Screening of key flavonoids and monoterpenoids for xanthine oxidase inhibitory activity-oriented quality control of Chrysanthemum morifolium Ramat. ‘Boju’ based on spectrum-effect relationship coupled with UPLC-TOF-MS and HS-SPME-GC/MS

This study aimed at obtaining precise quality control standards to efficiently screen Chrysanthemum morifolium Ramat. ‘Boju’ with strong xanthine oxidase (XO) inhibitory activity for developing C. morifolium ‘Boju’ extract based-hypouricemic functional food. The results indicated significant differences in volatile and phenolic profiles and XO inhibitory (XOI) activities of 31 batches of C. morifolium ‘Boju’ collected in herb/tea market. The minority of C. morifolium ‘Boju’ having abundant characteristic monoterpenoids and flavonoid aglycones showed strong XOI activities, while the majority of C. morifolium ‘Boju’ possessing few corresponding monoterpenoids and flavonoid aglycones exhibited moderate XOI activities. Seven XOI activity-directly related phenolics and ten XOI activity-indirectly related volatiles were identified by UPLC-ESI-QTOF/MS-based and HS-SPME-GC/MS-based spectrum-effect relationships, respectively. Three flavonoids (luteolin, apigenin and acacetin) identified as key XO inhibitors and four monoterpenoids (filifolone, α-terpineol, thymol and piperitenone) closely related to key XO inhibitors were screened for XOI activity-oriented quality control of C. morifolium ‘Boju’.