[A study on the relationship between tree age and bark quality in Magnolia officinalis].

Contents of magnolol and honokiol in 76 samples of Magnolia officinalis collected from 11 counties in Zhejiang, Fujian, Sichuan, Guangxi, Hunan, Jiangxi and Hubei are analyzed by means of HPLC. A study on the effect of tree age on effective ingredients in Magnolia offcinalis shows that the influence of tree age on the content of magnolol and honokiol is correlated with the varieties under cultivation, but a small effect on the content of the phenols with an indent at the tip of leaves. The content of magnolol in other types of leaves increases rapidly with increase in age, diameter of the trunk and thickness of the bark, with not many changes found at the age of 12 or up. Increase in age may be favorable to the full expression of oily characteristic. These results provide a scientific base for the determination of optimal time for harvesting bark from artificially established Magnolia officinalis stands.