MALONDIALDEHYDE AND 4-HYDROXY-2-NONENAL IN PLANT-TISSUE CULTURES - LC-MS DETERMINATION OF 2,4-DINITROPHENYLHYDRAZONE DERIVATIVES

The cytologically active secondary lipid peroxidation products, malond ialdehyde (MDA) and 4-hydroxy-2-nonenal (HNE) have been detected as th eir 2,4-dinitrophenylhydrazone (DNP) derivatives in plant tissue cultu res using LC-MS. This paper reports, for the first time, the use of LC -MS methodology to definitively identify 4-hydroxy-2-nonenal in plants . Limits of detection for the two derivatives are approximately 5pmol (1.2 x 10(-9)g; 1 mu M) and 0.1pmol (3 x 10(-11)g; 20nM) respectively. Mass spectrometer response was linear in the range from 2-200 mu M DN P-MDA and 0.02-10 mu M DNP-HNE. This methodology has been used to asse ss the formation of aldehydic secondary lipid peroxidation products in dedifferentiated callus cultures of Daucus carota. The finding that p rofiles of MDA and HNE can be correlated with embryogenic competence i s of considerable interest as oxidative status has already been implic ated as a regulatory factor in animal development.