Short communicationLC-MSn characterization of saponins in mate (Ilex paraguariens, St. Hil) and their quantification by HPLC-DAD

•Three free triterpenes and sixteen saponins were identified in yerba mate.•Five saponins were identified for the first time in yerba mate.•Ursolic acid was the main free aglycone (1.557-1.807 mg/g).•Saponin contents in four commercial brands varied from 4.4 to 5.5 mg/g.•Matesaponin D or J3a was the most abundant saponin.

Saponins are secondary plant metabolites constituted by a triterpenoid aglycone with one or more sugar chains. There is increasing interest in saponins due to their potential health effects. Yerba mate is an important source of saponins in many South American diets. The aim of this study was to develop a one-step procedure to isolate saponins from yerba mate, followed by their characterization by liquid chromatography/tandem high-resolution mass spectrometry (LC-ESI-MS) and quantification by high performance liquid chromatography-diode array (HPLC-DAD). Methanol extraction proved to be a highly effective method to extract yerba mate saponins. LC/MSn analysis allowed identifying three free triterpenes and 16 saponins of which five were identified for the first time. HPLC-DAD results revealed that ursolic acid was the main free aglycone (1.557-1.807 mg/g vs. 0.229-0.294 mg/g oleanolic acid and 0.024-0.036 mg/g hydroxylated aglycone). Saponin contents varied from 4.4 to 5.5 mg/g in four commercial brands, being matesaponin D or J3a the most abundant.

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