Synthesis and antioxidant evaluation of (S,S)- and (R,R)-secoisolariciresinol diglucosides (SDGs)
作者:Om P. Mishra、Nicholas Simmons、Sonia Tyagi、Ralph Pietrofesa、Vladimir V. Shuvaev、Roman A. Valiulin、Philipp Heretsch、K.C. Nicolaou、Melpo Christofidou-Solomidou
DOI:10.1016/j.bmcl.2013.07.062
日期:2013.10
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 mu M and 331.94 +/- 21.21 mu M, respectively), which compared well with that of natural (S,S)-SDG-1 (EC50 = 275.24 +/- 13.15 mu M). These values are significantly lower than those of ascorbic acid (EC50 = 1129.32 +/- 88.79 mu M) and a-tocopherol (EC50 = 944.62 +/- 148.00 mu 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 mu M; synthetic (S, S)-SDG-1: EC50 = 157.54 +/- 21.30 lM; synthetic (R, R)-SDG-2: EC50 = 123.63 +/- 8.67 mu 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. (C) 2013 Elsevier Ltd. All rights reserved.