Prebiotic selection and assembly of proteinogenic amino acids and natural nucleotides from complex mixtures
作者:Saidul Islam、Dejan-Krešimir Bučar、Matthew W. Powner
DOI:10.1038/nchem.2703
日期:2017.6
permits ribonucleotide synthesis, even from complex sugar mixtures. Remarkably, aminal formation also overcomes the thermodynamically favoured isomerization of glyceraldehyde into dihydroxyacetone because only the aminal of glyceraldehyde separates from the equilibrating mixture. Finally, we show that aminal formation provides a novel pathway to amino acids that avoids the synthesis of the non-proteinogenic
Multicomponent Assembly of Proposed DNA Precursors in Water
作者:Matthew W. Powner、Shao-Liang Zheng、Jack W. Szostak
DOI:10.1021/ja306176n
日期:2012.8.22
then show that 2-aminothiazole can take part in a 3-component carbon–carbon bond-forming reaction in water that leads to the diastereoselective synthesis of masked 2′-thiosugars regiospecifically tethered to purine precursors, which would lead to 2′-deoxynucleotides upon desulfurization. The possibility of an abiotic route to the 2′-deoxynucleotides provides a new perspective on the evolutionary origins
Deposition of new thia-containing Schiff-base iron (III) complexes onto carbon nanotube-modified glassy carbon electrodes as a biosensor for electrooxidation and determination of amino acids
Multiwallcarbonnanotubes (MWCNTs) were used as an immobilization matrix to incorporate an Fe (III)–Schiff base complex as an electron-transfer mediator onto a glassy carbon electrode surface. First, the preheated glassy carbon was subjected to abrasive immobilization of MWCNTs by gently rubbing the electrode surface on filter paper supporting the carbonnanotubes. Second, the electrode surface was
多壁碳纳米管(MWCNT)用作固定基质,将Fe(III)–Schiff碱配合物作为电子转移介体掺入玻璃碳电极表面。首先,通过在支撑碳纳米管的滤纸上轻轻摩擦电极表面,对预热的玻璃碳进行MWCNT的磨料固定。其次,通过浇铸100μLFe(III)络合物溶液(ACN中为0.01 M)来修饰电极表面。水溶液中修饰电极的循环伏安图显示了一对定义明确,稳定且几乎可逆的具有表面受限特性的还原氧化还原系统。MWCNTs和Fe(III)-Schiff碱配合物独特的电子和电催化性能的组合产生了显着的协同增效作用。通过循环伏安法表征了修饰电极在pH 1–9的水溶液中的电化学行为和稳定性。表观电子传递速率常数(K s)和传递系数(a)通过循环伏安法测定,分别约为7 s -1和0.55。修饰的电极在酸性溶液中具有非同寻常的正电位,对氨基酸的氧化表现出出色的催化活性。它们还显示出在宽pH范围,快速响应时间,高灵敏度,
Efficient Synthesis of Spirooxindole-Fused 3-Thiazoline Derivatives by a One-Pot Asinger-Type Reaction
A one-pot, three-component reaction has been developed and successfully employed for the synthesis of biologically relevant, highly functionalized spirooxindole-fused 3-thiazoline derivatives. Starting from ammonia, three mercapto carbonyl components and a series of substituted isatins, products were obtained in good yields (24 examples), by following a simple and rapid protocol. The obtained thiazolines
Synthesis of spiroketal-modified avermectin analogs: 23-nor-23-oxa- and 23-nor-23-thia-avermectins
作者:Peter T. Meinke、Stephen P. O'Connor、Michael H. Fisher、Helmut Mrozik
DOI:10.1016/s0040-4039(00)73495-2
日期:1994.7
The concise synthesis of avermectin analogs wherein the C23 carbon has been excised and replaced with an oxygen or sulfur atom is described. The new, heteroatom-substituted avermectins represent isosteres of 22,23-dihydro-avermectin B1a and, in the case of the sulfoxides and sulfones, are isosteric to avermectinB2a. These new avermectins bear diverse functionality at C24 and C25.