Molybdopterin Biosynthesis: Trapping of Intermediates for the MoaA-Catalyzed Reaction Using 2′-DeoxyGTP and 2′-ChloroGTP as Substrate Analogues.
作者:Angad P. Mehta、Sameh H. Abdelwahed、Hui Xu、Tadhg P. Begley
DOI:10.1021/ja502663k
日期:2014.7.30
molybdopterin biosynthesis. In this paper, we provide additional characterization of the MoaA reaction product, describe the use of 2′-chloroGTP to trap the GTP C3′ radical, generated by hydrogen atom transfer to the 5′-deoxyadenosyl radical, and the use of 2′-deoxyGTP to block a late step in the reaction sequence. These probes, coupled with the previously reported trapping of an intermediate in which C3′
Asymmetric Epoxidation of 1,1-Disubstituted Terminal Olefins by Chiral Dioxirane via a Planar-like Transition State
作者:Bin Wang、O. Andrea Wong、Mei-Xin Zhao、Yian Shi
DOI:10.1021/jo801576k
日期:2008.12.19
Various 1,1-disubstituted terminalolefins have been investigated for asymmetric epoxidation using chiral ketone catalysts. Up to 88% ee has been achieved with a lactam ketone, and a planar transition state is likely to be a major reaction pathway.
Asymmetric Epoxidation Catalyzed by N-Aryl-Substituted Oxazolidinone-Containing Ketones: Further Evidence for Electronic Effects
作者:Lianhe Shu、Pingzhen Wang、Yonghong Gan、Yian Shi
DOI:10.1021/ol020229e
日期:2003.2.1
[GRAPHICS]Ketones containing N-aryl-substituted oxazolidinones have been prepared and investigated for the epoxidation of cis-beta-methylstyrene, styrene, and 1-phenylcyclohexene. The attractive interaction between the phenyl group of the olefin and the oxazolidinone of the catalyst is enhanced by introducing an electron-withdrawing group onto the N-phenyl group of the catalyst. The information obtained gives a better understanding of the ketone-catalyzed epoxidation. In addition, the easy preparation of some of the ketones makes them good candidates for practical use.
Effective Asymmetric Epoxidation of Styrenes by Chiral Dioxirane
作者:David Goeddel、Lianhe Shu、Yi Yuan、O. Andrea Wong、Bin Wang、Yian Shi
DOI:10.1021/jo0520285
日期:2006.2.1
High enantio selectivity (80-92% enantiomeric excess (ee)) has been obtained for the epoxidation of various styrenes using an easily prepared ketone (4) catalyst.
SCREENING METHODS FOR AMYLOID BETA MODULATORS
申请人:Slon-Usakiewicz Jacek
公开号:US20110028719A1
公开(公告)日:2011-02-03
The present invention relates to methods for screening, identifying, and/or quantifying modulators of amyloid and/or aggregates, fibrils or components thereof, in particular modulators of amyloid β-peptide (Aβ) or Aβ fibrils. Aspects of the invention provide methods for screening putative modulators against an Amyloid target, in particular an Aβ target, so as to determine which modulators bind to or interact with the target, or interfere with the interaction of an indicator agent and the target. Particular aspects of the invention employ mass spectrometric methods for the screening of an Amyloid target against compound libraries, in particular mixtures of compounds or combinatorial libraries.