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Exploring processing chemistry, in particular the chemical transformation mechanisms involved, is a key step to elucidate the scientific basis in traditional processing of herbal medicines. Previously, taking Rehmanniae Radix (RR) as a case study, the holistic chemome (secondary metabolome and glycome) difference between raw and processed RR was revealed by integrating hyphenated chromatographic techniques-based targeted glycomics and untargeted metabolomics. Nevertheless, the complex chemical transformation mechanisms underpinning the holistic chemome variation in RR processing remain to be extensively clarified. As a continuous study, here a novel strategy by combining chemomics-based marker compounds mining and mimetic processing is proposed for further exploring the chemical mechanisms involved in herbal processing. First, the differential marker compounds between raw and processed herbs were rapidly discovered by untargeted chemomics-based mining approach through multivariate statistical analysis of the chemome data obtained by integrated metabolomics and glycomics analysis. Second, the marker compounds were mimetically processed under the simulated physicochemical conditions as in the herb processing, and the final reaction products were chemically characterized by targeted chemomics-based mining approach. Third, the main chemical transformation mechanisms involved were clarified by linking up the original marker compounds and their mimetic processing products. Using this strategy, a set of differential marker compounds including saccharides, glycosides and furfurals in raw and processed RR was rapidly found, and the major chemical mechanisms involved in RR processing were elucidated as stepwise transformations of saccharides (polysaccharides, oligosaccharides and monosaccharides) and glycosides (iridoid glycosides and phenethylalcohol glycosides) into furfurals (glycosylated/non-glycosylated hydroxymethylfurfurals) by deglycosylation and/or dehydration. The research deliverables indicated that the proposed strategy could advance the understanding of RR processing chemistry, and therefore may be considered a promising approach for delving into the scientific basis in traditional processing of herbal medicines., (Copyright © 2017 Elsevier B.V. All rights reserved.)

It is well-recognized that multiple components, the majority of which are secondary metabolites and carbohydrates, collectively contribute to the therapeutic effects of herbal medicines. The chemical characterization of herbal medicines has focused extensively on secondary metabolites but has largely overlooked carbohydrates. Here, we proposed an integrated chromatographic technique based targeted glycomics and untargeted metabolomics strategy simultaneously determining carbohydrates and secondary metabolites for the overall chemical profiling of herbal medicines; this strategy was successfully exemplified in an investigation of processing chemistry of Rehmanniae Radix (RR), a Chinese medicinal herb. It was demonstrated that the integrated strategy holistically illuminated the variations in the glycome and metabolome of RR samples processed by the traditionally-adopted nine cycles of steaming and drying, and further elucidated the processing-induced chemical transformation mechanisms of carbohydrates and secondary metabolites, and thereby revealed the inherent chemical connections between carbohydrates and secondary metabolites. The result suggested that the proposed strategy meets the technical demands for the overall chemical characterization of herbal medicines, and therefore could serve as a powerful tool for deciphering the scientific basis of herbal medicines. [ABSTRACT FROM AUTHOR]

Si-Jun-Zi decoction (SJZD) with ginseng as the principal medicinal herb is a traditional Chinese Medicine multi-herb prescription that commonly employed to treat colorectal cancer etc. Previous studies showed that nearly half of the commercial ginseng was sulfur-fumigated, one of the postharvest processing methods that commonly causes sulfur-dioxide (SO 2) residue and chemical composition transformation in medical herbs. In this study, the effect of sulfur-fumigated ginseng on global quality of SJZD was evaluated by UPLC-QTOF-MS/MS based metabolomics and multiple chromatographic techniques based glycomics strategies. For non-saccharides components, sulfur-fumigated ginseng led to the emergence of sulfur-containing derivatives and alteration of saponins and flavonoids in SJZD. For saccharide components, sulfur-fumigated ginseng decreased the total contents and molecular weights of polysaccharides, changed the monosaccharide composition of polysaccharides, and increased the contents of oligosaccharides and free monosaccharides of SJZD. The alterations of SJZD were aggravated with the sulfur-fumigated content of ginseng. Those phenomena might be attributed to 1) sulfur-fumigation caused the generation of sulfur-containing derivatives in ginseng, which further transferred to SJZD, and 2) sulfur-fumigation caused the residue of SO 2 in ginseng, which reduced the pH value and further changed the dissolution of saponins and flavonoids and accelerated the degradation of the polysaccharides to oligosaccharides and/or monosaccharides in SJZD. Furthermore, although storage reduced the SO 2 residue in sulfur-fumigated ginseng, it couldn't recover the alterations of chemical profiles in SJZD. In conclusion, sulfur-fumigated ginseng altered the global quality of SJZD, which promoted that extra attention must be paid during the application of herbal formulas that containing sulfur-fumigated herbs. • Sulfur-fumigated ginseng affected the chemical profiles of Sijunzi decoction (SJZD). • The evaluations were assessed by metabolomics and glycomics strategies. • Non-saccharide and saccharide components in SJZD were altered by fumigated ginseng. • Ginseng in high-extent fumigation showed more serious effect on SJZD. • Storage reduced SO 2 residue but not recovered changes of fumigated ginseng on SJZD. [ABSTRACT FROM AUTHOR]