Advanced procedure for the enzymatic ring opening of unsaturated alicyclic β-lactams
摘要:
Enantiopure beta-amino acids 1a-4a and beta-lactams 1b-4b were prepared simultaneously through the lipolase-catalysed enantioselective ring opening of unsaturated racemic beta-lactams (+/-)-1-(+/-)-4. High enantioselectivities (E >200) were observed when the reactions were performed with 1 equiv of water in iPr(2)O at 70degreesC. The resolved (1R,2S)-amino acids (yield greater than or equal to 45%) and (1S,5R)-, (1S,6R)- and (1S,8R)-lactams (yield greater than or equal to47%) could be easily separated. The ring opening of lactam enantiomers 1b-4b with 18% HCl afforded the corresponding beta-amino acid hydrochlorides 1c(.)HCl-4c(.)HCl (ee >95%). (C) 2004 Elsevier Ltd. All rights reserved.
An eight-membered cyclic beta-amino acid, 8-aminocyclooct-4-enecarboxylic acid, was designed as a conformationally restricted non-proteinogenic amino acid. A hybrid tripeptide containing this eight-membered cyclic beta-amino acid and 2-aminoisobutyric acids was synthesized by conventional solution methods. The conformation of the tripeptide was studied using X-ray analysis and was shown to form an
Helical folding of α/β-peptides containing β-amino acids with an eight-membered ring constraint
作者:Woohyung Lee、Sunmi Kwon、Philjae Kang、Ilia A. Guzei、Soo Hyuk Choi
DOI:10.1039/c4ob00266k
日期:——
αβα-Tripeptide that contains a cyclic β-amino acid with an eight-memberedring, a cis-2-aminocyclooct-5-enecarboxylic acid (cis-ACOE) or a cis-2-aminocyclooctanecarboxylic acid (cis-ACOC) displayed an 11/9-helical turn in the crystal state. The related α/β-peptide oligomers were shown to adopt 11/9-helical conformations in solution.
Poly-beta-peptides from functionalized beta-lactam monomers and antibacterial compositions containing same
申请人:Stahl S. Shannon
公开号:US20070087404A1
公开(公告)日:2007-04-19
Disclosed is a method of making β-polypeptides. The method includes polymerizing β-lactam-containing monomers in the presence of a base initiator and a co-initiator which is not a metal-containing molecule to yield the product β-polypeptides. Specifically disclosed are methods wherein the base initiator is potassium t-butoxide, lithium bis(trimethylsilyl)amide (LiN(TMS)
2
), potassium bis(trimethyl-silyl)amide, and sodium ethoxide, and the reaction is carried out in a solvent such as chloroform, dichloromethane, dimethylsulfoxide, or tetrahydrofuran.
NYLON-3 CO-POLYMERS AND SYNTHETIC LUNG SURFACTANT COMPOSITIONS CONTAINING SAME
申请人:Gellman Samuel H.
公开号:US20130004453A1
公开(公告)日:2013-01-03
Non-natural oligomers have recently shown promise as functional analogues of lung surfactant proteins Band C (SP-B and SP-C), two helical and amphiphilic proteins that are clitical for normal respiration. The generation of non-natural mimics of SP-B and SP-C has previously been restlicted to step-by-step, sequence-specific synthesis, which results in discrete oligomers that are intended to manifest specific structural attributes. Presented herein an alternative approach to SP-R mimicry that is based on sequence-random copolymers containing cationic and lipophilic subunits. These materials, members of the nylon-3 family, arc prepared by ling-opening polymelization of 13-lactams. The best of the nylon-3 polymers display promising in vitro surfactant activities in a mixed lipid film. Pulsating bubble surfactometry data indicate that films containing the most surface-active polymers attain adsorptive and dynamic-cycling properties that surpass those of discrete peptides intended to mimic SP-B.
POLY-BETA-PEPTIDES FROM FUNCTIONALIZED BETA-LACTAM MONOMERS AND ANTIBACTERIAL COMPOSITIONS CONTAINING SAME
申请人:WISCONSIN ALUMNI RESEARCH FOUNDATION
公开号:US20150322205A1
公开(公告)日:2015-11-12
Disclosed is a method of making β-polypeptides. The method includes polymerizing β-lactam-containing monomers in the presence of a base initiator and a co-initiator which is not a metal-containing molecule to yield the product β-polypeptides. Specifically disclosed are methods wherein the base initiator is potassium t-butoxide, lithium bis(trimethylsilyl)amide (LiN(TMS)
2
), potassium bis(trimethyl-silyl)amide, and sodium ethoxide, and the reaction is carried out in a solvent such as chloroform, dichloromethane, dimethylsulfoxide, or tetrahydrofuran.