Total Synthesis of γ-Alkylidenebutenolides, Potent Melanogenesis Inhibitors from Thai Medicinal Plant <i>Melodorum fruticosum</i>
作者:Genzoh Tanabe、Yoshiaki Manse、Teppei Ogawa、Naoki Sonoda、Shinsuke Marumoto、Fumihiro Ishikawa、Kiyofumi Ninomiya、Saowanee Chaipech、Yutana Pongpiriyadacha、Osamu Muraoka、Toshio Morikawa
DOI:10.1021/acs.joc.8b00986
日期:2018.8.3
Furthermore, the melanogenesis inhibitory activities of S- and R-1–4 were evaluated, with all shown to be potent inhibitors with IC50 values in the range 0.29–2.9 μM, regardless of differences in the stereochemistry at C-6. In particular, S-4 (IC50 = 0.29 μM) and R-4 (0.39 μM) showed potent inhibitory activities compared with that of reference standard arbutin (174 μM).
从甲醇提取物中分离出迄今未报道的甜叶菊(Annonaceae)中的γ-亚烷基丁烯内酯的成员(4 E)-6-苯甲酰氧基-7-羟基-2,4-庚二烯-4-内酯(4)花,连同已知的相关丁烯羟酸内酯,即(4 ž) -异构体(3)的4,melodrinol(1),和它的(4 ë) -异构体(2)。明确地确定在这些丁烯羟酸内酯的C-6位置上的绝对构型,两种对映体的第一全合成2 - 4经6-7步骤由可商购获得D-或L-核糖(D-和L-5)。使用相同的方案,还合成了两个对映体1。基于所有的合成化合物的手性HPLC分析(小号-和- [R -1-4),所有天然存在的丁烯羟酸内酯在C-6(对映体比率,6被分配为部分外消旋混合物相对于所述手性中心小号/ 6 - [R = 〜83/17)。此外,黑素生成抑制活性小号-和- [R -1 - 4进行了评价,与所有证明是有效的抑制剂与IC 50值在0.29–2.9μM范围内