Complete Stereoinversion of l-Tryptophan by a Fungal Single-Module Nonribosomal Peptide Synthetase
摘要:
Single-module nonribosomal peptide synthetases (NRPSs) and NRPS-like enzymes activate and transform carboxylic acids in both primary and secondary metabolism and are of great interest due to their biocatalytic potentials. The single-module NRPS IvoA is essential for fungal pigment biosynthesis. Here, we show that IvoA catalyzes ATP-dependent unidirectional stereo inversion of L-tryptophan to D-tryptophan with complete conversion. While the stereoinversion is catalyzed by the epimerization (E) domain, the terminal condensation (C) domain stereoselectively hydrolyzes D-tryptophanyl-S-phosphopantetheine thioester and thus represents a noncanonical C domain function. Using IvoA, we demonstrate a biocatalytic stereoinversion/deracemization route to access a variety of substituted D-tryptophan analogs in high enantiomeric excess.
One-Pot Biocatalytic Synthesis of Substituted<scp>d</scp>-Tryptophans from Indoles Enabled by an Engineered Aminotransferase
作者:Fabio Parmeggiani、Arnau Rué Casamajo、Curtis J. W. Walton、James L. Galman、Nicholas J. Turner、Roberto A. Chica
DOI:10.1021/acscatal.9b00739
日期:2019.4.5
d-Tryptophan and its derivatives are important precursors of a wide range of indole-containing pharmaceuticals and naturalproducts. Here, we developed a one-pot biocatalytic process enabling the synthesis of d-tryptophans from indoles in good yields and high enantiomeric excess (91% to >99%). Our method couples the synthesis of l-tryptophans catalyzed by Salmonella enterica tryptophan synthase with
Substituted 1-benzazepines and derivatives thereof
申请人:Tomazic Alenka
公开号:US20050234041A1
公开(公告)日:2005-10-20
This invention relates to substituted 1-benzazepines and derivatives thereof useful as anti-infective agents, to compositions, including pharmaceutical compositions, comprising such compounds, to processes for making these compounds and to methods of using these compounds for killing bacteria and other microorganisms or inhibiting bacterial and other microorganism growth.
using a novel type of axially chiral styrene-phosphine ligand SJTU-PHOS-1 was developed. This reaction demonstrated good functional group compatibility and a wide range scope of substrates in mild conditions. Moreover, the DFT calculations expounded the coordination mode of the metal catalyst and the axially chiral styrene-phosphine ligand in the enantioselectivity control.
Optimization of analytical method greenness scores: a case study of amino acid enantioseparations with carbonated aqueous systems
作者:Troy T. Handlovic、M. Farooq Wahab、Bailey C. Glass、Daniel W. Armstrong
DOI:10.1039/d3gc03005a
日期:——
incorporate the “cycle time” of the chromatograph, which provides a more accurate picture of solvent waste generation in high throughput chemical analyses. Using the principles of mathematical optimization, the AMGS was minimized with respect to flow rate to show that the ideal separation speed differs depending on the solvent composition. The AMGS reached values as low as 1.2 for ultrafast (<15 s) amino
分析和制备分离技术虽然被认为与工业制造工艺相比危害较小,但仍存在巨大的隐蔽环境威胁。过去五年中,绿色分析化学在提出测量分离方法绿色度的指标方面取得了重大进展。其中一项综合衡量标准是分析方法绿色度评分 (AMGS),它用于对文献中当前的对映体分离方法进行基准测试。在这项工作中,我们提出了实用和数学策略来最大限度地减少高性能液相色谱对映体分离中的 AMGS。生成并评估了 38 种蛋白质和非蛋白质氨基酸对映体的超过 456 个色谱图的案例研究。引入了一种生成碳酸水基洗脱液的可持续方法,并且 H 2 CO 3 * 添加剂被证明可以提高色谱品质因数(分辨率和效率),同时降低 AMGS。我们发现,与传统分析相比,具有表面多孔颗粒的窄直径色谱柱可将溶剂浪费减少 12 倍。AMGS 公式经过修改,纳入了色谱仪的“循环时间”,从而可以更准确地了解高通量化学分析中溶剂废物的产生情况。利用数学优化原理,将 AMGS
PORTER, JOHN;DYKERT, JOHN;RIVIER, JEAN, INT. J. PEPTIDE AND PROTEIN RES., 30,(1987) N 1, 13-21