Datura innoxia, Tropane Alkaloids, High Performance Liquid ChromatographyFor the determination of the hyoscyamine-scopolamine content in small quantities of fresh plant tissue an HPLC assay was developed; with a sensitivity of about 20 ng alkaloid per run. Analysis of the different organs of Datura innoxia plants are in accord with the concept that hyoscyamine is synthesized in the roots, whereas transformation to scopolamine starts in these organs and proceeds in the aerial parts of the plant.