The present research sought to compare the content of hyoscyamine/atropine and scopolamine in Scopolia carniolica and its contested variety, S. carniolica var. hladnikiana, with the aim of investigating differences that may be of taxonomical significance. A multi-phase liquid extraction and high-performance liquid chromatography were used to extract and analyse these alkaloids in different organs from plants collected over two years at three sites. Our results showed that hyoscyamine was almost twice as prevalent as scopolamine across our 87 samples. The differences between organ types were large, but so too were intra-organ differences; differences due to organs proved to be significant for hyoscyamine, while they were only marginally significant for scopolamine. The collection site also proved to have a significant influence, but only on hyoscyamine content. The year of collection and the variety proved to not be significant. Our results support the theory that these two varieties are likely one, a view argued by many others, though more work is needed to draw concrete taxonomical conclusions.
Keywords: Scopolia carniolica; Scopolia carniolica var. hladnikiana; Slovenia; Solanaceae; secondary metabolites; taxonomy; tropane alkaloids.