Phenolic acids and flavonoids from three Jacaranda Juss. (Bignoniaceae) and their acetylcholinesterase inhibitory activity

The genus Jacaranda Juss. (Bignoniaceae) is native to Central and South America and are known to have antioxidant, antimicrobial and anticancer activities. This study aimed to identify phenolic and flavonoid compounds from leaves and twigs of three species of the genus Jacaranda Juss. using HPLC-DAD-MS, ESI-MS and Tandem MS (ESI-MS/MS), as well as to evaluate the inhibitory activity of the extracts on the enzyme acetylcholinesterase. Leaves and twigs of Jacaranda caroba, Jacaranda mimosifolia and Jacaranda oxyphylla were dried and subjected to extraction with hexane, chloroform and methanol to obtain crude extracts. In the methanol extracts, a total of seventeen metabolites (mainly phenolic acids and flavonoids) were found. Methanol extracts from J. caroba and J. oxyphylla twigs showed a pronounced acetylcholinesterase inhibition (IC₅₀= 4.2 and 10.2 µg.mL^-1, respectively). This inhibition activity can be related to phenolic derivatives and flavonoids identified in methanol extracts of Jacaranda species.