Profile comparison and valorization of Tunisian Salvia aegyptiaca and S. verbenaca aerial part extracts via hyphenated high-performance thin-layer chromatography

Aerial parts of the rare species Salvia aegyptiaca L. and S. verbenaca L. were collected from arid habitats in southern Tunisia. Their polar (ethanol-water) and mid-polar (ethyl acetate) extracts were analyzed non-targeted via a developed high-performance thin-layer chromatography profiling hyphenated with 12 effect-directed assays and 8 different physico-chemical detections. Bioactive compound zones were observed with inhibiting activities on alpha-glucosidase, ss-glucosidase, ss-glucuronidase, acetylcholinesterase, butyrylcholinesterase and tyrosinase, with radical scavenging (antioxidative) effects, and with activities against Gram-negative and Gram-positive bacteria. The effect-directed profile patterns showed common bioactive zones for different collection sites of the same species and distinct differences between species. Such characteristic profiles can be used to prove authenticity. Genotoxic, estrogen-like and androgen-like compounds were not detected even at higher amounts applied (for extracts from 1.6 mg sample). In the physico-chemical profiling, further organic substances were selectively detected, which highlighted the complexity of the multi-component mixture. The Tunisian sage profiles were further compared to the frequently used S. folium L. and S. officinalis L. leaves, and to reference mixtures containing phenolic acids and tanshinones. Selected bioactive zones in the S. verbenaca extracts were characterized by high resolution mass spectrometry, and some mass signals were attributed to a caffeic acid derivative and to oleanolic and ursolic acids. Such effect-directed non-target profiling allows straightforward comparison not only of sage but of plant extracts in general. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The aerial parts of Salvia aegyptiaca L. and S. verbenaca L., rare species collected from arid habitats in southern Tunisia, were analyzed for their bioactive compounds using non-targeted analysis. The extracts showed inhibitory activities on various enzymes, antioxidant effects, and antibacterial activities. The study also identified other organic substances in the extracts and compared them with other herbal extracts.