TY  - JOUR
A1  - Lüth, Anja
A1  - Neuber, Corinna
A1  - Kleuser, Burkhard
T1  - Novel methods for the quantification of (2E)-hexadecenal by liquid chromatography with detection by either ESI QTOF tandem mass spectrometry or fluorescence measurement
T2  - Analytica chimica acta : an international journal devoted to all branches of analytical chemistry
N2  - Sphingosine-1-phosphate lyase (SPL) is the only known enzyme that irreversibly cleaves sphingosine-1-phosphate (S1P) into phosphoethanolamine and (2E)-hexadecenal during the final step of sphingolipid catabolism. Because S1P is involved in a wide range of physiological and diseased processes, determining the activity of the degrading enzyme is of great interest. Therefore, we developed two procedures based on liquid chromatography (LC) for analysing (2E)-hexadecenal, which is one of the two S1P degradation products. After separation, two different quantification methods were performed, tandem mass spectrometry (MS) and fluorescence detection. However, (2E)-hexadecenal as a long-chain aldehyde is not ionisable by electrospray ionisation (ESI) for MS quantification and has an insufficient number of corresponding double bonds for fluorescence detection. Therefore, we investigated 2-diphenylacetyl-1,3-indandione-1-hydrazone (DAIH) as a derivatisation reagent. DAIH transforms the aldehyde into an ionisable and fluorescent analogue for quantitative analysis. Our conditions were optimised to obtain the outstanding limit of detection (LOD) of 1 fmol per sample (30 mu L) for LC-MS/MS and 0.75 pmol per sample (200 mu l) for LC determination with fluorescence detection. We developed an extraction procedure to separate and concentrate (2E)-hexadecenal from biological samples for these measurements. To confirm our new methods, we analysed the (2E)-hexadecenal level of different cell lines and human plasma for the first time ever. Furthermore, we treated HT-29 cells with different concentrations of 4-deoxypyridoxine (DOP), which competitively inhibits pyridoxal-5-phosphate (P5P), an essential cofactor for SPL activity, and observed a significant decrease in (2E)-hexadecenal relative to the untreated cells.
KW  - (2E)-Hexadecenal
KW  - Sphingosine-1-phosphate lyase
KW  - Derivatisation
KW  - Tandem mass spectrometry
KW  - Fluorescence
Y1  - 2012
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35969
SN  - 0003-2670
VL  - 722
SP  - 70
EP  - 79
PB  - Elsevier
CY  - Amsterdam
ER  -