先前的研究表明,Fe II /α-酮戊二酸依赖性双加氧酶AsqJ诱导构巢曲霉在viridicatin生物合成中的骨架重排,从苯并[1,4]二氮杂-2,5-二酮底物生成喹诺酮骨架。我们报告说,仅通过改变苯并二氮杂二酮底物中的取代基,AsqJ即可催化另外的,完全不同的反应。通过底物筛选,功能探针的应用和计算分析来建立这种新机制。AsqJ消费税H 2由合适的苯并[1,4]二氮杂-2-5,5-二酮底物的杂环结构生成CO,生成喹唑啉酮。这种新颖的AsqJ催化途径由复杂底物中的单个取代基控制。AsqJ的这种独特的底物定向反应性可实现喹诺酮或喹唑啉酮的靶向生物催化生成,喹诺酮或喹唑啉酮是两种具有特殊生物医学相关性的生物碱框架。
Investigation for the cyclization efficiency of linear tetrapeptides: Synthesis of tentoxin B and dihydrotentoxin
作者:Ryota Sato、Kie Oyama、Hiroyuki Konno
DOI:10.1016/j.tet.2018.09.011
日期:2018.10
tentoxin B by the combination of Fmoc solid-phase peptide synthesis and cyclization in solution phase has been reported. An unusual aminoacid, an L-N-methyl-β-hydroxyphenylalanine derivative, which was assembled on solid support, was prepared from ethyl cinnamate. Cyclic tetrapeptide formation and cleavage of benzyl ether were optimized with DIPCI/HOBt/DIPEA and Et3SiH/Pd(OH)2, respectively.
A Novel Synthesis of N-But-3-enyl-α- and β-Amino Acids
作者:Andrew Hughes、T. Van Nguyen、Robert Brownlee
DOI:10.1055/s-0028-1088072
日期:2009.6
N-But-3-enyl-α- and β-aminoacids can be prepared by cleaving 1,3-oxazolidin-5-ones and 1,3-oxazinan-6-ones in the presence of allylsilanes and boron trifluoride etherate at room temperature in good to excellent yields. 1,3-oxazolidin-5-ones - 1,3-oxazinan-6-ones - amino acids - allylations - Lewis acids
Cyclodepsipeptides of the enniation-, PF1022-, and verticilide-family represent a diverse class of highly interesting naturalproducts with respect to their manifold biological activities. However, until now no stepwise solid-phase synthesis has been accomplished due to the difficult combination of N-methyl amino acids and hydroxycarboxylic acids. We report here the first stepwise solid-phase synthesis
In this paper, eight new galaxamide analogues (Z-1~Z-8) were synthesized and evaluated for their cytotoxic activities against five cancer cell lines, MCF-7, MD-MBA-231, HepG2, Hela, and A549, using MTT assays. The modified analogue Z-6 displayed broad spectrum cytotoxic activity toward each tested cell line with IC50 values of 1.65 ± 0.30 (MCF-7), 2.91 ± 0.17 (HepG2), 4.59 ± 0.27 (MD-MBA-231), 5.69
Microwave accelerated efficient synthesis of N-fluorenylmethoxycarbonyl/t-butoxycarbonyl/benzyloxycarbonyl-5-oxazolidinones
作者:Subramanyam J. Tantry、Kantharaju、Vommina V. Suresh Babu
DOI:10.1016/s0040-4039(02)02257-8
日期:2002.12
The synthesis of N-protected 5-oxazolidinones using amino acids, paraformaldehyde and p-toluene sulfonic acid in a minimum amount of toluene accelerated by microwave irradiation for 3 min in high yield is described. (C) 2002 Elsevier Science Ltd. All rights reserved.