Promotion of indole alkaloid production in Catharanthus roseus cell cultures by rare earth elements

Production of the indole alkaloids, ajmalicine or catharanthine, in cell suspension cultures of Catharanthus roseus was enhanced by cerium (CeO2 and CeCl3), yttrium (Y2O3) and neodymium (NdCl3). The yield of ajmalicine in these treated-cultures reached 51 mg l(-1) (CeO2), 40 mg l(-1) (CeCl3), 41 mg l(-1) (Y2O3) and 49 mg l(-1) (NdCl3) while catharanthine production reached to 36 mg l(-1) (CeO2) and 31 mg l(-1) (CeCl3). A major portion of increased alkaloids was released into medium in these treatments. But Sm2O3, SmCl3, La2O3, LaCl3, complex of chromium (III)-titanium (IV) and NaSeO4 treatments had little effect on alkaloid production of C. roseus cell cultures.