OBJECTIVETo reveal the relationship between the storage time of the bark of Magnolia officinalis and the content of phenols in it, and lay a theoretical foundation for the harvest, processing, management and storage.

METHODThe contents of magnolol and honokoiol in 15 bark samples, collected from the main producing areas in China, were determined in the time of freshly harvest and 3 and 10 years after respectively by HPLC method.

RESULTIt showed that within a certain period of time, bark storage was favorable to conversion and accumulation of phenols, that the content of magnolol tended to increase from year 0 to year 3, then followed by slight decrease with years on account of volatilization of phenols, but was still higher when the bark was stored for 10 years than that that when the bark was freshly harvested, and the content of honokoiol still tended to increase when the bark had been stored for 10 years.

CONCLUSIONThe phenols in bark of M. officinalis is quite stable and the bark can be stored for 10 years or longer.