Deuterated abscisic acid analogs for mass spectrometry and metabolism studies

Four analogs of abscisic acid (ABA) with deuterium atoms at non-exchangeable positions have been synthesized to be used as standards for quantitation of the plant hormone ABA by mass spectrometry and also to be employed as substrates for metabolism studies. Deuterium atoms were introduced in the side chain of the molecule, at C-4 and/or C-5, by deuteride or hydride reduction of a propargylic alcohol, an intermediate in the synthesis. As well, deuterium labels were introduced at the C-8' position by conjugate addition of a Grignard reagent containing the label to a cyclohexadienone intermediate, affording specific isotopically labeled ABA molecules with one to five deuterium atoms. Copyright (C) 2002 John Wiley Sons, Ltd.