Chemical constituents and bioactivities of the essential oils of Magnolia biondii flower buds from three provinces in China

Magnolia biondii flower buds are a well-known medicinal plant in China, and it is important to determine the differences in aroma, flavour components, and biological activity of the essential oils of M. biondii flower buds (EOM) from different origins. In this study, the essential oils of M. biondii flower buds from Sichuan (EOM-SC), Anhui (EOM-AH) and Henan (EOM-HN) provinces were extracted by hydrodistillation. The condition of the extraction process was optimized. The differences in the flavour compounds were further confirmed by GC-MS and relative odour activity value (ROAV) analyses. In addition, the antibacterial and antioxidant activity was also evaluated. The results showed that the optimized condition for steam distillation was water: flower powder ratio = 10:1 with extraction time for more than 3.0 h. Interestingly, special floral, fruity and freshness flavours were found for EOM-SC, and the medicinal herb and sweetness odours of EOM-HN were more prominent. The numbers and contents of flavour compounds in EOM-SC and EOM-HN were higher than those of EOM-AH. Eucalyptol, beta-pinene, linalool, alpha-terpineol and sabinene could be proposed as the key mutual flavour compounds for three essential oils. In addition, the strong floral, fruity and freshness aroma of EOM-SC could be associated with the high ROAVs of alpha-terpineol, linalool and sabinene. Moreover, EOM-SC exhibited better antibacterial and antioxidant activity than those of the other two essential oils.