| Six calli were induced from explants of Camptotheca acuminata, including root, stem and leaf. Two isocamptothecins (ICPT), named ICPTA and ICPTB, were discovered in the cultures of four of these calli through HPLC and MS analysis. Both ICPTA and ICPTB were confirmed to be new compounds of CPT family, which are effective anticancer compounds with lower toxicity to normal cells. The callus suitable for suspension cultures was established by means of manipulating the ratio of phytohormone in MS medium. The concentrations of 0.15 mg 1-1 2, 4-D and 0.6 mg 1-1 BA were validated to be the optimal recipe for cell growth, morphological development and accumulations of ICPTA and ICPTB. The cell aggregates with a size range of 2-4 mm were developed during cultivations.The time-courses of nutrient uptaking, cell growth and accumulations of ICPTA and ICPTB were investigated through flask batch cultivations. The maximum biomass concentration of 18.37 g 1-1 was achieved in which the contents of ICPTA and ICPTB were measured to be 3.67% and 1.33%, respectively. It was found that both inoculum density and age exerted their effects on cell growth profiles. The intracellular phosphate content was validated to be a good indicator of cell age. Kinetic models for substrate uptaking, cell growth and accumulations of ICPTA and ICPTB were developed and the corresponding model parameters were evaluated.Systemic acquired resistance for C. acuminata cells could be induced by adding salicylic acid (SA) into medium, through which the manipulation of biosynthesis of ICPTA and ICPTB was realized. The experimental results showed the volumetric productivities of ICPTA and ICPTB increased to 0.509 g 1-1 and 0.194 g 1-1, respectively, when 1 mg 1-1 SA was added in the 9th day. Meanwhile, the effect of rare earth La~3+ was also investigated. The volumetric productivities of 0.616 g 1-1 for ICPTA and 0.231 g 1-1 for ICPTB were achieved when 20 u M rare earth La~3+...
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