Elucidation of glycosylation sites of kaempferol di‐O‐glycosides from methanolic extract of the leaves of Prunus domestica subsp. syriaca

Abstract

Rationale Flavonol glycosides containing the glycosylation patterns 3,4′‐di‐O and 4′,7‐di‐O are rare in nature and they have not yet been studied in detail by electrospray ionization mass spectrometry (ESI‐MS(+/−), in contrast to the flavonol glycosides containing the glycosylation pattern 3,7‐di‐O. Method The leaves from Prunus domestica L. subsp. syriaca were extracted with pure methanol or, in order to perform hydrolysis and extraction simultaneously, with a 5% methanolic solution of hydrochloric acid. The high‐performance liquid chromatography (HPLC)/ESI‐MS(+/−) analyses were performed using a Waters model 2690 HPLC pump and a Waters/Micromass ZQ2000 mass spectrometer. Results Three kinds of kaempferol di‐O‐glycosides have been identified, namely kaempferol‐3‐O‐hexoside‐7‐O‐rhamnosides, kaempferol‐3‐O‐pentoside‐4′‐O‐rhamnosides and kaempferol 4′,7‐di‐O‐rhamnoside. The identification was performed on the basis of the abundances of the respective Y‐type product ions. Conclusions The abundances of [Yn0 − H]−·, Yn0− and Yn0+ product ions were of crucial importance for the determination of glycosylation patterns. The obtained results can be useful for HPLC/ESI‐MS identification of rare flavonol‐di‐O‐glycosides.

Phenolic Compounds of Six Unexplored Asteraceae Species from Asia: Comparison of Wild and Cultivated Plants

“…The reference compounds utilized in this study were purchased from Cayman Chemicals (Ann Arbor, MI, USA), ChemFaces (Wuhan, Hubei, China), Extrasynthese (Lyon, France), MCE Med Chem Express (Monmouth, NJ, USA), and Sigma-Aldrich (St. Louis, MO, USA), or were isolated and characterized in our laboratory [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] (Table S4).…”