Ionizable isotopic labeling reagents for relative quantification by mass spectrometry

US7982070B2 · kind B2 · utility

Assignee

• Wisconsin Alumni Research Foundation · US

Inventors

• Lloyd M. Smith · Atlanta, US
• Michael R. Shortreed · Portage, US
• Brian L. Frey · Madison, US
• Margaret F. Phillips · Madison, US
• Joshua J. Coon · Charlottesville, US
• Shane M. Lamos · Winooski, US
• Casey J. Krusemark · Woodside, US
• Peter Belshaw · Madison, US
• Madhusudan Patel · Somerville, US
• Neil L. Kelleher · Urbana, US

Key dates

• Filing date: Mar 21, 2007
• Grant date: Jul 19, 2011
• Expiry date: Dec 14, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T436/17
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Relative quantification of metabolites by Electrospray Ionization Mass Spectrometry (ESI-MS) requiring a mechanism for simultaneous analysis of multiple analytes in two or more samples. Labeling reagents that are reactive to particular compound classes and differ only in their isotopic kit facilitating relative quantification and providing tangible evidence for the existence of specific functional groups. Heavy and light isotopic forms of methylacetimidate were synthesized and used as labeling reagents for quantification of amine-containing molecules, such as biological samples. Heavy and light isotopic forms of formaldehyde and cholamine were also synthesized and used independently as labeling reagents for quantification of amine-containing and carboxylic acid-containing molecules, such as found in biological samples. Advantageously, the labeled end-products are positively charged under normal acidic conditions involving conventional Liquid Chromatography Mass Spectrometry (LC/MS) applications. Labeled primary and secondary amine and carboxylic acid end-products also generated higher signals concerning mass-spectra than pre-cursor molecules and improved sensitivity. Improved accur…