Chemical composition, phytotoxic potential, biological activities and antioxidant properties of Myrcia hatschbachii D. Legrand essential oil

Myrcia hatschbachii D. Legrand (Myrtaceae) is a native and endemic species from Brazil. This study investigated the essential oil composition, phytotoxic potential, in vitro toxicity, antioxidant properties and antibacterial activity of species. Chromatographic analysis of essential oil identified trans-calamanene, (E)-caryophyllene and spathulenol as major components. Antioxidant capacity was determined by the DPPH• scavenging method and phosphomolybdenum complex formation assay. Antibacterial activity was evaluated using the Minimal Inhibitory Concentration test, demonstrating that the essential oil was active toward Enterococcus faecalis and Staphylococcus aureus. Phytotoxic activity of essential oil was analyzed by testing interference on germination and growth of Lactuca sativa, demonstrating significant inhibition of the hypocotyls and radicles of seeds. Preliminary toxicity studies were determined using Artemia salina, resulting in an LC50 of 409.92 µg/mL, and through hemolytic activity. The results of the phytotoxic activity point to a possible application for Myrcia hatschbachii in the development of natural herbicides and the in vitro toxicity assays suggests the performance of antitumoral activity tests, having in mind the prospection of antineoplastic drugs

Composition, antioxidant properties, and biological activities of the essential oil extracted from Ocotea diospyrifolia (Meisn.) Mez.

The article has aimed to characterize the essential oil extracted from Ocotea diospyrifolia (Meisn.) Mez. leaves, in terms of its chemical composition and antioxidant, hemolytic, and phytotoxic potentials, as well as its toxicity against Artemia salina. The major constituents identified by CG-MS were δ-elemene, spathulenol, and β-atlantol. When screened for potential biological activities, the essential oil presented low toxicity against Artemia salina, and a capacity of lysing red blood cells. Also, the evaluation of its in vitro antioxidant activity, using the phosphomolybdenum method, showed better results when compared to butylhydroxytoluene (BHT) and rutin. In conclusion, the results obtained showed certain in vitro toxicity, leading to an interesting target for cytotoxicity evaluations of carcinoma cells

Estudo químico, morfoanatômico, propriedades antioxidantes e atividades biológicas de partes aéreas de Myrceugenia acutiflora (Kiaersk.) D. Legrand & Kausel, Myrtaceae

Orientador: Profa. Dra. Marilis Dallarmi MiguelCoorientador: Prof. Dr. Obdulio Gomes MiguelDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Ciências Farmacêuticas. Defesa : Curitiba, 27/02/2018Inclui referências: p.79-92Área de concentração: Insumos, medicamentos e correlatosResumo: Myrceugenia acutiflora (Kiaersk.) D. Legrand & Kausel, Myrtaceae, é uma espécie nativa da América do Sul e endêmica no Sul e Sudeste do Brasil. Está representada por árvores e arbustos de 2 a 12 metros de altura que florescem de janeiro a março e frutificam nos meses de julho e agosto. Até o momento não foram descritos estudos químicos e farmacognósticos da espécie. Este trabalho teve como objetivos analisar a morfoanatomia e histoquímica de partes aéreas; realizar triagem fitoquímica preliminar, extrair e caracterizar os componentes do óleo essencial; e avaliar as atividades antioxidante, antimicrobiana e tóxica in vitro de extratos, frações e óleo essencial. O estudo morfoanatômico evidenciou estômatos paracíticos, tricomas tectores e estruturas semelhantes a tricomas dibraquiados, na face abaxial das folhas. A análise histoquímica mostrou a presença de amido em folhas, caules e pecíolos; e compostos fenólicos apenas nos pecíolos. Drusas foram encontradas em todas as partes estudadas. Na análise fitoquímica preliminar, no extrato de folhas, foram encontrados flavonoides na fração hidroalcoólica e iridoides nas frações hexano e clorofórmio. No extrato de caules foram encontrados esteroides na fração hexano; iridoides nas frações hexano e clorofórmio; e triterpenos na fração clorofórmio. Taninos, saponinas, heterosídeos cianogênicos e aminogrupos foram encontrados nos extratos aquosos de ambas as partes da planta. Foi isolado e identificado dos extratos brutos de folhas e caules; e da coluna cromatográfica da fração remanescente de caules, o ácido 3,3',4-tri-o-metil elágico, um derivado do ácido elágico. Na caracterização dos constituintes químicos do óleo essencial por cromatografia gasosa acoplada a espectrômetro de massas, foram identificados 67 compostos, sendo o composto majoritário o ?-cariofileno, um sesquiterpeno presente em vários óleos essenciais. A capacidade antioxidante foi realizada por 2 metodologias, através da formação do complexo do fosfomolibdênio e inibição do radical DPPH!. Em ambos os testes, os extratos aquosos e as frações mais polares obtiveram melhor atividade antioxidante. Na atividade antimicrobiana pelo método da difusão em disco, apenas o óleo essencial mostrou atividade inibitória contra uma das cepas utilizadas no teste, a bactéria gram positiva Staphylococcus aureus. No ensaio de toxicidade frente à Artemia salina, o extrato bruto de folhas teve atividade tóxica baixa e o óleo essencial teve atividade tóxica elevada, maior que o controle positivo sulfato de quinidina. A espécie Myrceugenia acutiflora possui vários metabólitos secundários e atividades biológicas, demonstrando seu potencial farmacológico.Abstract: The species Myrceugenia acutiflora (Kiaersk.) D. Legrand & Kausel, Myrtaceae, is native of South America and is present in South and Southeast regions of Brazil. It is represented by trees and shrubs of 2 to 12 meters tall that blossoms from january to march and produces fruits between july and august. To date, no phytochemical and pharmacognostic studies of the species have been described. The objectives of this work were to perform morphoanatomical and histochemical analyses of aerial parts; to perform preliminary phytochemical screening, to extract and characterize the components of essential oil; and to evaluate antioxidant, antimicrobial and toxic activities of extracts, fractions and essential oil. The morphoanatomical study showed paracityc stomata, tector trichomes and structures that resemble dibraquiate trichomes in the lower surface (abaxial) of the leaves. The histochemical analyses showed presence of starch in the leaves, stems and petioles; and phenolic compounds only in petioles. Druses were found in all of the parts studied. In the preliminary phytochemical screening, in the leaves' extract, it was found flavonoids in hydroalcoholic fraction and iridoids in the hexane and chloroform fractions. In the stems' extract it was found steroids in the hexane fraction; iridoids in the hexane and chloroform fractions; and triterpenes in the chloroform fraction. Tannins, saponins, cyanogenic heterosides and amino groups were found in aqueous extract from both parts of the plant. It was isolated and identified from the crude extracts of leaves and stems; and from the column chromatography of hydroalcoholic fraction of stems, the 3,3',4-tri-o-methylellagic acid, a derived from ellagic acid. In the characterization of the chemical constituents from the essential oil by gas chromatography coupled to mass spectrometry, 67 compounds were identified, being the major component ?- caryophyllene, a sesquiterpene present in many essential oils. The antioxidant capacity was performed by 2 methodologies, formation of the phosphomolybdenum complex and inhibition of DPPH! radical. In both tests, the aqueous extracts and the more polar fractions had the best results. In the evaluation of antimicrobial activity by disk diffusion method, only the essential oil presented inhibitory activity against one of the strains used in the test, the gram positive bacteria Staphylococcus aureus. In the toxicicity assay against Artemia salina, the crude extract from the leaves had low toxic activity and the essential oil had high toxic activity, higher than the positive control quinidine sulfate. The species Myrceugenia acutiflora has many secondary metabolites and biological activities, demonstrating its pharmacological potential