Chemical Constituents and Antileishmanial and Antibacterial Activities of Essential Oils from Scheelea phalerata.

Scheelea phalerata Mart. ex Spreng (Arecaceae) is a palm tree found in the Brazilian cerrado. There are no topics related to volatile oils from S. phalerata leaves in the literature. This work determines its chemical composition and evaluates the biological activity under two different seasonal conditions (dry and rainy seasons). The dry essential oil yield was 0.034 ± 0.001% and the rainy essential oil yield was 0.011 ± 0.003%. Both essential oils presented different qualitative and quantitative compositions (99.4 and 98.5%). The main constituents of the dry essential oil were phytol (36.7%), nonadecane (9.7%), linolenic acid (9.1%), (Z)-hex-3-en-1-ol (4.2%), and squalene (4.0%). The main constituents of the rainy essential oil were phytol (26.1%), palmitic acid (18.7%), hexan-1-ol (15.6%), (Z)-hex-3-en-1-ol (9.7%), and oleic acid (4.0%). The antileishmanial activity against promastigotes of Leishmania amazonensis was observed only for the rainy season essential oil (IC50 value of 165.05 ± 33.26 µg mL-1). A molecular docking study showed that alcohols exert a paramount efficacy and that the action of some essential oil compounds may be similar to that of amphotericin B. Still, only the essential oil from the dry season showed moderate antibacterial activity against S. sanguinis (MICs 200-400 µg mL-1). The cytotoxicity against Vero cells was identical (>512) for both essential oils. The novel data here for both chemical characterization and biological activity, in particular, evidence that the action of these compounds is similar to that of amphotericin B, provide valuable information to the drug-discovery field.

Chemical Composition, Antifungal, and Cytotoxicity Activities of Inga laurina (Sw.) Willd Leaves.

The species Inga laurina is native to the Brazilian Cerrado. There are no studies about the chemical composition and biological activities of extracts of this endangered species. The ethanolic extract and its successive fractions are rich in phenolic compounds and presented good antifungal activities. HPLC/MS-MS/MS and H1/C13 analysis led to the identification of seventeen compounds, most of which are gallic acid derivatives, myricetin and quercetin glycosides. The ethyl acetate fraction (EAF) contained high levels of total phenolics, expressed in milligrams of gallic acid equivalents per gram of extract (475.3 ± 1.9 mg GAE gextract -1) and flavonoids expressed in milligrams of quercetin equivalents per gram of extract (359.3 ± 10.6 mg QE gextract -1). This fraction was active against fungi of the Candida genus. The EAF showed MIC value 11.7 µg mL-1 against C. glabrata and a selectivity index of 1.6 against Vero cells. The flavonol glycoside myricetin-3-O-rhamnoside was isolated for the first time from the Inga laurina. These results make I. laurina a promising plant as a source of pharmaceutical and biological active antifungal compounds.

Antifungal and cytotoxicity activities of Banisteriopsis argyrophylla leaves.

OBJECTIVES: This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites. METHODS: The EtOAc fraction (EAF) obtained from the ethanolic extract of B. argyrophylla leaves showed better antifungal potential against Candida spp. In this fraction, ten flavonoids have been identified by UHPLC-ESI-MSn . Then, EAF was submitted to column chromatography to give four new fractions (A1-A4). The cytotoxicity was determined against Vero cells. KEY FINDINGS: The EAF showed better antifungal potential against Candida spp. with minimum inhibitory concentrations (MICs) between 31.25 and 93.75 µg/ml. The (-)-catechin (fraction A1) showed a MIC of 2.83 µg/ml against Candida glabrata. Fractions A2, A3 and A4 were rich in quercetins and kaempferols and showed good inhibitory concentrations (5.86-46.87 µg/ml) against C. albicans, C. glabrata and C. tropicalis. CONCLUSIONS: The EtOH extract, fractions and the isolated (-)-catechin showed lower toxicity to Vero cells than cisplatin, used as a positive control. Thus, the leaves of B. argyrophylla are a promising source of antifungal agents.

Bioassay-guided fractionation and antimicrobial and cytotoxic activities of Cassia bakeriana extracts

ABSTRACT The antimicrobial potential of extracts of bark and leaves of Cassia bakeriana Craib, Fabaceae, against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method. For crude ethanol extracts and organic fractions tested, the bark dichloromethane phase showed a significant antibacterial effect, with MIC values ranging from 12.5 to 100 µg/ml for most of the microorganisms tested. Thus, a bioassay-guided fractionation of this fraction was performed. This fractionation led to isolation of the 1,8-dihydroxy-anthraquinone-3-carboxylic acid, also known as cassic acid or rhein. It is the first time that this bioactive anthraquinone has been isolated from this plant. Rhein exhibited good selectivity and high activity against anaerobic microorganisms, with MIC values ranging between 3.12 µg/ml (11.0 µM) and 25 µg/ml (88.0 µM). These results were considered very promising since the most active samples and rhein showed greater selectivity against oral microorganisms than toxicity to Vero cells.

Batch-injection analysis with amperometric detection of the DPPH radical for evaluation of antioxidant capacity.

This work proposes the application of batch-injection analysis with amperometric detection to determine the antioxidant capacity of real samples based on the measurement of DPPH radical consumption. The efficient concentration or EC50 value corresponds to the concentration of sample or standard required to scavenge 50% DPPH radicals. For the accurate determination of EC50, samples were incubated with DPPH radical for 1h because many polyphenolic compounds typically found in plants and responsible for the antioxidant activity exhibit slow kinetics. The BIA system with amperometric detection using a glassy-carbon electrode presented high precision (RSD = 0.7%, n = 12), low detection limit (1 µmol L(-1)) and selective detection of DPPH (free of interferences from antioxidants). These contributed to low detection limits for the antioxidant (0.015 and 0.19 µmol L(-1) for gallic acid and butylated hydroxytoluene, respectively). Moreover, BIA methods show great promise for portable analysis because battery-powered instrumentation (electronic micropipette and potentiostats) is commercially available.

Chemical Constituents and Evaluation of Antimicrobial and Cytotoxic Activities of Kielmeyera coriacea Mart. & Zucc. Essential Oils.

Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL(-1)). The outer bark and wood EOs showed MICs of 100 µg mL(-1) for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.

Seasonal variation of the chemical composition and antimicrobial and cytotoxic activities of the essential oils from Inga laurina (Sw.) Willd.

The seasonal chemical composition of essential oils from Inga laurina was determined by GC/MS. In the stem bark's essential oil extracted during the dry season, the presence of terpenoids (30.05%) stood out, and phytol (9.76%) was the major compound identified. For the stem bark oil obtained during the rainy season, in addition to terpenoids (26.63%), a large amount of fatty acids (46.84%) were identified, in particular palmitic acid (25.40%). Regarding the leaves' essential oil obtained in the dry season, esters (42.35%) were the main components. The main ester present was (Z)-hex-3-enyl benzoate (10.15%) and the major compound of this oil was (Z)-hex-3-en-1-ol (14.23%). Terpenoids (33.84%), long-chain alkanes (27.04%) and fatty acids (21.72%) were the main components of the essential oil from leaves in the rainy season. Phytol (33.21%), nonacosane (21.95%) and palmitic acid (15.20%) were the major compounds identified. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method and cytotoxic activity was carried out with Vero cells. The essential oils from the rainy season showed a better inhibition of the bacterial growth with Minimal Inhibitory Concentrations (MIC) values of 25 or 50 µg·mL⁻¹ for aerobic bacteria, and high selectivity against bacteria was observed. The large amount of fatty acids in rainy season oils may be related to the better inhibitory effects observed.

Atividade antioxidante de extratos de folhas de ora-pro-nóbis (Pereskia aculeata Mill. ) usando métodos espectrofotométricos e voltamétricos in vitro / Antioxidant activity of ora-pro-nobis (Pereskia aculeata Mill. ) leaves extracts using spectrophotometric and voltammetric assays in vitro

Atualmente tem crescido a busca por plantas como fontes naturais de antioxidantes. Plantas com esta propriedade podem ser utilizadas para melhorar a qualidade de alimentos, seja para fins nutritivos ou de conservação, como também para a prevenção de doenças relacionadas ao aparecimento de radicais livres. A Pereskia aculeata Mill. (Ora-pro-nóbis) é uma espécie da família Cactaceae e suas folhas são consumidas por muitas pessoas. Neste contexto, este trabalho estudou o teor de fenóis totais (método Folin-Ciocalteau) e de proantocianidinas (vanilina sulfúrica), correlacionando-os com a atividade antioxidante (radical DPPH, sistema b-caroteno/ácido linoleico e voltametria por pulso diferencial) de extratos em acetona 80%, etanol 70% e água das folhas da espécie P. aculeata Mill., apresentando o extrato em acetona 80% maior teor de fenóis totais e proantocianidinas. Com relação à atividade antioxidante frente ao radical DPPH, o extrato em acetona 80% se apresentou ligeiramente melhor que o em etanol 70%. A técnica de voltametria por pulso diferencial mostrou que o extrato em acetona 80% apresenta constituintes com maior potencial redutor que o extrato em etanol 70%. Os dados obtidos a partir da voltametria corroboram com os resultados obtidos pelo método tradicional de DPPH. Os extratos em etanol 70% e em água apresentaram melhor atividade antioxidante pelo sistema b-caroteno/ácido linoleico, o que sugere a presença de outra classe de compostos que atuam na inibição do b- caroteno. Portanto, as folhas da espécie Pereskia aculeata podem ser consideradas como fonte potencial de compostos antioxidantes.

Currently, the search for plants as natural sources of antioxidants has been growing because they can be used to improve the nutritive or preservation properties of food, as soon as for the prevention of diseases related to free radicals. The Pereskiaaculeata Mill. (Ora-pro-nóbis,) is a specie of Cactaceae family and its leaves are consumed by many people. In this context, this paper studied the total phenols (Folin-Ciocalteu) and proanthocyanidins (vanillin sulfuric) correlating with the antioxidant activity (DPPH, b-carotene/linoleic acid system and differential pulse voltammetry) of extracts of 80% acetone, 70% ethanol and water of Pereskiaaculeata Mill. leaves. The 80% acetone extract showed higher total phenols and proanthocyanidins. Regarding to the antioxidant activity by DPPH radical scavenger, the 80% acetone extract was slightly better than 70% ethanol extract. The differential pulse voltammetry technique displayed that the 80% acetone extract presented constituents with greater reducing potential than the ones presented in 70% ethanol extract, what can corroborate the results obtained. The 70% ethanol and water extracts has shown better antioxidant activity by b-carotene/linoleic acid system, what probably suggests the presence of another compounds classes that are responsible for the inhibition the b-carotene. Therefore, the Pereskiaaculeata Mill. showed that its leaves may be considered as a potential source of antioxidant compounds.

Chemical composition, cytotoxic and antimicrobial activity of essential oils from Cassia bakeriana Craib. against aerobic and anaerobic oral pathogens.

The chemical composition of the essential oils from leaves, bark and wood of Cassia bakeriana Craib. was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL⁻¹ for most of the tested bacteria, including Streptococcus mutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC50 of 153 µg·mL⁻¹), while wood oil exhibited the highest toxicity to Vero cells. C. bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C. bakeriana.

A new approach for quantifying furanodiene and curzerene: a case study on the essential oils of Eugenia uniflora L., Myrtaceae (pitangueira) leaves

The essential oil obtained from the leaves of Eugenia uniflora L., Myrtaceae, which grows in the Brazilian savannah, was studied by gas chromatography mass spectrometry (GC-MS). Furanodiene (1.2 percent) was thermally rearranged to curzerene (85.1 percent) to produce a combined content of 86.3 percent. GC analysis carried out under mild conditions (with a constant temperature of 100 ºC) showed that the furanodiene concentration was three-fold greater than the curzerene concentration, i.e., the essential oil contained 64.7 percent furanodiene and 21.6 percent curzerene. Germacrene B also rearranged to γ-elemene and the concentration of both was 2.3 percent. Special care should be taken when conventional gas chromatography analysis is used for quantifying compounds that can rearrange at high temperatures.

Analysis of a Brazilian green propolis from Baccharis dracunculifolia by HPLC-APCI-MS and GC-MS / Análise de uma própolis verde brasileira da Baccharis dracunculifolia por CLAE-ICPA-EM e CG-EM

Ethanol and dichloromethane extracts of a Brazilian green propolis from Baccharis dracunculifolia were analyzed by HPLC-APCI-MS and GC-MS, respectively. The HPLC-APCI-MS technique, at the positive mode, furnished a complete and unequivocal chemical composition of the green propolis sample. It serves as fingerprint for different propolis samples. The composition of the ethanol extract consisted mainly of cinnamic acid and derivatives, flavonoids, benzoic acid and a few benzoates, non-hydroxylated aromatics, and aliphatic acids and esters, which are normally not reported in the literature because they do not absorb UV light. The main constituents of the dichloromethane extract were prenylated compounds, alkanes and terpenoids.

Os extratos em etanol e diclorometano de uma própolis verde de Baccharis dracunculifolia foram analisados por CLAE-ICPA-EM e CG-EM, respectivamente. A técnica de CLAE-EM-ICPA, no modo positivo, forneceu uma completa e inequívoca composição química da amostra de própolis verde. Ela serve como impressão digital para amostras diferentes de própolis. A composição do extrato em etanol consistiu fundamentalmente de ácido cinâmico e derivados, flavonóides, ácido benzóico e alguns benzoatos, aromáticos não hidroxilados, e ácidos e ésteres alifáticos, os quais são normalmente ignorados na literatura porque não absorvem luz UV. Os constituintes principais do extrato em diclorometano foram compostos prenilados, alcanos e terpenóides.

Variação química no óleo essencial das folhas de seis indivíduos de Duguetia furfuracea (Annonaceae) / Chemical variability of the essential oil of the leaves from six individuals of Duguetia furfuracea (Annonaceae)

Duguetia furfuracea, Annonaceae, uma invasora de pastagens, é também usada na medicina tradicional em diversos estados no Brasil. Devido à significante diferença de odor entre dois grupos de indivíduos desta planta em um remanescente de cerrado em Campo Grande, Mato Grosso do Sul, seis amostras foram selecionadas de acordo com a intensidade de odor em suas folhas: In-01, In-03 e In-05: odor pronunciado (Perfil A); In-02, In-04 e In-06: odor fraco ou ausência de odor (Perfil B). As folhas foram coletadas e submetidas a hidrodestilação para obtenção dos óleos essenciais, os quais foram analisados por CG/EM. Uma boa compatibilidade foi encontrada entre os resultados obtidos por CG/EM e a análise olfativa adotada para as amostras: espécimes odor pronunciado apresentaram uma alta porcentagem de monoterpenos e alguns sesquiterpenos: In-01 (β-felandreno, 42,2 por cento; mirceno, 6,8 por cento; α-felandreno, 4,6 por cento); In-03 (terpin-4-ol, 21,6 por cento; sabineno, 17,3 por cento; p-cimeno, 5,6 por cento); In-05 (sabineno, 25,1 por cento; terpin-4-ol, 16,2 por cento; p-cimeno, 8,3 por cento). Apenas sesquiterpenos foram encontrados nos espécimes que apresentaram odor fraco ou ausência do mesmo (com constituinte majoritário biciclogermacreno: 21,4 por cento, 24,0 por cento, and 29,1 por cento, respectivamente, para os In-02, In-04 e In-06).

Duguetia furfuracea, Annonaceae, a pasture weed, is also used in folk medicine in several Brazilian states. Because of the significant difference in odor between two groups of this plant in a remnant patch of savanna in Campo Grande county, Mato Grosso do Sul, six samples were selected according to the odor intensity in the leaves (In-01, In-03, and In-05: pronounced odor; In-02, In-04, and In-06: weak odor or its absence). The leaves were collected and subjected to steam distillation for extraction of essential oils, which were analyzed by GC-MS. A good agreement was found between CG/MS results and olfactory evaluation of the samples: specimens exhibiting leaf scent had a high percentage of monoterpenes and some sesquiterpenes, as follows: In-01 (β-phellandrene, 42.2 percent; myrcene, 6.8 percent; α-phellandrene, 4.6 percent); In-03 (terpin-4-ol, 21.6 percent; sabinene, 17.3 percent; p-cymene, 5.6 percent); In-05 (sabinene, 25.1 percent; terpin-4-ol, 16.2 percent; p-cymene, 8.3 percent). Only sesquiterpenes were found in the specimens having weakly scented or scentless leaves (main constituent bicyclogermacrene: 21.4 percent, 24.0 percent, and 29.1 percent, respectively, for In-02, In-04 and In-06).

Um marcador químico de fácil detecção para a própolis de Alecrim-do-Campo (Baccharis dracunculifolia) / An easily detectable chemical marker for the Baccharis dracunculifolia propolis

O presente trabalho apresenta um marcador químico (MQ) volátil, de fácil detecção por cromatografia gasosa, para a própolis do alecrim-do-campo (Baccharis dracunculifolia). Trata-se do composto volátil mais abundante no extrato em diclorometano de própolis verdes dessa planta, mas que aparece, também, em diferentes concentrações, em extratos de diclorometano de própolis marrom, preta, vermelha e amarela, provenientes de regiões que contêm Baccharis dracunculifolia. O MQ está presente no extrato dos ápices vegetativos de alecrim em concentração significativa, mas sua concentração na folha de alecrim é baixa. Própolis de regiões sem alecrim não possuem o MQ. Este composto foi isolado recentemente e se trata do 3-prenilcinamato de alila. Amostras comerciais de extratos etanólicos de própolis verdes foram analisadas e a de primeira qualidade, tipo exportação, apresentou maior concentração de MQ. Tal descoberta facilita o rápido controle de qualidade de extratos etanólicos de própolis verdes.

In the present work a volatile chemical marker (CM) for the Baccharis dracunculifolia (Bd) propolis is proposed, which is easily detectable by gas chromatography. It is the most abundant volatile compound in dichloromethane extracts of green propolis from this plant, but it appears also, in different concentrations, in dichloromethane extracts of brown, dark and red propolis from regions where Bd grows. The CM is present in significative concentration in the bud extract of Bd, in contrast to the leaf extract where its concentration is low. Propolis from regions without Bd does not contain the CM. This compound was recently isolated; it is the allyl 3-prenylcinnamate. Commercial samples of green propolis ethanol extract were analyzed and the first quality one (exportation standard) presented the highest concentration on CM. This finding makes easier the quality control of green propolis extracts sold at the market.