Effects of Culture Conditions on Bisbenzylisoquinoline Alkaloid Production in Cultured Roots of Stephania cepharantha

Abstract

Bisbenzylisoquinoline alkaloid production was studied in roots of Stephania cepharantha (Menispermaceae). Various cultural conditions influenced alkaloid production. Low concentrations of gibberellin suppressed browning of the cultured roots, and stimulated their growth and the production of bisbenzylisoquinoline alkaloids. Reducing the major element concentration of B5 medium by half increased root growth and alkaloid content. Elimination of the ammonium sulfate from B5 medium also increased the root alkaloid content, but it decreased growth as well. The optimal sucrose concentration was 3%. Cytokinin did not promote alkaloid production. As a result of these investigations, a modified B5 medium (SB5 medium) was developed for the production of bisbenzylisoquinoline alkaloids by cultured roots of S. cepharantha. The cultured roots grew well in this medium, with about a 20-fold dry weight increase in 30 days. The aromoline content in cultured roots was more than 1% and berbamine content more than 0.5% of the dry wt. The alkaloid levels of these cultured roots are much higher than those of the plants.