A General Inhibitor Scaffold for Serine Proteases with a (Chymo)trypsin-Like Fold: Solution-Phase Construction and Evaluation of the First Series of Libraries of Mechanism-Based Inhibitors
Efficient preparation of D-aspartic acid .BETA.-methyl ester as a aspoxicillin material by optical resolution, epimerization, and asymmetric transformation.
A visible light-mediated, decarboxylative, desulfonylative Smiles rearrangement for general arylethylamine syntheses
作者:David M. Whalley、Hung A. Duong、Michael F. Greaney
DOI:10.1039/d0cc05049k
日期:——
A decarboxylative, desulfonylative Smiles rearrangement is presented that employs activated-ester/energy transfer catalysis to decarboxylate β-amino acid derived starting materials at room-temperature under visible light irradiation. The radical Smiles rearrangement gives a range of biologically active arylethylamine products highly relevant to the pharmaceutical industry, chemical biology and materials
Purification and characterization of Stenotrophomonas maltophilia-derived l-amino acid ester hydrolase for synthesizing dipeptide, isoleucyl-tryptophan
In the present study, we purified α-amino acid ester hydrolase (AEH) from cell-free extracts of the Stenotrophomonas maltophilia strain HS1. The approximately 70-kDa AEH from S. maltophilia HS1 (SmAEH) was homogeneous in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analyses, and was present as a tetramer in gel-filtration experiments. The activity of the SmAEH enzyme was then determined by monitoring the synthesis of the antihypertensive agent dipeptide isoleucyl-tryptophan (Ile-Trp) from isoleucyl methyl ester (Ile-OMe) and tryptophan (Trp). In these experiments, SmAEH had wide substrate specificity for acyl donors, such as Gly-OMe, β-Ala-OMe, Pro-OMe and Trp-OMe and Ile-OMe, and maximal activity were observed under conditions of pH 9.0 and 30 °C. SmAEH also showed the greatest stability at pH 9.0, whereas its activity was reduced by 40% after 10-min incubation at approximately 50 °C. In subsequent activity assays in the presence of various metal ions, Ag+ strongly inhibited enzyme activity. Finally, SmAEH activity was completely inhibited by phenylmethanesulfonyl fluoride (PMSF), suggesting that the protein is a serine protease.
Clay Column Chromatography for Optical Resolution: A Series of Derivatized Amino Acids
作者:Akihiko Yamagishi、Shohei Yamamoto、Kazuyoshi Takimoto、Kenji Tamura、Masumi Kamon、Fumi Sato、Hisako Sato
DOI:10.1246/bcsj.20220077
日期:2022.6.15
Chromatographic resolution of a series of derivatized aminoacids was attempted on a column packed with an ion-exchange adduct of Δ-[Ru(phen)3]2+ (phen = 1,10-phenanthroline) and synthetic hectorite. An aminoacid was modified to N-3, 5-dinitrobenzoyl aminoacid methyl ester (denoted by DNB-aa-me). For aa = Ala, Phe, Leu, Ile, Ser, Val, Thr, Tyr, Asp and Glu, racemic DNB-aa-me was resolved nearly to