Analysis and biological Activity of Taxane diterpenoids contained in Yew Trees

1.对东北红豆杉(针叶和种子)、南方红豆杉(种子、树皮和针叶)和云南红豆杉(种子)三种红豆杉的化学成分进行了研究，共分离出紫杉类、黄酮类、木脂类、蜕皮甾类、松烷类、9(10→20)-松油烷类化合物、挥发油及其衍生物约200个化合物。从三种红豆杉中分离得到70多个新的紫杉类化合物，包括几乎所有的结构类型，并通过包括一维和二维核磁共振技术在内的波谱方法确定了它们的结构。2(3→20)-紫杉烷和双环紫杉烷类化合物在自然界中很少见。在过去的研究中，仅报道了8个2(3，→，20)-双环紫杉烷和6个双环紫杉烷。在这项工作中，除了6个已知的双环紫杉烷和8个已知的2(3→20)-紫杉烷中的6个外，19个新的双环紫杉烷和10个新的2(3→20)-紫杉烷被添加到这两个较小的基团中。几个重要中间体为首次从红豆杉中分离得到，特别是含有4(5)，11-二烯的紫杉类化合物和具有7-en-9-1结构单元(轮枝烯骨架)的双环类化合物在过去的研究中从未从红豆杉属植物中分离得到。因此，从红豆杉中分离这两种化合物可能有助于紫杉烷二萜类化合物的生物合成，也为紫杉醇及其相关化合物的全合成提供了新的线索。结果表明，分布于四国地区的紫杉叶中紫杉醇含量较高，其中一种双环紫杉烷二萜类化合物具有抗癌活性。

1. Three kinds of yew trees, Japanese yew Taxus cuspidata (needles and seeds) and Chinese yews T. mairei (sees, bark, and needles) and T. yunnanensis (seeds), were investigated, and about 200 compounds including taxoids, flavonoids, ligananes, ecdysteroids, abietanes, 9(10→20)-abeo abietanes, vomifoliol and its derivatives were isolated.2. More than 70 new taxoids including almost all the structural types were isolated form above three kinds of yew trees, and their structures were established through spectroscopic methods including 1D and 2D NMR techniques.3. 2(3→20)-Abeotaxanes and bicyclic taxoids were rare in the nature. Among more than 300 taxoids only eight 2(3→20)-abeotaxanes and six bicyclic taxoids were reported in the past researching. In this work, besides six known bicyclic taxoids and six out of eight known 2(3→20)-abeotaxanes, nineteen new bicyclic taxoids and ten new 2(3→20)-abeotaxanes were added to these two smaller groups.4. Several crucial intermediates were isolated from yew trees for the first time, especially taxoid with 4(5),11-diene and bicyclic taxoid with a 7-en-9-one structural unit (a verticillene skeleton) has never been isolated from Taxus species in the past studies. Accordingly, the isolation of these two kinds of compounds from yew trees may shed light on the biosynthesis of taxane diterpenoids, and also afford new clues for the total synthesis of paclitaxel and related compounds.5. It was found that T. cuspidata distributed in Shikoku area contained a relatively high level of taxol in the leaves, and that a bicyclic taxane diterpenoids showed the anticancer activity.