Identification of the Anti-oxidants in Flos Chrysanthemi by HPLC-DAD-ESI/MS(n) and HPLC Coupled with a Post-column Derivatisation System

Introduction: Flos Chrysanthemi (Jiju) is a traditional Chinese medicine (TCM) that is known to have anti-oxidant activity; in this study, on-line HPLC-DAD-ESI/MS(n) and HPLC-DAD-DPPH methods have been developed for rapidly screening and identifying free-radical scavengers in Jiju extract.

Objective: To develop an efficient method for the simultaneous identification and detection of the anti-oxidant components in Flos Chrysanthemi (Jiju).

Methodology: A concentrated methanol extract of Flos Chrysanthemi from Jiaxiang County (Jiju) was first separated into phases soluble in water, petroleum ether and n-butanol. The off-line 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging method was then used to evaluate the anti-oxidant activity of each phase in vitro. The results showed that the n-butanol extract had the highest anti-oxidant activity, and its anti-oxidant compounds were analysed by HPLC-DAD-ESI/MS(n) and HPLC coupled with a post-column derivatisation (PCD) system supplied with DPPH, aluminium chloride or sodium acetate solutions.

Results: A total of 17 compounds were separated and identified, three of which were identified in Jiju for the first time, and seven active compounds serve as the chemical basis of the anti-oxidant efficacy of Jiju.

Conclusion: The methods described here allow rapid separation and convenient identification of the multiple constituents in Jiju, and may be applied to other complex natural matrices.