Study on the effects of sulfur fumigation on chemical constituents and antioxidant activity of Chrysanthemum morifolium cv. Hang-ju

The traditional after-harvesting drying method of C. morifolium cv. Hang-ju (HJ) is sun drying, but recently sulfur fumigation is increasingly used as a cheap and convenient method. However, the effects of sulfur fumigation on chemical constituents and potential activities of HJ were unknown. A comprehensively comparison of the chemical profiles between non-fumigated HJ (NHJ) and sulfur-fumigated HJ (SHJ) was conducted by HPLC fingerprints analysis and the discrepant peaks were identified or tentatively assigned by HPLC-ESI/MS(n). Dramatic chemical changes were found that the contents of 4 flavonoid aglycones remarkably increased while those of 7 glycosides significantly reduced which suggested that sulfur-fumigation induced flavonoid glycosides transformed into aglycons by hydrolysis reaction. A significant loss of hydroxycinnamoylquinic acids showed the sulfur fumigation was a destructive effect on HJ. Principal component analysis (PCA) was employed to rapidly discriminate NHJ and SHJ samples. By ICP-OES analysis, it was found that the residue of sulfur of SHJ were three times higher than NHJ (p<0.05). The antioxidant activity of NHJ and SHJ were evaluated by DPPH and FRAP assay, and the results showed that NHJ had much stronger antioxidant activities than SCF (p<0.05). Combining the results of chemical analysis, residue of sulfur and pharmacological evaluation, it showed that the sulfur fumigation was a destructive effect on HJ.