethanol extract was not effective at any of the concentrations tested. Chemical analyses showed the presence of compounds with known antimicrobial activity, including 1,8-cineole, geranial, germacrene-D, limonene, linalool, and menthol.

Composition and antimicrobial activity of essential oils from aromatic plants used in Brazil

Oleos essenciais foram obtidos a partir das partes aéreas de Mentha piperita, M. spicata, Thymus vulgaris, Origanum vulgare, O. applii, Aloysia triphylla, Ocimum gratissimum e O. basilicum através de arraste de vapor em sistema tipo Clevenger. Os óleos foram avaliados quanto à atividade antimicrobiana contra bactérias e contra a levedura Candida albicans pelo método de bioautografia. A concentração mínima inibitória dos óleos com atividade positiva foi em seguida determinada pelo método da microdiluição. De acordo com os resultados, a maioria dos óleos essenciais estudados foram efetivos contra Enterococcus faecium e Salmonella cholerasuis. A.triphylla e O. basilicum apresentaram inibição moderada contra Staphylococcus aureus enquanto apenas A. tryphila e M. piperita foram capazes de inibir a levedura Candida albicans. Os óleos foram analisados quimicamente por técnicas de CG e CG-EM de modo a determinar os compostos majoritários presentes.