ABSTRACT: In the title compound, C(18)H(18)FNO(3), the dihedral angles between the two benzene rings and the plane through the acrylate group and the fluoro-phenyl ring are 61.58?(8) and 13.33?(9)°, respectively. Mol-ecules are linked into ribbons through C-H?O and N-H?O hydrogen bonds, and further linked by C-H?? inter-actions, forming a three-dimensional network.
Project description:The title compound, C(18)H(18)FNO(3), consists of three individually planar subunits, namely two substituted benzene rings and one amino-acrylate group. The dihedral angle between the two benzene rings is 47.48?(8)°. The amino-acrylate group forms dihedral angles of 57.95?(7) and 11.27?(6)° with the methoxy-phenyl and fluorophenyl rings, respectively.
Project description:The title compound, C(18)H(17)F(2)NO(3), consists of three individually planar subunits, namely two benzene rings and one amino-acrylate group. The amino-acrylate group forms dihedral angles of 5.92?(7) and 50.21?(6)° with the difluoro and methoxy benzene rings, respectively. The dihedral angle between the two benzene rings is 55.25?(7)°. The mol-ecules exhibit intra-molecular N-H?O and N-H?F inter-actions and form a three-dimensional network via inter-molecular C-H?O and C-H?? hydrogen bonds.
Project description:In the title compound, C(18)H(18)O(5), the dihedral angle between the two benzene rings is 55.2?(3)°. The ethyl acrylate linkage is planar and forms dihedral angles of 21.3?(3) and 41.0?(3)°, respectively, with the hydroxy-phenyl and methoxy-phenyl rings. In the crystal structure, mol-ecules are linked into zigzag chains along the b axis by O-H?O hydrogen bonds.
Project description:In the title compound, C(18)H(14)Cl(2)O(4), the mean planes of the methyl acrylate unit and the phenyl ring of the benzaldehyde are approximately orthogonal to each other, making a dihedral angle of 83.31?(6)°. The O atom of the aldehyde group is displaced significantly from the phenyl ring plane by 0.226?(2)?Å. The methyl acrylate group adopts an E conformation. In the crystal, inversion dimers linked by pairs of C-H?O hydrogen bonds generate R(2) (2)(24) loops.
Project description:In the title compound, C(18)H(18)O(2), the methyl acrylate substituent adopts an extended E conformation with all torsion angles close to 180°. The mean plane of the acrylate unit and the phenyl ring are approximately orthogonal to each other, making a dihedral angle of 81.40?(6)°. The position of the carbonyl group with respect to the olefinic double bond is typically S-trans. The crystal packing is stabilized by inter-molecular C-H?? inter-actions.
Project description:Responses of Escherichia coli as they are treated to 15 ug/ml Indol-acrylate in Bonner-Vogel Keywords: time course Overall design: Escherichia coli cells sampled at several time points (5, 15, 30, 60 min) after addition of Indol-acrylate (15 ug/ml) in Bonner-Vogel vs 0 min untreated
Project description:Responses of Escherichia coli as they are treated to 10 ug/ml Indol-acrylate in Bonner-Vogel Keywords: time course Overall design: Escherichia coli cells sampled at several time points (5, 15, 30, 60 min) after addition of Indol-acrylate (10 ug/ml) in Bonner-Vogel vs 0 min untreated
Project description:The title compound, C(22)H(24)O(5), consists of two substituted benzene rings linked by an ethyl acrylate group. The dihedral angle between the two benzene rings is 58.39?(7)°. The crystal packing is governed by two C-H?O inter-actions, one of which forms centrosymmetric dimers with a graph-set descriptor of R(2) (2)(18).
Project description:Sulbactam is a mechanism-based inhibitor of beta-lactamase enzymes used in clinical practice. It undergoes a complex series of chemical reactions in the active site that have been studied extensively in the past three decades. However, the actual species that gives rise to inhibition in a clinical setting has not been established. Recent studies by our group, using Raman microscopy and X-ray crystallography, have found that large quantities of enamine-based acyl-enzyme species are present within minutes in single crystals of SHV-1 beta-lactamases which can lead to significant inhibition. The enamines are formed by breakdown of the cyclic beta-lactam structures with further transformations leading to imine formation and subsequent isomerization to cis and/or trans enamines. Another favored form of inhibition arises from attack on the imine by a second nucleophilic amino acid side chain, e.g., from serine 130, to form a cross-linked species in the active site that can degrade to an acrylate-like species irreversibly bound to the enzyme. Thus, the imine is at a branch point on the reaction pathway. Using sulbactam and 6,6-dideuterated sulbactam we follow these alternate paths in WT and E166A SHV-1 beta-lactamase by means of Raman microscopic studies on single enzyme crystals. For the unlabeled sulbactam, the Raman data show the presence of an acrylate-like species, probably 3-serine acrylate, several hours after the reaction is started in the crystal. However, for the 6,6-dideutero analogue the acrylate signature appears on the time scale of minutes. The Raman signatures, principally an intense feature near 1530 cm-1, are assigned based on quantum mechanical calculations on model compounds that mimic acrylate species in the active site. The different time scales observed for acrylate-like product formation are ascribed to different rates of reaction involving the imine intermediate. It is proposed that for the unsubstituted sulbactam the conversion from imine to enamine, which involves breaking a C-H bond, is aided by quantum mechanical tunneling. For the 6,6-dideutero-sulbactam the same step involves breaking a C-D bond, which has little or no assistance from tunneling. Consequently the conversion to enamines is slower, and a higher population of imine results, presenting the opportunity for the competing reaction with the second nucleophile, serine 130 being the prime candidate. The hydrolysis of the resulting cross-linked intermediate leads to the observed rapid buildup of the acrylate product in the Raman spectra from the dideutero analogue. The protocol used here, essentially running the reactions with the two forms of sulbactam in parallel, provides an element of control and enables us to conclude that, for the unsubstituted sulbactam, the formation of the cross-linked intermediate and the final irreversible acrylate product is not a significant route to inhibition of SHV-1.
Project description:The purpose of this work was to investigate the effect of multifunctionality on material properties of synthetic polymer aerogels. For this purpose, we present the synthesis and characterization of monolithic dendritic-type urethane-acrylate monomers based on an aliphatic/flexible (Desmodur N3300), or an aromatic/rigid (Desmodur RE) triisocyanate core. The terminal acrylate groups (three at the tip of each of the three branches, nine in total) were polymerized with 2,2'-azobis(isobutyronitrile) (AIBN) via free radical chemistry. The resulting wet-gels were dried with supercritical fluid (SCF) CO?. Aerogels were characterized with ATR-FTIR and solid-state <sup>13</sup>C NMR. The porous network was probed with N?-sorption and scanning electron microscopy (SEM). The thermal stability of aerogels was studied with thermogravimetric analysis (TGA). Most aerogels were macroporous materials (porosity > 80%), with high thermal stability (up to 300 °C). Aerogels were softer at low monomer concentrations and more rigid at higher concentrations. The material properties were compared with those of analogous aerogels bearing only one acrylate moiety at the tip of each branch and the same cores, and with those of analogous aerogels bearing norbornene instead of acrylate moieties. The nine-terminal acrylate-based monomers of this study caused rapid decrease of the solubility of the growing polymer and made possible aerogels with much smaller particles and much higher surface areas. For the first time, aliphatic/flexible triisocyanate-based materials could be made with similar properties in terms of particle size and surface areas to their aromatic/rigid analogues. Finally, it was found that with monomers with a high number of crosslinkable groups, material properties are determined by multifunctionality and thus aerogels based on 9-acrylate- and 9-norbornene-terminated monomers were similar. Materials with aromatic cores are carbonizable with satisfactory yields (20?30% <i>w</i>/<i>w</i>) to mostly microporous materials (BET surface areas: 640?740 m² g<sup>-1</sup>; micropore surface areas: 360?430 m² g<sup>-1</sup>).