Efficient one-pot per-O-acetylation–thioglycosidation of native sugars, 4,6-O-arylidenation and one-pot 4,6-O-benzylidenation–acetylation of S-/O-glycosides catalyzed by Mg(OTf)<sub>2</sub>
A sequential one-pot per-O-acetylation–S-/O-glycosidation of native mono and disaccharides undersolventfreeconditionsusing 0.5 mole% of Mg(OTf)2 as a non-hygroscopic, recyclable catalyst is reported. Regioselective 4,6-O-arylidenation of glycosides and thioglycosides with benzaldehyde or p-methoxybenzaldehyde dimethyl acetal is catalyzed by 10 mole% of Mg(OTf)2 to produce the corresponding 4,6-O-arylidenated
Solvatochromic Fluorescence of a GFP Chromophore-Containing Organogelator in Solutions and Organogels
作者:Meng-Shiue Tsai、Chin-Han Lee、Jye-Chian Hsiao、Shih-Sheng Sun、Jye-Shane Yang
DOI:10.1021/acs.joc.1c01911
日期:2022.2.4
has superior fluorescence stability and quantum efficiency as well as solvatofluorochromicity than the one in the liquid phase. In addition, the phenomenon of fluorescence turn-on occurs when the gel is formed in protic solvents. These features have been applied to perform multicolor fluorescence patterning, chemical vapor sensing, data encryption and decryption, and real-time fluorescence cell imaging
GLYCOSYLTRANSFERASE REVERSIBILITY FOR SUGAR NUCLEOTIDE SYNTHESIS AND MICROSCALE SCANNING
申请人:Thorson Jon S.
公开号:US20130004979A1
公开(公告)日:2013-01-03
The present invention generally relates to materials and methods for exploiting glycosyltransferase reversibility for nucleotide diphosphate (NDP) sugar synthesis. The present invention provides engineered glycosyltransferase enzymes characterized by improved reaction reversibility and expanded sugar donor specificity as compared to corresponding non-mutated glycosyltransferase enzymes. Such reagents provide advantageous routes to NDP sugars for subsequent use in a variety of biomedical applications, including enzymatic and chemo-enzymatic glycorandomization.
作者:Nabamita Basu、Sajal K. Maity、Soumik Roy、Shuvendu Singha、Rina Ghosh
DOI:10.1016/j.carres.2011.01.003
日期:2011.4
Glycosides and thioglycosides based on monosaccharides in reaction with benzaldehyde dimethylacetal or p-methoxybenzaldehyde dimethyl acetal undergo FeCl3-catalyzed (20 mol %) regioselective 4,6-0-arylidenation producing the corresponding acetals in high yields. FeCl3 also mediates acetalation of glycosides and thioglycosides of cellobiose, maltose, and lactose affording the corresponding 4',6'-O-benzylidene acetals, which were isolated after their acetylation in situ with acetic anhydride and pyridine. The combined yields (two steps) of these final products are also high (61-84%). The procedure is applicable to a wide variety of functional groups including -OBn. (C) 2011 Elsevier Ltd. All rights reserved.