Abstract:

The contents of 1-deoxynojirimycin (DNJ) in the fruits of black mulberry (Morus nigra L.) were measured using
ultra performance liquid chromatography (UP LC). Dried fruits were pulverized and extracted with 0.05 mol/L HCl, and then
incubated with 9-fluorenylmethyl chloroformate (FMOC-Cl) in pH 8.5 borate buffer to produce the complex DNJ-FMOC.
The concentration of DNJ-FMOC was detected by UP LC coupled with UV detector. A CORTECSTM C18 column was used
and the column temperature was kept at 28 ℃. The mobile phase was acetonitrile-0.5% acetic acid solution (28:72, V/V) with
a flow rate of 0.6 mL/min. The UV detection wavelength was 254 nm. The results indicated that DNJ was separated well
with a linearity ranging from 0.5 to 20 μg/mL. The limit of detection (LOD) was 0.1 μg/mL and the correlation coefficient (r)
between the peak area of DNJ-FMOC and DNJ concentration was 0.999 970 and the average recovery from spiked samples
was 106.4%. The tests for precision, stability, reproducibility and recovery rate showed that the method was stable and
reliable, and could be used as an effective method for the determination of DNJ content in black mulberry fruits.

Key words: Morus nigra L., 1-deoxynojirimycin, ultra performance liquid chromatography, UV detection