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Substituted Benzene Ring (substituted + benzene_ring)
Selected AbstractsStructure,activity relationships for gene activation oestrogenicity: Evaluation of a diverse set of aromatic chemicalsENVIRONMENTAL TOXICOLOGY, Issue 1 2002T. Wayne Schultz Abstract Structure,activity relationships for oestrogenicity were developed based on 120 aromatic chemicals evaluated in the Saccharomyces cerevisiae -based Lac -Z reporter assay. Relative gene activation was compared to 17,-estradiol and varied over eight orders of magnitude. Analysis of the data compared to 17,-estradiol identified three structural criteria that were related to xenoestrogen activity and potency: (1) the hydrogen-bonding ability of the phenolic ring mimicking the A-ring, (2) a hydrophobic centre similar in size and shape to the B- and C-rings, and (3) a hydrogen-bond donor mimicking the 17,-hydroxyl moiety of the D-ring, especially with an oxygen-to-oxygen distance similar to that between the 3- and 17,-hydroxyl groups of 17,-estradiol. Binding data were segregated into activity clusters including strong, moderate, weak, and detectable gene expression, and those compounds that were inactive. The hydrogen-bonding ability of hydroxy group in the 3-position on 17,-estradiol was observed to be essential for gene activation. Compounds with a 4-hydroxyl substituted benzene ring and a hydrophobic moiety of size and shape equivalent to the B-ring of 17,-estradiol were generally observed to be weakly active compounds. Moderately active compounds have a 4-hydroxyl substituted benzene ring with a hydrophobic moiety equivalent in size and shape to the B- and C-ring of 17,-estradiol, or have a high hydrogen-bond donor capacity owing to the presence of halogens on a nonphenolic ring. Strongly active compounds, similar to 4,4,-diethylethylene bisphenol (DES), possess the same hydrophobic ring structure as described for moderately active compounds and an additional hydroxyl group with an oxygen-to-oxygen distance close to that exhibited by the 3- and 17-hydroxyl groups of 17,-estradiol. © 2002 by Wiley Periodicals, Inc. Environ Toxicol 17: 14,23, 2002 [source] Chemoselective Reagents for Covalent Capture and Display of Glycans in Microarrays,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2010Emiliano Cló Abstract Glycobiology has made very significant progress in the past decades. However, further progress will significantly depend on the establishment of novel methods for miniaturized, high-throughput analysis of glycan,protein interactions. Robust solid-phase chemical tools and new, chemoselective reagents for biologically meaningful display of surface-immobilized glycans are likely to play a key role. Here we present four new bifunctional linkers that allow highly chemoselective capture of unprotected glycans in solution to form glycan-linker conjugates for direct construction of glycan microarrays (glycochips). The bifunctional linkers carry O -linked aminooxy moieties, some with N -substituents at one end and an amino group at the other. In addition, they contain a substituted benzene ring for UV traceability and improved purification of glycan-linker conjugates. NMR spectroscopic studies in solution proved that N -substituted aminooxy linkers provided model glycan-linker conjugates with the ,-glucopyranoside configuration, i.e. the ring-closed form required for biological recognition. Then an ensemble of glycan-linker conjugates were assembled from mannobiose, lactose, and N -acetyl-lactosamine and used for covalent printing of glycan microarrays. The stability of oximes were studied both in solution and on-chip. In solution, two of the linkers provided glycan-linker conjugates with a remarkable stability at pH 4 or higher, on-chip this relative stability was upheld. Two of the linkers, with different properties, are recommended for the glycobiology toolbox for the construction of glycan microarrays from unprotected glycans. [source] Preferred conformations in the solid state of some ,-(p -phenylsulfinyl)- p -substituted acetophenonesACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2000Paulo R. Olivato Information on the geometrical structures of ,-(p -phenylsulfinyl)- p -substituted acetophenones X,PhC(O)CH2S(O)Ph,Y [X = OMe, Y = H (1); X = NO2, Y = OMe (2); X = OMe, Y = NO2 (3); IUPAC names: (1) 4-methoxyphenyl phenylsulfinylmethyl ketone; (2) 4-nitrophenyl 4-methoxyphenylsulfinylmethyl ketone; (3) 4-methoxyphenyl 4-nitrophenylsulfinylmethyl ketone] have been obtained from X-ray diffraction analyses. A comparison of these results with those previously obtained from X-ray diffraction and ab initio computations of ,-methylsulfinylacetophenone, PhC(O)CH2S(O)Me, indicated that (1) and (2) adopt in the crystal a cis1 conformation and (3) assumes a quasi-gauche geometry. The stabilization of these conformations in the crystal is discussed in terms of the dipole moment coupling, Coulombic and intramolecular charge transfer interactions between the oppositely charged atoms of the C=O and S=O dipoles. The p -substituted benzene ring is quasi -coplanar with the sulfinyl group for (1) and (3), but is quasi -perpendicular for (2). Conjugation and repulsion between the sulfinyl sulfur lone pair and the ,-benzene ring seem to be responsible for the observed geometries. [source] Synthesis and structures of substituted triphenyl(phenylimino)phosphoranesACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2010Roeland De Borger Three substituted triphenyl(phenylimino)phosphoranes, namely (4-cyanophenylimino)triphenylphosphorane, C25H19N2P, (I), (4-nitrophenylimino)triphenylphosphorane, C24H19N2O2P, (II), and (3-nitrophenylimino)triphenylphosphorane, C24H19N2O2P, (III), were synthesized as precursors for the preparation of substituted diphenylcarbodiimides. All three compounds display a supramolecular arrangement in which the substituted benzene rings are organized in an antiparallel fashion. The nitro group on the ring participates in C,H...O and O..., interactions, forming intermolecular dimers. Compound (III) shows disorder which involves the rotation of one of the phenyl rings of the triphenylphosphine group. [source] | ||||||||||