Study On The Biotransformation Of Artemisinic Acid And Dihydroartemisinic Acid By Plant Cultured Cells

To investigate the biotransformation of artemisinic acid(QS) by the transgenic crown gall tissues of Panax quinquefolium,30%(v/v) H2O2, which was first chosen in the study,with the substrate QS was added to the suspension cells, and then a hydroxylated and glucosylated product isolated by various chromatographic methods was identified as 15-hydroxyl-artemisinic acid-β-D-glucose ester(GQS-5), a new compound was not reported yet. In the cultured cells of Artemisia annua., two epimeric products,3-α-hydroxy-dihydroartemisinic acid(Ⅱa) and 3-β-hydroxydihydroartemisinic acid(Ⅱb) were obtained after two days of QS administrated to the suspension cells. The results indicate that QS and QQS are able to be hydroxylated and glucosylated by plant cultured cells.Furthermore, the time-course curves of biotransformation were also investigated with HPLC for the sake of studying the effects of co-culture time on bioconversion in the two plant suspension cultured systems. In the crown gall tissues of P. quinquefolium, the production of GQS-5, mainly accumulated in the cultured cells, could be to 18.3% in accordance with the exogenous substrate QS got the highest conversion rate at the same time. However, in the suspension cultured cells of A. annua, to which QQS had been administrated, the yields ofⅡa andⅡb could reach a maximum mole ratio of 2.6% and 15.7% after 1-d incubation, respectively.