Determination of Carbamates and Thiocarbamates in Water, Soil and Sediment of the Formoso River, TO, Brazil.

Considering the increase in agricultural production in Brazil, the use of pesticides for this production, and that there are no studies on pesticides in the region, the presence of carbamates and thiocarbamates was investigated in different environmental compartments of the Formoso River, TO, Brazil, by UHPLC/MS/MS. The collections were made on the banks of this river, in the area of influence of the agricultural project. The active principles were not found in the soil and sediment samples, only the propoxur principle was found in the water, reaching values of up to 0.025 µg L-1 . It was found that the biodiversity of the Tocantinense savannah is under threat, because even though only one of the substances surveyed, propoxur and its derivatives, has been detected, they are substances of high toxicity and tendency to contaminate surface and groundwater to varying degrees and irreversible damage to different species.

Characterization and application of a lanthanide-based metal-organic framework in the development and validation of a matrix solid-phase dispersion procedure for pesticide extraction on peppers (Capsicum annuum L.) with gas chromatography-mass spectrometry.

The metal-organic framework [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ was synthetized and characterized by X-ray diffractometry, differential thermogravimetric analysis, and infrared spectroscopy. The material was tested for the development and validation of a matrix solid-phase dispersion procedure for extraction of atrazine, bifenthrin, bromuconazole, clofentezine, fenbuconazole, flumetralin, procymidone, and pirimicarb, from peppers, with analysis using gas chromatography with mass spectrometry in the selected ion monitoring mode. The method developed was linear over the range tested (50.0-1000.0 µg/kg for procymidone and 200.0-1000.0 µg/kg for all other pesticides), with correlation coefficients ranging from 0.9930 to 0.9992. Experiments were carried out at 250.0, 500.0, and 1000.0 µg/kg fortification levels, and resulted in recoveries in the range of 52.7-135.0%, with coefficient of variation values between 5.2 and 5.4%, respectively, for [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ sorbent. Detection and quantification limits ranged from 16.0 to 67.0 µg/kg and from 50.0 to 200.0 µg/kg, respectively, for the different pesticides studied. The results were compared with literature data. The developed and validated method was applied to real samples. The analysis detected the presence of residues of pesticides procymidone, fenbuconazole, flumetralin, clofentezine, atrazine, and bifenthrin.

Residuos de plaguicidas organofosforados y carbamatos en aguas subterráneas de bebida en las zonas rurales de Plottier y Senillosa, Patagonia Norte, Argentina / Organophosphate and carbamate pesticide residues in drinking groundwater in the rural areas of Plottier and Senillosa, North Patagonia, Argentina

Plottier y Senillosa son dos localidades contiguas que forman parte del área de producción agrícola del Alto Valle de Río Negro y Neuquén, Patagonia Norte. Entre los plaguicidas más utilizados predominan las familias de neonicotinoides, carbamatos y organofosforados. El conocimiento de los niveles de estos compuestos en aguas superficiales y subterráneas se ha convertido en un tema de interés social debido a su posible impacto en el ambiente y la salud. El objetivo del presente trabajo fue determinar niveles de residuos de plaguicidas en agua subterránea utilizada para bebida en zonas rurales de Plottier y Senillosa. Se analizaron carbamatos: propoxur, carbofuran, pirimicarb, carbaril y organofosforados: clorpirifos, dimetoato, metidation, fenaminfos, triazofos, fosmet y metil azinfos, por cromatografía gaseosa (GC), en seis sitios de muestreo, durante la época de aplicación y no aplicación de insecticidas. No se detectaron residuos de los plaguicidas estudiados por el método analítico utilizado. El límite de detección fue 0,010 µg/L para organofosforados y 0,030 µg/L para carbamatos. Estos resultados indican que las buenas prácticas agrícolas aplicadas en la zona así como las características fsicoquímicas del suelo, su espesor y el contenido de materia orgánica y las propiedades fsicoquímicas de los plaguicidas estudiados son factores que contribuyen favorablemente a la calidad del agua de bebida de la población rural.

Plottier and Senillosa are two adjoining towns that belong to the agricultural production area of Upper Valley, Río Negro and Neuquén, North Patagonia. Among the most widely used pesticides, neonicotinoids, carbamates and organophosphates are predominant. The levels of these compounds in surface and groundwater have become a topic of public concern, since the possible impact on health and environment. The aim of this study was the determination of pesticide residue levels in drinking ground-water in the rural areas of Plottier and Senillosa. Carbamates: propoxur, carbofuran, pirimicarb, carbaryl and organophosphate: chlorpyrifos, dimethoate, methidathion, fenaminfos, triazophos, phosmet, azinphos methyl, were analyzed by GC in six sampling sites during insecticide application and non-application season. No pesticide residues were detected by the analytical method used. The detection limit for organophosphates was 0.010 µg/L and 0.030 µg/L for carbamates. These results indicate that good agricultural practices, the physicochemical characteristics of the soil, its thickness, the content of organic matter and the physicochemical properties of pesticides studied are factors that positively contribute to the drinking water quality in the rural population.

Santacruzamate A, a potent and selective histone deacetylase inhibitor from the Panamanian marine cyanobacterium cf. Symploca sp.

A dark brown tuft-forming cyanobacterium, morphologically resembling the genus Symploca, was collected during an expedition to the Coiba National Park, a UNESCO World Heritage Site on the Pacific coast of Panama. Phylogenetic analysis of its 16S rRNA gene sequence indicated that it is 4.5% divergent from the type strain for Symploca and thus is likely a new genus. Fractionation of the crude extract led to the isolation of a new cytotoxin, designated santacruzamate A (1), which has several structural features in common with suberoylanilide hydroxamic acid [(2), SAHA, trade name Vorinostat], a clinically approved histone deacetylase (HDAC) inhibitor used to treat refractory cutaneous T-cell lymphoma. Recognition of the structural similarly of 1 and SAHA led to the characterization of santacruzamate A as a picomolar level selective inhibitor of HDAC2, a Class I HDAC, with relatively little inhibition of HDAC4 or HDAC6, both Class II HDACs. As a result, chemical syntheses of santacruzamate A as well as a structurally intriguing hybrid molecule, which blends aspects of both agents (1 and 2), were achieved and evaluated for their HDAC activity and specificity.

Mariculture and natural production of the antitumoural (+)-discodermolide by the Caribbean marine sponge Discodermia dissoluta.

Biotechnological research on marine organisms, such as ex situ or in situ aquaculture and in vitro cell culture, is being conducted to produce bioactive metabolites for biomedical and industrial uses. The Caribbean marine sponge Discodermia dissoluta is the source of (+)-discodermolide, a potent antitumoural polyketide that has reached clinical trials. This sponge usually lives at depths greater than 30 m, but at Santa Marta (Colombia) there is a shallower population, which has made it logistically possible to investigate for the first time, on ways to supply discodermolide. We thus performed in situ, 6-month fragment culture trials to assess the performance of this sponge in terms of growth and additional discodermolide production and studied possible factors that influence the variability of discodermolide concentrations in the wild. Sponge fragments cultured in soft mesh bags suspended from horizontal lines showed high survivorship (93 %), moderate growth (28 % increase in volume) and an overall rise (33 %) in the discodermolide concentration, equivalent to average additional production of 8 µg of compound per millilitre of sponge. The concentration of discodermolide in wild sponges ranged from 8 to 40 µg mL(-1). Locality was the only factor related to discodermolide variation in the wild, and there were greater concentrations in peripheral vs. basal portions of the sponge, and in clean vs. fouled individuals. As natural growth and regeneration rates can be higher than culture growth rates, there is room for improving techniques to sustainably produce discodermolide.

Determination of poorly fluorescent carbamate pesticides in water, bendiocarb and promecarb, using cyclodextrin nanocavities and related media.

The effect of native cyclodextrins (alpha, beta, or gammaCD with six, seven and eight glucose units, respectively), hydroxypropyl-beta-cyclodextrin (HPCD), chitosan (CHT) and glucose in water solution or water with n-propylamine (PA) as co-solvent upon the UV-vis and fluorescence properties of poorly fluorescent N-methyl carbamates pesticides (C) as bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-ol methylcarbamate, BC) and promecarb (3-methyl-5-(1-methylethyl)phenol methylcarbame, PC) was examined. Fluorescent enhancement was found for both substrates with all CDs in water or PA-water except from PC with alphaCD. The addition of CHT increases the fluorescence of BC but decreases the fluorescence of PC, and glucose addition gives in both cases no spectral changes. Host-guest interaction was clearly determined by fluorescence enhancement with betaCD and HPCD with a 1:1 stoichiometry for the complexes (C:CD). The values obtained for the association constants (K(A), M(-1)) were (6+/-2)x10(2) and (2.3+/-0.3)x10(2) for BC:betaCD and BC:HPCD complexes, respectively. For PC:betaCD and PC:HPCD the values of K(A) were (19+/-2)x10(2) and (21+/-2)x10(2), respectively. The ratio of the fluorescence quantum yields for the bound and free substrates (phi(CCD)/phi(C)) was in the range 1.74-3.8. The limits of detection (L(D), microg mL(-1)) for the best conditions were (0.57+/-0.02) for BC with HPCD and (0.091+/-0.002) for PC with betaCD in water. Application to the analysis in pesticide spiked samples of tap water and fruit yields satisfactory apparent recoveries (84-114%), and for the extraction procedure in fruits and a commercial formulation, recoveries were of 81-98% and 104%, respectively. The method is rapid, simple, direct, sensitive and useful for pesticide analysis.