It is found in the bark of Magnolia grandiflora[1] and in M. virginiana flowers.

[3] 4-O-Methylhonokiol further attenuates memory impairment in presenilin 2 mutant mice through reduction of oxidative damage and inactivation of astrocytes and the ERK pathway.

[4] The different neuroprotective effects reported in rodent models may be mediated via CB2 receptors.

[5] 4-O-Methylhonokiol activates CB2 receptors and also inhibits the oxygenation of the major endocannabinoid 2-AG via COX-2 in a substrate-selective manner, thus leading to potential synergistic effects at CB receptors.

[6] The same study also provided data that 4-O-methylhonokiol can readily pass the blood–brain barrier.