Júlio César Rodrigues Lopes Silva

The essential oils extracted from plants can demonstrate biological activity against a significant number of pathogens and/or antioxidant activity. The objective was to extract and identify the substances present in the essential oil of leaves, peel, and seeds of 'Bengal' lychee. Leaves and fruits of Litchi chinensis Sonn. were collected from an orchard located at the São Manuel Experimental Farm, Faculty of Agronomic Sciences at the São Paulo State University (FCA/Unesp/Brazil). The extraction of the essential oil was performed by hydrodistillation using a Clevenger-type apparatus. The analysis of the essential oil was carried out using gas chromatography coupled with a mass spectrometer and a flame ionization detector. The qualitative and quantitative analyses of the chemical composition and the yield of essential oil were performed in triplicate, and the data were subjected to multivariate analysis. The essential oil yield ranged from 0.03% to 0.19%, with the highest percentage observed in the lychee peel. Twenty-two compounds were identified in the leaf, eighteen in the peel, and twenty in the seed. γ-Himachalene was the most abundant in the essential oil of the leaf, peel, and seed, with 30.36%, 51.85%, and 39.95%, respectively. The essential oil of lychee contains compounds with potential for use in various industrial sectors.

Produtos agroecológicos tem sido requeridos pela população devido ao baixo impacto ambiental. Diante da demanda, a Lippia rotundifolia pertence à família Verbenaceae, é um espécie aromática do Cerrado brasileiro de alto potencial biológico. Devido à sua eficácia, objetivou-se avaliar a o teor e a composição química do óleo essencial de Lippia rotundifolia Cham., bem como avaliar seu potencial como larvicida agroecológico contra larvas do Aedes aegypti Linn. Para atingir esse objetivo, o óleo essencial foi obtido por hidrodestilação e analisado por cromatografia gasosa acoplado ao espectrômetro de massas. As larvas de Aedes aegypti foram expostos ao hidrolato e em diferentes concentrações de óleo essencial (300, 250, 125, 62,5 e 31,25 μg.mL-¹). O óleo essencial apresentou teor de 3,09%. A análise química detectou 27 compostos. O composto principal foi o mirceno (15,52%). Todos os tratamentos apresentaram atividade larvicida com forte ação sedativa. A menor concentração após 24h apresentou mais de 80% de mortalidade. A concentração letal foi de 232μg.mL­-¹. A Lippia rotundifolia apresenta 3,09% de teor de óleo essencial. Os compostos mirceno, (Z)-tagetona e β-cariofileno são os representantes químicos da espécie. A espécie tem potencial contra larvas do mosquito Aedes aegypti, podendo ser utilizada na formulação de produtos larvicidas para controle de sua população.

Lychnophora pinaster, known as arnica-mineira, is endemic to campos rupestres, at risk of extinction. The present study aimed to characterize the ecogeography and phenolic constituents of 11 L. pinaster populations collected in the mesoregions North, Jequitinhonha, Metropolitan of Belo Horizonte and Campos das Vertentes in the state of Minas Gerais, Brazil. Phenolic constituents were identified and quantified by Ultra-high performance liquid chromatography- mass spectrometry. Lychnophora pinaster occurs in sites at high altitude (700 and 1498 m), annual rainfall of up to 1455 m, soils with low fertility and predominantly loamy texture. Therefore, it can be considered tolerant to acidic soils, with low availability of nutrient. The most abundant substances in all populations were vitexin (18 - 1345 ng/g) and chlorogenic acid (60 - 767 ng/g). The 11 populations formed four groups in relation to the phenolic constituents, with group 1 consisting of the populations of the North Mesoregion (GM, OD) and Jetiquinhonha (DIMa), group 2, the Metropolitan of Belo Horizonte (SRM, NLSC, SM, RPS, CTRA), group 3, the North Mesoregion (ODMa and DI), and group 4, the Campos das Vertentes (CC). Among the populations, only those from the Metropolitan of Belo Horizonte showed correlation of soil properties with phenolic constituents.

Varronia curassavica is a medicinal species native to Brazil; its anti-inflammatory properties are attributed to α-humulene and β-caryophyllene. This study to investigated the population variability of V. curassavica. Leaves were collected from 40 individuals of a natural population and transferred to glass flasks (2 mL). The volatiles were extracted and analyzed using static headspace gas chromatography coupled with mass spectrometry (HS-GC-MS). A total of 17 compounds were detected: monoterpenes (1.6% - 68%) and sesquiterpenes (25.7% - 79.0%), including α-humulene and β-caryophyllene. Multivariate analysis was performed to estimate the dissimilarity of individuals separated the compounds into four groups. Group I was characterized by the content of α-pinene, groups II and IV by β-caryophyllene, and group III by β-pinene. The abundance of α-humulene showed small variations; while β-caryophyllene showed larger variations that contributed to the population variability. This is the first report on the chemical composition analysis of volatile compounds in V. curassavica using the HS-GC-MS technique.

This study aimed to characterize the chemical composition of the leaf essential oil (EO) of mandarin and tangor trees obtained by steam distillation and hydrodistillation. Leaf samples were collected during the pruning period from seven citrus cultivars in a property located in Pareci Novo, Rio Grande do Sul state, South Brazil. The leaves underwent hydrodistillation and steam distillation, and the obtained EO was analyzed by GC-MS and GC-FID. In general, the Citrus deliciosa mandarins had higher EO yields than the ‘Ponkan’ and tangors in both methods. The Citrus deliciosa mandarin trees presented higher amounts of methyl N-methyl anthranilate and γ-terpinene. In the EO of ‘Ponkan’, ‘URSBRS Hada’ and ‘Murcott’, there was a predominance of linalool and terpinen-4-ol. The extraction method influenced the contents of the compounds mainly, while the genetic factors determined the variations in the composition of the essential oil of citrus leaves.

Lippia alba (Mill.) N. E. Br. (Verbenaceae) is an aromatic shrub whose essential oils have stood out as a promising source for application in several industrial fields. In this study, the essential oils chemical characterization of eight new L. alba genotypes was performed. The selected materials were collected from the Active Germplasm Bank of the Agronomic Institute and the essential oils were extracted by hydrodistillation. Flow-modulated comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) was employed for chemical characterization and evaluation of possible co-eluted compounds. In addition, the chemical analyses were submitted to multivariate statistical analyses. From this investigation, 73 metabolites were identified in the essential oils of the genotypes, from which α-pinene, β-myrcene, 1,8-cineole, linalool, neral, geranial, and caryophyllene oxide were the most abundant compounds among the accessions. This is the first report disclosing α-pinene in higher amounts in L. alba (19.69%). In addition, sabinene, trans-verbenol, myrtenol, (E)-caryophyllene, α-guaiene, germacrene D, and α-bulnesene were also found in relevant quantities in some of the genotypes, and myrtenal and myrtenol could be well separated through the second dimension. Such results contributed to the understanding of the chemical composition of those new genotypes, being important to drive a future industrial applicability and studies in genetic breeding.

The objective of this work was to evaluate the growth and essential oil content after transplantation and cutting of Lippia rotundifolia accessions from a natural population from the state of Minas Gerais, Brazil. Eight accessions were evaluated (PVP, GIG, RPE, ODA, JFE, PRP, SGS, and RTI) in six periods (60, 81, 102, 123, 144, and 165 days after transplanting and cutting), in a completely randomized experimental design. The following parameters were assessed: average width and length of the basal, median, and apical pair of leaves; plant height; stem diameter; and number of leaves. At 165 days, the yield of essential oil and the fresh and dry phytomass of the aerial part were also evaluated. Sixty days after the last evaluation, regrowth was measured from height, stem diameter, and number of leaves. The JFE accession stands out for emission of leaves, with a better development at 165 days after transplanting. RPE and PRP respond well to regrowth at 102 and 123 days after cutting, respectively. The SGS accession shows a high essential oil yield of 2.2%, and PVP, a low yield of 0.3%.