Transformações químicas do (+)-10b,14-diol-allo-aromadendrano, isolado de duguetia glabriuscula r. e. fries (r. e. fries) (annonaceae) e avaliações biológicas de alguns derivados obtidos

The sesquiterpene (+)-allo-aromadendrane-10b-14-diol 1 was the lead compound to the preparation of several derivatives in order to test their biological activity against A. salina, C. sphaerospermum, E. coli and S. aureus. In this way the monoalcohols (+)-viridiflorol 4, 9 and 11 were synthesized from 1 together with the acetal 6, the ketal 7, and the ketone 8. The oxirane 3 and nitrile 5 were also prepared using as an intermediate the tosylate derivative 2.

Nova rota de preparação do 2-cloro-1,3,2-dioxofosfolana e 2-cloro-4,5-benzo-1,3,2-dioxofosfolana e caracterização por espectroscopia de RMN multinuclear

A new method for the preparation of 2-chloro-1,3,2-dioxaphospholane (1) and 2-chloro-4,5-benzo-1,3,2-dioxaphospholane (2), are reported. The modifications introduced in the synthetic route improved the yield and facilitated the control of reaction, but the synthesis require longer reaction time. The compounds were characterized by ¹H, 13C{¹H} and31P{¹H} NMR spectroscopy. Due to the complexity of the spin system AA'BB'X (A, A', B, B' = ¹H; X = 31P) of 2, a simulation of the ¹H NMR spectra was done and it's in agreement with the bibliography.

Determinação do coeficiente de distribuição (Kd) de benzo(a)pireno em solo por isotermas de sorção

Leaking of diesel oil from gas stations is frequent in Brazil. The presence of polycyclic aromatic hydrocarbons (PAHs), which are highly toxic is an indication of contamination by heavy hydrocarbons from diesel oil. Here were present the determination of the distribution coefficient (Kd) of benzo(a)pyrene (the most carcinogenic of the PAHs) in tropical soils using the sorption isotherm model. The sorption curves acquired for benzo(a)pyrene were of the S-type, probably due to the water/methanol experimental conditions. The sorption curves allowed calculation of the distribution coefficient (Kd). The experimental Kd values were lower than those calculated from literature Koc values (partition coefficient normalized by organic carbon), due mainly to the cosolvency effect and the percentage of organic matter and clay in soil.

Avaliação do destino e bioacumulação de benzo(a)pireno através de simulação computacional

The objective of this work was to evaluate the environmental distribution of benzo(a)pirene, a polycyclic aromatic hydrocarbon, by the EQC model. The modeling of the contaminant distribution was accomplished by means of the fugacity model applied to a hypothetical scenario constituted by air, water, soil and sediment. The modeling and simulations revealed that the soil is the preferential compartment. We also discuss the implications of the results about fate and ecological risks associated with benzo(a)pirene. We concluded that the emissions of HPAs can not be ignored and bioaccumulation among others risks can be induced.

Benzo(a)pireno, carbamato de etila e metanol em cachaças

The objective of this work was to evaluate the presence of benzo(a)pyrene (BaP), ethyl carbamate (EC) and methanol in 61 samples of cachaça. The quantification of BaP was carried out using HPLC with fluorescence detection, EC concentrations was determined by GC/MS and that of methanol, by GC/FID. In all samples, the concentration of methanol remained below 5 mg 100 mL-1 absolute alcohol. The results of BaP varied from <0.03 to 0.86 μg L-1; the values of EC exceeded the limit established by Brazilian legislation (150 μg L-1) in 53% of the samples.

Analysis of the structural and electronic properties of 1-(5-Hydroxymethyl - 4 -[ 5 - (5-oxo-5-piperidin-1-yl-penta-1,3dienyl)-benzo[1,3]dioxol-2-yl] -tetrahydro-furan-2-yl)-5-methyl-1H-pyrimidine-2,4dione molecule

The structural and electronic properties of 1-(5-Hydroxymethyl - 4 -[ 5 - (5-oxo-5-piperidin- 1 -yl-penta- 1,3 -dienyl)-benzo [1,3] dioxol- 2 -yl]-tetrahydro -furan-2 -yl)-5-methy l-1Hpyrimidine-2,4dione (AHE) molecule have been investigated theoretically by performing density functional theory (DFT), and semi empirical molecular orbital calculations. The geometry of the molecule is optimized at the level of Austin Model 1 (AM1), and the electronic properties and relative energies of the molecules have been calculated by density functional theory in the ground state. The resultant dipole moment of the AHE molecule is about 2.6 and 2.3 Debyes by AM1 and DFT methods respectively, This property of AHE makes it an active molecule with its environment, that is AHE molecule may interacts with its environment strongly in solution.

Benzo(a)pireno em óleos de milho produzidos e comercializados no Brasil

Óleos de milho de diferentes marcas, produzidos e comercializados no Brasil, foram analisados quanto à presença de benzo(a)pireno (B(a)P). A metodologia utilizada envolveu extração com ciclohexano, purificação em coluna de silica gel e determinação por cromatografia líquida de alta eficiência com detector de fluorescência. Todas amostras analisadas mostraram-se contaminadas por B(a)P e os níveis determinados variaram entre as diferentes marcas analisadas e entre diferentes lotes de mesma marca, dentro da faixa de 0,85 a 25,17 µg/kg. Entre 49 amostras analisadas no período de dois anos, apenas uma apresentou nível de contaminação por B(a)P abaixo do limite referencial de 1 µg/kg.

Determinação de benzo(a)pireno em pescados

No presente estudo, peixes, camarões, mexilhões e carnes de siri frescos e processados, comercializados na região metropolitana de Campinas (SP), foram analisados quanto à presença de benzo(a)pireno (B(a)P). A metodologia utilizada envolveu extração com n-hexano, limpeza em Sep-Pak sílica plus e determinação por Cromatografia Líquida de Alta Eficiência com Detector de Fluorescência. A presença de B(a)P foi detectada em todas as amostras analisadas (n=35), em quantidades variando na faixa de 0,03 a 4,54 µg/kg. Os maiores níveis de contaminação foram encontrados em produtos defumados (níveis médios=2,5 µg/kg) e mexilhões (níveis médios=2,4 µg/kg). Considerando-se o potencial carcinogênico desse contaminante e a importância desse grupo de alimentos na dieta, um programa de monitoramento deve ser iniciado para identificar e controlar a fonte de contaminação de pescados por B(a)P.

Compuestos volátiles libres y enlazados glicosídicamente en la pulpa de la uva Caimarona (Pourouma cecropiifolia Mart.)

Los componentes volátiles presentes en la pulpa de la uva Caimarona se estudiaron mediante GC-MS. Éstos se extrajeron por tres técnicas: evaporación del aroma asistida con solvente (Solvent Assisted Flavour Evaporation SAFE), extracción continua líquido-líquido (LL) y destilación por arrastre con vapor-extracción simultanea con solvente orgánico (DES). En general los componentes volátiles predominantes en la pulpa fueron alcoholes alifáticos y terpénicos. Las notas olfativas del extracto SAFE fueron descritas como floral tenue y verde herbal similares a las exhibidas por la pulpa fresca. Este extracto presentó como componentes mayoritarios linalol 1,2-propanodiol y salicilato de metilo. En contraste, el extracto LL presentó notas que recuerdan la uva pasa y el vino moscatel y sus componentes mayoritarios fueron el ácido acético, el salicilato de metilo y el 2,6-dimetil-2(Z),7-octadien-1,6-diol. El extracto DES fue descrito con notas fresca, floral, cereal y amargo y está constituido por un reducido número de componentes mostrando el efecto negativo de la temperatura en la extracción; sus componentes mayoritarios fueron 1,2-propanodiol, linalol y salicilato de metilo. Adicionalmente, los componentes volátiles mayoritarios liberados por hidrólisis enzimática (Rohapect D5L) de los glicósidos de la pulpa fueron ácido acético, ácido benzoico y vainillina. Cabe destacar que aunque el linalol no se encontró entre las agliconas volátiles, se detectaron los dioles biogenéticamente relacionados: 3,7-dimetil-1,5-octadien-3,7-diol y los isómeros E y Z del 2,6-dimetil-2,7-octadien-1,6-diol.

Eleutherinone, a novel fungitoxic naphthoquinone from Eleutherine bulbosa (Iridaceae)

The dichloromethane extract prepared from the underground parts of Eleutherine bulbosa (Miller) Urban (Iridaceae) showed strong activity in the direct bioautography assay with the phytopathogenic fungus Cladosporium sphaerospermum. This assay was used to guide the fractionation of this extract and allowed the isolation of four compounds: the new naphthoquinone eleutherinone[8-methoxy-1-methyl-1,3-dihydro-naphtho(2,3-c)furan-4,9 -dione] and the known compounds, previously isolated from this species, eleutherin [9-methoxy-1(R),3(S)-dimethyl-3,4-dihydro-1H-benzo(g)isochromene-5,10-dione], isoeleutherin [9-methoxy-1(R),3(R)-dimethyl-3,4-dihydro-1H-benzo(g)isochromene-5,10-dione], and eleutherol [4-hydroxy-5-methoxy-3(R)-methyl-3H-naphtho(2,3-c)furan-1 -one]. All quinonoid compounds showed strong antifungal activity in the bioautography assay at 100 µg/spot, while eleutherol was inactive.

Síntesis de espirobrasinoesteroides análogos de la 6-desoxocastasterona

The synthesis of two new spirostanic analogs of the natural occurring brassinosteroid 6-desoxocastasterone (1) is described. The scheme consists in the formation and elimination of tigogenin mesylate followed by catalytic dihydroxylation of the resulting D2-steroid (3) and acetylation of the 2a, 3a-diol introduced.Treatment diacetate (5) with NaNO2/BF3.Et2O and chromatography in alumina led to a 23-keto (6) which on reduction produced the 23S alcohol (8) as major product. Saponification of the 2a, 3a-diacetoxy-23-keto compound (6) and the 2a,3a-diacetoxy-23-hydroxy compound (8) led to the spirobrasinosteroids (7) and (9).13C NMR and ¹H RMN characteristics derived from substitution at C23 are briefly discussed.

Determinação dos hidrocarbonetos saturados e policíclicos aromáticos presentes no material particulado da atmosfera amazônica

It was identified and quantified several organic compounds in the atmosphere of a site into Amazon Basin with high impact of biomass burning emission. It was important to know the particulate matter composition with respect to n-alkanes and PAH associated with the particulate matter because they provided indication on the main sources contributing to airborne particles, the contribution of natural vs. man-made emission and the aging of the particles. The main classes of compounds observed were n-alkanes, PAH and nitro-PAH. It was observed the formation of nitro-PAH from photochemical reactions. The aerosol mass concentration is mainly associated with fluoranthene, pyrene and benzo(ghi)perylene. Environmental and direct emissions samples (flaming and smoldering) were collected and analysed.

Estudo fitoquímico das cascas do caule de Duguetia glabriuscula - Annonaceae, biomonitorado pelo ensaio de toxicidade frente a Artemia salina leach

The extract obtained from stem bark of Duguetia glabriuscula - Annonaceae was evaluated by Brine Shrimp Lethality test (BSL). The bioactive compounds, oxobufoline and lanuginosine, two oxoaporphine alkaloids were isolated by activity-guided fractionation. In addition, the compounds asaraldehyde, (+)-allo-aromadendrane-10beta, 14-diol, and two aporphine alkaloids, polyalthine and oliveridine were also obtained.

Novel santalane sesquiterpenoids from the stem bark of Duguetia glabriuscula - Annonaceae

Five novel santalane-type sesquiterpenes were isolated from the stem bark of Duguetia glabriuscula - Annonaceae. Their structures have been established on the basis of spectral data and chemical evidences (¹H and 13C NMR, HMQC, HMBC) as (+)-alpha-santal-10-en-9-ol (1), (+)-alpha-santalan-10,11-epoxy-9-ol (2), alpha-santal-11-en-9,10-diol (3), (+)-alpha-santalan-9,10,11-triol (4), and (+)-alpha-santalan-9,11-epoxy-10-ol (5). Polycarpol, a triterpenoid, was also obtained.

Fotodegradação de hidrocarbonetos policíclicos aromáticos em placas de sílica impregnadas com dióxido de titânio

Photodegradation of the PAHs anthracene, chrysene and benzo[k]fluoranthane on silica gel impregnated with TiO2 and over glass plates holding TiO2 was studied. Silica gel plates holding these substances were exposed to solar radiation, developed with hexane and photographed under ultra-violet light. The plates containing benzo[k]fluoranthene were also analysed by both diffuse reflectance and laser induced fluorescence. Diffuse reflectance spectra of the fluorescent spot from non irradiated plates showed small differences when compared with those obtained from irradiated plates. These spectral differences are compatible with formation of less conjugated compounds during irradiation. Fluorescence and time resolved fluorescence spectra observed after irradiation were identical to those obtained with benzo[k]fluoranthene in methanol. On plates holding silica, PAH degradation requires longer periods of solar irradiation when compared with those plates containing silica impregnated with TiO2. Glass plates impregnated with TiO2 also showed very rapid PAH degradation.