INFLUENCE OF PRECURSORS ON PRODUCTION OF ISOQUINOLINE ALKALOIDS IN TISSUE-CULTURES OF CEPHAELIS-IPECACUANHA

The exogenous feeding of precursors e.g. shikimic acid and L-phenylala nine (50 mg l-1) influenced the overall bioproduction of cephaeline in callus cultures of Cephaelis ipecacuanha. The concentration of cephae line was practically doubled in the medium (0.109% mg) and callus (0.0 35% mg) following supplementation with shikimic acid (50 mg l-1). Like wise the addition Of L-phenylalanine (50 mg l-1) also enhanced cephael ine production both in the medium (0.075% mg) and callus (0.003%). How ever, neither shikimic acid nor phenylalanine had any real effect on e metine production. The exogenous feeding of L-phenylalanine (50 mg l-1 ) and shikimic acid (50 mg l-1) to suspension cultures of C. ipecacuan ha influenced bioproduction of cephaeline, which was detected in appre ciable quantities only in the medium, while the biosynthesis of emetin e remained unaffected. The cephaeline content was increased to 0.129% mg from 0.076% mg in control cultures on treatment with shikimic acid (50 mg l-1), while phenylalanine enhanced bioproduction up to 0.13% mg . The supplementation of L-phenylalanine and shikimic acid to immobili zed cell cultures significantly influenced bioproduction of cephaeline to the extent of 1.068% and 1.093% mg, respectively, over the control cultures (0.585% mg). Both precursors failed to influence emetine pro duction in callus, cell and immobilized cultures of Cephaelis ipecacua nha.