RESUMO Para uma cultura importante e expressiva como o milho, a resistência de Spodoptera frugiperda J.E. Smith a vários inseticidas atraiu a atenção no mundo para pesquisar o potencial inseticida de compostos naturais. Para o manejo da resistência, os compostos naturais associados a inseticidas sintéticos podem ser uma ferramenta promissória por reduzirem a aplicação das moléculas sintéticas para que não percam sua eficácia, além de promover o controle das pragas. O linalol é um terpenoide considerado como inseticida potencial, pode ser facilmente obtido naturalmente uma vez que é encontrado em alta concentração no óleo essencial de Ocimum basilicum. Portanto, o presente estudo teve como objetivo avaliar a toxicidade deste óleo essencial e sua combinação com deltametrina no controle de Spodoptera frugiperda. Através do ensaio de dose-resposta, foi estimada a toxicidade aguda (DL50) do óleo essencial e da deltametrina. Adicionalmente, foi também avaliada a combinação entre ambos, alcançando uma redução de 80% da DL50 de deltametrina para se obter o mesmo resultado quando o piretroide foi administrado sozinho. A partir dos nossos resultados, espera-se que uma combinação de uso de compostos naturais e inseticidas sintéticos possa ser uma prática promissora, auxiliando no manejo da resistência de pragas e principalmente reduzindo os impactos ambientais de compostos tóxicos.

ABSTRACT For an important and expensive crop such as corn, the resistance of Spodoptera frugiperda J.E. Smith to various pesticides has led to research throughout the world for a potential insecticide from a natural source. For the management of pest resistance, natural compounds associated with synthetic insecticides can be a promising tool because they can reduce the application of the synthetics molecules while maintaining their effectiveness and promoting the control of the pests. Linalool is a potential insecticide that is easily obtained because it is found in high concentrations in the essential oil of Ocimum basilicum L. Therefore, the present study aimed to evaluate the toxicity of this essential oil and its combination with deltamethrin to control S. frugiperda. Through dose response assays, the acute toxicities (LD50) of the essential oil and deltamethrin were estimated. Additionally, the combination of these materials was also assessed, attaining a reduction of 80% of the LD50 of deltamethrin while obtaining the same result as when the pyrethroid was administered alone. From these results, it is expected that the combination of natural compounds and synthetic insecticides will be a promising practice, helping to manage resistance while reducing the environmental impact of toxic compounds.

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.

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%) was thermally rearranged to curzerene (85.1%) to produce a combined content of 86.3%. 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% furanodiene and 21.6% curzerene. Germacrene B also rearranged to γ-elemene and the concentration of both was 2.3%. Special care should be taken when conventional gas chromatography analysis is used for quantifying compounds that can rearrange at high temperatures.

The bioactive compounds and antioxidant activity presented by Conilon coffee (C. Canephora) variety, produced in the Espírito Santo State, Brazil, were quantified. The light roast coffee showed the highest level of total phenols, trigonelline, caffeic and chlorogenic acids. The proanthocyanidin level was the highest for dark roast coffee, while caffeine level didn't show significative changes for the light and middle roast coffees. All the Conilon coffee extracts showed antioxidant activity depending on bioactive compounds concentration and roasting degree. The coffee samples submitted to a light roasting degree showed the highest antioxidant activity.

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.

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.

O presente trabalho estudou os compostos bioativos (ácidos clorogênicos, trigonelina, cafeína, fenóis totais e proantocianidinas), grupos hidroxila ácidos e atividade antioxidante de um café arábica proveniente do Cerrado Mineiro e de seu PVA (grãos pretos, verdes e ardidos). As amostras foram preparadas nas torras clara (180 ± 10 °C; 6,0 ± 1,0 minutos), média (180 ± 10 °C; 8,0 ± 1,0 minutos) e escura (180 ± 10 °C; 10,0 ± 1,0 minutos). Considerando-se a média das três torras do café e do PVA, a diferença observada no teor de todos os constituintes acima não foi significativa (p > 0,05), exceto com o teor de grupos hidroxila ácidos que foi ligeiramente superior no PVA e cafeína calculada pelo método semiquantitativo que foi superior no café. Portanto, dentre esses constituintes, os compostos com grupos ácidos seriam os únicos que poderiam contribuir para explicar a grande diferença de sabor existente entre o café de grãos sadios e o de PVA. Tanto o café como o PVA apresentaram atividade seqüestradora do radical DPPH. nas três torras, sendo a atividade do café sempre superior. Analisando-se as variações dos teores de cafeína, fenóis totais, proantocianidinas, grupos hidroxila ácidos, trigonelina e ácidos clorogênicos, não foi possível explicar a atividade antioxidante superior apresentada pelo café da torra média (CE50 de 2,3 mg.mg-1 de DPPH.).

This work reports the results of the investigation of bioactive compounds (chlorogenic acids, trigonelline, caffeine, total phenolics, and proanthocyanidins), total acid groups, and the antioxidant activity of the Arabian coffee (Coffea arabica) from the Brazilian cerrado (vast tropical savannah) (Minas Gerais state) and its defective beans (Black, green, and sour beans). The samples were prepared using three roasting degrees: light (180 ± 10 °C; 6,0 ± 1,0 minutes), medium (180 ± 10 °C; 8,0 ± 1,0 minutos), and dark (180 ± 10 °C; 10,0 ± 1,0 minutes). Considering the average of the three roasts per coffee and defective beans, the difference observed for the content of all constituents listed above was not significant (p > 0,05). Exceptions are the content of acid hydroxyl groups, which were slightly greater in the coffee defective beans and the content of caffeine, calculated using the semi-quantitative method, which was higher in the coffee itself. Both the coffee and its defective beans presented scavenging activity against DPPH. radical; however, the coffee antioxidant activity was always higher. The variations observed in the content of caffeine, total phenols, proanthocyanidins, phenolic acid groups, trigonelline, and chlorogenic acid levels can not explain the higher antioxidant activity observed for the medium roasted coffee (EC50 of 2,3 mg.mg-1 of DPPH.).

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.

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%; mirceno, 6,8%; α-felandreno, 4,6%); In-03 (terpin-4-ol, 21,6%; sabineno, 17,3%; p-cimeno, 5,6%); In-05 (sabineno, 25,1%; terpin-4-ol, 16,2%; p-cimeno, 8,3%). Apenas sesquiterpenos foram encontrados nos espécimes que apresentaram odor fraco ou ausência do mesmo (com constituinte majoritário biciclogermacreno: 21,4%, 24,0%, and 29,1%, 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%; myrcene, 6.8%; α-phellandrene, 4.6%); In-03 (terpin-4-ol, 21.6%; sabinene, 17.3%; p-cymene, 5.6%); In-05 (sabinene, 25.1%; terpin-4-ol, 16.2%; p-cymene, 8.3%). Only sesquiterpenes were found in the specimens having weakly scented or scentless leaves (main constituent bicyclogermacrene: 21.4%, 24.0%, and 29.1%, respectively, for In-02, In-04 and In-06).

RESUMO Neste estudo, foram analisados os principais componentes químicos da madeira da Moquinia polymorpha (LESS.) DC., conhecida como candeia ou cambará, nativa da região Sul de Minas Gerais. A composição química dessa madeira foi: 47,5% de α-celulose, 25,4% de hemiceluloses A e B, 24,0% de lignina, 73,2% de holocelulose, 3,82% de extrativos em etanol:cicloexano (1:1, v v-1), 3,21% em etanol e 4,04% em água quente. Nos compostos voláteis identificados, destacaram-se: α-curcumeno, α- diidroturmerona, β-diidroturmerona, cedranol, 1-ciclopentil-3-[2,4-dimetil-fenil]propano. A análise dos fenóis totais foi conduzida com base nos extratos metanol-água (MA) e acetona-água (AA), em que esse último apresentou maior rendimento. O teor de fenóis totais foi determinado pelos métodos Folin-Ciocalteau e Azul da Prússia modificado. No método Folin-Ciocalteau, foram encontrados 0,93 mg g-1 de madeira para o extrato MA e 1,56 para o extrato AA e no método azul da Prússia modificado, foram determinados 2,74 mg g-1 de madeira para o extrato MA e 4,42 para o extrato AA. O teor de proantocianidinas foi determinado pelos métodos da vanilina e n-butanol:ácido. No método n-butanol:ácido, foram encontrados 0,012 mg g-1 de madeira para o extrato MA e 0,017 para o extrato AA e, no método da vanilina, foram determinados 0,29 mg g-1 de madeira para o extrato MA e 0,58 para o extrato AA. Não foram detectados 3-deoxi-proantocianidinas.

ABSTRACT In this study, the main chemical components of Moquinia polymorpha (LESS.) DC. (candeia or cambará) wood were investigated. This wood is native in the Southern region of Minas Gerais - Brazil. The chemical composition was: 47.5% of α-cellulose, 25.4% of A and B hemicelluloses, 24.0% of lignin, 73.2% of holocellulose, 3.82% of ethanol:cyclohexane (1:1, v v-1) extractives, 3.21% of ethanol extractives and 4.04% of hot water extractives. The volatile composition was mainly: α-curcumene, α-dihydroturmerone, β- dihydroturmerone, cedranol, 1-cyclopentyl-3-[2,4-dimethylphenyl]propane. The total phenols analysis was carried out on methanol:water (MW) and acetone:water (AW) extracts. The last one presented better yield. The total phenols were determined by Folin-Ciocalteau and the modified Prussian blue assays. Folin- Ciocalteau yielded 0.93 mg g-1 of wood for MW extract and 1.56 for AW extract; modified Prussian blue yielded 2.74 mg g-1 of wood for MW extract and 4.42 for AW extract. Proanthocyanidins were determined by n-buthanol-acid and vanillin assays. The n-buthanol acid yielded 0.012 mg g-1 of wood for MW extract and 0.017 for AW extract; vanillin: 0.29 mg g-1 of wood for MW extract and 0.58 for AW extract. 3-deoxy- proanthocyanidins were not detected.