Synthesis of Intrinsically Blue-Colored bis-Nitronyl Nitroxide Peptidomimetic Templates and Their Conformational Preferences as Revealed by a Combined Spectroscopic Analysis,The Journal of Organic Chemistry

当前位置： X-MOL 学术 › J. Org. Chem. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Synthesis of Intrinsically Blue-Colored bis-Nitronyl Nitroxide Peptidomimetic Templates and Their Conformational Preferences as Revealed by a Combined Spectroscopic Analysis
The Journal of Organic Chemistry ( IF 3.3 ) Pub Date : 2017-09-18 00:00:00 , DOI: 10.1021/acs.joc.7b01498
Marta De Zotti ₁ , Karen Wright ₂ , Edouard d’Aboville ₂ , Antonio Toffoletti ₁ , Claudio Toniolo _{1,

3} , Giovanna Longhi ₄ , Giuseppe Mazzeo ₄ , Sergio Abbate ₄ , Fernando Formaggio _{1,

3}

Affiliation

The intrinsically blue-colored Ullman imidazolinyl nitronyl nitroxide (NN) mono-radicals have found various applications, in particular as spin probes and organic magnetic materials. Here, we present the solution-phase synthesis, extensive characterization, and conformational analysis of the first peptidomimetics with two pendant, chiral nitronyl nitroxide free radical units. Two (R)-Aic(NN) residues, where Aic(NN) is 2-amino-5-nitronylnitroxide-indan-2-carboxylic acid, have been inserted at positions i and i+3 of the pentapeptide Boc-(R)-Aic(NN)-(Ala)₂-(R)-Aic(NN)-Ala-OMe and the hexapeptide Boc-[Ala-(R)-Aic(NN)-Ala]₂-OMe as well. The two compounds were obtained in good yields and high purities. Thanks to a combination of several spectroscopic techniques (IR absorption, NMR, VCD, and EPR) we gained clear evidence that both compounds adopt a right-handed 3₁₀-helical conformation with both nitronyl nitroxide pendants positioned on the same side of the helix. This peptidomimetic/free radical system is a potentially excellent template for the preparation of a set of appropriate analogs with exciting applications in the area of host–guest organic chemistry, or to spectroscopically evaluate in-depth the intramolecular exchange interactions in this type of probe.

中文翻译：

固有的蓝色双-硝基一氧化氮-拟肽模板的合成及其构象偏爱的组合光谱分析

固有的蓝色Ullman咪唑啉基硝酰基硝基氧（NN）单自由基已经发现了各种应用，特别是作为自旋探针和有机磁性材料。在这里，我们介绍了具有两个侧链手性硝酰基硝基氧自由基单元的第一个拟肽的固溶相合成，广泛的表征和构象分析。在五肽Boc-（R）的位置i和i +3处插入了两个（R）-Aic（NN）残基，其中Aic（NN）为2-氨基-5-硝酰基硝基氧-茚满-2-羧酸-Aic（NN）-（Ala）_2-（R）-Aic（NN）-Ala-OMe和六肽Boc- [Ala-（R）-Aic（NN）-Ala] ₂-OMe也是。两种化合物均以高收率和高纯度获得。由于多种光谱技术（红外吸收，NMR，VCD和EPR）的结合，我们获得了明确的证据，证明这两种化合物均采用右旋3 ₁₀螺旋构型，且两个硝酰基硝基氧化物侧基均位于螺旋的同一侧。这种拟肽/自由基系统是潜在的优秀模板，可用于制备一组合适的类似物，在宿主-客体有机化学领域具有激动人心的应用，或通过光谱法深入评估此类探针中的分子内交换相互作用。

更新日期：2017-09-18

点击分享查看原文

点击收藏

阅读更多本刊最新论文