对氨基苯甲酸酯类紫外吸收性能的定量构效关系——Ⅱ.化合物紫外吸收光谱的构效关系

对十个化合物的紫外吸收性能进行了测定。对其紫外吸收构效关系进行了探索,用振子强度f_n的概念来反映化合物的紫外吸收强度。结果表明f_n与PPP量子化学参数SOSC修之间存在着定量关系。在考虑到溶剂和不同取代基的影响后,发现紫外吸收频率和PPP量子化学参数——前线轨道能量差△E_(?),之间也有良好的线性关系。

Trimethyl-1,4-Benzoquinone Synthesis via 2,3,6-Trimethylphenol Catalytic Oxidation by Oxygen in the Presence of Non-Keggin-Type Mo-V-Phosphoric Heteropoly Acid Solutions

In the present study, the modified （non-Keggin-type） aqueous solutions of Mo-V-phosphoric heteropoly acids HaPzMoyVx,Oh （HPA-x＇） were applied as homogeneous catalysts for the two-stage oxidation of TMP （2,3,6-trimethylphenol） by oxygen into TMQ （2,3,5-trimethyl-l,4-benzoquinone）, the latter being the key intermediate in the synthesis of vitamin E. The TMQ yield was analyzed regarding solvent type, reaction temperature, molar HPA-x ＇：TMP ratio, and the concentration of vanadium （V） in the HPA-x＇ solution. The TMQ yield was found to depend strongly on the catalyst redox potential and the rate of electron transfer. The results obtained enabled to establish the optimal reaction conditions as well as to suggest the reaction mechanism. In the target reaction, which proceeds in the two-phase system, the TMQ yield is higher than 99%. After phase separation, the catalyst is rapidly regenerated by oxygen and reused.

植物次生代谢物质生物合成的研究

概述了4种植物次生代谢物质:生物碱、萜类化合物、黄酮类化合物、醌及苯甲酸衍生物的生物合成的研究情况。