Fingerprint and Identification of Chemical Constituents of the Extract of Fructus Ligustri Lucidi-Ecliptae Herba

  OBJECTIVE  To establish high performance liquid chromatography (HPLC) fingerprints of the extract of Fructus Ligustri Lucidi-Ecliptae Herba and to identify the structure of its chemical constituents.

  METHODS  The chromatographic separation was performed on ZORBAX Extend C₁₈ (250 mm×4.6 mm, 5 μm) column with the mobile phase consisting of acetonitrile and 0.1% formic acid solution in gradient elution mode at a flow rate of 1.0 mL·min^-1. The optimum column temperature was set at 35 ℃, the detection wavelength was 265 nm, and the injection volume was 10 μL. The HPLC fingerprints of 15 batches of herb pair from different origins were established. Then, similarity evaluation, cluster analysis, and orthogonal partial least squares discriminant analysis were carried out. The chemical structures of the constituents of the herb pair were identified based on the high-resolution mass spectrometry utilizing the UPLC-Q-Exactive Orbitrap MS in positive and negative-ion modes.

  RESULTS  As a result, the similarity of the 15 batches of samples varied from 0.865 to 0.992. A total of 16 common peaks were identified in the fingerprints, and 7 of them were identified by comparision with the reference substances. Furthermore, 55 chemical compounds were detected, and 7 of them were accurately identified based on the reference substances, and the chemical structures of the rest 48 components were temporarily speculated.

  CONCLUSION  The fingerprint method established in this study is simple, reliable, and reproducible, and can be further used for the quality control of Fructus Ligustri Lucidi-Ecliptae Herba herb pair. The developed UPLC-Q-Exactive Orbitrap MS method can be applied to identify the structures of chemical constituents in this herb pair and lay a foundation for further research.