Enantioselective Enzymatic Reduction of Acrylic Acids
作者:Chihui An、Megan H. Shaw、Annika Tharp、Deeptak Verma、Hongming Li、Heather Wang、Xiao Wang
DOI:10.1021/acs.orglett.0c02959
日期:2020.11.6
identified, and optimization studies led to the development of an enzymatic protocol for the reduction of α,β-unsaturated acids under mild, aqueous conditions. The substrate scope includes aromatic- and aliphatic-substituted acrylic acids, as well as cyclic α,β-substituted acrylic acids, yielding chiral α-substituted acids with exquisite levels of enantioselectivity (>99% ee).
?2- and ?3-Peptides with Proteinaceous Side Chains: Synthesis and solution structures of constitutional isomers, a novel helical secondary structure and the influence of solvation and hydrophobic interactions on folding
作者:Dieter Seebach、Stefan Abele、Karl Gademann、Gilles Guichard、Tobias Hintermann、Bernhard Jaun、Jennifer L. Matthews、J�rg V. Schreiber、Lukas Oberer、Ulrich Hommel、Hans Widmer
DOI:10.1002/hlca.19980810513
日期:——
the previously prepared β-peptides (35–39) showed NH/ND exchange rates (in MeOH at room temperature) with τ1/2 values of up to 60 days, unrivalled by short chain α-peptides. All β-peptides 1–7 were designed to be able to attain the previously described 31-helical structure (Figs. 1 and 2). CD Measurements (Fig. 4), indicating a new secondary structure of certain β-peptides constructed of β2- and β3-amino
Dolastatin D (1), a cytotoxic cyclic depsipeptide possessing the novel β-amino acid (2R,3R)-3-amino-2-methylbutanoic acid [(2R,3R]-3] as a component, has been isolatedfrom the Japanese seahareDolabellaauricularia. The absolute stereostructure of 1 was elucidated on the basis of spectroscopic analysis and chemical degradation and was further confirmed by synthesis.
具有新型β-氨基酸(2 R,3 R)-3-氨基-2-甲基丁酸[(2 R,3 R ] -3 ]作为成分的细胞毒性环状二肽肽Dolastatin D(1)已被开发出来。分离自日本海兔Dolabella auricularia,在光谱分析和化学降解的基础上阐明了1的绝对立体结构,并通过合成进一步证实。