Photolabile Protecting Groups for Nitroxide Spin Labels

✍ Scribed by Seven, Ibrahim; Weinrich, Timo; Gränz, Markus; Grünewald, Christian; Brüß, Silke; Krstić, Ivan; Prisner, Thomas F.; Heckel, Alexander; Göbel, Michael W.

• Book ID: 126853035
• Publisher: John Wiley and Sons
• Year: 2014
• Tongue: English
• Weight: 270 KB
• Volume: 2014
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.201301692

✦ Synopsis

Abstract

Nitroxide spin labels can be protected against critical conditions of DNA/RNA or peptide synthesis by reduction and alkylation with light‐sensitive groups such as nitrobenzyl‐ or aminocoumarins. High chemical stability qualifies tetraethylisoindoline 5 and, with some restrictions, (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxy (TEMPO) precursor 4 as building blocks for spin‐labeled biopolymers. The yield of recovered nitroxides (80–95 %) is sufficient for PELDOR experiments. A protected TEMPO phosphoramidite was successfully used to synthesize a short spin‐labeled DNA with high yield and purity.