Production of the triterpenoid quassin in callus and cell suspension cultures of Picrasma quassioides Bennett.

Plant cell and suspension cultures have been established from stem cuttings of Picrasma quassioides Bennett. The effect of 244 different types/concentrations of plant growth regulators on growth and quassin accumulation in callus tissue was investigated. Best growth, in terms of wet/dry weight after four weeks growth, was obtained on B5 media supplemented with 2% glucose, 10% coconut milk, 0.5 mg.l(-1) zeatin riboside and 1.5 mg.l(-1) IBA. The highest yields of quassin (0.014-0.018%) were detected on this same media supplemented with 1.0 mg.l(-1) IBA and varying concentrations of zeatin riboside. Suspension cultures were easily established on B5 media supplemented with 2% glucose, 1.0 mg.l(-1) 2,4-D and 0.5 mg.l(-1) kinetin. The carbon source had a marked effect on quassin accumulation with 0.32% quassin being detected when cells were grown in 2% galactose. This is comparable to the highest reported quassin yield for the whole plant.