Microwave-assisted extraction of edible Cicerbita alpina shoots and its LC-MS phenolic profile

Abstract

Background: Crude extracts obtained from the edible shoots of Cicerbita alpina using microwave-assisted extraction have been qualitatively profiled by liquid chromatography coupled with an ion trap mass spectrometry detector and an electrospray ionization interface (LC/ESI-MS(3) ) for their phenolic content. The main challenge of the present investigation was to create a working strategy designed to obtain a rich phenolic profile despite the limited amount of starting plant material and phytochemical data available.

Results: The best extraction conditions (temperature 90 °C; time 5 min; solvent methanol:water 50:50; sample weight 3 g) were achieved using a full factorial 2(4) experimental design. Fifteen compounds, including flavonoid conjugates and phenolic acid derivatives, were detected and tentatively identified. The total phenolic content varied from 93.58 mg g(-1) gallic acid equivalents (GAE), for the cultivated plant to 10.54 mg g(-1) GAE for the wild one, whereas the total flavonoid content varied from 145.00 mg g(-1) rutin for the cultivated plant to 25.22 mg g(-1) rutin for the wild one.

Conclusion: A total of 11 compounds are herein reported, for the first time, as coming from this plant source.

Keywords: Cicerbita alpina; LC/ESI-MS; full 24 factorial design; microwave-assisted extraction; phenolics.