Analogue Chromophore Study of the Influence of Electronic Perturbation on Color Regulation of Photoactive Yellow Protein†
摘要:
We report a unique lambda(max) shift of the absorption maximum of a photoactive yellow protein (PYP) analogue reconstituted with a fluorinated chromophore (F-PYP). The difference in lambda(max), between the free chromophore and the protein was significantly larger than that with the native chromophore. We concluded that the unusual,lambda(max) shift is caused by the electronegative character of the fluorine atom and not by steric hindrance. This result suggests that formation of a hydrogen bond between the fluorine atom and one or more amino acid residues could neutralize its electron-withdrawing character. The properties of analogues of PYP with brominated and methylated chromophore could be explained as an effect of steric hindrance.
Analogue Chromophore Study of the Influence of Electronic Perturbation on Color Regulation of Photoactive Yellow Protein†
摘要:
We report a unique lambda(max) shift of the absorption maximum of a photoactive yellow protein (PYP) analogue reconstituted with a fluorinated chromophore (F-PYP). The difference in lambda(max), between the free chromophore and the protein was significantly larger than that with the native chromophore. We concluded that the unusual,lambda(max) shift is caused by the electronegative character of the fluorine atom and not by steric hindrance. This result suggests that formation of a hydrogen bond between the fluorine atom and one or more amino acid residues could neutralize its electron-withdrawing character. The properties of analogues of PYP with brominated and methylated chromophore could be explained as an effect of steric hindrance.
Stereoselective synthesis of aryl 1,2- cis -furanosides and its application to the synthesis of the carbohydrate portion of antibiotic hygromycin A
作者:Yuan Xu、Hua-Chao Bin、Fu Su、Jin-Song Yang
DOI:10.1016/j.tetlet.2017.02.079
日期:2017.4
An efficient methodology for the synthesis of aryl 1,2-cis-furanosidic linkages has been developed with 2-quinolinecarbonyl (Quin) group substituted furanose ethyl thioglycosides as glycosyl donors. The method permits a wide range of phenol acceptors to be used, thus resulting in the formation of structurally diverse phenol furanosides in good to excellent chemical yields with complete 1,2-cis anomeric