Introduction – S-adenosyl-L-methionine (SAM) plays an important role in many biochemical reactions in plants. It is mainly
used as a methyl donor for methylation reactions, but it also participates in, for example, the biosynthesis of polyamines and
the plant hormone ethylene.
Objective – To develop a fast capillary electrophoresis technique to separate SAM in fruits and fruit juices without any prepurification
Methodology – Four different extraction solutions and two extraction timeswere tested, ofwhich5%trichloroacetic acid (TCA)
for 10 minwas found most suited. A glycine : phosphate buffer (200 : 50 mM, pH 2.5)was found optimal to analyse SAM in TCA
extracts. Analyseswere preformed on different climacteric and non-climacteric fruits and fruit juices. The calibration curvewas
created in degraded tomato extract. The CE-method was compared with a more conventional HPLC method described in
Results – The CE technique made it possible to completely separate the S,S- and R,S-diastereoisomeric forms of SAM. The CE
method proved to be very fast (20 min total running time instead of 42 min) and more sensitive (limit of detection of 0.5 mM
instead of 1 mM) compared with the conventional HPLC method.
Conclusion – Fast measurements of SAM in fruits and juices are favoured by capillary electrophoresis in a 200 : 50 mM
glycine : phosphate (pH 2.5) buffer system.