Fig. 1.

HPLC-DAD chromatogram of a phenolic-enriched maple syrup extract (MSX) showing 37 compounds identified as follows: (1) 4-hydroxy-2-(hydroxymethyl)-5-methyl-3(2H)-furanone, (2) 3,4-dihydro-5-(hydroxymethyl)pyran-2-one, (3) 5-(hydroxymethyl)furfural, (4) 2-hydroxy-3,4-dihydroxyacetophenone, (5) 4-(hydroxymethyl)-1,2-benzenediol, (6) catechol, (7) C-veratroylglycol, (8) threo,threo-1-[4-(2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethoxy)-3-methoxyphenyl]-1,2,3-propanetriol, (9) 2,3-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone, (10) 4-acetylcatechol, (11) tyrosol, (12) catechaldehyde, (13) 1,2-diguaiacyl-1,3-propanediol, (14) 3′,5′-dimethoxy-4′-hydroxy-2-hydroxyacetophenone, (15) leptolepisol D, (16) 3,4-dihydroxy-2-methylbenzadehyde, (17) vanillin, (18) fraxetin, (19) syringaldehyde, (20) syringenin, (21) scopoletin, (22) threo-guaiacylglycerol-β-O-4′-dihydroconiferyl alcohol, (23) erythro-guaiacylglycerol-β-O-4′-dihydroconiferyl alcohol, (24) 5-(3″,4″-dimethoxyphenyl)-3-hydroxy-3-(4′-hydroxy-3′-methoxybenzyl)-4-(hydroxymethyl) dihydrofuran-2-one, (25) 1-(2,3,4-trihydroxy-5-methylphenyl)ethanone, (26) erythro-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2,6-dimethoxyphenoxy]-1,3-propanediol, (27) icariside E4, (28) 3′,4′,5′-trihydroxyacetophenone, (29) dehydroconiferyl alcohol, (30) sakuraresinol, (31) secoisolariciresinol, (32) acernikol, (33) (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, (34) 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, (35) 4,4′-dihydroxy-3,3′,5,5′-tetramethoxystilbene, (36) 4,4′-dihydroxy-3,3′,5′-trimethoxystilbene, and (37) (E)-3,3′-dimethoxy-4,4′-dihydroxystilbene.