Nitroxide mediated degradation of anthocyanidins
Summary: The degradation of the six anthocyanidins (pelargonidin, cyanidin, delphinidin, peonidin, petunidin and malvidin) mediated by the nitroxides: 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempo), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) and 4-methoxy-2,2,6,6-tetramethylpiperidine1-ox...
Permalink: | http://skupnikatalog.nsk.hr/Record/nsk.NSK01000734936/Details |
---|---|
Matična publikacija: |
Croatica chemica acta 82 (2009), 3 ; str. 707-713 |
Glavni autor: | Butković, Vjera (-) |
Vrsta građe: | Članak |
Jezik: | eng |
Predmet: | |
Online pristup: |
Croatica Chemica Acta |
LEADER | 02148caa a2200265 ir4500 | ||
---|---|---|---|
001 | NSK01000734936 | ||
003 | HR-ZaNSK | ||
005 | 20180430140143.0 | ||
007 | ta | ||
008 | 100427s2009 ci ||| ||eng | ||
035 | |9 (HR-ZaNSK)737558 | ||
035 | |a (HR-ZaNSK)000734936 | ||
040 | |a HR-ZaNSK |b hrv |c HR-ZaNSK |e ppiak | ||
042 | |a croatica | ||
080 | |a 54 |2 MRF 1998. | ||
100 | 1 | |a Butković, Vjera | |
245 | 1 | 0 | |a Nitroxide mediated degradation of anthocyanidins / |c Vjera Butković. |
300 | |b Ilustr. | ||
504 | |a Bibliografija: 38 jed. | ||
520 | 8 | |a Summary: The degradation of the six anthocyanidins (pelargonidin, cyanidin, delphinidin, peonidin, petunidin and malvidin) mediated by the nitroxides: 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempo), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) and 4-methoxy-2,2,6,6-tetramethylpiperidine1-oxyl (4-CH3O-Tempo) at 25 °C in aqueous acid solution was investigated spectrophotometrically and by EPR and HPLC measurements. The reaction kinetics were followed under pseudo-first order conditions using a large excess of nitroxide reactants. The spontaneous degradation of anthocyanidins under these conditions is several orders of magnitude slower, and it did not influence the measurements. However, it was found that the reaction rate increases with the age of acidified nitroxide solutions, reaching a maximum after 24 hours. This result indicates that in every case the oxoammonium cation, generated by disproportionation of nitroxyl radicals, is somewhat more reactive toward anthocyanidins than the nitroxyl itself. The products were identified by HPLC as ring substituted benzoic acids. The relative reactivities of the six anthocyanidins and the accelerating influence of the p-substituent of nitroxides on the reaction is discussed | |
653 | 0 | |a Antocijanidin |a Dušikovi oksidi |a Kisela vodena otopina |a Spektrofotometrija |a HPLC |a Tekućinska kromatografija | |
773 | 0 | |t Croatica chemica acta |x 0011-1643 |g 82 (2009), 3 ; str. 707-713 |w nsk.(HR-ZaNSK)000001621 | |
981 | |b B02/09 | ||
998 | |a Luko100427 |c vol2o130307 |a mild1804 | ||
856 | 4 | 2 | |u http://hrcak.srce.hr/cca |y Croatica Chemica Acta |