Integrated identification/confirmatory and targeted analysis of epoxyeicosatrienosic acids in human serum by LC-TOF MS and automated on-line SPE-LC-QqQ MS/MS.

A combined strategy is here proposed for qualitative/quantitative targeted analysis of epoxyeicosatrienoic acids (EETs) in human serum. Identification of EET regioisomers was initially carried out by LC-TOF MS in high accuracy mode under optimum conditions for chromatographic separation of the four isomers with an isocratic method using 40:40:20 (v/v/v) methanol-acetonitrile-water containing 0.02% acetic acid. Confirmatory analysis was supported on MS/MS experiments using the hybrid QqTOF mass analyzer by targeted fragmentation of the precursor ion fitting with the molecular formula C20H32O3 (319.2279 m/z). Identification of selective fragment ions in high accuracy mode enabled the localization of the epoxy functional group and, therefore, the assignation of chromatographic peaks to each EET isomer. After qualitative analysis, an automated method was developed for analysis of EETs in human serum by direct analysis using an on-line platform based on SPE-LC-QqQ MS/MS in selected reaction monitoring. Recovery factors estimated with a dual-cartridge configuration were above 87% for all metabolites either using non-spiked and spiked serum at three different concentrations. Precision, calculated as within-laboratory repeatability and expressed as relative standard deviation, ranged from 2.5 to 9.9% with detection limits below 0.15 ng mL(-1). The optimization of the method was completed with a stability study under different conditions to assess the suited conditions for analysis of EET intermediate metabolites. Finally, concentration ranges of EETs were measured in nine healthy individuals.

The genotoxicity of acrylamide and glycidamide in big blue rats.

Acrylamide (AA), a mutagen and rodent carcinogen, recently has been detected in fried and baked starchy foods, a finding that has prompted renewed interest in its potential for toxicity in humans. In the present study, we exposed Big Blue rats to the equivalent of approximately 5 and 10 mg/kg body weight/day of AA or its epoxide metabolite glycidamide (GA) via the drinking water, an AA treatment regimen comparable to those used to produce cancer in rats. After 2 months of dosing, the rats were euthanized and blood was taken for the micronucleus assay; spleens for the lymphocyte Hprt mutant assay; and liver, thyroid, bone marrow, testis (from males), and mammary gland (females) for the cII mutant assay. Neither AA nor GA increased the frequency of micronucleated reticulocytes. In contrast, both compounds produced small (approximately twofold to threefold above background) but significant increases in lymphocyte Hprt mutant frequency (MF, p < 0.05), with the increases having dose-related linear trends (p < 0.05 to p < 0.001). Neither compound increased the cII MF in testis, mammary gland (tumor target tissues), or liver (nontarget tissue), while both compounds induced weak positive increases in bone marrow (nontarget tissue) and thyroid (target tissue). Although the genotoxicity in tumor target tissue was weak, in combination with the responses in surrogate tissues, the results are consistent with AA being a gene mutagen in the rat via metabolism to GA.

Biocatalysis of nitro substituted styrene oxides by non-conventional yeasts.

Yeast strains (410) from more than 45 different genera were screened for the enantioselective hydrolysis of nitro substituted styrene oxides. These strains included 262 yeasts with known epoxides hydrolase activity for various other epoxides. Epoxide hydrolase activity for p-nitrostyrene oxide (pNSO) (177 strains) and m-nitrostyrene oxide (mNSO) (148 strains) was widespread in the yeasts, while activity for o-nitrostyrene oxide (oNSO) was less ubiquitous (22 strains). The strains that displayed enantioselectivity in the hydrolysis of one or more of the nitro substituted styrene oxides (35 strains) were also screened against styrene oxide (SO). Rhodosporidium toruloides UOFS Y-0471 displayed the highest enantioselectivity for pNSO (ee 55%, yield 35%) while Rhodotorula glutinis UOFS Y-0653 displayed the highest enantioselectivity for mNSO (ee > 98%, yield 29%), oNSO (ee 39%, yield 19%) and SO (ee > 98%, yield 19%). (R)-Styrene oxide was preferentially hydrolysed to the corresponding (R)-diol with retention of configuration at the stereogenic centre. In the case of the nitro substituted styrene oxides the absolute configurations of the remaining epoxides and the formed diols were not established.

Acidos grasos esenciales en la producción actual de oleaginosas de la República Argentina: posibilidades futuras de diversificación / Essential fatty acids in the present vegetable oils production of the República Argentina: future possibiities in the diversification trends production

Se presenta un resumen de los logros alcanzados durante casi 50 años en un tema fundamental del conocimiento de las características de composición acídica de aceites vegetales de producción masiva en la república Argentina. Su desarrollo, en parte coincidente con la evolución del conocimiento analítico, ha sido de utilidad a la nutrición, normalización, legislación alimentaria, tecnología, uso y contralor de aceites vegetales y de pulpa de frutos. El progreso observado en los avances de modernas técnicas de la Biotecnología tiende a una apertura en la diversificación de la producción

Acidos grasos esenciales en la producción actual de oleaginosas de la República Argentina: posibilidades futuras de diversificación / Essential fatty acids in the present vegetable oils production of the República Argentina: future possibiities in the diversification trends production

Se presenta un resumen de los logros alcanzados durante casi 50 años en un tema fundamental del conocimiento de las características de composición acídica de aceites vegetales de producción masiva en la república Argentina. Su desarrollo, en parte coincidente con la evolución del conocimiento analítico, ha sido de utilidad a la nutrición, normalización, legislación alimentaria, tecnología, uso y contralor de aceites vegetales y de pulpa de frutos. El progreso observado en los avances de modernas técnicas de la Biotecnología tiende a una apertura en la diversificación de la producción