Preparation of S-glycoside surfactants and cysteine thioglycosides using minimally competent Lewis acid catalysis
作者:Lajos Z. Szabó、Dillon J. Hanrahan、Evan M. Jones、Erin Martin、Jeanne E. Pemberton、Robin Polt
DOI:10.1016/j.carres.2015.12.008
日期:2016.3
Here we report a method for the preparation of anomerically pure beta-S-glycopyranosides (1,2-trans-glycosides) from the corresponding peracetate donors. S-glycosylation was performed in CHCl3 at reflux in the presence of a catalytic amount of InBr3. Deacylation of the intermediate peracetates were achieved under Zemplen conditions. Five pyranose examples, monosaccharides D-glucose and D-galactose
[EN] COSMETIC PROCESS FOR ATTENUATING WRINKLES<br/>[FR] PROCÉDÉ COSMÉTIQUE POUR ATTÉNUER LES RIDES
申请人:OREAL
公开号:WO2016050788A1
公开(公告)日:2016-04-07
The invention relates to a cosmetic process for wrinkled skin, comprising either the topical application to the skin of an extemporaneous mixture of a cosmetic composition comprising a polysaccharide polymer grafted with (meth)acrylate groups and of a crosslinking thiol compound having one or more thiol groups; or the sequential application to the skin of a cosmetic composition comprising a polysaccharide polymer grafted with (meth)acrylate groups, followed by the application of a crosslinking thiol compound having one or more thiol groups, or of a cosmetic composition containing same. The invention also relates to the use of the mixture of said grafted polysaccharide polymer and of said crosslinking thiol as a skin tensioning agent. The invention also relates to a cosmetic composition obtained by mixing a cosmetic composition comprising said grafted polysaccharide polymer and said crosslinking thiol. The invention relates to a kit comprising a first cosmetic composition comprising said grafted polysaccharide polymer and a second composition comprising said crosslinking thiol, the first and second compositions each been packaged in a distinct packaging assembly.
to covalently bind Lewis basic fluoride ions in a relatively stable fluorosulfite anion (FSO2−). Herein we report the application of liquid SO2 as a promoting solvent for glycosylation with glycosyl fluorides without any external additive. By using various temperature regimes, the method is applied for both armed and disarmed glucose and mannose-derived glycosyl fluorides in moderate to excellent yields
液态SO 2是一种极性溶剂,可溶解共价和离子化合物。二氧化硫也具有路易斯酸性质,包括在一个相对稳定的fluorosulfite阴离子的能力共价结合路易斯碱性氟化物离子(FSO 2 - )。在本文中,我们报道了液态SO 2作为促进剂用于糖基氟化物的糖基化而没有任何外部添加剂的应用。通过使用各种温度方案,该方法可用于中等和极高产率的武装和解除武装的葡萄糖和甘露糖衍生的糖基氟化物。一系列新戊酰基保护的O-和S-甘露糖苷,以及C的一个实例合成甘露糖苷以证明糖基受体的范围。通过19 F NMR光谱证实了在液体SO 2中与糖基氟糖基化的过程中,亚硫酸氢盐物质的形成。提出了通过溶剂分离的离子对进行的二氧化硫辅助的糖基化机制,而观察到的α,β-选择性是受底物控制的,并且取决于热力学平衡。
CdSe quantum dot-encapsulated molecularly imprinted mesoporous silica particles for fluorescent sensing of bisphenol A
作者:Youngdo Kim、Jae Bum Jeon、Ji Young Chang
DOI:10.1039/c2jm34798a
日期:——
We prepared a highly sensitive molecularly imprinted fluorescent sensor by using a CdSe quantum dot (QD) as a signal transducer and a mesoporous silica nanoparticle as an imprinting material. Bisphenol-A (BPA) was chosen as a model template, which is known as an endocrine disruptor. Binding sites were selectively formed between the pores and CdSe QDs were encapsulated in the pores of the mesoporous silica. QD-encapsulated, molecularly imprinted mesoporous silica (QD-MIMS) particles exhibited excellent molecular recognition properties in terms of both sensitivity and selectivity. Owing to the proximity of the binding sites to the QDs, a significant, concentration-sensitive fluorescence quenching was observed in the presence of BPA. QD-MIMS showed a linear Stern–Volmer relationship for BPA and its analogs. QD-MIMS had a much larger quenching constant for BPA (by more than ten times) than for BPA analogs, demonstrating the high selectivity of QD-MIMS.
A Pd-catalyzed hydrothiocarbonylation of unactivated terminal alkenes is presented. According to this protocol, aliphatic thioesters were synthesized with exclusive linear selectivity under mild reaction conditions. Good to excellent yields (up to 91% yield), broad substrate scope, broad functional group tolerance, and utility of the method demonstrated the advantages of this protocol.