We recently found that ethanolic extracts of Chinese M. officinalis were composed of magnolol (1.25%),
honokiol (1.81%) and 4-O-methylhonokiol (1.24%) (Lee et al., 2009e). These quantitative and qualitative differences of components from Magnolia bark are proposed to be due to studying different Magnolia species, different extracting solvents and different analytic methods or different growing areas. For example, obovatol was extracted from M. obovata but not from M. officinalis (Table 1).