An integrated strategy of secondary metabolomics and glycomics to investigate multi-component variations in wine-processing of medicinal herbs and functional foods: A case study on Fructus Corni

Fructus Corni (FC), as a promising Chinese medicinal herb, has aroused considerable interest. Generally, FC needs to be processed according to the limited standard policy in China before clinical application, while the investigations on the specific processing methods (such as wine steaming or high-pressure wine steaming) are unclear. A comprehensive metabolomics strategy based on integrated non-targeted metabolomics and targeted glycomics in this paper was implemented to investigate the influences of the different processing technologies such as steaming, wine steaming, high-pressure steaming, high-pressure wine steaming, wine immersion, and wine stir-frying on FC, respectively. UHPLC-Q-TOF-MS/MS was employed for identifying and distinguishing the secondary metabolites. A total of 85 components were identified in all groups. The results of PCA score plots showed that the crude and processed samples had a complete separation, and wine steamed and high-pressure wine steamed samples could be a category, indicating that the two processed products had a similar quality. Multiple chromatography including HPLC (C18)-PDA, HPLC (NH2)-ELSD, and HPGPC-ELSD was used for determining the molecular weight distributions, the monosaccharide compositions of polysaccharides, and the contents of free monosaccharides and oligosaccharides. The results indicated that the content and composition of saccharides were different in crude and different processed FC. The polysaccharides were composed of fucose, arabinose, galactose, glucose, galacturonic acid, mannose and rhamnose, and the free monosaccharides were composed of fucose, arabinose, galactose, glucose, mannose, rhamnose and fructose in all FC samples. The PCA score plots of the glycomics indicated that the crude and high-pressure wine steamed FC could be a category, showing that the two groups had similar chemical compositions. Ultimately, the simulation processing experiments indicated that the transformation of morroniside, polysaccharides, oligosaccharides, fructose, and glucose to 5-HMF through the reactions of dehydration and deglycosylation was the potential mechanism of enhancing the effects by processing. Conclusionly, the saccharides should be investigated as thoroughly as the secondary metabolites, and the high-pressure wine steamed FC could be an alternative to wine steamed FC.