Ion mobility mass spectrometry tags for quantitative applications and methods thereof

A compound having the formula of

• A-Q-X-L-T or A-X-Q-L-T (II)
• wherein
• A is a normalizing group comprising a structural unit;
• Q is a cyclic group comprising three or more groups selected from oxo-hydrocarbon groups and amino-hydrocarbon groups;
• X is a cleavable group;
• L is a linker comprising the structural unit;
• and
• T is an oligomer comprising a group capable of forming an intra-molecular complex with Q.

A method for analyzing peptides, comprising:

• reacting a sample of peptides with one or more compounds having the formula (I) thereby forming one or more compounds of the formula (II):
• A-Q-X-L or A-X-Q-L (I)
• A-Q-X-L-T or A-X-Q-L-T (II)
• wherein
• A is a normalizing group comprising a structural unit;
• Q is a cyclic group comprising three or more ethylene-oxide units;
• X is a cleavable group;
• L is a linker comprising the structural unit;
• and
• T is a peptide comprising terminal guanidinium moiety, wherein the guanidinium moiety is capable of forming intra-molecular complex with Q;
• separating the formed compounds of formula (I) by ion mobility;
• and
• causing cleavage of the cleavable group and dissociation of the compounds of formula (II) forming fragments.