Plant-derived essential oils affecting settlement and oviposition of Bemisia tabaci (Genn.) biotype B on tomato

The silverleaf whitefly Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is an economically important pest of tomatoes Solanum lycopersicum (L.), causing irregular ripening on fruits and transmitting several plant pathogenic geminiviruses. The management of this pest is commonly based on repetitive spraying with synthetic pesticides, causing serious environmental damages and increase of resistance by insect population. In the present study, essential oils from the leaves of Artemisia camphorata Vill., Ageratum conyzoides L., Foeniculum vulgare Mill., Lippia alba (Mill.) N. E. Br., Plectranthus neochilus Schltr., and Tagetes erecta L. were investigated for their possible repellent and oviposition-deterrent effects against B. tabaci biotype B on tomato. In a multi-choice assay, P. neochilus essential oil was the most active repellent and oviposition deterrent. Essential oils of A. conyzoides and T. erecta significantly deterred the female B. tabaci biotype B from laying eggs on treated tomato leaflets compared with the control. (E)-Caryophyllene (30.67 %) and the monoterpenes α-pinene (15.02 %) and α-thujene (11.70 %) were identified as the major constituents of the essential oil of P. neochilus. Our findings demonstrated the potential of essential oil of P. neochilus and other oils in the reduction of settlement and oviposition of B. tabaci biotype B on tomato. © 2012 Springer-Verlag Berlin Heidelberg.

Database of the Amazon aromatic plants and their essential oils

The aromatic flora of the Amazon has been inventoried for 30 years. In this sense, were made over 500 field trips to collect over 2500 plants and to obtain more than 2000 essential oils and aroma concentrates, all of them submitted to GC and GC-MS. This work led to the creation of a database for the aromatic plants of the Amazon, which catalogs general information about 1250 specimens. The database has allowed the publication of the chemical composition of the oils and aromas of more than 350 species, associated with a larger number of chemical types. The essential oils of many species offer optimum conditions for economic exploitation and use in national and international market of fragrances, cosmetics, agricultural and household pesticides.

The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms

The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs) compared to 0.2% chlorhexidine (CHX) and 1% sodium hypochlorite (NaOCl) on multi-species biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL) and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10): C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride (NaCl)]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. Next, the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05). C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, and 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases.

Characterization of the chemical composition of the essential oils from Annona emarginata (Schltdl.) H. Rainer 'terra-fria' and Annona squamosa L.

O objetivo do presente estudo foi caracterizar a composição química do óleo essencial das folhas de Annona emarginata (Schltdl.) H. Rainer 'terra-fria' e Annona squamosa L. As espécies foram cultivadas em casa de vegetação, com aplicação semanal de solução nutritiva até completar 18 meses, quando se realizaram a colheita e a secagem das folhas para a extração do óleo essencial, analisado por cromatografia gasosa acoplada à espectrometria de massas, para estudo dos perfis químicos. Onze substâncias majoritárias foram encontradas no óleo essencial de A. emarginata: (E)-cariofileno-29,29%; (Z)-cariofileno-16,86%; γ-muroleno-7,54%; α-pineno-13,86%; tricicleno-10,04%. No óleo de A. squamosa, 10 substâncias foram detectadas, entre elas: (E)-cariofileno-28.71%; (Z)-cariofileno-14,46%; α-humuleno-4,41%; canfeno-18,10%; α-pineno-7,37%, e β-pineno-8,71%; longifoleno-5,64%; majoritárias. (E)-cariofileno; (Z)-cariofileno; α-humuleno; canfeno; α-pineno, e β-pineno foram as seis substâncias comuns às duas espécies.

Dry and wet seasons set the phytochemical profile of the Copaifera langsdorffii Desf. essential oils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Healing Actions of Essential Oils from Citrus aurantium and d-Limonene in the Gastric Mucosa: The Roles of VEGF, PCNA, and COX-2 in Cell Proliferation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antimicrobial activity of essential oils

Natural products have been studied aiming to understand their biological properties. Thus, this study aimed to investigate the antimicrobial activity of twenty-seven essential oils (EOs) used in aromatherapy procedures, a natural therapy with great emphasis currently used against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa strains. The agar dilution method was carried out and minimal inhibitory concentration against 50% and 90% of strains (MIC50% and MIC90% values) were reported. The S.aureus strains were highly susceptible with MIC90% from 0.21mg/mL to black pepper (Piper nigrum) and tea tree (Melaleuca alternifolia) to 26.52mg/mL with copaiba (Copaifera officinalis) EO. Cinnamon (Cinnamomum cassia) and clove (Syzygium aromaticum) EOs were effective against E.coli (2.0mg/mL) while the S.aromaticum EO was against P.aeruginosa (8.29mg/mL). Thus, the higher susceptibility of Gram-positive bacteria when compared with Gram-negative strains was found, and a large variability in the potential antibacterial has also been observed.

Increased atmospheric carbon dioxide concentration: effects on eucalypt rust (Puccinia psidii), C:N ratio and essential oils in eucalypt clonal plantlets

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Composition and antifungal activity against Candida albicans, C. parapsilopisis, Candida krusei and Cryptococcus neoformans of essential oils from leaves of Piper and Peperomia species

This study was addressed to investigate the composition and antifungal activity of essential oils from leaves of Piperaceae species (Piper aduncum, Piper amalago, Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper gaudichaudianum, Piper solmsianum, Piper regnellii, Piper tuberculatum, Piper umbelata and Peperomia obtusifolia) against Candida albicans, C. parapsilosis, C. krusei and Cryptococcus neoformans. The essential oils from P. aduncum, P. gaudichaudianum and P. solmsianum showed the highest antifungal activity against Cryptococcus neoformans with the MIC of 62.5, 62.5 and 3.9 mg.mL-1, respectively. The oil from P. gaudichaudianum showed activity against C. krusei with MIC of 31.25 mg.mL-1.

Chemical Composition and Trypanocidal Activity of the Essential Oils from Hedychium coronarium J. Koenig (Zingiberaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolite profiles of essential oils in citrus peels and their taxonomic implications

China is an important center of origin for the genus Citrus L. of the family Rutaceae and is rich in wild Citrus species. The taxonomy of Citrus has been a subject of controversy for more than a half century. We propose that the metabolite profiles of Chinese native Citrus species can be used for classification and understanding of the taxonomic relationships within the Citrus germplasm. In this study, triplicate gas chromatography-mass spectrometry (GC-MS) metabolite profiles of 20 Citrus species/varieties were acquired, including 10 native varieties originating in China. R-(+)-limonene, alpha-pinene, sabinene and alpha-terpinene were found to be major characteristic components of the essential oils analyzed in this study, and these compounds contributed greatly to the metabolic classification. The three basic species of the subgenus Eucitrus (Swingle's system), i.e., C. reticulata Blanco, C. medica L. and C. grandis Osb., were clearly differentiated based upon their metabolite profiles using hierarchical cluster analysis (HCA) and partial least square-discriminant analysis (PLS-DA). All the presumed hybrid genotypes, including sweet orange (C. sinensis Osb.), sour orange (C. aurantium L.), lemon (C. limon Burm.f.), rough lemon (C. jambhiri Lush.), rangpur lime (C. limonia Osb.) and grapefruit (C. paradisi Macf.), were grouped closely together with one of their suggested parent species in the HCA-dendrogram and the PLS-DA score plot. These results clearly demonstrated that the metabolite profiles of Citrus species could be utilized for the taxonomic classification of the genus and are complementary to the existing taxonomic evidence, especially for the identification and differentiation of hybrid species.

Essential oils from herbs against foodborne pathogens in chicken sausage

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria

The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.