Figure 4
Synthesis of L -[14C]galactono-1,4-lactone from L -[1-14C]galactose in courgette fruit exudate. Radiochromatograms obtained from exudate incubated with L-[1-14C]galactose for 30 min at 30°C. The reaction was stopped by the addition of H3PO3 prior to removal of precipitate and analysis by HPLC with online flow scintillation detection. Individual chromatograms show reactions containing L-[1-14C]galactose and heated (100 °C) exudate (A), fresh exudate (B), desalted exudate (C) and desalted exudate with addition of 0.5 mM NAD (D). The elution times of authentic L-[1-14C]galactose (L-Gal), L-[1-14C]galactonolactone (L-GalL) and L-[1-14C]galactonic acid (L-GalA) are shown.