Department of Medicine, Pulmonary Allergy and Critical Care Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
Bioorg Med Chem Lett. 2013 Oct 1;23(19):5325-8. doi: 10.1016/j.bmcl.2013.07.062. Epub 2013 Aug 2.
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 μM and 331.94±21.21 μM, respectively), which compared well with that of natural (S,S)-SDG-1 (EC50=275.24±13.15 μM). These values are significantly lower than those of ascorbic acid (EC50=1129.32±88.79 μM) and α-tocopherol (EC50=944.62±148.00 μM). 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 μM; synthetic (S,S)-SDG-1: EC50=157.54±21.30 μM; synthetic (R,R)-SDG-2: EC50=123.63±8.67 μM] 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.
芝麻素二葡萄糖苷（SDGs）（S，S）-SDG-1（亚麻籽中的主要异构体）和（R，R）-SDG-2（亚麻籽中的次要异构体）由香草醛通过芝麻素（6）和葡萄糖供体 7 通过简洁的路线合成，其中包括非对映异构体二葡萄糖苷衍生物（S，S）-8 和（R，R）-9 的色谱分离。合成的（S，S）-SDG-1 和（R，R）-SDG-2 表现出强大的抗氧化特性（EC50=292.17±27.71 μM 和 331.94±21.21 μM），与天然（S，S）-SDG-1（EC50=275.24±13.15 μM）相当。这些值明显低于抗坏血酸（EC50=1129.32±88.79 μM）和α-生育酚（EC50=944.62±148.00 μM）。化合物（S，S）-SDG-1 和（R，R）-SDG-2 对羟基[天然（S，S）-SDG-1：3.68±0.27；合成（S，S）-SDG-1：2.09±0.16；合成（R，R）-SDG-2：1.96±0.27]、过氧[天然（S，S）-SDG-1：2.55±0.11；合成（S，S）-SDG-1：2.20±0.10；合成（R，R）-SDG-2：3.03±0.04]和 DPPH[天然（S，S）-SDG-1：EC50=83.94±2.80 μM；合成（S，S）-SDG-1：EC50=157.54±21.30 μM；合成（R，R）-SDG-2：EC50=123.63±8.67 μM]自由基也表现出强大的清除活性。这些结果证实了先前对天然存在的（S，S）-SDG-1 的研究，并确定了（S，S）-SDG-1 和（R，R）-SDG-2 是有效的抗氧化剂和自由基清除剂，具有潜在的体内应用价值。
