Qualitative analysis on chemical constituents from different polarity extracted fractions of the pulp and peel of ginger rhizomes by ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Rationale: Ginger pulp is the dried rhizome scraped off the skin which originates from Zingiber officinale Rosc., a Zingiberaceae plant. Ginger peel is the dried rhizome skin of Zingiber officinale Rosc. (Zingiberaceae). The present work aims to investigate the different chemical constituents that are related to the medicinal properties of the ginger pulp and ginger peel.

Methods: A rapid ultra-high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-QTOF/MS) method was developed for qualitative analysis of the constituents in different polarity extracted fractions of the pulp and peel of ginger rhizomes.

Results: A total of 83 compounds were identified from the pulp and peel of ginger rhizomes, including 36 diarylheptanoids, 25 gingerols and 22 other compounds. Nine of these were new compounds. In total, 46, 27, 65 and 51 compounds were identified from the crude extract, petroleum ether, ethyl acetate, and n-butanol fractions of the ginger pulp, respectively, and 60, 30, 70 and 62 compounds were identified from the crude extract, petroleum ether, ethyl acetate, n-butanol fractions of the ginger peel, respectively. Each identified compound is marked on the corresponding chromatogram.

Conclusions: The integrated method is sensitive and reliable for searching the different chemical constituents from different polarity extracted fractions of the ginger pulp and ginger peel. This work may provide a significant contribution to research into the medicinal properties of the ginger pulp and ginger peel.