Krüger S., Mirgos M., Morlock G.E.

A healthy diet is an important factor in a healthy lifestyle that is becoming increasingly important in today’s society. The fruits of European elder (Sambucus nigra L.) are a rich source of bioactive compounds like anthocyanins. In this study, dried and fresh fruits of four cultivated and six wild growing plants were investigated for their anthocyanin pattern and content as well as their bioactive compounds. After separation on HPTLC plates silica gel 60 F254 with a mixture of ethyl acetate, 2-butanone, formic acid and water, the plates were quantitatively evaluated by densitometry and also subjected to various (bio)assays to investigate the samples for compounds acting as radical-scavengers, antimicrobials, estrogens, and acetylcholinesterase or tyrosinase inhibitors. The mean contents for the two most abundant anthocyanins in European elderberries, confirmed by HPTLC-ESI-MS, ranged from 159 to 647 mg⁄100 g in fresh and from 166 to 2764 mg⁄100 g in dried fruits for cyanidin-3-sambubioside, and from 112 to 521 mg⁄100 g in fresh and 95 to 226 mg⁄100 g in dried fruits for cyanidin-3-glucoside. Additionally, the anthocyanin content was higher in berries of cultivars than of wild growing plants. The anthocyanins’s radical scavenging activity and antimicrobial effect against Aliivibrio fischeri were confirmed. Further, a radical scavenging compound affecting A. fischeri and acting as acetylcholinesterase inhibitor was tentatively assigned by its protonated molecule at m⁄z 456 as either ursolic or oleanolic acid by HPTLC-ESI-MS. HPTLC hyphenated with bioassays and mass spectrometry was selected as method of choice for fingerprinting, pattern recognition, and bioprofiling of elderberry samples as well as quantitation and confirmation of bioactive compounds therein.

Key words: Flavonoids, HPTLC-MS, Bioactivity, Elderberry, Effect-directed analysis, Bioassays