Effects of sulfur fumigation and heating desulfurization on quality of medicinal herbs evaluated by metabolomics and glycomics: Codonopsis Radix, a pilot study

Sulfur fumigation and heating desulfurization are used together in the post-harvest processing of many medicinal herbs. However, little is known about the effects of sulfur fumigation on saccharide components, nor about the effects of heating desulfurization on all herbal constituents. In this study, metabolomics and glycomics were integrated to investigate the effects of these two processes on the chemistry of Codonopsis Radix (CR) as a pilot study. The results showed that both sulfur fumigation and heating desulfurization significantly changed the non-saccharide small-molecule metabolome and the glycome of CR in different ways. Chemical mechanisms, such as esterification, glycosidic hydrolysis, esterolysis, amide bond hydrolysis, oxidation and dehydration, are proposed to be involved. These facts strongly inspire that, in addition to investigations of how sulfur fumigation impacts non-saccharide small-molecule metabolites, researches on heating desulfurization and saccharides should be conducted so as to enable accurate, comprehensive evaluation of the quality of sulfur-fumigated herbs.