LC coupled to ion-trap MS for the rapid screening and detection of polyphenol antioxidants from Helichrysum stoechas.
Liquid Chromatography-Ion Trap Mass Spectrometry with an atmospheric pressure chemical ionization (APCI) interface in the negative and positive-ion modes in parallel to UV-diode-array detection (DAD), was applied for the rapid detection/characterization in crude extracts of the water-soluble antioxidant phenolics from Helichrysum stoechas. APCI-MS provides unequivocal molecular weight data of these compounds and useful information about their structures (diagnostic fragments ions), which were confirmed by the UV-DAD fingerprints. This combined approach allows the identification of ten constituents, including the three naturally occurring isomers of caffeoylquinic acid (CGAs), namely neo-chlorogenic acid, chlorogenic acid and crypto-chlorogenic acid, 2 isomeric dicaffeoyl quinic acids, 2 isomeric naringenin glucosides, quercetin, kaempferol and apigenin glucosides and a tetrahydroxychalcone-glucoside. The water-soluble extract from H. stoechas, standardized in both total polyphenol and kaempferol-3-glucoside content, exhibits strong antioxidant activity in vitro when tested in both artificial membrane systems (phosphatidylcholine liposomes) and in a cell model (rat erythrocytes).
Carini
M
M
Istituto Chimico Farmaceutico Tossicologico, Milano, Italy. marina.carini@unimi.it
Aldini
G
G
Furlanetto
S
S
Stefani
R
R
Facino
R M
RM
D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D019659:Asteraceae / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D005419:Flavonoids; D013058:Mass Spectrometry / Q000379:methods*; D010636:Phenols / Q000032:analysis*; D011108:Polymers / Q000032:analysis*; D059808:Polyphenols; D051381:Rats; D013056:Spectrophotometry, Ultraviolet
D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D011108:Polymers; D059808:Polyphenols