LC-ESI-MS-MS analysis of tropane alkaloids from Datura stramonium and Datura tatula L. hairy root extracts and the potential antifungal activity against Fusarium oxysporum.

This study focuses on the analysis of methanolic extract from transgenic hairy roots of Datura stramonium (DS) and Datura tatula (DT) induced by strain A4 of Agrobacteium rhizogenes bacteria and grown in vitro on B5 medium. Liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) was used to identify tropane alkaloids and to quantify the main alkaloids. The antifungal properties against Fusarium oxysporum (FO) growth in vitro were also investigated using the disc diffusion method. Results show that hyoscyamine is the major alkaloid , followed by scopolamine, the second major alkaloid produced by both species. Quantitative analysis shows that DT produces the best hyoscyamine yield of 16 mg g-1 DW compared to scopolamine produced at a low level of 0.3 mg g-1 DW for the same extract. DS produced 7 mg g-1 DW hyoscyamine and 0.16 mg g-1 DW scopolamine. Spectrophotometric analysis of the extract using the MS2 detector indicates the existence of six common molecules in both species, which are littorine, norlittorine, 3-tigloyloxytropane, 3'-hydroxylittorine, 6,7-dihydroxy-3-tigloyloxytropane, 6 hydroxyl-3-tigloyloxytropane, based on their molecular mass detection and ionisation fragmentation. Furthermore, the methanolic extract has an antifungal property against FO. Indeed, the highest level of toxicity was obtained with DT where the inhibition rate of FO mycelium attends 40.94% after seven days of disc infusion.