(15)N-Labeled ionic probes for bioanalytical mass spectrometry

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Chemical Synthesis

Background:

• Developing efficient ionization methods is crucial for analyzing complex molecules in mass spectrometry.
• Stable isotopically labeled probes can enhance sensitivity and accuracy in analytical measurements.
• Lanthanum (La) complexes offer unique properties for potential applications in ionization techniques.

Purpose of the Study:

• To synthesize novel stable isotopically labeled probes based on a La-complex and a 2,6-bis(oxazolin-2-yl)pyridine (pybox) ligand.
• To evaluate the effectiveness of these probes in the ionization of large complex molecules.
• To demonstrate the utility of the (15)N-labeled pybox-La complex for analyzing bioactive peptides via cold-spray ionization mass spectrometry.

Main Methods:

• Synthesis of novel stable isotopically labeled probes: succinimide-tetramethylpybox (NHS-TMpybox), maleimide-tetramethylpybox (Mal-TMpybox), and 4-(tetramethylpybox)-butyl bromoacetate (BrAc-TMpybox).
• Utilizing a (15)N-labeled pybox-La complex as the core ionization agent.
• Employing cold-spray ionization mass spectrometry (CSI-MS) for the analysis of various compounds.

Main Results:

• Successful synthesis of novel stable isotopically labeled pybox-based probes.
• Demonstration of the La-complex-based probe's effectiveness in ionizing large complex molecules.
• Effective ionization of bioactive peptides was achieved using the (15)N-labeled pybox-La complex with CSI-MS.

Conclusions:

• The developed La-complex-based probe ionization method is effective for analyzing complex samples.
• The synthesized stable isotopically labeled probes, particularly the (15)N-labeled pybox-La complex, show significant value in mass spectrometry.
• This approach offers a promising tool for the analysis of challenging biomolecules like peptides.