Acutissimanide (1), a new lignin, together with 11 known polyphenols (2-12) were isolated from the bark of the deciduous oak tree, Quercus acutissima Carruth. The structure of compound 1 was determined using multidimensional (1)H and (13)C NMR and mass spectroscopy. The antioxidant properties of compounds 1-12 were investigated using a 1,1-diphenyl-2-picryhydrazyl radical-scavenging assay with compounds 6-11 displaying significant antioxidant activity (EC50 values of 5.2-23.7 μM). Our findings suggest the extracts of Q. acutissima Carruth are a potential source of natural antioxidant additives for use in the food and other allied industries.
Keywords: Acutissimanide; Q. acutissima Carruth; antioxidant activity; polyphenols.