Amylose was prepared by enzymatic polymerization of alpha-D-glucose 1-phosphate dipotassium catalyzed by a phosphorylase using two kinds of the primers derived from maltopentaose, and then it was chemically bonded to silica gel to be used as a chiral stationary phase (CSP) in high-performance liquid chromatography. In method I, maltopentaose was first lactonized and allowed to react with (3-aminopropyl)triethoxysilane to form an amide bond. Amylose chains with a desired chain length and a narrow molecular weight distribution were then constructed by the enzymatic polymerization. The resulting amylose bearing a trialkoxysilyl group at the terminal was allowed to react with silica gel for immobilization. In method II, maltopentaose was first oxidized to form a potassium gluconate at the reducing terminal. After the enzymatic polymerization was performed with the potassium gluconate, the amylose end was lactonized to be immobilized to 3-aminopropyl-silanized silica gel through amide bond formation. Two amylose-conjugated silica gels thus obtained were treated with a large excess of 3,5-dimethylphenyl isocyanate to convert hydroxy groups of amylose to corresponding carbamate residues. The CSP derived through method II was superior in chiral recognition to the CSP derived from method I and showed better resolving power and higher durability against solvents such as tetrahydrofuran compared with a coated-type CSP. Influences of degree of polymerization of amylose, the spacer length between amylose and silica gel, and mobile phase compositions on chiral recognition were investigated.

The objective of our research was to prepare novel conjugates between polysaccharides and vinyl polymers by applying enzymes as polymerization catalyst for polysaccharide synthesis. An approach was attained using amylose-substituted styrene macromonomers (vinylbenzyl amylose amide, VAA; the number-average degree of polymerization of amylose = 24 and 150) which were synthesized from maltopentaose-substituted styrene (VM5A) by phosphorylase-catalyzed polymerization of glucose 1-phosphate. Radical homo- and copolymerization of VAA gave an uncommon type of graft copolymers consisting of polystyrene and polyacrylamide backbones and amylose side chains of uniform length. Water-insoluble amylose was solubilized into water by incorporating VAA units into polyacrylamide main chains and also by hydroxypropylation of the amylose moieties of water-insoluble copolymers. Structural features of these graft copolymers were discussed on the basis of amylose−iodine complexation investigated by UV spectroscopy. Schematic structures of two different types of polystyrene-graft-amylose prepared via homopolymerization of VAA and via enzymatic elongation from poly(VM5A) were proposed. These amylose-carrying polyacrylamide and polystyrene prepared by applying enzyme-catalyzed polymerization are of interest as a new type of biomedical material and a well-defined model for conformational analysis.

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The polycrystalline silicalite membrane was prepared on a porous sintered stainless steel support and its pervaporation performance was investigated using an acetic acid / water mixture as a feed. The silicalite membrane selectively permeates acetic acid in the concentration of the feed acetic acid in the region of 5 to 40 vol%.

Iron(II)/EDTA/ascorbate-mediated oxidative damage to specific amino acid residues (tryptophan) of serum albumin was studied. The active species generated by Fe(II)/EDTA/ascorbate preferred to react with tryptophan residues rather than histidine or other amino acids. The observation of preferential damage to tryptophan residues of the protein was fully suported by a model experiment using a tryptophan analogue. The reaction of Fe(II)/EDTA/ascorbate to the protein was significantly suppressed by mannitol and dimethysulfoxide, suggesting the participation of the hydroxyl radical generated via Fenton's reaction. The result was supported by the hydroxyl radical assay using 2deoxyribose. 3285Ascorbate is definitely an essential compound present at high concentrations in some mammalian tissues such as adrenals, leucocytes, brain, eyes, and pneumocytes. 1) As a reductant in food and biological systems, ascorbate by itself has been the focus of numerous basic studies. 2 ) However, the beneficial roles of ascorbate have focused attention also on its involvement in detrimental processes, which might be mostly attributed to the autoxidation of ascorbate by itself. 3 ) Ascorbate is relatively stable in pure water, while in the presence of catalytic amounts of metal ion, it is rapidly oxidized to dehydroascorbate through an electron-transfer from ascorbate to meta1. 4 -6 ) The rate of reaction is known to depend on pH, catalyst, oxygen pressure, temperature, etc. The function of ascorbate is to reduce the metal ion [M(n + 1)) (Eq. (1)), and to serve as a source for superoxide (0 2 -) (Eq. (2)) and hydrogen peroxide (H 2 0 2 ) (Eq. (3)). The reduced metal ion [M(n)] is conducted via a Fenton's reaction to generate the most potent oxidant, the hy-* To whom correspondence should be addressed. droxyl radical COH) (Eq. (4)).M(n+ 1) + ascorbatẽ M(n)+dehydroascorbate(1)M(n)+H 2 0 2~M (n+ l)+OH-+ ·OH (4) Accordingly, the cytotoxicity of ascorbate in the presence of metal ions has been interpreted in terms of the generation of oxygen-derived free radicals. 7 )In vitro, a metal/ascorbate system promotes the oxidative scission of various food and biological materials such as· polysaccharides,8) proteins,7,9-14) and DNA 15 ) and also mediates the specific oxygenation of a histamine analogue. 16 ) Especially, it is of a great interest that this system gives rise to the specific modification of histidine residues of the protein. 10 -14 ) We have confirmed that approximately 60% of histidine residues of the protein and peptides were selectively modified

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Summary:The long-term survival rate following acute myocardial infarction (AMI) was studied in 358 patients in central Japan who were monitored for 8 to 20 years after discharge from hospital for AMI. Fifteen-year cardiac survival rates were 65% in males and 72% in females. In both sexes, the survival rate decreased with increasing age at the time of AMI. The survival rate was significantly lower in recurrent MI than in first MI patients. Those who had smoked cigarettes before AM1 or had hyperlipidemia during hospitalization did not show any significant decrease in cardiac survival rate, which may be due to cessation of smoking or control of hyperlipidemia after AMI. The 15-year survival rate was significantly lower in patients with a past history of angina pectoris or hypertension. Patients with a large infarct had a lower survival rate, as did those with a large cardiothoracic ratio on chest x-ray, and those who received digitalis during hospitalization. On the other hand, patients who were administered anticoagulants during hospitalization had a higher survival rate. Multiple regression analysis gave similar results. In conclusion, factors that reduced long-term survival rate after AM1 were older age at time of the first attack, reduced cardiac function, and a history of angina pectoris or hypertension. Anticoagulant therapy appeared to improve the long-term survival rate.