Do lipases also catalyse the ring cleavage of inactivated cyclic trans-β-lactams?
摘要:
Twelve-membered cyclic cis- and trans-beta-lactams 1b and 2b and the corresponding cyclic cis- and trans-beta-amino acid enantiomers, 1a, 1e and 2a, 2c were prepared through the CAL-B-catalysed enantio selective ring cleavage of racemic cis-13-azabicyclo[10.2.0]tetradecan-14-one, (+/-)-1, and trans-13-azabicyclo[10.2.0]tetradecan-14-one, (+/-)-2. High enantioselectivities (E > 200) were observed for the ring opening of both the cis- and trans-beta-lactams when the Lipolase-catalysed reactions were performed with 0.5 equiv of H2O in i-Pr2O at 70 degrees C. The resolved beta-lactams 1b and 2b (yield >= 47%) and beta-amino acids 1a and 2a (yield >= 32%) could be easily separated. (c) 2006 Published by Elsevier Ltd.
Poly-β-peptides from functionalized β-lactam monomers and antibacterial compositions containing same
申请人:Stahl Shannon S.
公开号:US09120892B2
公开(公告)日:2015-09-01
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:WISCONSIN ALUMNI RESEARCH FOUNDATION
公开号:US10736915B2
公开(公告)日:2020-08-11
Non-natural oligomers have recently shown promise as functional analogues of lung surfactant proteins B and C (SP-B and SP-C), two helical and amphiphilic proteins that are critical for normal respiration. The generation of non-natural mimics of SP-B and SP-C has previously been restricted 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-B mimicry that is based on sequence-random copolymers containing cationic and lipophilic subunits. These materials, members of the nylon-3 family, are prepared by ring-opening polymerization of β-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. Attachment of an N-terminal octadecanoyl unit to the nylon-3 copolymers affords further improvements by reducing the percent surface area compression to reach low minimum surface tension.
非天然低聚物最近有望成为肺表面活性蛋白 B 和 C(SP-B 和 SP-C)的功能类似物,这两种螺旋状两亲性蛋白对正常呼吸至关重要。以前,SP-B 和 SP-C 的非天然模拟物的生成一直局限于分步、序列特异性合成,从而产生离散的低聚物,以显示特定的结构属性。本文介绍的另一种 SP-B 拟态方法是基于含有阳离子和亲油亚单位的序列随机共聚物。这些材料属于尼龙-3 家族,是通过 β-内酰胺的开环聚合反应制备的。最好的尼龙-3 聚合物在混合脂膜中显示出良好的体外表面活性。脉动气泡表面活性测定法的数据表明,含有表面活性最强的聚合物的薄膜所具有的吸附性和动态循环特性超过了用于模拟 SP-B 的离散肽。在尼龙-3 共聚物上连接一个 N 端十八碳酰单位可降低表面积压缩百分比,从而达到较低的最小表面张力,从而进一步提高了性能。
Nylon-3 Polymers That Enable Selective Culture of Endothelial Cells
作者:Runhui Liu、Xinyu Chen、Samuel H. Gellman、Kristyn S. Masters
DOI:10.1021/ja408634a
日期:2013.11.6
Substrates that selectively encourage the growth of specific cell types are valuable for the engineering of complex tissues. Some cell-selective peptides have been identified from extracellular matrix proteins; these peptides have proven useful for biomaterials-based approaches to tissue repair or regeneration. However, there are very few examples of synthetic materials that display selectivity in supporting cell growth. We describe nylon-3 polymers that support in vitro culture of endothelial cells but do not support the culture of smooth muscle cells or fibroblasts. These materials may be promising for vascular biomaterials applications.
Lipase-catalyzed kinetic resolution of 7-, 8- and 12-membered alicyclic β-amino esters and N-hydroxymethyl-β-lactam enantiomers
作者:Zsuzsanna Cs. Gyarmati、Arto Liljeblad、Mikko Rintola、Gábor Bernáth、Liisa T. Kanerva
DOI:10.1016/j.tetasy.2003.08.028
日期:2003.11
Enzymatic kinetic resolutions of methyl cis-2-aminocycloheptane-, 2-aminocyclooctane- and 2-aminocyclododecanecarboxylates with Candida antarctica lipase A in diisopropyl ether (E > 200) and of the corresponding N-hydroxymethyl-beta-lactams with Pseudomonas cepacia lipase in dry acetone (E from 27 to > 200) has been performed with 2,2,2-trifluoroethyl butanoate as the best acyl donor, with both enantiomers being obtained. trans-13-Hydroxymethyl-13-azabicyclo[10.2.0]tetradecan-14-one was resolved with vinyl butanoate and Candida antarctica lipase B (E=26) in acetone. (C) 2003 Elsevier Ltd. All rights reserved.
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.