摘要:

AbstractThe electrochemical reduction behavior of bilirubin (BR) at platinum electrode in DMF wag investigated by cyclic voltammetry,in situelectron spin resonance spectroscopy and insiturapid scanning thin layer spectroelectrochemistry. Experimental results revealed that the reduction of BR firstly undergoes an ECE process:. The generated (BR)3−2can be re‐oxidized to BR and then to purpurin (Pu) by a series of oxidation processes:. However, the re‐reduction reactions of Pu are not the reverse processes. The different reduction mechanisms are discussed in d

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130402

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractExact quantum calculations of reaction probabilities have been carried out using hyperspherical coordinates for the collinear reaction O+HCI(v⩽1) → OH(v′⩽1)+Cl. A generalized LEPS potential energy surface with a barrier height of 8.12 kcal/mol has been used in the calculations. According to the calculated results we found that (1) the reaction probability oscillates with energy, (2) the reaction probability shows vibrational adiabaticity, although it is poorer than that for symmetric reaction Cl + HCl. The analysis of resonance has also been done. The reaction rate constants and average cross sections have been calculated by TST‐CEQ method. The rate constants are in agreement with that by QCT and smaller than the experimental one. Finally, the threshold has been estimated and is in good agreement with that of the l

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130403

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractCarbon monoxide oxidation on Pd(10 w.t.%)‐alumina was studied byin‐situinfrared spectroscopy. It was found that the oxidation reactivities vary with different CO adspecies: linear COad>2‐fold bridged COad>multi‐bridg

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130404

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractThe supramolecular inclusion compound of β‐cyclodextrin (β‐CD, host) with (η5‐cyclopentadienyl)tricarbonylmanganese [MnCp(CO)3, guest] was obtained in a crystalline state. The host‐guest compound is thermally stable and do not liberate the guest on heating at 100°C in vacuum. It was characterized by elemental analysis,1H NMR, differential scanning thermal (DSC) analysis and TLC. Continuous variation plot by NMR method shows that β‐CD formed 1:1 inclusion compound with MnCp(CO)3. On the basis of1H NMR spectra and the model building with Corey Pauling Koltum (CPK) models, the most probable inclusion mo

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130405

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractSeveral aspects of the application of silver electrode to the electrochemical studies of hemoglobin have been discussed in this paper. The silver electrode could not only be used directly as the electrode for the electrochemical studies of hemoglobin, but also react with phenothiazine and benzimidasole to give stable and useful mediator‐coated electrodes. In addition, the silver electrode could help sodium dodecyl sulfate to give full play to its promoting effect on the protei

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130406

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractThe laser photolysis ofN‐diisopropyl phosphoryl tryptophyl tyrosine dipeptide methyl ester (N‐DiPP‐TrpH‐TyrOH) has been carried out utilizing a KrF(248 nm) laser. The direct intramolecular ET between TrpH+ residue and TyrOH residue was detected first and the ET bet‐ween Trp and TyrOH became slow. It was suggested that phosphoryl group stabilize neighbour radical of aromatic ring by hyperconjugation. In combination with computer modeling we obtained the kinetic parameters of the ET and proved that phosphoryl groups took part in the process of ET. The results should be significant for biological system since every biological process involves the phosphorylation or nonphosph

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130407

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractSix new compounds, α,β‐KaHb,[GeW9M3(H2O)3O37]xH2O(M = Al, Ga, In;a+ 6 =7) and α‐K9H5[Ge2W18Ga6(H2O)3O74]·20H2O, were synthesized from the lacunary precursors a and β‐GeW9O10−34and characterized by elemental analysis, spectroscopy and electrochemistry. Tungsten‐183 NMR spectra of the title complexes consist of two lines with intensity ratio 2:1 as expected for trisubstituted heteropoly anions. The intensity ratio of α‐Ga compound is 1:2, which is different from others(2:1). With the help of FAB mass spectrum, we concluded that it is a dimer withD3hstructure in aqueous, and the others exist by monomers

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130408

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractVarious methods for synthesis of 2‐methyl‐5,6‐(1,4,7,10,13‐pentaoxatridecamethylene)benzotellurazole (8) aredescribed. Under different conditions, alkylation of compound 8 with methyl iodide gave telluronium salt 1,2‐dimethyl‐5,6‐(1,4,7,10,13‐pentaoxatridecamethylene)benzotellurazolium iodide (15) or quaternary ammonium salt 2,3‐dimethyl‐5,6‐(l,4,7,10,13‐pentaoxatridecamethylene)benzotellurazolium iodide (14) in high yields, repectively. The cyanine dye 3,3'‐dimethyl‐5,6,5',6'‐bis(1,4,7,10,13‐pentaoxatridecamethylene)telluracarbocyanine iodide (16) is obtained by condensation of 14 with ethyl orthoformate in acetic anhydride. The visible absorption of th

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130409

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractA structural gene (750 bp), which codes for a type 1 ribosome inactivating protein, trichosanthin, has been designed according to the codon usage of highly expressed gene inE. coliand chemically synthesized. In the synthesized gene, twenty‐seven unique restriction sites were evenly dispersed with an average distance between two adjacent sites less than 50 bp to facilitate a systematic investigation on structure‐functional relationship of this protein by she‐directed mutagenesis. To synthesize it, the whole gene was divided into three large fragments (EP, PN and NH) which were assembled from several chemical synthetic oligonucleotides by enzymatic method. The assembly of both the fragment BP from six oligonucleotides (A‐F) and the fragment PN from four oligomers (G‐J) was catalysed by T4DNA ligase in using the single stranded DNA method [Chen, H.‐B.et al., Nucl. Acids Res.,18, 871(1990)]. And fragment NH was formed from three duplexes K, L and M by the classical double stranded DNA method. Finally, each fragment was cloned into vector pUC18 in succession to form the plasmid, pC0TCS, to complete the whole gene synthesis. The sequencing data for the synthetic gene coincides with the d

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130410

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY

摘要:

AbstractFourteen new 1‐acyl‐5‐aryl biurets were synthesized by the reaction of aryl ureas with acylisocyanates. The latter was obtained from acyl chloride and lead cyanate in dichloromethane, using pyridine as catalyst. The structures of compounds 3a–‐n were confirmed by IR,1H NMR and M

ISSN:1001-604X    

DOI:10.1002/cjoc.19950130411

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1995

数据来源: WILEY