A rapid screening by liquid chromatography mass spectrometry and fast-atom bombardment tandem mass spectrometry of phenolic constituents with radical scavenging activity, from Krameria triandra roots

Liquid chromatography/mass spectrometry (particle beam interface, electron impact ionization), fast-atom bombardment mass spectrometry (FAB-MS) (negative-ion mode) and FAB-tandem mass spectrometry (MS/MS) techniques were applied for the rapid detection/characterization of low-to-intermediate molecular weight polyphenol constituents of Krameria triandra roots with radical scavenging activity; this determined in a well established membrane model of lipid peroxidation (phosphatidylcholine liposomes). LC/MS analysis of the more lipophilic fractions of the drug (antioxidant activity: ICS,, the concentration which gives 50% inhibition, 5.8 mu g/mL petrol extract; IC50 3.7 mu g/mL chloroform extract) evidences at least 9 components belonging to the class of lignans; FAB-MS/MS analysis of the butylacetate extract (IC50 = 0.23 mu g/mL) caffeoyl esters, catechin-glucosides, dimeric procyanidines and their corresponding phenylpropanoyd derivatives.