Abstract:In order to excavate the development and utilization potential of Michelia champaca leaves, the bioactivity and chemical composition of ethanol extract from leaves obtained by ultrasonic extraction were studied. The results showed that 20% and 80% ethanol extracts had antioxidant potential ability by using DPPH∙ free radical scavenging assay and reducing power of iron ion. There was cytotoxicity to HacaT cells, when the concentration of 20% or 80% extracts was more than 12.5 or 6.25 μg/mL, respectively. A total of 206 compounds were obtained from ethanol extract from M. champaca leaves by UPLC-MS combined with software spectrum library, including flavonoids, alkaloids, fatty acids, alcohols and so on. Among the flavonoids, rutin, quercetin and kaempferol could be identified clearly by standard product verification. The contents of compounds in ethanol extracts of M. champaca leaves were different among different months, and the distribution of components in spring and summer were significantly different from that in autumn and winter. Besides, some compositions had seasonal characteristics. In conclusion, Michelia champaca leaves had potential in the development of daily chemical products, and the harvest time could be selected according to the actual composition.