线叶旋复花化学成分的研究

1964年我们从菊科植物线叶旋复花(Inula linariaefolia Turcz)中提得一个新的倍半萜内酯,药理试验表明具有明显的抗肿瘤Hela细胞、祛痰、抑制霉菌等活性。通过波谱分析并结合早期的化学工作,现已确定它即为同属植物I.britannica中分得的britanin,但britanin的立体结构尚未见报道。根据~1HNMR以及其衍生物的旋光谱的研究,推定britanin的立体结构应为ambros ll(13)-en-2β,4β,6α,8α-tetraol-12-oic-(12,8)-lactone,26-aiacetate(7),分子中的七元环则以椅式构象存在。此外,还鉴定了同一植物中分得的另成分为蒲公英醇软脂酸酯(taraxasteryl palmitate)。     

用转化率计算动力学拆分中对映体过量的研究

本文从理论上讨论了酶催化不可逆动力学拆分反应中底物的对映体过量ee(S)与转化率c的定量关系式并通过实验数据对以上关系式进行了验证。     

线叶旋复花化学成份的研究

Xian-Ye-Xuan-Fu-Hua, the flowers of Inula linariaefolia Turcz (Compositae), is a commonly known Chinese medicinal herb and used as expectorant as well as for the treatment of some malignant tumors. The chemical investigation of its active principles by our early work in 1964 resulted in the isolation of a new sesquiterpene lactone (m.p. 190-192`C, (α)D-24 in CHCl3), which possesses significant inhibitory action against Hela cells and fungi in vitro. Besides, it also shows some expectorant activity in preliminary pharmacological tests. Analyses of the spectral data (IR, UV, ^1H NMR, 13C NMR, MS) and our early results of chemical reactions suggested that the compound is the same as britanin 1 (m.p. 192-194`C, (α)D-26 in CHCl3) studied Chugunov in 1971. However its stereochemistry remained unsolved. On careful examination of the 360 MHZ 1H NMR data (in CDCl3 and in C6D6) and the Cotton effects of ORD spectra of its saturated lactone and cyclopentanone derivatives, we considered that britanin must be ambros-11(13)-en-2β, 4β, 6α, 8α-tetraol-12-oic-(12,8)- lactone, 2, 6-diacetate (7). Since the large values for J6,7, J7,8, J8,9, J9,10 and J1,10 indicate the existence of successive a-a trans coupling in all vicinal protons form C6 to C1, the cofnformation of the cycloheptane ring must be in chair from. The other constitutent isolated from the same plant has been identified as taraxasteryl palmitate.     

包公藤甲素及其类似物的绝对构型研究

本文采用Pr(dpm)3诱导CD裂分Cotton效应法、激子手性法和Horean法对新缩瞳剂包公藤甲素(1)及其类似物包公藤丙素(2)、凹脉丁公藤碱(3)及两者的N-甲基化物(4、5)进行了研究。确定了它们的绝对构型分别为: (2S, 6S)2β-羟基-6β-乙酰氧基去甲莨菪烷、(2S, 6S)-2β, -6β-二羟基去甲莨菪烷、(2S,7R)-2β, 7β-二羟基去甲莨菪烷、(2S, 6S)-2β, 6β-二羟基莨菪烷和(2S, 7R)-2β, 7β-二羟基莨菪烷。通过构象分析和用绝对构型已知的化合物验证, 初步解释了Horeau法的测定结果。     

脂肪酶两次拆分在有机合成中的应用

本文介绍了几种脂肪酶催化的两次拆分法,此法可用于高产率地制备高光学纯手性有机化合物.     

氯化锌催化合成正辛基葡萄糖苷反应机理研究

报道了氯化锌催化合成正辛基-D-吡喃葡萄糖苷反应机理的研究,考察了影响产物构型的因素.实验结果表明D-葡萄糖C-2取代基是影响产物α、β-异构体比例的重要因素.