1 2 - Alkenal - scavenging ability of m - diphenols 1

8 2 ABSTRACT 9 The reaction between m-diphenols (resorcinol, 2-methylresorcinol, 2,5-10 dimethylresorcinol, 3-methylphenol, orcinol, and phloroglucinol) and 2-alkenals (2-11 pentenal and 2-octenal) was studied in an attempt to understand the chemical pathways 12 involved in the scavenging ability of m-diphenols for the 2-alkenals produced as a 13 consequence of lipid oxidation. Phenols reacted chemically with 2-alkenals producing a 14 number of 2H-chromenols, chromandiols, chromanols, and dihydropyrano[3,2-15 g]chromenes, which were isolated and identified by 1D and 2D nuclear magnetic 16 resonance (NMR) spectroscopy and mass spectrometry (MS). The identification of all 17 these compounds allowed proposing a general reaction pathway for these reactions. 18 These results confirm that the 2-alkenal-scavenging ability of m-diphenols is a 19 consequence of its structure. This is a complex reaction in which many different 20 products are formed. The most stable products were the chromandiols. However, the 21 main reaction products were the 2H-chromenols. These products were instable and 22 disappeared as a consequence of polymerization and browning reactions. 23 24