化学模拟生物固氮——Ⅸ 铁钼辅基模型化合物的合成和性能表征

本文曾在全国化学摸拟生物固氮协作组领导小组扩大会议(昆明,1980,8)上宣读。[中文文摘]采用乙二醇基阴离子作为活插头(可通过水解除去的双配位螯形配位体),对前文提出的合成方法作了重要改进,以期所合成的铁钼辅基模型化合物中Mo~(Ⅳ(Ⅲ))第一配位界内两个不稳定的配位体处于相邻的位置,如厦门模型Ⅲ(或厦门模型Ⅱ)所要求。合成和重组活性评价结果,重组活性比使用乙腈等为活插头的提高2个数量级,化学催化活性和选择性接近于天然FeMo-co水平。[英文文摘]A significant improvement has been made to the method previously proposed[3] for synthesizing FeMo-co modeling compounds. With the use of ethylene glycolate anion as labilizable blocking agent (hydrolyzable bidentatc chelating ligand)to protect two neighboring coordination sites in the first coordination sphere of MoIV(III) of the synthesized FeMo-co modeling compound, an increase in reconstituted-nitrogenase activity of 2 orders of magnitude of the sample synthesized (as compared with the use of acetoni-trile or other monodentare ligands as bloeking agents)has been obtained.Catalytic activity and selectivity assays as well as preliminary characterization by EPR method have also been made

Isolation and Purification of Triacontanol from Bees-wax and Bran-wax and Its Properties

[中文文摘]蜂蜡或糠蜡用乙醇处理,然后用碱醇在苯中皂化,由蜂蜡所得不皂化物再经戊醇-盐酸提取,中层用苯重结晶;由糠蜡所得不皂化物用丙酮萃取后真空分馏,其一馏份也用苯重结晶,两者都得白色鳞片状晶体(m.p.85.5—56.5℃)。其乙酰化物用乙醇重结晶得白色片状晶体(m.p.69—70℃)。元素定量分析及红外光谱分析表明:该物质是三十烷醇-1。[英文文摘]Bees-wax or Bran-wax is treated with alcohol and then saponified with alc. alkali in benzene. The unsapontficd substance from been-wax is extrated with amyl alcohol-HCL and the middle layer recrystallized from benzene. The unsaponif ied substance from bran-wax is extracted with acetone, the extr-actact after removal of acetone is vacuum-fractionated, one of the distillates also recrystallized from benzene. Both give white scale-like crystals m. p. 85.5-86.5℃. The acetylated derivative is recrystallized from alcohol to give white plate-like crystals.m.p.69-70℃.Elemental quantitative analysis and IR spectral analysis show the substance to be 1-triacontanol

Chemical Modeling of Biological Nitrogen FixationⅥ. Synthesis and Catalytic Activities of FeMo-co Modeling Compounds

[中文文摘]本文讨论了先前我们提出的固氨酶活性中心骈联双座双立方烷原子簇结构模型的一些特征。根据这一模型。设计了铁钼辅基模型化合物的合成方案,合成了三系列的铁钼辅基模型化合物,其Mo、S~*、Fe之比如同这一模型所要求的,为1:～6:6～8。由氯化物系列和柠檬酸盐进行配位体交换而得到的柠檬酸盐系列中的两个样品,在KBH_4还原C_2H_2为C_2H_4的反应中具有很高的催化活性(按每个Mo计算,转变数为20～30分~(-1))和选择性(91～95％),接近天然的铁钼辅基的水平,并在与Av突变种UW_(45)重组后,按Shah和Brill的方法测定,显示出明显的固氮酶活性。[英文文摘]Some features of the twin-sited dicubane-clurter structural model of nitrogenase active-center previously proposed by us are diseased. Based upon this model, a method for the synthesis of FeMo-co modeling compounds has been designed.Three series of FeMo-co modeling compounds have been synthesized, with Mo : S*: Fe=l:-6 :6-8 as required by the model. Two samples of the citrate series, obtained by ligand exchange of the chioridc series with citrate, have been found to exhibit very high catalytic activity (tur-over number per Mo:20~30min-1)and selectivity (92-95%C2H4),approaching that of FeMo-co,in the reduction of C2H4 to C2H4 by KBH4,and to show a certain well-confirmed nitrogenase activity as assayed by Shah and Bill's method after reconstitution with Av mutant UW45