Negative ion 'chip-based' nanospray tandem mass spectrometry for the analysis of flavonoids in glandular trichomes of Lychnophora ericoides Mart

This abstract reports a method for the analysis of secondary metabolites stored in glandular trichomes, employing negative ion 'chip-based' nanospray tandem mass spectrometry. The analyses of glandular trichomes from Lychnophora ericoides, a plant endemic to Brazilian 'cerrado' and used in traditional medicine as an anti-inflammatory or analgesic agent, led to the identification of five flavonoids (chrysin, pinocembrin, pinostrobin, pinobanksin and 3-O-acetylpinobanksin) by direct infusion of the glandular trichomes extracts to the ESI source. All the flavonoids present in the extract have no oxidation at ring B, which results in a modification of the fragmentation pathways when compared to that of the oxidised flavonoids already described in the literature. The absence of the anti-inflammatory di-C-glucosylflavone vicenin-2, as well as any other flavonoid glycosides, in the glandular trichomes was also clearly demonstrated. This fact supports the traditional preparation method of this species for medical purposes, which uses intact leaves of the plant only after maceration for several days, certainly leading to a more efficient extraction of this bio-active compound.

Acknowledgement: Supported by FAPESP, CNPq and CAPES