TY - JOUR
T1 - Low-energy collision-induced fragmentation of negative ions derived from diesters of aliphatic dicarboxylic acids made with hydroxybenzoic acids
AU - Nishshanka, Upul
AU - Attygalle, Athula B.
PY - 2008/11
Y1 - 2008/11
N2 - Diesters of ortho-hydroxybenzoic acid (salicylic acid) made with glutaric, adipic, and pimelic acids are the monomers of some potential drug candidates for aspirin patches. Collision-induced dissociation (CID) spectra of negative ion derived from these compounds show a 120-Da 'neutral loss' specific to the ortho isomers. In contrast, the anions derived from diesters of meta- and para-hydroxybenzoic acids show a 138-Da loss for an elimination of elements of hydroxybenzoic acid by a charge-remote mechanism. Deuterium labeling studies confirmed that the hydrogen atom transferred for hydroxybenzoic acid loss originates specifically from the α position of the dicarboxylic acid moiety. Although all spectra showed a peak at m/z 137, a charge-mediated process specific for the ortho compounds renders it the most prominent peak in the spectra of ortho compounds. Appropriate deuterium labeling experiments demonstrated that the hydrogen atom transferred for the formation of the m/z 137 ion in ortho compounds is specifically derived from the α position of the dicarboxylic acid moiety.
AB - Diesters of ortho-hydroxybenzoic acid (salicylic acid) made with glutaric, adipic, and pimelic acids are the monomers of some potential drug candidates for aspirin patches. Collision-induced dissociation (CID) spectra of negative ion derived from these compounds show a 120-Da 'neutral loss' specific to the ortho isomers. In contrast, the anions derived from diesters of meta- and para-hydroxybenzoic acids show a 138-Da loss for an elimination of elements of hydroxybenzoic acid by a charge-remote mechanism. Deuterium labeling studies confirmed that the hydrogen atom transferred for hydroxybenzoic acid loss originates specifically from the α position of the dicarboxylic acid moiety. Although all spectra showed a peak at m/z 137, a charge-mediated process specific for the ortho compounds renders it the most prominent peak in the spectra of ortho compounds. Appropriate deuterium labeling experiments demonstrated that the hydrogen atom transferred for the formation of the m/z 137 ion in ortho compounds is specifically derived from the α position of the dicarboxylic acid moiety.
KW - Aspirin
KW - CID
KW - Even-electron ions
KW - Fragmentation
KW - Negative ions
KW - Transdermal drug delivery
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U2 - 10.1002/jms.1426
DO - 10.1002/jms.1426
M3 - Article
C2 - 18521832
AN - SCOPUS:55249127551
SN - 1076-5174
VL - 43
SP - 1502
EP - 1511
JO - Journal of Mass Spectrometry
JF - Journal of Mass Spectrometry
IS - 11
ER -