Sulfonylimines of Polychloroaldehydes in Reaction with Thioamides

N-(2,2,2-Trichloroethylidene)- and N-(2-phenyl-2,2-dichloroethylidene)amides of aromatic sulfonic acids react with thioacetamide, thiourea, and N-acetylthiourea at equimolar reagents ratio to furnish N-(1-arenesulfonamido-2,2,2-trichloroethyl)- and N-(1-arenesulfonamido-2-phenyl-2,2-dichloroethyl)thioamides. The reaction with deficient amount of thiourea results in N,N'-bis(1-arenesulfonamido-2-polychloroethyl)-thiocarbamides.     

Stereoselective Michael addition of 6-amino-1,3-dimethyl-2,4-pyrimidinedione to the exocyclic methylene of three sesquiterpene lactones. 1H and 13C NMR evidence of a new C-C bond and lactam formation

The Stereoselective addition of the pyrimidine derivative 1 to the exocyclic methylene of the α,β unsaturated dehydrocostus lactone 2, Ivalin acetate 3 and Zaluzanin A diacetate 4, was achieved resulting in a new C-C bond formation. In the cases of compounds 3 and 4, after the addition, the lactone was cleaved followed by reclosure into a lactam ring system.     

Effects of size of noncovalent complexes on their stability during collision-induced dissociation

The size-dependent stability of noncovalent complexes under collision-induced dissociation (CID) conditions was studied on a quadrupole ion trap mass spectrometer. Complexes of heme, tetraphenylporphyrin iron(III) (TPP-Fe), and tetraphenylporphyrin manganese(III) (TPP-Mn) with several histidine-containing peptides and model compounds were formed by electrospray ionization (ESI) and their stability was probed by variable-energy CID. It was found that the stability of complexes with the same (or nearly the same) binding energy has a linear dependence on the complex size (or total number of degrees of freedom). This approach will allow comparisons of variable-energy CID data for noncovalent complexes with different binding energies and could be used to help in structural elucidation of some complexes formed by multidentate ligands. The linearity of size effects on the stability of the complexes was also tested in three crown ether/protonated primary amine systems.     

1,3-dipolar cycloaddition of trimethylsilyl azide to propynals and dimerization of 1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazole-5-carbaldehydes to tricyclic bis-hemiaminals

Reactions of trimethylsilyl azide with 3-trimethylsilyl-2-propynal and 2-propynal were studied. X-Ray analysis of the molecular structure of 4-trimethylsilyl-1H-1,2,3-triazole-5-carbaldehyde showed that the carbonyl group appears in the s-cis conformation with respect to the double C=C bond in the heteroring. The effect of the temperature and polarity of the medium on the ability of 1H-1,2,3-triazole-5-carbaldehyde to undergo dimerization to tricyclic bis-hemiaminals was examined by IR and ¹H NMR spectroscopy.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1852–1857.Original Russian Text Copyright © 2004 by Demina, Novopashin, Sarapulova, Larina, Smolin, Fundamenskii, Kashaev, Medvedeva.     

Human Biomonitoring of Selected Hazardous Compounds in Portugal: Part I—Lessons Learned on Polycyclic Aromatic Hydrocarbons,Metals, Metalloids,and Pesticides

Human biomonitoring (HBM) data provide information on total exposure regardless of the route and sources of exposure. HBM studies have been applied to quantify human exposure to contaminants and environmental/occupational pollutants by determining the parent compounds, their metabolites or even their reaction products in biological matrices. HBM studies performed among the Portuguese population are disperse and limited. To overcome this knowledge gap, this review gathers, for the first time, the published Portuguese HBM information concerning polycyclic aromatic hydrocarbons (PAHs), metals, metalloids, and pesticides concentrations detected in the urine, serum, milk, hair, and nails of different groups of the Portuguese population. This integrative insight of available HBM data allows the analysis of the main determinants and patterns of exposure of the Portuguese population to these selected hazardous compounds, as well as assessment of the potential health risks. Identification of the main difficulties and challenges of HBM through analysis of the enrolled studies was also an aim. Ultimately, this study aimed to support national and European policies promoting human health and summarizes the most important outcomes and lessons learned through the HBM studies carried out in Portugal.     

Human Biomonitoring of Selected Hazardous Compounds in Portugal: Part II—Lessons Learned on Mycotoxins

Human biomonitoring (HBM) data provide information on total exposure regardless of the route and sources of exposure. HBM studies have been applied to quantify human exposure to contaminants and environmental/occupational pollutants by means of determining the parent compounds, their metabolites, or even their reaction products in biological matrices. HBM studies performed among the Portuguese population are dispersed and limited. Thus, to overcome this knowledge gap, this work reviews the published Portuguese HBM information concerning mycotoxins detected in the urine, serum, milk, hair, and nails of different groups of the Portuguese population. This integrative approach to the available HBM data allows us to analyze the main determinants and patterns of exposure of the Portuguese population to the selected hazardous compounds, as well as to assess the potential health risks. We also aimed to identify the main difficulties and challenges of HBM through the analysis of the enrolled studies. Ultimately, this study aims to support national and European policies in promoting human health by summarizing the most important outcomes and lessons learned through the HBM studies carried out in Portugal.     

Reactive Polymeric Dyes as Textile Auxiliaries

Commercial and synthetic azobenzene derivatives were used for the synthesis of hydrophilic polymeric dyes. Two strategies based respectively on the polymerization of dye methacrylic derivatives with different monomers and on the functionalization of reactive polymers were investigated. Polymers containing rather small amounts of the selected dyes were generally obtained, very likely because of the electron withdrawing effect of azo chromophores. Almost quantitative conversions were recorded in the reaction of commercial dyes with maleic anhydride/methyl vinyl ether alternating copolymers. Some of the prepared polymeric dyes were preliminarily tested as textile finishing agents.