Biomonitoring the Vitex gardneriana Shauer (Lamiaceae) toxic effects to shed light on bioactive compounds against a major coconut pest mite.

The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), is a major pest of coconut plantations (Cocos nucifera L.) worldwide. Here, we conducted a bioguided phytochemical approach using toxicity and repellency bioassays of nonpolar extract and its fractions of Vitex gardneriana Schauer (Lamiaceae) leaves to this pest. Nonpolar crude extract was fractionated by column chromatography using solvents with increased polarity and binary mixtures, resulting in five semipurified groups. The biomonitoring bioassay provided active fractions and led to the isolation and characterization of the bioactive compound squalene, a biosynthetic precursor of 20-hydroxyecdysone, which plays an important role in plant defense against arthropods. The LC50 of the crude extract of V. gardneriana for A. guerreronis was estimated to be 0.185 mg·mL-1 and LC80 = 4.123 mg·mL-1. Also, the extract was highly repellent to this pest for up to 24 h. The fractions of V. gardneriana, and also squalene, caused mortality to A. guerreronis. The potential of V. gardneriana fractions/squalene as biopesticides for controlling A. guerreronis in coconut plantations is discussed herein

Chemical composition similarity between the essential oils isolated from male and female specimens of each five Baccharis species

In the few studies published on essential oils from female and male specimens of Baccharis species, strong differences between the compositions of both samples were always found. The experiments conducted in this study make use of strategies to minimize the interference from genetic and environmental factors. Essential oils from leaves of female and male specimens of five Baccharis species were investigated by gas chromatography-mass spectrometry plus flame ionization detector (GC-MS-FID): B. caprariaefolia and B. dracunculifolia, which have been previously studied with similar aims; and B. coridifolia, B. semiserrata var. elaegnoides and B. pentaptera, the latter two not yet mentioned in the literature. The results were followed by hierarchical cluster analysis, verifying the formation of groups indicative of the great similarity of essential oils from male and female specimens of all five species. The study reinforces the value of field observation in natural product research and points genetic and ecological factors as main responsible for differences in the secondary metabolites of the studied plants._________________________________________________________________________________________ RESUMO: Nos poucos estudos publicados comparando óleos essenciais de espécimes femininos e masculinos de espécies Baccharis, fortes diferenças entre as composições de ambas as amostras foram sempre encontradas. Os experimentos realizados nesta pesquisa utilizam estratégias para minimizar a interferência de fatores genéticos e ecológicos. Os óleos essenciais das folhas de espécimes femininos e masculinos de cinco espécies Baccharis foram pesquisados com uso de um cromatógrafo gasoso acoplado a um espectrômetro de massas e a um detector de ionização de chama (CG-EM-DIC): B. caprariaefolia e B. dracunculifolia, já pesquisadas anteriormente com objetivos similares; e B. coridifolia, B. semiserrata var. elaegnoides e B. pentaptera, as duas últimas ainda não mencionadas na literatura química. Os resultados foram acompanhados por análise hierárquica de grupos, verificando-se a formação de grupos indicativos da grande similaridade entre óleos essenciais dos espécimes masculinos e femininos de todas as cinco espécies. O estudo reafirma o valor das observações de campo na pesquisa de produtos naturais, e aponta fatores genéticos e ecológicos como principais responsáveis por diferenças no metabolismo secundário das plantas estudadas

Optimization of atmospheric pressure photoionization for the crude oil analysis using ultra-high resolution mass spectrometry

Design of experiments (DOE) applied to mass spectrometry (MS), mainly focusing on the optimization of ionization techniques, has been applied to optimize experiments in order to provide the highest amount of information with the lowest number of experiments. However. DOE has not been used in petroleomics. For the first time, we applied DOE to optimize the main parameters associated with the crude oil analysis in a petroleomics approach. For the ionization technique, atmospheric pressure photoionization (APPI) has been selected and data were acquired in a high resolution (400,000 at m/z 400) and high mass accuracy (< 1 ppm) Fourier transform ion cyclotron resonance (FT-ICR) MS. Full and fractional two-level factorial designs were applied for the APPI(+/-) FT-ICR MS data set from two different crude oil samples with distinct physical and chemical characteristics. The standard ionization parameters that affect the MS responses of the crude oil analysis were optimized for both APPI(+)-MS and APPI(-)-MS. Such ionization parameters were then successfully applied to a crude oil and its saturated, aromatics, resin and asphaltene fractions, all with superior features of merit. Thus, the optimized APPI(+/-)-MS parameters should serve as reference and can be used as a guide for new studies in petroleomics304819829FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2013/19161-4Sao Paulo Research Foundation (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2013/19161-4]; Petrobra

Synthesis of enaminones with stationary stereochemistry

Five enaminones 4a-e derived from the reaction of 2,4,4-trimethyl-2-oxazoline anion with ethyl acetate, ethyl benzoate, ethyl cyclohexanoate, ethyl hexanoate and ethyl p-methyl benzoate, respectively, were obtained and characterized by 13C-NMR, ¹H-NMR, FTIR, and mass spectral analysis. The enaminones 4a and 4b were also analysed by X-ray diffraction. Enaminone 4a crystallized in the monoclinic P2(1)/n space group with a = 9.1450(20) Å, b = 10.5150(20) Å, c = 9.5670 (20) Å, beta= 106.21(30)°, Z = 4. Enaminone 4b crystallized in the monoclinic P2(1)/c space group with a = 16.0520(30) Å, b = 26.0460(50) Å, c = 12.3520 (20) Å, beta = 111.900(30)°, Z = 4. All five enaminones were found to have an extensive pi electron delocalization and to have the same configuration where the double bond is trapped by an internal hydrogen bond between the NH and the C=O