Callus induction and content variation of major active constituents of Magnolia officinalis subsp.biloba
Objective To study the callus induction and the content of active components magnolol and honokiol from Magnolia officinalis subsp.biloba and to find a new way to obtain medicinal ingredients in order to supplement the medicinal resources.Methods Different vegetative organs from different provenances were adopted as explants,and different kinds of plant regulators with different concentration were used to induce the callus.The precursor compounds,L-phenylalanine and D,L,β-phenylalanine,were added into the subculture medium to induce the synthesis of callus; HPLC method was used to detect the total phenolic content ofmagnolol and honokiol in callus obtained through different culturing ways.Results The optimal callus induction medium was: B5 + 6-BA 2.0 mg/L + 2,4-D 1.5 mg/L; The total phenolic content of callus induced from different provenances had a significant difference in the range of 0.004%-0.228%; There was difference of total phenolic content in different regetative organs as explants,the callus cultured from young stems had the highest magnolol and honokiol content of 0.25%; Adding the precursor compound D,L,β-phenylalanine into the subculture medium could effectively improve the total phenolic content of callus by 8-10 times.Conclusion There is little content of magnolol and honokiol in the callus ofM.officinalis subsp.biloba,and the synthesis of total phenolic contents are significantly different in the callus from different provenances and different organs.D,L,β-phenylalanine could effectively improve the synthesis of total phenolic content in callus,and this research has the important significance for sustainable utilization of resources ofM.officinalis subsp.biloba.