An eco-friendly method for extraction and quantification of flavonoids in Dysphania ambrosioides

ABSTRACT Dysphania ambrosioides (L.) Mosyakin and Clemants (Syn: Chenopodium ambrosioides L.), Amaranthaceae, is a plant with antibacterial, antifungal, antioxidant, antiparasitic and antitumor properties that is commonly used in Brazilian folk medicine. In this work we performed the optimization of ultrasound-assisted extraction of flavonoids in the aerial parts of D. ambrosioides. The flavonoid concentrations, as rutin equivalents, were quantified with the aid of a validated spectrophotometric method. The Box-Behnken (33) design with response surface methodology, for the independent variables, extraction time, temperature, and ethanol content, were used for the optimization of ultrasound-assisted extraction. The analytical method was selective, linear, without matrix interference, accurate, precise and robust. The best conditions for the ultrasound-assisted extraction of flavonoids were: time of 60 min, temperature of 57 °C and ethanol content of 57% (w/w). The methods of extracting and quantifying flavonoids developed in the present study have provided be eco-friendly, simple, and useful to determine the flavonoid content, expressed as rutin equivalents, in the aerial parts of D. ambrosioides.

Quantification of catechin in the spray-dried extract of Pimenta pseudocaryophyllus

Abstract This paper describes the quantification of catechin in the spray-dried extract of Pimenta pseudocaryophyllus (Gomes) Landrum, Myrtaceae, citral chemotype using a validated HPLC-PDA method. The method employs a RP-18 column with acetonitrile:water-orthophosphoric acid 0.05% (gradient system) and UV detection at 210 nm. The method was demonstrated to be simple, sensitive, specific, linear, precise, accurate and robust. The response was linear over a range of 5-200 µg/ml (r > 0.999). The range of recoveries was 92.27-102.54%. The relative standard deviation values for intra- and inter-day precision studies were 4.30 and 3.78%, respectively. This assay can be readily utilized as quality control method for catechin in the dried extract of P. pseudocaryophyllus.

Leaf morphology and venation of Psidium species from the Brazilian Savanna

ABSTRACT The Brazilian Savanna biome has the largest plant diversity among savannas worldwide and is the predominant biome in Goiás state, Brazil. Among plant species previously catalogued in the Brazilian Savanna, the Myrtaceae family has received attention, as these plants show great economic potential for its medicinal properties, food and ecological importance, highlighting in this context the Psidium genus. In order to contribute to the differentiation of problematic taxonomic groups, such as Myrtaceae, and to quality control of its plant material, morphological and venation leaf studies of four species of Psidium were performed. For this purpose, leaf samples of Psidium firmum O.Berg., P. myrsinites DC., P. laruotteanum Cambes., and P. guineense Sw. were collected from Goiás State University, Anápolis Air Base, and Serra de Caldas Novas State Park and submitted to classical techniques for morphological and leaf venation characterizations. The results showed that P. firmum presents brochidodromous secondary veins, marginal last venation of the fimbrial type, an abaxial surface with a grooved midrib, flat secondary veins on both sides, an apex obtuse to mucronate, and a rounded base. P. guineense presents trichomes on both surfaces, a grooved midrib on the adaxial surface and a prominent midrib on the abaxial surface, which distinguishes this species from all other Myrtaceae species examined in the present study. The species P. guineense and P. firmum presented a set of differential leaf characteristics among the others taxa of the genus, clearly separating these plants in the morphological identification key.

Composição química e atividade antimicrobiana dos óleos essenciais das folhas e flores de Callistemon viminalis (sol. ex Gaertn.) G. Don ex. Loudon (Myrtaceae) / Chemical composition and antimicrobial activity of essential oils of leaves and flowers of Callistemon viminalis (sol. ex Gaertn.) G. Don ex. Loudon (Myrtaceae)

O presente trabalho teve como objetivo determinar a composição química e avaliar a atividade antimicrobiana dos óleos essenciais obtidos das folhas (frescas e secas) e flores da Callistemon viminalis. Os óleos essenciais foram analisados por CG/EM. A concentração inibitória mínima (CIM) foi determinada utilizando o método de microdiluição em caldo frente a bactérias Gram-positivas e Gram-negativas. De um total de 96,72%, 98,70% dos compostos identificados nos óleos essenciais foram monoterpenos. O 1,8-cineol foi o componente majoritário no óleo essencial das folhas frescas (70,43%), folhas secas (71,71%) e flores (42,39%), seguido do tricicleno com 12,97% nas folhas frescas, 8,20% nas folhas secas e 28,08% nas flores. A CIM para todos os micro-organismos testados foi ≥ a 2.000 μg/mL. Esse estudo é o primeiro relato sobre a composição química e atividade antimicrobiana do óleo essencial das flores de C. viminalis.

The aim of this study was to determine the chemical composition and the antimicrobial activity of essential oils of Callistemon viminalis leaves (fresh and dried) and flowers. The essential oils were analyzed by GC/MS and the minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria was determined by the broth microdilution method. Between 96.72% and 98.70% of the compounds identified in the essential oils were monoterpenes. 1,8-Cineole was the major component in the essential oils of fresh leaves (70.43%), dried leaves (71.71%) and flowers (42.39%), followed by tricyclene: 12.97% in the fresh leaves, 8.20% in the dried leaves and 28.08% in the flowers. The MIC for all microorganisms tested was ≥ 2,000 μg/mL, for all the essential oil samples. This study is the first report on the chemical composition and antimicrobial activity of essential oil from the flowers of C. viminalis.

Chemical variability of the essential oils from fruits of Pterodon emarginatus in the Brazilian Cerrado

Pterodon emarginatus Vogel, Fabaceae, is a tree species commonly known as "sucupira-branca". It is a popular medicinal plant in the Brazilian cerrado (Savanna). This study investigates the chemical variability of the essential oils from fruits of P. emarginatus. The fruits were collected from five sites in the Brazilian Cerrado and their essential oils were analyzed by GC/MS. The results obtained by Principal Component and Cluster Analysis identified two groups: cluster I containing β-caryophyllene and δ-elemene and cluster II containing α-copaene, β-cubebene, allo-aromadendrene, α-cubebene and γ-muurulene. The Canonical Discriminant Analysis was used to differentiate between clusters on the basis of essential oil composition. The results showed high variability in the composition of the essential oils from fruits of P. emarginatus, contributing to studies of domestication of this species.

Essential oils in aerial parts of Myrcia tomentosa: composition and variability

Species in the Myrtaceae family are used in folk medicine to treat gastrointestinal disorders, infectious diseases and hemorrhagic conditions and are known for their essential oil contents. Gas chromatography coupled with mass spectrometry (GC-MS) was used to characterize the chemical composition of essential oils of the leaves, stem bark and flowers of Myrcia tomentosa (Aubl.) DC., as well as to assess the chemical variability in the constituents of the essential oils of the leaf. Soil and foliar analyses were also performed to determine the mineral compositions. Principal component analysis (PCA) was used to examine the interrelationships between the obtained data. The most abundant component in the essential oils of the flowers was (2E,6E)-methyl farnesoate, whereas hexadecanoic acid was the most abundant essential oil component in the stem bark. The leaf essential oils showed seasonal variation in their chemical composition, with bicyclogermacrene and (2E,6E)-methyl farnesoate as the major chemical components. Forty-four constituents were identified, and only nine compounds were found in all of the samples. Sesquiterpenes were mainly produced in the flowers and leaves. The PCA showed a positive correlation between the oxygenated sesquiterpenes and the foliar nutrients Cu and P. Significant statistical correlations were verified between the climatic data, foliar nutrients and essential oil compositions.

Determinação de taninos e metilxantinas no guaraná em pó (Paullinia cupana Kunth, Sapindaceae) por cromatografia líquida de alta eficiência / Determination of tannins and methylxanthines in powdered guarana (Paullinia cupana Kunth, Sapindaceae) by high performance liquid chromatography

As sementes de guaraná (Paullinia cupana Kunth, Sapindaceae) são utilizadas como estimulante e os principais constituintes químicos são as metilxantinas e os taninos, tais como catequina e epicatequina. Este trabalho teve por objetivo investigar um método por cromatografia líquida de alta eficiência (CLAE) para quantificar, simultaneamente, cafeína, teofilina, teobromina, catequina e epicatequina em pó de guaraná. Os valores obtidos foram comparados com os resultados encontrados no método espectrofotométrico da Farmacopéia Brasileira IV ed. Pelo método cromatográfico, os teores de metilxantinas e taninos totais foram de 4,04 por cento e 1,48 por cento, respectivamente. Os teores de metilxantinas e taninos totais, obtidos pelo método espectrofotométrico, foram de 4,88 por cento e 4,05 por cento, respectivamente. Acredita-se que, nas condições experimentais empregadas, o método espectrofotométrico não foi específico, quantificando outras substâncias fenólicas presentes no guaraná. Portanto, sugere-se o emprego desse método cromatográfico no controle de qualidade do guaraná em pó, por ser preciso, sensível, específico e rápido.

The seeds of Paullinia cupana Kunth, Sapindaceae, are used as a stimulant and the main chemical constituents are the methylxanthines and tannins, as catechin and epicatechin. This study aimed to investigate a method by high performance liquid chromatography (HPLC) to quantify both caffeine, theophylline, theobromine, catechin and epicatechin in powdered of P. cupana. The values obtained were compared with the results of the spectrophotometric method of the Brazilian Pharmacopoeia IV ed. For the chromatographic method, the levels of methylxanthines and total tannins were 4.04 percent and 1.48 percent, respectively. The levels of methylxanthines and total tannins obtained by the spectrophotometric method, were 4.88 percent and 4.05 percent, respectively. It is believed that, under our experimental conditions, the spectrophotometric method was not specific and quantified others phenolic substances present in the P. cupana. Therefore we suggest the use of this chromatographic method in quality control of P. cupana powder, to be accurate, sensitive, specific and fast.

Estudo farmacognóstico das folhas de Pimenta pseudocaryophyllus (Gomes) L.R. Landrum - Myrtaceae / Pharmacognostic study about Pimenta pseudocaryophyllus (Gomes) L. R. Landrum leaves - Myrtaceae

O intuito deste trabalho de pesquisa foi obter parâmetros de controle de qualidade para a identificação da matéria-prima vegetal (folha) de Pimenta pseudocaryophyllus (Gomes) L. R. Landrum - Myrtaceae que ocorre no cerrado brasileiro. Para tanto foram coletadas amostras em Minas Gerais - Brasil e no Distrito Federal - Brasil e as exsicatas foram depositadas no Herbário da UFG n. UFG-27.159 e no Herbário Ezechias Paulo Heringer n. 21.745-0, respectivamente. Parte desse material botânico foi preparada para análises macro e microscópicas. Outra parte foi seca, triturada e usada para a triagem fitoquímica. O estudo mostrou que as folhas de P. pseudocaryophyllus são hipoestomáticas, têm grande quantidade de tricomas unicelulares na superfície abaxial, têm cavidades secretoras contendo compostos lipídicos e as células epidérmicas possuem paredes celulares espessas. Na triagem fitoquímica foram detectados compostos fenólicos, taninos e flavonóides. Os taninos foram dosados por diferentes métodos envolvendo reações colorimétricas e de precipitação com proteínas. Os diferentes resultados verificados chamam a atenção para a necessidade de se especificar o método utilizado juntamente com o limite mínimo de taninos totais estabelecido. Os resultados obtidos configuram-se como importantes parâmetros para o controle de qualidade da matéria-prima vegetal e denotam que a espécie em estudo possui um importante potencial fitoterápico que merece ser investigado em estudos farmacológicos e toxicológicos.

The goal of this research was to obtain quality control parameters for the identification of the plant drug of Pimenta pseudocaryophyllus (Gomes) L. R. Landrum that occurs in Brazilian savannah. So, two samples were collected, one in Minas Gerais state - Brazil, and the other one in Brasilia city - DF - Brazil, and the vouchers were deposited in the UFG Herbarium code number UFG-27159 and Ezechias Paulo Heringer Herbarium code number 21745-0, respectively. Part of the botanical material in both samples was prepared for microscopic analysis. The other one was air-dried, crushed to powder and used for phytochemical screening. The study has shown that P. pseudocaryophyllus leaves are hypostomatic, there are abundant unicellular trichomes in abaxial surface, there are secretory cavities with oily content and epidermal cells have thick wall. Tannins, phenolic compounds and flavonoids were detected in the phytochemical screening. The tannins had been quantified by different methods involving colorimetric and protein precipitation reactions, getting different results. This fact calls the attention for the necessity of specifying the method used together with the minimum tannins limit established. The results configure as important parameters for the quality control of the plant material and denote that the species in study take an important potential as herbal medicine that it deserves to be investigated in pharmacologic and toxicologic studies.