Protective effect of the ethanol extract of Magnolia officinalis and 4-O-methylhonokiol on scopolamine-induced memory impairment and the inhibition of acetylcholinesterase activity - Lee, Y K; Yuk, D Y; Kim, T I; Kim, Y H; Kim, K T; Kim, K H; Lee, B J; Nam, S Y; Hong, J T (J Nat Med, 2009)