Tentative characterisation of iridoids, phenylethanoid glycosides and flavonoid derivatives from Globularia alypum L. (Globulariaceae) leaves by LC-ESI-QTOF-MS.

INTRODUCTION: Globularia alypum L., belonging to the Globulariaceae family, is a perennial wild shrub found throughout the Mediterranean area, Europe, and Africa. This plant is widely used to treat many diseases, but no previous work on the phytochemical composition of the Algerian G. alypum species has yet been reported.
OBJECTIVE: To investigate the phytoconstituents of the methanolic extract of G. alypum using an LC-ESI-QTOF-MS method.
METHODS: Ground air-dried leaves of G. alypum were macerated with methanol at room temperature for 24 h. The supernatant was filtered and concentrated to dryness under reduced pressure in a rotary evaporator, and extracts were recovered with methanol and filtered. Afterwards, the G. alypum extract was injected into the LC-ESI-QTOF-MS system.
RESULTS: The combined LC-MS/MS led to the tentative characterisation of 63 phytochemicals. In this work, a large number of compounds have been characterised in the leaf-extract analysis of this plant. Among others, 24 iridoids and secoiridoids were found, of which nine compounds have not previously been recorded in G. alypum. Also, nine unusual phenylethanoid glycosides were characterised for the first time in this species.
CONCLUSION: The method used has proved to be a valued tool for the characterisation of a wide range of compounds from G. alypum leaves. This work constitutes a detailed investigation of the chemical composition of G. alypum leaves, which are widely used in different traditional systems of medicine.