Carbohydrates as nucleophiles in conjugate addition for preparation of muramic acid analogues
作者:Bernd Becker、Joachim Thiem
DOI:10.1016/s0957-4166(00)80384-5
日期:1994.12
Benzyl 2-acetamido-6-O-benzyl-3-O-[(S)-1-carboxy-isopropyl]-α-D-glucopyranoside (15) was synthesized stereoselectively by conjugate addition reaction, starting irom benzyl 2-acetamido-6-O-benzyl-2-deoxy-α-D-glucopyranoside (9) and crotonic acid ethyl ester under phase transfer conditions. The dipeptide L-Ala-D-Glu(OMe)OMe was coupled to 15 to give compuond 25 an analogue of the adjuvant active muramyl
Phosphine-Dependent Photoinitiation of Alkyl Thiols under Near-UV Light Facilitates User-Friendly Peptide Desulfurization
作者:Naresh M. Venneti、Ganesh Samala、Rana M. I. Morsy、Lawrence G. Mendoza、Albert Isidro-Llobet、Janine K. Tom、Subha Mukherjee、Michael E. Kopach、Jennifer L. Stockdill
DOI:10.1021/jacs.2c10625
日期:2023.1.18
excesses of phosphine reagents and thiol additives or low-abundance metal catalysts. Here, we report a phosphine-only photodesulfurization (POP) using near-UV light that is clean, high-yielding, and requires as little as 1.2 equiv phosphine. The user-friendly reaction gives complete control to the chemist, allowing solvent and reagent selection based on starting material and phosphine solubility. It
肽作为药物靶点的重要性正在稳步上升,因此迫切需要高效、绿色的制备方法。合成工具箱中的一个关键缺陷是缺乏工业上可行的肽脱硫方法。如果没有这个工具,通常用于组装多肽和蛋白质的强大的天然化学连接反应仍然无法用于药物靶点的工业制备。目前的脱硫方法需要大量过量的膦试剂和硫醇添加剂或低丰度金属催化剂。在这里,我们报告了一种使用清洁、高产且低至 1.2 当量磷化氢的近紫外光的仅磷化氢光脱硫 (POP)。用户友好的反应给化学家完全控制,允许根据起始材料和膦溶解度选择溶剂和试剂。它可以在一系列溶剂中进行,包括水或缓冲液、受保护或未受保护的肽、低稀释度或高稀释度以及克规模。易氧化的氨基酸、π键、芳香环、硫胺键、硫酯和聚糖都对 POP 反应稳定。我们强调了这种方法对工业相关目标脱硫的效用,包括环肽和胰高血糖素样肽 1 (GLP-1(7-36))。该方法还与 NCL 缓冲液兼容,我们通过利那洛肽、抑肽酶和小麦蛋白
PROTEINOUS EMULSIFIER, PROCESS FOR ITS PREPARATION, AND EMULSIFIED COSMETIC PREPARATION CONTAINING SAME
申请人:KANEBO, LTD.
公开号:EP0160103A1
公开(公告)日:1985-11-06
A proteinous emulsifier is obtained by reacting an amino acid ester with a hydrophilic protein in the presence of endopeptidase to bind the amino group of the amino acid ester to the carboxyl terminal of a hydrophilic protein decomposition product through an amide bond. This emulsifier has a typical surfactant structure wherein the hydrophobic amino acid ester moiety is bound to the end of the hydrophilic protein moiety. It slightly stimulates skin and shows a strong emulsifying effect and a good moisture retention, thus being extremely suitable as emulsifier for various cosmetic preparations such as creams, milky lotions, etc.
Cotte, Alain; Bader, Benjamin; Kuhlmann, Juergen, Chemistry - A European Journal, 1999, vol. 5, # 3, p. 922 - 936
作者:Cotte, Alain、Bader, Benjamin、Kuhlmann, Juergen、Waldmann, Herbert
DOI:——
日期:——
Synthesis of the palmitoylated and prenylated C-terminal lipopeptides of the human R- and N-Ras proteins
作者:T. Schmittberger、H. Waldmann
DOI:10.1016/s0968-0896(98)00251-x
日期:1999.5
For the study of biological phenomena influenced by the R- and N-Ras proteins, characteristic peptides which embody the correct lipid modifications of their parent proteins (palmitoyl thioesters, geranylgeranyl thioethers, and farnesyl thioethers), as well as analogues thereof, may serve as efficient tools. For the construction of such acid- and base labile peptide conjugates the allyl ester was developed as C-terminal protecting group. Allyl esters are cleaved selectively and in high yields from lipidated peptides by Pd(0)-mediated allyl transfer to accepting N- or C-nucleophiles like morpholine and N,N-dimethylbarbituric acid. This protecting group technique formed the key step in the synthesis of the characteristic S-palmitoylated and S-isoprenylated C-terminus of human R-Ras and human N-Ras proteins, as well as several analogues thereof. Deprotections are so mild that no undesired side reactions of the lipid conjugates are observed. (C) 1999 Elsevier Science Ltd. All rights reserved.