RIS ID
77128
Abstract
Gas-phase transformation of synthetic phosphatidylcholine (PC) monocations to structurally informative anions is demonstrated via ion/ion reactions with doubly deprotonated 1,4-phenylenedipropionic acid (PDPA). Two synthetic PC isomers, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (PC16:0/18:1) and 1-oleoyl-2-palmitoyl-sn-glycero-3-phosphocholine (PC18:1/16:0), were subjected to this ion/ion chemistry. The product of the ion/ion reaction is a negatively charged complex, [PC + PDPA – H]−. Collisional activation of the long-lived complex causes transfer of a proton and methyl cation to PDPA, generating [PC – CH3]−. Subsequent collisional activation of the demethylated PC anions produces abundant fatty acid carboxylate anions and low-abundance acyl neutral losses as free acids and ketenes. Product ion spectra of [PC – CH3]− suggest favorable cleavage at the sn-2 position over the sn-1 due to distinct differences in the relative abundances. In contrast, collisional activation of PC cations is absent of abundant fatty acid chain-related product ions and typically indicates only the lipid class via formation of the phosphocholine cation. A solution phase method to produce the gas-phase adducted PC anion is also demonstrated. Product ion spectra derived from the solution phase method are similar to the results generated via ion/ion chemistry. This work demonstrates a gas-phase means to increase structural characterization of phosphatidylcholines via ion/ion chemistry.
Grant Number
ARC/CE0561607
Grant Number
ARC/DP120102922
Publication Details
Stutzman, J. R., Blanksby, S. J. & Mcluckey, S. A. (2013). Gas-phase transformation of phosphatidylcholine cations to structurally informative anions via ion/ion chemistry. Analytical Chemistry, 85 (7), 3752-3757.