Effects of elevated ozone on phenolic substances content and total antioxidative capacity of Quercus mongolica leaves

An open-top chamber experiment was conducted to examine the effects of elevated atmospheric O3 ( 80 ±8 nmol · mol-1 ) on the total phenols, flavonoid, condensed tannin, and MDA contents , and the total antioxidative capacity of Quercus mongolica leaves. Elevated O 3 increased the contents of total phenols and condensed tannin by 48. 17% and 26. 77% (P<0. 05) , and the flavonoid and MDA contents by 24. 66% and 5. 26% (P >0. 05) , respectively. The total antioxidant capacity of Q. mogonlica leaves determined by DPPH method was enhanced significantly ( P < 0. 05 ) , and had an obvious linear relationship with the contents of total phenols and condensed tannin.