Room-temperature ionic liquids are useful as solvents for organic synthesis, electrochemical studies, and separations. We wished to examine whether their high solubalizing power, negligible vapor pressure, and broad liquid temperature range are advantageous if they are used as matrixes for UV-MALDI. Several different ionic matrixes were synthesized and tested, using peptides, proteins, and poly(ethylene glycol) (PEG-2000). All ionic liquids tested have excellent solubilizing properties and vacuum stability compared to other commonly used liquid and solid matrixes. However, they varied widely in their ability to produce analyte gas-phase ions. Certain ionic matrixes, however, produce homogeneous solutions of greater vacuum stability, higher ion peak intensity, and equivalent or lower detection limits than currently used solid matrixes. Clearly, ionic liquids and their more amorphous solid analogues merit further investigation as MALDI matrixes.

The capability for accurate mass measurements is an important attribute of Fourier transform mass spectrometry (FTMS). Unlike other instrumental methods in mass spectrometry, FTMS still offers significant opportunities to improve mass measurement accuracy (MMA), making it an area of research. This review covers the published literature in FTMS from the late 1970s to the present. We discuss the development and evolution of mass calibration that give accuracies in the low ppm range. We sketch the derivation and show the common foundation of these mass calibration procedures. We also describe the relation of mass calibration and the fundamentals of ion motion and space-charge effects, and we review efforts to improve the basic calibration procedure particularly those that correct for effects of space charge. The advent of matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) have opened the door for FTMS to be used for analyzing at high performance biopolymers, including proteins, oligodeoxynucleotides (ODNs), oligosaccharides, and synthetic polymers. We also discuss the utility of FTMS for accurate mass measurement in these areas and some practical ways to improve MMA. # 2004 Wiley Periodicals, Inc., Mass Spec Rev 24:286-309, 2005

Targeting tryptophan is a promising strategy to achieve high levels of selectivity for peptide or protein modification. A chemoselective peptide modification method via photocatalytic tryptophan β-position conjugation has been discovered. This transformation has good substrate scope for both peptide and Michael acceptor, and has good chemoselectivity versus other amino acid residues. The endogenous peptides, glucagon and GLP-1 amide, were both successfully conjugated at the tryptophan β-position. Insulin was studied as a nontryptophan control molecule, resulting in exclusive B-chain C-terminal-selective decarboxylative conjugation. This transformation provides a novel approach toward peptide modification to support the discovery of new therapeutic peptides, protein labeling and bioconjugation.

The KCNN4 potassium-ion channel has been reported to play an important role in regulating antigen-induced T cell effector functions in vitro. This study presents the first evidence that a selective KCNN4 blocker, TRAM-34, confers protection against experimental autoimmune encephalomyelitis (EAE) in the mouse model. Treatment with the KCNN4 blocker did not prevent infiltration of T cells in the spinal cord, but resulted in the reduction of both the protein and the message levels of TNF-a and IFN-c as well as the message levels of several other pro-inflammatory molecules in the spinal cord. Plasma concentrations of TRAM-34 within a 24-h period were between the in vitro IC 50 and IC 90 values for the KCNN4 channel. The effect of TRAM-34 was reversible, as indicated by the development of clinical EAE symptoms within 48 h after withdrawal of treatment. In summary, our data support the idea that KCNN4 channels play a critical role in the immune response during the development of MOG-induced EAE in C57BL/6 mice.See accompanying Commentary: http://dx

A comatrix of anthranilic acid and nicotinic acid is optimum for the matrix-assisted laser desorption/ionization time of flight determination of oligodeoxynucleotides that are comprised of up to 21 nucleotides. A detection limit of approximately 200 amol was obtained for an oligonucleotide 21mer. The comatrix system is also suitable for quantification of oligodeoxynucleotides provided an internal standard having one more or less nucleotide than the number in the analyte is used. Furthermore, the matrix, when used in combination with the ladder method of sequencing, allows the complete sequence of tens of picomoles of model oligodeoxynucleotides to be determined.

General methods for the highly site-selective Suzuki monocoupling of 3,5-dichloropyridazines have been discovered. By changing the ligand employed, the preferred coupling site can be switched from the 3-position to the 5-position, typically considered the less reactive C-X bond. These conditions are applicable to the coupling of a wide variety of aryl-, heteroaryl-, and vinylboronic acids with high selectivities, thus enabling the rapid construction of diverse arrays of diarylpyradazines in a modular fashion.

The emergence and evolution of new immunological cancer therapies has sparked a rapidly growing interest in discovering novel pathways to treat cancer. Toward this aim, a novel series of pyrrolidine derivatives (compound ) were identified as potent inhibitors of ERK1/2 with excellent kinase selectivity and dual mechanism of action but suffered from poor pharmacokinetics (PK). The challenge of PK was overcome by the discovery of a novel 3()-thiomethyl pyrrolidine analog . Lead optimization through focused structure-activity relationship led to the discovery of a clinical candidate suitable for twice daily oral dosing as a potential new cancer therapeutic.

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