Carbonyl containing compound high-throughput quantitative analysis using isobaric multiplex reagents

A method of analyzing a target molecule having an aldehyde, ketone, or carboxylic acid group, said method comprising the steps of:

• a) providing the target molecule;
• b) labeling the target molecule with a tagging reagent, thereby generating a labeled molecule, wherein said tagging reagent comprises:
• i) a reporter group, ii) an aldehyde reactive group, ketone reactive group, or carboxylic acid reactive group, and iii) a balancing group located between the reporter group and the aldehyde reactive group, ketone reactive group, or carboxylic acid reactive group,
• wherein labeling the target molecule comprises reacting the aldehyde reactive group, ketone reactive group, or carboxylic acid reactive group with an aldehyde, ketone, or carboxylic acid of the target molecule to generate the labeled molecule,
• wherein one or more atoms in the reporter group, the balancing group, or both, are isotopically heavy versions of the one or more atoms, said tagging reagent having the formula of:
• wherein,
• R1 is the aldehyde reactive group, ketone reactive group, or carboxylic acid reactive group, wherein the aldehyde reactive group, ketone reactive group, or carboxylic acid reactive group is any functional group able to react with an aldehyde, ketone, or carboxylic acid of the target molecule;
• R2 and R3, independently of one another, are selected from the group consisting of branched and unbranched Ci to C12 alkyl groups, C4 to C12 cycloalkyl groups, C2 to C12 alkenyl groups, C5 to C12 cycloalkenyl groups, C6 to C12 aryl groups and C7 to C12 arylalkyl groups, wherein each of R2 and R3 optionally contain one or more 13C atoms and one or more deuterium atoms;
• R4, R5 and R6, independently of one another, are selected from the group consisting of hydrogen, deuterium, branched and unbranched C1 to C12 alkyl groups, C4 to C12 cycloalkyl groups, C2 to C12 alkenyl groups, C5 to C12 cycloalkenyl groups, C6 to C12 aryl groups and C7 to C12 arylalkyl groups, wherein each of R4, R5 and R6 optionally contain one or more 13C atoms and one or more deuterium atoms;
• CV and Cx, independently of one another, are 12C or 13C,
• OU and OY, independently of one another, are 16O or 18O;
• and
• Nz and NW, independently of one another, are 14N or 15N;
• c) fragmenting the labeled molecule to generate an immonium ion from the labeled molecule;
• and
• d) detecting and analyzing fragments of the labeled molecule.