Acylated anthocyanins from sprouts of Raphanus sativus cv. Sango: Isolation, structure elucidation and antioxidant activity

作者：Matera Riccardo; Gabbanini Simone; Berretti Serena; Amorati Riccardo; De Nicola Gina Rosalinda; Iori Renato; Valgimigli Luca^*

来源：Food Chemistry, 2015, 166: 397-406.

DOI：10.1016/j.foodchem.2014.06.056

• Anthocyanins
• Phenolic acids
• Radish sprouts
• Peroxyl radicals
• NMR
• Mass spectrometry

Little is known,on structure-activity relationships of antioxidant anthocyanins. Raphanus sativus cv Sango sprouts are among the richest sources (270 mg/100 g fresh weight). We isolated from sprouts' juice 9 acylated anthocyanins, including 4 new compounds. All comprise a cyanidin core bearing 3-4 glucose units, multiply acylated with malonic and phenolic acids (ferulic and sinapic). All compounds were equally effective in inhibiting the autoxidation of linoleic acid in aqueous micelles, with rate constant for trapping peroxyl radicals k(inh) = (3.8 +/- 0.7) x 10(4) M-1 s(-1) at 37 degrees C. In acetonitrile solution k(inh) varied with acylation: (0.9-2.1) x 10(5) M-1 s(-1) at 30 degrees C. Each molecule trapped a number n of peroxyl radicals ranging from 4 to 7. Anthocyanins bearing sinapic acid were more effective than those bearing the ferulic moiety. Under identical settings, deacylated cyanin, ferulic and sinapic acids had kinh of 0.4 x 10(5), 0.3 x 10(5) and 1.6 x 10(5) M-1 s(-1) respectively, with n ranging 2-3. Results show the major role of acylation on antioxidant performance.

• 出版日期2015-1-1