Synthesis and antioxidant evaluation of (S,S)- and (R,R)-secoisolariciresinol diglucosides (SDGs).

ABSTRACT: Secoisolariciresinol diglucosides (SDGs) (S,S)-SDG-1 (major isomer in flaxseed) and (R,R)-SDG-2 (minor isomer in flaxseed) were synthesized from vanillin via secoisolariciresinol (6) and glucosyl donor 7 through a concise route that involved chromatographic separation of diastereomeric diglucoside derivatives (S,S)-8 and (R,R)-9. Synthetic (S,S)-SDG-1 and (R,R)-SDG-2 exhibited potent antioxidant properties (EC50=292.17±27.71 ?M and 331.94±21.21 ?M, respectively), which compared well with that of natural (S,S)-SDG-1 (EC50=275.24±13.15 ?M). These values are significantly lower than those of ascorbic acid (EC50=1129.32±88.79 ?M) and ?-tocopherol (EC50=944.62±148.00 ?M). Compounds (S,S)-SDG-1 and (R,R)-SDG-2 also demonstrated powerful scavenging activities against hydroxyl [natural (S,S)-SDG-1: 3.68±0.27; synthetic (S,S)-SDG-1: 2.09±0.16; synthetic (R,R)-SDG-2: 1.96±0.27], peroxyl [natural (S,S)-SDG-1: 2.55±0.11; synthetic (S,S)-SDG-1: 2.20±0.10; synthetic (R,R)-SDG-2: 3.03±0.04] and DPPH [natural (S,S)-SDG-1: EC50=83.94±2.80 ?M; synthetic (S,S)-SDG-1: EC50=157.54±21.30 ?M; synthetic (R,R)-SDG-2: EC50=123.63±8.67 ?M] radicals. These results confirm previous studies with naturally occurring (S,S)-SDG-1 and establish both (S,S)-SDG-1 and (R,R)-SDG-2 as potent antioxidants and free radical scavengers for potential in vivo use.

SUBMITTER: Mishra OP 

PROVIDER: S-EPMC3809892 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature