Table 3.

Antioxidant activities of chemical compounds isolated from maple syrup showing 50% inhibitory concentrations (IC₅₀) in the diphenylpicrylhydrazyl (DPPH) radical scavenging assay.

Compd	Identification	IC50(μM)	Ref
(MS-BuOH)
1	Lyoniresinol	101.5 ± 5.9	[29]
2	Secoisolariciresinol	147.9 ± 3.6	[29]
3	Dehydroconiferyl alcohol	1040.9 ± 103	[29]
4	5′-methoxy-dehydroconiferyl alcohol	136.7 ± 3.9	[29]
5	Guaiacylglycerol-β-O-4′-coniferyl alcohol	943.5 ± 21.9	[29]
6	Guaiacylglycerol-β-O-4′-dihydroconiferyl alcohol	1335.9 ± 47.6	[29]
7	3-[4-[(6-deoxy-R-l-mannopyranosyl)oxy]-3-methoxyphenyl]methyl]-5-(3,4-dimethoxyphenyl)-dihydro-3-hydroxy-4-(hydroxymethyl)-2(3H)-furanone	679.3 ± 45.6	[29]
8	Scopoletin	68.2 ± 31.2	[29]
9	Fraxetin	46.5 ± 3.6	[29]
10	(E)-3,3′-dimethoxy-4,4′-dihydroxystilbene	>2600	[29]
11	2-Hydroxy-3′,4′-dihydroxyacetophenone	51.8 ± 8.1	[29]
12	1-(2,3,4-Trihydroxy-5-methylphenyl)ethanone	31.3 ± 0.6	[29]
13	Catechaldehyde	35.5 ± 3.7	[29]
14	Vanillin	>2600	[29]
15	Syringaldehyde	357.1	[29]
16	Gallic acid	20.3 ± 0.3	[29]
17	Syringic acid	191.85 ± 20.99	[29]
18	(E)-coniferol	115	[29]
19	C-veratroylglycol	641 ± 1 0.6	[29]
20	Catechol	89.5 ± 2.7	[29]
(MS-EtOAc)
21	5-(-(3″,4″-Dimethoxyphenyl)-3-hydroxy-3-(4′-hydroxy-3′-methoxybenzyl)-4-(hydroxymethyl)dihydrofuran-2-one	946.37 ± 58.5	[54]
22	(Erythro, erythro)-1-[4-[2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy]-3,5-dimethoxyphenyl]-1,2,3-propanetriol	1540.91 ± 0.5	[54]
23	(Erythro, threo)-1-[4-[2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy]-3,5-dimethoxyphenyl]-1,2,3-propanetriol	925 ± 179.0	[54]
24	Erythro-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2,6-dimethoxyphenoxy]-1,3-propanediol	740.20 ± 3.4	[54]
25	2-[4-[2,3-Dihydro-3-(hydroxymethyl)-5-(3-hydroxypropyl)-7-methoxy-2-benzofuranyl]-2,6-dimethoxyphenoxy]-1-(4-hydroxy-3-methoxyphenyl)-1,3-propanediol	655.29 ± 14.4	[54]
26	Acernikol	478.95 ± 42.1	[54]
27	Leptolepisol D	578.49 ± 1.3	[54]

Compd	Identification	IC50(μM)	Ref
28	Buddlenol E	422.94 ± 2.4	[54]
29	(1S,2R)-2-[2,6-Dimethoxy-4-[(1S,3aR,4S,6aR)-tetrahydro-4-(4-hydroxy-3,5-dimethoxyphenyl)-1H,3H-furo [3,4-c]furan-1-yl]phenoxy]-1- (4-hydroxy-3 methoxyphenyl)-1,3-propanediol	207.93 ± 41.3	[54]
30	Syringaresinol	68.90 ± 5.7	[54]
31	Isolariciresinol	694.44 ± 110.2	[54]
32	Icariside E4	1810.28 ± 265.6	[54]
33	Sakuraresinol	2876.44 ± 44.0	[54]
34	1,2-Diguaiacyl-1,3-propanediol	703.12 ± 141.4	[54]
35	2,3-Dihydroxy-1-(3,4-dihydroxyphenyl)-1-propanone	111.78 ± 5.1	[54]
36	2,3-Dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone	258.40 ± 33.8	[54]
37	3-Hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)propan-1-one	321.53 ± 31.9	[54]
38	4-Acetylcatechol	138.16 ± 28.2	[54]
39	3′,4′,5′-Trihydroxyacetophenone	10125 + 1668.0	[54]
40	3,4-Dihydroxy-2-methylbenzaldehyde	254.17 ± 32.5	[54]
41	Protocatechuic acid	97.83 ± 24.0	[54]
42	Tyrosol	163.93 ± 15.2	[54]
43	Isofraxidin	813.81 ± 37.7	[54]
44	4-hydroxycatechol	139.42 ± 13.3	[54]
45	phaseic acid	903.57	[54]
46	MSX-1	97.6 ± 4.73	[14]
47	MSX-2	102.4 ± 7.25	[14]