Analysis of polyacetylenes by HPLC in hairy root cultures of Lobelia inflata cultivated in bioreactor

Lobelia inflato L. contains pharmacologically important secondary metabolites. The main alkaloid is lobeline which has a stimulatory effect on the respiratory centre. Recently high quantity of polyacetylenes was determined in the plant and hairy root cultures. With the aim of increasing of the secondary metabolite production hairy root cultures were produced (by direct infection of the sterile plants with Agrobacterium rhizogenes strain R1601). A new HPLC method was developed for the determination of lobetyolin and lobetyolinin, the main polyacetylene compounds of L. inflata hairy roots. The analysis was performed on Hypersil MOS column (250 x 4 mm I.D.). The mobile phase was 15:85 (v/v) mixture of acetonitrile and water. Peaks were identified by addition of standards and by DAD. The external standardized method allowed the determination of lobetyolin and lobetyolinin with good sensitivity and reliability. This method was used to measure the polyacetylene contents of hairy roots grew intensively in bioreactor. High contents of lobetyolin (3.6%) and lobetyolinin (0.8-1.6%) were detected in the hairy roots because of their great biosynthetic capacity.