The last few years have seen a tremendous improvement in the methods used to protect hydroxy groups with trityls. However, there is limited work on the selective protection and deprotection of ambident nucleophiles (e.g. amines, alcohols and sulfurs) with trityls and p-methoxy substituted trityls. Methoxysubstituted trityl functions have been used as N-protecting groups in pro-drugs, designed t...

Electron paramagnetic resonance (EPR) spectroscopy is a powerful and widely used technique for studying structure and dynamics of biomolecules under bio-orthogonal conditions. In-cell EPR is an emerging area in this field; however, it is hampered by the reducing environment present in cells, which reduces most nitroxide spin labels to their corresponding diamagnetic N-hydroxyl derivatives. To d...

Dynamic nuclear polarization of 17O was studied using four different polarizing agents – the biradical TOTAPOL, and the monoradicals trityl and SA-BDPA, as well as a mixture of the latter two. Field profiles, DNP mechanisms and enhancements were measured to better understand and optimize directly polarizing this low-gamma quadrupolar nucleus using both monoand bi-radical polarizing agents. Enha...

The multifunctional character and stability of PTM radicals makes them appealing in a broad range fields, from active components molecular optoelectronics to agents bio-applications.

5' tritylated oligonucleotides binding hydrophobically to low trityl cellulose/sepharose (< 15 microMTr/ml) retain their hydrogen-bonding specificities for complementary sequences. This, constitutes a novel mode of attaching affinity ligands to solid supports, is more convenient than existing methods, and proceeds with 100% yield. The salt, dielectric constant and temperature dependence of thes...

B ernd H enkel, Lianshan Zhang, Carsten G oldam m er, Ernst Bayer* Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany Z. Naturforsch. 51b, 1339-1346 (1996); received April 10, 1996 HIV 1-Protease, Trityl-Linker, Fragment Condensation, Peptide Synthesis, Ionspray-MS, Chiral Gas-chromatography A new trityl-linker for the strategy of combined...

This article reports the development and evaluation of two nano-emulsions (F45T-03/HFB and F15T-03/PFOB) containing fluorinated trityl radicals dissolved in perfluorocarbons. Preparation with a high-pressure homogenizer conferred sub-micronic size to both nano-emulsions. In vitro and in vivo EPR spectroscopy showed that the nano-emulsions had much greater oxygen sensitivity than the hydrophilic...

Beta-hydroxy amides 6 and 7 were treated with triphenylphosphonium anhydride trifluoromethane sulfonate (3), or the cyclic analogue 4, to generate 2-oxazolines 5 and 8 under mild conditions. The reaction was optimised by examining the number of equivalents of reagents 3 or 4, or diisopropylethyl amine required to best effect cyclisation. The effects of altering the reaction temperature, reactio...