Juvenile hormone (JH III) is an important example of a chemical signaling derived from the terpene biosynthetic pathway. Because of its impact on many species’ reproductive and developmental processes, analytical approaches must be developed to accurately identify and measure it in biological samples. In this technical note, we explored the gas-phase dissociative behavior of JH III using tandem mass spectrometry combined with electrospray ionization to provide diagnostic fragment-ions for quantitative purposes.

Copalic (CA) and kaurenoic (KA) acids are the main diterpenes found in the oleoresin extracted from the copaiba tree (Copaifera sp). This study aimed to characterize the metabolism of CA and KA in rat and human liver microsomes using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The in vitro assays showed deviations from the Michaelian kinetics in the metabolism of CA and KA. Putative metabolites of CA and KA were characterized by LC-MS/MS using electrospray ionization (ESI) with time of flight (LC-ESI-TOF) and ion-trap (LC-ESI-IT) systems and identified as a CA isomer and 16,17-dihydroxy-kaurenoic acid, respectively. CA and KA are subject to extensive metabolism with each passage through the liver with extraction ratios (E) estimated as 0.97 and 0.99, respectively. In conclusion, the kinetic parameters and metabolites described here might support drug development and the traditional use.

RESUMO Bemisia tabaci (Hemiptera: Aleyrodidae) é um inseto polífago que causa danos diretos e indiretos na cultura do tomateiro. A pulverização com inseticidas sintéticos é um dos principais métodos de controle, porém, o uso abusivo dessa ferramenta pode impactar o ambiente e os seres humanos. Este estudo avaliou a bioatividade de extratos de plantas das famílias Asteraceae e Meliaceae sobre B. tabaci biótipo B em tomateiro. Um ensaio preliminar avaliou os efeitos dos extratos a 2% (p/v) sobre a infestação e oviposição dessa mosca-branca. Os efeitos ninficida e ovicida do extrato clorofórmico de Trichilia pallida - TP-Cl em seis concentrações foram avaliados. Finalmente, a TP-Cl CL50 foi estimada. Todos os extratos foram repelentes para a mosca-branca, com exceção de T. pallida (etanólico) e Melia azedarach (hexânico), considerados neutros em 24 h. Todos os extratos causaram deterrência para oviposição. Todas as concentrações de TP-Cl apresentaram atividade ninficida e as maiores promoveram as menores médias de viabilidade de ovos. A CL50 foi de 0,0955%. Os resultados evidenciaram o potencial dos extratos para serem usados como agentes alternativos de controle de B. tabaci biótipo B em tomateiro.

ABSTRACT Bemisia tabaci (Hemiptera: Aleyrodidae) is a polyphagous insect that causes direct and indirect damage on tomato. Spraying with synthetic insecticides is one of the main control tools for the whitefly; however, the abusive use of this tool can impact the environment and human beings. In this study we evaluated the bioactivity of extracts from plant species from Asteraceae and Meliaceae families on B. tabaci biotype B in tomato. A preliminary bioassay evaluated the effects of the extracts at 2% (w/v) on infestation and oviposition of this whitefly. Then, the nymphicidal and ovicidal effects of the chloroformic extract of Trichilia pallida - TP-Cl at six concentrations were performed. Finally, the TP-Cl LC50 was estimated. All extracts were repellent to the whitefly, except that ones from T. pallida (ethanolic) and Melia azedarach (hexanic), considered neutral at 24 h. All the extracts caused deterrence of oviposition. All concentrations of TP-Cl revealed nymphicidal activity and the highest ones provided the lowest egg viability averages. The estimated LC50 was 0.0955%. These results provide evidence for the potential of the extracts to be used as alternative control agents of B. tabaci biotype B in tomatoes.

In 2002, the Brazilian Chemical Society have promoted several activities aiming to prepare a document to discuss the education in Chemistry in Brazil, the new model of research funding, the area situation and its perspectives. The document drew up diagnoses and brought up proposals that were organized into six mobilizing axes. Among its conclusions it was expected an alignment of scientific and technological research, considering the central role of Chemistry in solving problems and overcoming challenges affecting the education, full citizenship, climate changes, food production and quality, access to and quality of water, energy security, preservation of ecosystems and species, emerging diseases and quality of life. The current moment brings again challenges, imposed by a new technological generation, the transformations of the urban societies and by the commitment with a sustainable development. This article seeks to outline a panorama, using as background the Industry 4.0, the Society 5.0, the Sustainable Development Objectives, the creation of the EMBRAPII, the SENAI Institutes of Innovation and the role of the graduate programs in Chemistry, in order to construct a new agenda under the scope of the SBQ for the next 15 years.

ABSTRACT Aspergillus spp. cause economic impacts due to aflatoxins production. Although the toxicity of aflatoxins is already known, little information about their ecological roles is available. Here we investigated the compounds produced by Aspergillus nomius ASR3 directly from a dead leaf-cutter queen ant Atta sexdens rubropilosa and the fungal axenic culture. Chemical analyses were carried out by high-resolution mass spectrometry and tandem mass spectrometry techniques. Aflatoxins B1 and G1 were detected in both the axenic culture and in the dead leaf-cutter queen ant. The presence of these mycotoxins in the dead leaf-cutter queen ant suggests that these compounds can be related to the insect pathogenicity of A. nomius against A. sexdens rubropilosa.

Abstract Methanolic extracts of the Brazilian endemic ascidian Eudistoma vannamei have been extensively studied for their cytotoxic activity against several human cancer cell lines. Previous work reported the occurrence of purine derivatives and staurosporine alkaloids as the major nitrogen-containing compounds. In this study, we report the occurrence of three pyrimidine alkaloids in addition to cholesterol, sitosterol and stigmasterol.

ABSTRACTThe genus Erythrina, Fabaceae, is widely distributed in tropical and subtropical regions. Their flowers, fruits, seeds and bark are frequently used in folk medicine for its effects on the central nervous system such as anticonvulsant, antidepressant, analgesic, sedative, and hypnotic effects. Erythraline has been reported as one of the active compounds from Erythrina, but until now there are no pharmacokinetics data about this compound and only few results showing a putative metabolism were reported. To improve the information about erythraline metabolism, this article reports and discusses, for the first time, the in vitrometabolism biotransformation of erythraline by cytochrome P450 enzymes.

The best time of production of the cyclohexadepsipeptide beauvericin by the endophytic fungus Fusarium oxysporum SS46 in Czapek medium was evaluated. The highest level of beauvericin production was found on day 21 of fermentative culture, as assessed by quantitative analysis by high performance liquid chromatography coupled with a photodiode array detector. Precursor-directed biosynthesis experiments were carried out to produce new analogues of beauvericin by feeding F. oxysporum with ten analogues of L-phenylalanine. In order to evaluate which precursor analogues were incorporated by the microorganism, the obtained extracts were analyzed using matrix-assisted laser desorption ionization - time-of-flight mass spectrometry (MALDI-TOF/TOF). The precursor-directed biosynthesis studies led to the biosynthesis of novel beauvericin derivatives by replacement of one, two, or all three L-phenylalanine residues in beauvericin with DL-3-fluorophenylalanine, L-3-fluorophenylalanine, L-4-fluorophenylalanine, or L-tyrosine. Beyond these precursor analogues, one unit of L-4-aminophenylalanine, L-4-chlorophenylalanine, DL-4-bromophenylalanine, or L-4-bromophenylalanine was also incorporated by the endophyte F. oxysporum SS46. Units of L-4-nitrophenylalanine and L-histidine were not incorporated by the microorganism to produce unnatural beauvericins.

The present study evaluated the chemical profile of polar extracts of Calendula officinalis L., Asteraceae, that were grown under different cultivation conditions: chemical fertilisation, organic fertilisation and mulching. Furthermore, we investigated metabolite variations during plant development by comparing the metabolites from harvested plants at 60 and 120 days after planting. We used HPLC-DAD-MS/MS to tentatively identify metabolites. In total, we identified seven known compounds: five flavonoid glycosides and two caffeoylquinic acids derivatives. There were no statistically significant differences in the expression of metabolites from plants grown under the examined soil treatments. However, five substances varied according to harvest time, suggesting that the biosynthesis of polar metabolites of Calendula officinalis is not affected by changes in soil composition. Therefore, this plant could represent a source for phytomedicines with a constant content of polar metabolites.

Four goyazensolide-type sesquiterpene lactones - lychnofolide, centratherin, goyazensolide and goyazensolide acetate - were thoroughly studied by NMR experimental techniques. ¹H NMR, 13C NMR {¹H}, COSY, HMQC, HMBC, J-res. and NOE experiments were performed to provide the needed structural information. Complete and unequivocal assignment, including the determination of all multiplicities, was obtained for each structure and the data collections are presented in tables.

The species Eremanthus mattogrossensis, known as "veludo do cerrado" (cerrado velvet), is native to the Brazilian Cerrado. Because the amount of metabolites present in plants may be influenced by biological and environmental factors, here we conducted an HPLC-DAD-MS/MS investigation of the metabolite concentrations found in the MeOH/H2O extract of the leaves of this species. The main compounds were identified and quantified, and the metabolites were grouped by chemical class (caffeoylquinic acids, flavonoids, and sesquiterpene lactone). Statistical analysis indicated a straight correlation between the quantity of metabolites and seasonality, suggesting that environmental properties elicit important metabolic responses.

Erythrina verna is a medicinal plant used to calm agitation popularly known as mulungu. We purchased the barks of E. verna from a commercial producer and analyzed the alkaloid fraction of the bark by CG-MS and HRESI-MS. Five erythrinian alkaloids were identified: erysotrine, erythratidine, erythratidinone, epimer, and 11-hydroxieritratidinone. Here we report the compound 11-hydroxieritratidinone for the first time as a natural product.

Piplartine (PPTN) is an alkaloid amide found in Piper species that presents different activities. PPTN determination in rat plasma is necessary to better understand its biological effects. The aim of this study was to develop a sensitive LC-MS/MS method for the determination of PPTN in rat plasma. The performance criteria for linearity, sensitivity, precision, accuracy, recovery, and stability have been assessed and were within the recommended guidelines. The validated method proved to be suitable in a pilot study of PPTN kinetic disposition in rat plasma after a single intraperitoneal dose, and represents an appropriate tool to further pharmacokinetic studies.