the selected detection modes (Fig. 5). For general informationon organic compounds present in the extract, one segment wasimmersed into the universal anisaldehyde sulfuric acid reagent.The zone x exhibited a yellow color (Fig. S-7d and e). Zone xwas not detectable with the natural product reagent according toNeu as well as the aluminum chloride reagent (Fig. S-7b and c).Both results excluded a flavonoid or polyphenolic structure (withvicinal hydroxy groups or a neighboring keto group) of zone x.However, more substance-specific reagents indicated the presenceof other functional groups: firstly, the zone a reacted with 2,4-dinitrophenylhydrazine indicating ketone or aldehyde groups andformed a violet zone; secondly, after having stained the HPTLCplate with Dragendorff’s reagent, zone x showed an intense red-brownish color, which indicated the presence of a heterocyclic,positively charged nitrogen in this compound (Fig. 5, tracks 6and 7).For further investigation of substance x, the developed platesections were subjected to three other enzymatic or biologicalassays. The antimicrobial substance x exerted also an inhibition ofthe bioluminescence activity of A. fischeri bacteria (Fig. 5, track 2).Moreover, it showed a significant inhibitory activity in the enzy-matic assays with acetylcholinesterase and -glucosidase (Fig. 5,tracks 4 and 5). The general antibacterial potential of -glucosidaseinhibitors was already reported [38]. This effect was also discoveredfor substance x in S. officinalis in this study. All in all, these multi-detection results expanded the knowledge on the biological activityof substance x in S. officinalis, by revealing its potential value againstFig
diseases such as cholinergic decline, e.g. in Alzheimer’s disease. Thepositive results of the enzymatic and biological assays supportedthe broad bioactivity of substance x.