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本文报道了小麦在小麦赤霉菌的诱发下产生抗素毒,经过分离提取和化学结构鉴定,得知有抑制小麦赤霉菌的抗毒素的化学成分为丁二醇。再用3种丁二醇异构体作小麦赤霉菌生长的抑菌试验,都有抑菌效果。 相似文献
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运用荧光及紫外-可见吸收光谱法研究了胡椒酸丁二醇单酯(简称BPM)与牛血清白蛋白(BSA)的相互作用。实验结果表明,胡椒酸丁二醇单酯与BSA形成基态复合物导致BSA内源性荧光猝灭,猝灭机理主要为静态猝灭和非辐射能量转移,其猝灭速率常数为Kq为1.077×1013L/(mol.s)(25℃)、0.946×1013L/(mol.s)(37℃)。利用荧光猝灭反应测得结合常数KA为2.6×106(25℃)、3.4×106(37℃),结合位点数n为1.30(25℃)、1.33(37℃)。根据Frster能量转移理论得到结合距离r=2.92nm(25℃)、2.66nm(37℃)和能量转移效率E=0.45(25℃)、0.43(37℃)。通过热力学参数计算,确定胡椒酸丁二醇单酯与BSA的相互作用是熵增加和吉布斯自由能降低的自发过程,主要作用力是疏水作用力。 相似文献
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Shun Ping Wang Xiao Deng Yang Qing Quan Bai 《International Journal of Polymer Analysis and Characterization》2013,18(2):119-125
A comparative kinetic study of the urethane reactions of phenyl isocyanate and 1,2-, 1,3-, and 1,4-butanediol was carried out in dichloromethane solution with zirconium (IV) acetylacetonate as catalyst. In situ FT-IR was used to follow the kinetics of the reactions at a constant temperature of 15°–30°C. The rate constants for the reaction of the primary hydroxyl group and the secondary hydroxyl group were calculated as k prim and k sec, respectively. Analysis of the second-order rate constants of these systems indicated that k prim follows 1,2-butanediol >1,3-butanediol >1,4-butanediol. The ratio of k prim/k sec in 1,2-butanediol was the highest and the order followed was the same as with the reaction rate. Activation energies and Eyring parameters were also determined for the urethane reaction of butanediols. 相似文献
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Chi‐Tsai Lin 《中国化学会会志》2015,62(5):443-448
2,3‐Butanediol dehydrogenase (Bdh) plays important roles in reduction of acetoin to 2,3‐butanediol, an important platform chemical with many industrial applications. Here, a TcBdh cDNA (1348 bp, GenBank accession JF896462) encoding a putative Bdh was cloned from Taiwanofungus camphorata. The deduced amino acid sequence is similar to the Bdhs from other species. A 3‐D structural model of TcBdh has been constructed based on the known structure of Pseudomonas putida formaldehyde dehydrogenase (PpFdh, PDB code 1KOL). To characterize the TcBdh protein, the coding region was subcloned into an expression vector pYEX‐S1 and transformed into Saccharomyces cerevisiae. The recombinant His6‐tagged TcBdh was expressed and purified by Ni2+‐nitrilotriacetic acid Sepharose. The purified enzyme showed a single band of 49 kDa on 12% sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The Michaelis constant (KM) value of the recombinant enzyme for acetoin was 8.5 mM. The enzyme’s optical pH was 6. The thermal inactivation of the enzyme showed a half‐life of 5.3 min at 45 °C. 相似文献
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Thermodynamics of single-phase complex systems of glucose + alcohol + water is significantly important in food and pharmaceutical industries. The water activity is a practical parameter in thermodynamic characterization in food and pharmaceutical and other biological industries, which its value has an important role in growing microorganisms and rate of reactions. In this work, the NRTL-NRF excess Gibbs function has extended for ternary system of water, different alcohols (as second molecular solvent) and a special molecular solute like a sugar. The extended NRTL-NRF model with three parameters was used for correlation of the osmotic coefficient of the aqueous systems of glucose and alcohol at different concentrations. The data of the osmotic coefficient of water for these systems are obtained by an isopiestic method. The adjustable parameters are calculated by optimization of the experimental data of the osmotic coefficient using the Nedler–Mead algorithm. It is shown that the results of the modified NRTL-NRF model demonstrate low deviation from the experimental data. 相似文献
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Yulia Ryabenkova Peter J. MiedziakDavid W. Knight Stuart H. TaylorGraham J. Hutchings 《Tetrahedron》2014
The oxidation of four butanediols under base-free conditions has been investigated using a set of Au, Pd and Pt catalysts prepared using sol-immobilization. The supported nanoparticles are found to be active with bimetallic alloys having much higher activity when compared with the monometallic counterparts. In general the AuPt catalysts are the most active and in all cases the corresponding C4 oxidation products were observed with high selectivity; sequential reaction of these products leads to the formation of acetic acid as an undesired by-product. 相似文献
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