Abstract
Gagaminine, a steroidal alkaloid isolated from the roots of Cynanchum wilfordii, exhibited potent inhibitory effects on aldehyde oxidase activity and lipid peroxidation. To determine whether it would be possible to mass produce this active component, which would be useful for animal tests, we tried to synthesize it using in vitro cell culture methods with various growth conditions. In a previous study it was found that calli were easily induced from the stem of this medicinal plant and cultivated effectively on MS medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) 2 mg/l. In this work we attempted to determine the effects of various culture conditions on cell growth and gagaminine synthesis in suspension culture. Gagaminine production was increased markedly when cell growth proceeded to the death phase. Cell growth was more effective with 5% (v/v) sucrose, in the light (at 38 μE/m2 · s), on medium containing 2,4-D 2 mg/l, with 2.5 g/10 ml medium as the initial cell concentration. The concentration of gagaminine was optimal with 3% sucrose, in darkness on medium 2,4-D 1 mg/l, with 2.5 g/10 ml medium as an initial cell concentration. However, the highest growth rate was 0.18 d−1, when the gagaminine concentration was seven- and three-fold (at 140 μ/ml) that of the plant stem and 10 ml of medium respectively, on the 50 ml of medium in suspension culture.
