Effects of fabrication parameters on the enzyme loading and sensor response of enzyme-carrying conductive polymer electrodes.

Hydrogen peroxide sensors where horseradish peroxidase (HRP) is incorporated into pyrrole/3-alkylsulfonate pyrrole copolymer films deposited on an SnO2 electrode (HRP/Py-PS electrode) were investigated with regard to the effects of the fabrication parameters (electropolymerization charge, deposition current density, and electrodeposition solution pH) on the amount of surface-immobilized enzyme and the sensor response. The amount of incorporated enzyme was determined with a method recently developed by ourselves. The results suggest that the amount of entrapped enzyme increases almost linearly with the total charge passed, and strongly depends on the polymer film growth rate and the electropolymerization pH. These findings open up a way to control the amount of enzyme and the resultant response of the biosensor by modifying the preparation conditions.     

First Catenane‐Containing Phosphino Groups: A Step toward a Catenane Ligand

A novel [2] catenane containing a diphenylphosphino group on each ring was prepared. Synthesis of the new catenane involved the use of tetraamide rings to form an efficient pseudorotaxane intermediate. The catenane was found to be applicable as a ligand for metal-catalyzed reactions such as Suzuki-Miyaura coupling.     

New diterpene pyrone-type compounds, metarhizins A and B, isolated from entomopathogenic fungus, Metarhizium flavoviride and their inhibitory effects on cellular proliferation

To date, entomopathogenic fungi have not been extensively examined by natural product chemists. In this study, we isolated novel pyrone diterpene-type compounds, metarhizins A (1) and B (2), from methanol extracts of entomopathogenic fungus, Metarhizium flavoviride. They showed potent and selective antiproliferative activity against both insect and human cancer cell lines. These results indicate that metarhizins A (1) and B (2) can be used as novel lead compounds for anti-cancer agents and probes for cell cycle regulation. To further investigate the structural requirements for this inhibitory activity, we synthesized many metarhizin derivatives and evaluated their antiproliferative activities.     

Synthesis of affinity column of phosphatidylinositol-3,4-diphosphate

Phosphatidylinositol polyphosphates (PIPx) are related with tyrosine kinase activation, cell proliferation and carcinogenesis. In order to investigate the action mechanism of PIPx, it is desirable to synthesize affinity column of PI-3,4-P2, which is expected to be able to isolate the binding proteins of PI-3,4-P2. Thyramine reacted with CH-Sepharose 4B giving column 13. The p-amino group of 3'-(1',2'-distearoyl-glyceryl)-1-(2-p-aminobenzyl)-3,4-di-O-phosphoryl-myo-inosityl phosphate (12) was diazotized, then diazo-coupled with column 13 to give PI-3,4-P2 affinity column 14. This PI-3,4-P2 affinity column is an effective tool to pick up binding proteins of PI-3,4-P2.     

A ferroelectrically switchable columnar liquid crystal phase with achiral molecules: superstructures and properties of liquid crystalline ureas

Novel columnar liquid crystalline compounds N,N'-bis(3,4,5-trialkoxylphenyl)ureas 1a-c (R = n-C(8)H(17), n-C(12)H(25), and n-C(16)H(33)) were synthesized, and their phase transitions were measured by differential scanning calorimetery. The superstructures were investigated by X-ray diffraction, polarized light optical microscopy, and IR spectroscopy. The compounds exhibited both rectangular and hexagonal columnar phases in which the urea molecules in each column were stacked in one direction with strong hydrogen bonds. To confirm the ferroelectric switching, optoelectronic experiments were carried out, and the hexagonal columnar phases of 1b and 1c gave a sharp peak of spontaneous polarization in response to an applied triangular wave electric field (0.1-18 Hz). This is the first example of ferroelectrically switchable columnar liquid crystal phases generated by achiral molecules.     

Aggregation of Chlorophyll a' in Aqueous Methanol

An aggregate of chlorophyll a' (Chi a' , C13²-epimer of ChI a ) formed in a methanovwater (40160, vol/vol) mixed solvent was examined by visible absorption, circular dichro-ism (CD), fluorescence and resonance Raman spectrosco-pies in relation to its possible involvement in the core of photosystem I reaction center. The Chl a' aggregate exhibited a sharp, double-peaked absorption spectrum (690 and 715 nm) accompanied by an intense, conservative CD signal. The fluorescence excitation polarization spectrum showed that the doublet results from the exciton splitting in a single aggregate species. Time-dependent changes in the spectroscopic properties clearly point to a simple transformation process from one molecular species to another, though a minor component appears to coexist. This conclusion was supported also by the principal multicom-ponent spectral estimation analysis of the transients of absorption spectra. The species formed at the initial stage is most probably a T-shaped dimer or oligomer, which is then gradually converted into the final major product, presumably a stacked dimer. In both of these states, the Chl molecules are linked together via direct coordination of the C13'keto carbonyl oxygen onto the Mg atom of neighboring molecules, as suggested by almost identical resonance Raman spectra in ordinary and deuterated methanovwater mixed solvents. The stacked dimers probably further associate to form a colloidal state in this solvent system. Based on these results, a model for the Chl a' aggregation is proposed.     

2，5-二烷基-1，4-苯二酚类衍生物的新合成方法

研究了合成2，5-二烷基-1，4-苯二酚衍生物的新方法，该方法是以2-取代烷 基1，4-环已二酮为原料，在LiCl催化下，与各种醛缩合反应就得2，5-二烷基-1， 4-苯二酚衍生物，是一种由非芳香环化合物合成2，5-二烷基-1，4-苯二酚衍生物 的新方法。应用该方法简便地合成了天然化合物η-生育酚。     

5-Fluorouracil derivatives XXIII. Synthesis and antitumor activities of 1-carbamoyl-5-fluorouracils having aromatic ring

In order to get good antitumor agents especially better than 5-fluorouracil, tegafur and l-hexylcarbamoyl-5-fluorouracil (HCFU), fourty nine 1-carbamoyl-5-fluorouracil having aromatic ring were synthesized from 5-fluorouracil and isocyanates or mines. Antitumor activity was tested in the L1210 tumor system, and 5 compounds gave better value of therapeutic ratio than 5-fluorouracil, tegafur, HCFU. 1-(4-Methoxybenzylcarbamoyl)-5-fluorouracil gave the best result.     

Nachweis und Bestimmung des Mangans sowie seine Trennung von anderen Elementen

Ohne Zusammenfassung