Objective: To study the effect of several factors on the quantity of hypericin in H. perforatum callus.
Method: High efficiency liquid phase chromatography and plant tissue culture were applied.
Result and conclusion: When the ratio of nitro-nitrogen to amina-nitrogen is 3:1, the callus biomass is 1.6-fold and the synthetic mass of hypericin rises. 0.1-0.20 mg x L(-1) mannose improves the content of total hypericin. The addition of PVP or PVPP can promote improvement of the growth and biosynthesis of callus.