Bioorganically Chemical Studies on Antitumor Substances contained in Trees

1.番荔枝内酯的生物有机化学研究：采用立体选择性反应，合成了番荔枝内酯的生物合成中间体--鳞毛菌素-A、环氧菌素A和二尿黄素。对合成的环氧菌素A的光谱分析表明，天然环氧菌素A的结构是错误的。在此基础上，采用手性构筑块的立体选择性方法合成了(8^2R)和(8^2S)-Corossoline和(+)-4-deoxigantecin，即番荔枝内酯。目的：1.番荔枝科植物紫薇生物活性成分的分离与结构鉴定尝试分离出新的沸烯类化合物。紫杉烷二萜类化合物的化学转化研究1)紫杉主要成分紫杉碱的立体选择性脱乙酰化反应，得到9，10-脱乙酰基紫杉碱。2)2，5，7，9，10，13，20-七乙酰基-3，8-二乙基-3，8，11-三烯与Pd(Ph_3P)_4在醋酸中反应得到2，5，10，13，20-五乙酰-3，8-二乙基-3，7-二烯-9-酮。该化合物与从红豆杉中分离得到的一个新的次要化合物红豆杉相同。3)在HgOAc_2存在下，5-十桂酰基紫杉碱与乙烯基乙醚的侧链延伸得到了一个新的带有20-甲酰甲基的紫杉烯类似物。

1. Bioorganically chemical research on Annonaceous acetogenins : Squamostanal-A, epoxyrollin A and diepomuricanin, which were proposed as biosynthetic intermediates for Annonaceous acetogenins, were synthesized by using stereoselective reactions. The spectral analysis of the synthesized epoxyrollin A showed that the structure proposed for natural epoxyrollin A is mistaken. Furthermore, (8^2R) and (8^2S)-corossoline and (+)-4-deoxygigantecin, Annonaceous acetogenins, were synthesized by the stereoselective methods using chiral bulding blocks. Separation and structural elucidation of biologically active components from Uvaria purpurea, a Chinese plant of Annonaceae species, was tried to separate new derivatives belong to zeylenol.2. Studies on the chemical transformation of taxanediterpenoids.1) Stereoselective deacetylation of taxinine, a major component of Japanese yew, using chemical (Mg(OCH_3)_2 )and enzymatic methods (pancreatine) gave 9,10-deacetyl taxinine.2) Treatment of 2,5,7,9,10,13,20-heptaacetyl 3,8-secotaxa-3,8,11-triene with Pd(Ph_3P)_4 in acetic acid gave 2,5,10, 13,20-pentaacetyl-3,8-secotaxa-3,7-die-9-one. Which was identical with a new minor compound separated from Chinese yew, Taxus mairel.3) Side chain elongation of 5-decinnamoyl taxinine with vinylethylether in the presence of Hg(OAc)_2 gave a new analog of taxanditerpenenoid with 20-formylmethyl group.