Analysis and biological Activity of Taxane diterpenoids contained in Yew Trees

1.本文对日本红豆杉和中国红豆杉三种红豆杉树种的针叶和种子进行了研究。mairei（sees，bark，and needles）和T.从云南红豆杉（种子）中分离得到约200个化合物，包括紫杉烷类、黄酮类、木黄酮类、蜕皮甾类、松香烷类、9（10→20）-abeo松香烷类、vomifoliol及其衍生物.从上述三种红豆杉中分离得到70多个新的紫杉烷类化合物，包括几乎所有的结构类型，并通过1D和2D NMR等波谱方法确定了它们的结构. 2（3→20）-Abeotaxane和双环紫杉烷在自然界中较为罕见。在300多个紫杉烷类化合物中，只有8个2（3→20）-abeotaxane和6个双环紫杉烷类化合物的文献报道。在这两组化合物中，除了6个已知的双环紫杉烷和8个已知的2（3→20）-abeotaxane中的6个外，还增加了19个新的双环紫杉烷和10个新的2（3→20）-abeotaxane。其中4（5），11-二烯紫杉烷和7-烯-9-酮双环紫杉烷（轮枝孢烯骨架）为首次从红豆杉中分离得到。因此，从红豆杉中分离得到这两类化合物，为紫杉烷类二萜的生物合成提供了新的思路，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，T.四国地区的虎杖叶片中含有较高含量的紫杉醇，且具有抗癌活性的是一种双环紫杉烷型二萜类化合物。

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.