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 ’.