Hydrochloric Acid → Limonin

Participants

Reaction Conditions

Reaction Steps

In particular, aqueous solutions of limonin-17-β-D-glucopyranoside (0.35 mg/L) adjusted to pH value of 2.0, 3.0, and 3.5, respectively, by adding trace amounts of hydrochloric acid (1 mol/L) were maintained at different temperatures (4, 20, 30° C.) for up to 14 weeks in closed vials in the dark. At regular time intervals, samples (5 μL) were withdrawn with a syringe and were analyzed for the generation of limonin by means of LC-MS/MS on a Synergi Fusion, 150×2 mm i.d., 4 μm column (Phenomenex). To achieve this, chromatography was performed with a flow rate of 250 μL/min starting with a mixture (80/20, v/v) of 0.1% aqueous formic acid and acetonitrile, increasing the acetonitrile content to 40% within 10 min, then to 80% within 5 min, held for 5 min, and, finally, to 100% within 5 min. Using negative electrospray ionization, limonin was analyzed in the multiple reaction monitoring (MRM) mode using the mass transition m/z 469→229. Quantitative analysis was performed by comparing the peak areas obtained for the mass trace with those of defined standard solutions of limonin in methanol.

Provenance & Evidence