Abstract:

In the present study, secoisolariciresinol diglucoside and p-coumaric acid methyl ester were separated from
flaxseeds by a novel method combining flash column chromatography with preparative thin layer chromatography.
Secoisolariciresinol diglucoside was transformed into secoisolariciresinol and anhydrosecoisolariciresinol or
into secoisolariciresinol monoglucosides during the acid hydrolysis. Six compounds were isolated from the acid
hydrolysates of flaxseeds, and were respectively identified as secoisolariciresinol monoglucoside, secoisolariciresinol,
anhydrosecoisolariciresinol, p-coumaric acid methyl ester, ferulic acid methyl ester, and 5-hydroxymethyl-2-furfural on the
basis of their spectral data. p-Coumaric acid glucoside methyl ester, p-coumaric acid methyl ester and ferulic acid methyl
ester were separated for the first time from the flaxseed hydrolysates, which were produced by the transesterification of
p-coumaric acid glucoside, p-coumaric acid, and ferulic acid with methanol in hydrolysis. Interestingly, secoisolariciresinol
diglucoside, secoisolariciresinol monoglucoside, and secoisolariciresinol had scavenging capabilities against 1,1-diphenyl-
2-picrylhydrazyl (DPPH) free radical, hydroxy radical and superoxide aion radicals, and had a good dose-effect relationship
between their concentrations and antioxidant activities.

Key words: flaxseed, lignans, hydrolysates, antioxidant activities