An aryldihydronaphthalene lignan with a novel type of ring system and further new lignans from linum perenne L.
An aryldihydronaphthalene lignan with a novel type of ring system and further new lignans from linum perenne L.
复制标题
具有新型环系的芳基二氢萘木脂素以及来自多年生亚麻的新木脂素。
作者：
T. Schmidt;S. Vössing;M. Klaes;S. Grimme
从亚麻科(Linaceae)多年生亚麻(Linum perenne L.)地上部分的二氯甲烷提取物中，除分离出3种芳基萘类木脂素外，还分离出4种芳基二氢萘类木脂素。该主要成分含有一种新型的闭环结构，通过羟甲基桥在芳基二氢萘骨架的A环和D环之间进行额外的环化反应，得到一种新型的2，8-二氢-3 H-苯并[E]萘并[1，8-BC]奥西平环系，迄今未见木脂素或任何其他天然产物的报道。我们将这部小说命名为不同寻常的木脂素利诺西平。此外，还分离到3个芳基二氢萘(1个新化合物和2个已知化合物)。根据CD光谱确定了利诺西平及其相关的二氢萘木脂素在C-8位的绝对立体化学为R，与含时密度泛函(TDDFT)量子力学模拟结果吻合较好。芳基二氢萘在亚麻属或亚麻科植物中的存在尚未见报道。
From the dichloromethane extract of aerial parts of Linum perenne L. (Linaceae), in addition to three lignans of the arylnaphthalene type (justicidin B, isojusticidin B and retrohelioxanthin), we isolated four lignans of the aryldihydronaphthalene type. The major constituent contains a novel type of ring closure, formed by additional cyclisation between rings A and D of the aryldihydronaphthalene skeleton via an oxymethylene bridge, yielding a novel 2,8-dihydro-3 H-benzo[ E]naphtho[1,8- BC]oxepine ring system hitherto unreported for a lignan or any other natural product. We named this novel unusual lignan linoxepin. In addition, three further aryldihydronaphthalenes (one new and two known) were isolated. The absolute stereochemistry at C-8 of linoxepin and the related dihydronaphthalene lignans was established as R on grounds of CD spectra which were in good agreement with results of time dependent density functional (TDDFT) quantum mechanical simulations. The occurrence of aryldihydronaphthalenes in the genus Linum or the Linaceae has not been reported before.