Production of the sedative triterpene galphimine B in Galphimia glauca tissue culture

A tissue culture method is described for callus formation from Galphimia gl auca (Mapighiaceae) in MS (Murashige & Skoog) medium supplemented with vari ous growth regulators. Best induction was achieved when using hypocotyls as explants in medium supplemented with 2 mg/l of 2,4-dichlorophenoxyacetic a cid (2,4-D). Major cellular growth of calluses was obtained with naphthalen eacetic acid (Z mg/l) + kinetin (1 mg/l), Subcultivation of calluses using various concentrations of 2,4-D allowed the production of the sedative nor- seco-triterpenoid, galphimine B and a new related compound. The structure o f the new constituent was elucidated as 6-acetoxygalphimine B. The highest accumulation of active constituent 1 (1.5 x 10(-2) dry weight) was achieved when 4 mg/l of the hormone were used, and this experimental condition allo wed the detection of only galphimine B. A preliminary screening of the meth anolic extracts prepared from calluses, using the isolated guinea-pig ileum as a general test system for pharmacological effects, demonstrated that th e most active material was the one with the highest concentration of galphi mine B. Total accumulation of this sedative triterpene, in the optimized ti ssue culture conditions, was in the same order of magnitude as the value qu antified for wild plants (4.5 x 10(-2) dry weight).