Naslov
Gas phase ligation of Fe+ and Cu+ ions with some flavonoids

Autori
Kazazić, Snježana P. ; Butković, Vjera ; Srzić, Dunja ; Klasinc, Leo

Izvornik
Journal of Agricultural and Food Chemistry (0021-8561) 54 (2006), 22; 8391-8396

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Flavonoids; antioxidants and antiradical activity; DFT calculation; FTICR MS; ligation and fragmentation products with Fe+ and Cu+

Sažetak
It was assumed that gas phase ligation of metal monocations by flavonoids might provide some insight on the intrinsic antioxidant activity of the latter. Thus, the ligation of Fe+ and Cu+ ions by apigenin (1), luteolin (2), kaempferol (3), quercetin (4), myricetin (5) and naringenin (6) was investigated in the gas phase in a Fourier transform mass spectrometer (FTMS). Both of the metal ions, which were produced by laser desorption ionization (LDI), bind consecutively to two neutral flavonoid molecules either with or without the simultaneous loss of some part (H, CO, H2O) of the latter. The flavonoids are present in the instrument at steady concentrations. The formation of flavonoid positive ions by charge exchange is also a common observation but is accompanied, in some cases, with a loss of H, CO or H2O fragments. The reaction paths and observed fragmentations are presented. The results are supported by DFT B3LYP calculations that indicate a preference for metal ion attack at C-ring and not at the B-ring site considered to be mainly responsible for flavonoid antioxidant activity.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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