Chemical Characterization and Quality Evaluation of Forsythia suspensa Flowers Based on HS-GC-MS, UPLC-QTOF-MS and HPLC-DAD Analysis

Forsythia suspensa is a medicinal and edible shrub, whose fruit is a commonly used herbal medicine. Forsythia suspensa flowers (FFs) exhibit significant edible and medicinal potential, but research on the chemical composition and quality evaluation remain limited. In this study, HS-GC-MS, UPLC-QTOF-MS and HPLC-DAD were combined for the chemical characterization and quality evaluation of FFs. HS-GC-MS was used to characterize volatile components and build fingerprints of FFs. UPLC-QTOF-MS was applied for qualitative analysis of non-volatile constituents, and the HPLC fingerprint was established to assess the consistency of FF samples. A validated HPLC-DAD method was adopted for determination of seven non-volatile components (chlorogenic acid, rutin, forsythoside A, (+)-pinoresinol-4-O-β-D-glucopyranoside, phillyrin, quercetin and phillygenin) in FF samples. Forty-four volatile and thirty-two non-volatile compounds were characterized. HS-GC-MS and HPLC fingerprints of FF were established, and fifteen volatile and seven non-volatile constituents were identified as common peaks. The established GC-MS and HPLC fingerprint method had good specificity and could be used for the quality evaluation of FF. Chemometric based on quantitative results showed significant differences in non-volatile constituents in FF samples from different producing regions. This work provided a reliable method and useful information for the chemical characterization and quality evaluation of FF. Further research will focus on biological activities of FF and its active components, laying a foundation for its application in pharmaceutical and food industries.