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81.
Brandon C. Presley Marisol S. Castaneto Barry K. Logan Susan A. Jansen-Varnum 《Biomedical chromatography : BMC》2020,34(9):e4884
FUB-AMB, an indazole carboxamide synthetic cannabinoid recreational drug, was one of the compounds most frequently reported to governmental agencies worldwide between 2016 and 2019. It has been implicated in intoxications and fatalities, posing a risk to public health. In the current study, FUB-AMB was incubated with human liver microsomes (HLM) to assess its metabolic fate and stability and to determine if its major ester hydrolysis metabolite (M1) was present in 12 authentic forensic human blood samples from driving under the influence of drug cases and postmortem investigations using UHPLC–MS/MS. FUB-AMB was rapidly metabolized in HLM, generating M1 that was stable through a 120-min incubation period, a finding that indicates a potential long detection window in human biological samples. M1 was identified in all blood samples, and no parent drug was detected. The authors propose that M1 is a reliable marker for inclusion in laboratory blood screens for FUB-AMB; this metabolite may be pharmacologically active like its precursor FUB-AMB. M1 frequently appears in samples in which the parent drug is undetectable and can point to the causative agent. The results suggest that it is imperative that synthetic cannabinoid laboratory assay panels include metabolites, especially known or potential pharmacologically active metabolites, particularly for compounds with short half-lives. 相似文献
82.
Gabrielle A. Leith Allison M. Rice Brandon J. Yarbrough Anna A. Berseneva Richard T. Ly Charles N. Buck III Dr. Denis Chusov Amy J. Brandt Prof. Dr. Donna A. Chen Benjamin W. Lamm Prof. Dr. Morgan Stefik Kenneth S. Stephenson Dr. Mark D. Smith Prof. Dr. Aaron K. Vannucci Dr. Perry J. Pellechia Prof. Dr. Sophya Garashchuk Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6056-6062
The effect of donor (D)–acceptor (A) alignment on the materials electronic structure was probed for the first time using novel purely organic porous crystalline materials with covalently bound two- and three-dimensional acceptors. The first studies towards estimation of charge transfer rates as a function of acceptor stacking are in line with the experimentally observed drastic, eight-fold conductivity enhancement. The first evaluation of redox behavior of buckyball- or tetracyanoquinodimethane-integrated crystalline was conducted. In parallel with tailoring the D-A alignment responsible for “static” changes in materials properties, an external stimulus was applied for “dynamic” control of the electronic profiles. Overall, the presented D–A strategic design, with stimuli-controlled electronic behavior, redox activity, and modularity could be used as a blueprint for the development of electroactive and conductive multidimensional and multifunctional crystalline porous materials. 相似文献
83.
84.
Kyung Min Lee Brandon M. Lynch Paul Luchette Timothy J. White 《Journal of polymer science. Part A, Polymer chemistry》2014,52(6):876-882
The photomechanical response and photochemistry of a conventional, unsubstituted azobenzene‐functionalized liquid crystalline polymer network (azo‐LCN) is contrasted to that of an analogous material prepared with meta‐fluorinated azobenzene chromophores. The polydomain azo‐LCN materials exhibit nearly identical thermomechanical and optical properties. Photomechanical characterization indicates that the fluorination of the azobenzene chromophore reduces the deflection of cantilevers composed of the materials by 50%, which spectroscopic analysis reveals is due to a reduction in the ability of this material to isomerize and potentially reorient. This work is further confirmation that the underlying photochemistry of azobenzene is a primary contributor to the generation of photomechanical work in these materials. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 876–882 相似文献
85.
Stack the Bowls: Tailoring the Electronic Structure of Corannulene‐Integrated Crystalline Materials
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Allison M. Rice Ekaterina A. Dolgopolova Brandon J. Yarbrough Gabrielle A. Leith Corey R. Martin Kenneth S. Stephenson Rebecca A. Heugh Amy J. Brandt Prof. Dr. Donna A. Chen Dr. Stavros G. Karakalos Dr. Mark D. Smith Prof. Dr. Kelsey B. Hatzell Dr. Perry J. Pellechia Prof. Dr. Sophya Garashchuk Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (International ed. in English)》2018,57(35):11310-11315
We report the first examples of purely organic donor–acceptor materials with integrated π‐bowls (πBs) that combine not only crystallinity and high surface areas but also exhibit tunable electronic properties, resulting in a four‐orders‐of‐magnitude conductivity enhancement in comparison with the parent framework. In addition to the first report of alkyne–azide cycloaddition utilized for corannulene immobilization in the solid state, we also probed the charge transfer rate within the Marcus theory as a function of mutual πB orientation for the first time, as well as shed light on the density of states near the Fermi edge. These studies could foreshadow new avenues for πB utilization for the development of optoelectronic devices or a route for highly efficient porous electrodes. 相似文献
86.
Selection of Secondary Structures of Heterotypic Supramolecular Peptide Assemblies by an Enzymatic Reaction
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Jie Li Ziqing Zhan Xuewen Du Jiaqing Wang Brandon Hong Prof. Dr. Bing Xu 《Angewandte Chemie (International ed. in English)》2018,57(36):11716-11721
In a model study to investigate the consequence of reactions of intrinsically disordered regions (IDRs) of proteins in the context of the formation of highly ordered structures, we found that enzymatic reactions control the secondary structures of peptides during assembly. Specifically, phosphorylation of an α‐helix‐dominant peptide results in mostly disordered conformations, which become β‐strand‐dominant after enzymatic dephosphorylation to regenerate the peptide. In the presence of another peptide largely with a β‐strand conformation, direct coassembly of the peptides results in amorphous aggregates consisting of α‐helix and β‐strand peptides, but the enzymatically generated peptide coassemblies (from the phosphopeptide) mainly adopt a β‐strand conformation and form ordered structures (e.g., nanofibers). These results indicate that enzymatic dephosphorylation instructs conformationally flexible peptides to adopt thermodynamically favorable conformations in homotypic or heterotypic supramolecular assemblies. 相似文献
87.
A transition metal-mediated, atom-economical approach toward the crucial A and D rings of miyakolide is described. A Pd-catalyzed alkyne-alkyne coupling/6- endo- dig cyclization is employed to assemble the A ring fragment. The key D ring pyran is constructed utilizing an Ru-catalyzed alkene-alkyne coupling followed by a Pd-catalyzed allylic alkylation to establish the all-cis stereochemistry. 相似文献
88.
Grace C. Thaggard Dr. Gabrielle A. Leith Daniil Sosnin Dr. Corey R. Martin Kyoung Chul Park Margaret K. McBride Dr. Jaewoong Lim Brandon J. Yarbrough Buddhima K. P. Maldeni Kankanamalage Gina R. Wilson Austin R. Hill Dr. Mark D. Smith Prof. Dr. Sophya Garashchuk Prof. Dr. Andrew B. Greytak Prof. Dr. Ivan Aprahamian Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202211776
Confinement-imposed photophysics was probed for novel stimuli-responsive hydrazone-based compounds demonstrating a conceptual difference in their behavior within 2D versus 3D porous matrices for the first time. The challenges associated with photoswitch isomerization arising from host interactions with photochromic compounds in 2D scaffolds could be overcome in 3D materials. Solution-like photoisomerization rate constants were realized for sterically demanding hydrazone derivatives in the solid state through their coordinative immobilization in 3D scaffolds. According to steady-state and time-resolved photophysical measurements and theoretical modeling, this approach provides access to hydrazone-based materials with fast photoisomerization kinetics in the solid state. Fast isomerization of integrated hydrazone derivatives allows for probing and tailoring resonance energy transfer (ET) processes as a function of excitation wavelength, providing a novel pathway for ET modulation. 相似文献
89.
Tifton 85 bermudagrass, developed at the ARS-USDA in Tifton, GA, is grown on over ten million acres in the USA for hay and
forage. Of the bermudagrass cultivars, Tifton 85 exhibits improved digestibility because the ratio of ether- to ester-linked
phenolic acids has been lowered using traditional plant breeding techniques. A previously developed pressurized batch hot
water (PBHW) method was used to treat Tifton 85 bermudagrass for enzymatic hydrolysis. Native grass (untreated) and PBHW-pretreated
material were compared as substrates for fungal cultivation to produce enzymes. Cellulase activity, measured via the filter
paper assay, was higher for fungi cultivated on PBHW-pretreated grass, whereas the other nine enzyme assays produced higher
activities for the untreated grass. Ferulic acid and vanillin levels increased significantly for the enzyme preparations produced
using PBHW-pretreated grass and the release of these phenolic compounds may have contributed to the observed reduction in
enzyme activities. Culture supernatant from Tifton 85 bermudagrass-grown fungi were combined with two commercial enzyme preparations
and the enzyme activity profiles are reported. The amount of reducing sugar liberated by the enzyme mixture from Hypocrea jecorina (after 192 h incubation with untreated bermudagrass) individually or in combination with feruloyl esterase was 72.1 and 84.8%,
respectively, of the commercial cellulase preparation analyzed under the same conditions. 相似文献
90.