Synthesis of the isotope‐labeled derivatization reagent for carboxylic acids, 7‐(N,N‐dimethylaminosulfonyl)‐4‐(aminoethyl)piperazino‐2,1,3‐benzoxadiazole (d₆) [DBD‐PZ‐NH₂ (D)], and its application to the quantification and the determination of relative amount of fatty acids in rat plasma samples by high‐performance liquid chromatography/mass spectrometry

Abstract

The isotope-labeled benzofurazan derivatization reagent for carboxylic acids, 7-(N,N-dimethylaminosulfonyl)-4-(aminoethyl)piperazino-2,1,3-benzoxadiazole (d6) [DBD-PZ-NH2 (D)] was synthesized. DBD-PZ-NH2 (D) was used for the accurate quantification of fatty acids by liquid chromatography/mass spectrometry (LC/MS). The standard fatty acids were derivatized with DBD-PZ-NH2 (D) to the stable isotope-labeled compounds for the fatty acids derivatives of DBD-PZ-NH2 and used for the internal standards. The obtained calibration curves for fatty acids were linear over the range 0.1-200 microM (r2 > 0.999). Fatty acids in plasma samples were determined after derivatization with DBD-PZ-NH2 and analyzed by LC/MS using standard fatty acid DBD-PZ-NH2 (D) derivatives as internal standards. Furthermore, the relative amounts of fatty acids in two plasma samples were determined after derivatization with DBD-PZ-NH2 and DBD-PZ-NH2) (D). The isotope-labeled derivatization reagent was useful for accurate quantification and the determination of relative amounts of the metabolites in biological samples having the target functional group.

Synthesis of benzofurazan derivatization reagents for carboxylic acids in liquid chromatography/electrospray ionization–tandem mass spectrometry

“…Derivatization of octanoic acid was carried out according to a similar method described in a previous paper (Tsukamoto et al, 2005(Tsukamoto et al, , 2006. Briefly, a 20 μL aliquot of octanoic acid (500 μM) in acetonitrile, 20 μL of derivatization reagent (DAABD-AE, DAABD-PZ or DAABD-APy; 5 mM) in acetonitrile-DMF (1:1, v/v), 20 μL of DMAP (50 mM) in acetonitrile and 20 μL of EDC (25 mM) in water were added to a vial.…”

Development of versatile isotopic labeling reagents for profiling the amine submetabolome by liquid chromatography–mass spectrometry

“…To date, several CIL reagents have been developed to quantify organic amines, carboxylic acids, carbonyl compounds and some other types of metabolites with varying degrees of performance [1,4,5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. These research activities are mainly driven by the need of dealing with different classes of metabolites; a universally applicable derivatization reagent for LC-MS is not available at the present.…”

“…Although the method allows for rapid and accurate quantification of amine-containing metabolites [26][27][28][29], metabolite identification, particularly for unknown metabolites, is a challenge due to the lack of structural information in the MS/MS spectra of dansyl labeled metabolites. Tsukamoto et al developed H 6 -/D 6 -7-(N,Ndimethylaminosulfonyl)-4-(aminoethyl)-piperazino-2,1,3-benzoxadiazole (H 6 -/D 6 -DBD-PZ-NH 2 ) to profile fatty acids in rat plasma samples [8] and Shimbo et al reported the use of p-N,N, N-trimethylammonioanilyl N 0 -hydroxysuccinimidyl carbamate iodide (TAHS) and D 3 -TAHS for amino acid quantification [30]. Because deuterium was used in the labeling reagents, isotopic effect on retention time in RPLC was observed (i.e., H-and D-labeled same metabolite eluted out at different time, thereby subjecting to different matrix effect and ion suppression).…”

LC–MS determination of bioactive molecules based upon stable isotope-coded derivatization method

“…5) [69,70]. The methyl protons of the dimethylamine moiety in the reagents were exchanged for deuterium with methyl iodide-d 3 .…”