Neurotrophic sesquiterpene-neolignans from magnolia obovata: structure and neurotrophic activity

Abstract Novel sesquiterpene-neolignans, eudesobovatos A ( 1 ) and B ( 2 ), eudesmagnolol ( 3 ), eudeshonokiols A ( 4 ) and B ( 5 ), clovanemagnolol ( 6 ), and caryolanemagnolol ( 7 ), have been isolated from the bark of Magnolia obovata . Their structures were elucidated to be sesquiterpenes (eudesmol, 4,4,8-trimethyltricyclo [6.3.1.0 2,5 ] dodecane-1,9-diol, and clovanediol) combined through ether bond with neolignans such as obovatol, honokiol, and magnolol on the basis of spectral data, degradation, and/or synthesis. Compounds 1 , 6 , and 7 were found to exhibit interesting neurotrophic activity on a neuronal cell culture system derived from fetal rat hemisphere.