Table 3.

Antioxidant activity of 1–10.

Compound	% Inhibition of at 100 μg/mL	IC50 b,d
20% MeOH a	38.2	918.9 c,d
50% MeOH a	66.2	17.5 c,d
100% MeOH a	67.3	15.5 c,d
1	86.4	11.2
2	61.8	62.7
3	47.7	260.0
4	64.3	38.9
5	61.1	64.7
6	63.8	53.9
7	67.4	55.6
8	65.8	61.4
9	66.1	53.4
10	72.5	44.2
v. C e	100	76.4

^a eluted fraction of maple sap; ^b IC₅₀ values, in μM; ^c IC₅₀ values, in μg/mL; ^d IC₅₀ based on triplicate five-point titration; ^e v. C: ascorbic acid.