Metabolomic analysis of the pharmacological active substances in four ginger varieties

Background: The bioactive compounds of ginger (Zingiber officinale), including gingerols, diarylheptanoids, and flavonoids, are important for human health because of their anticancer, anti-oxidant, and anti-inflammatory properties. Results: The UPLC/Q-TOF-MS profiles of four ginger samples, Zingiber officinale 'Yujiang No.1' (YJ), Zingiber officinale 'Shandong dajiang' (SD), Zingiber officinale 'Shandong xiaojiang' (SX) and Zingiber officinale 'Luoping xiaohuangjiang' (LP) were compared to gain insight into the differences in their rhizome content. A total of 1,810 metabolites were detected across the four varieties with 111, 72, 57, and 92 metabolites shared between the LP/YJ, SX/YJ, SX/SD and LP/SD ginger samples, respectively, with a p value of < 0.05 and a fold change of ≥1. Among the four libraries, 186 differentially expressed metabolites were identified. The metabolic pathways associated with the production of the bioactive compounds of ginger included those for stilbenoid, diarylheptanoid, and gingerol biosynthesis, flavonoid biosynthesis, steroid hormone biosynthesis, and diterpenoid biosynthesis. Among the differentially accumulated metabolites, gingerols and α-zingiberene were found in higher amounts in the SD and LP than in the SX and YJ varieties. The steroid hormones and terpenoids were found in higher amounts in LP than the other ginger samples. Conclusion: The LP and SD varieties could be utilized as a source of medicinal ginger, while SX and YJ are more suited to incorporation into food because of their lighter taste related to their lower content of gingerols. The differences in active ingredients combined with analysis of the KEGG pathway allowed prediction of the metabolite synthetic pathways involved in the ginger component biosynthesis and lays the foundation for the further development and use of specific ginger varieties as medicinal resources.