Adsorption of the Vapor Phase Components in Cigarette Smoke by Activated Carbon in Vented Filters

Using vented charcoal filters, the adsorption efficiencies of acetaldehyde, isoprene and acetone, the major components in the vapor phase of cigarette smoke, were studied. Filter ventilation was found to raise the adsorption efficiency of the adsorbent. The effect of increasing the ventilation rate through the filter was greatest for the adsorption of acetaldehyde. In order to clarify the effects of decreases of the flow rate and the concentration caused by ventilation, the adsorption by unvented charcoal filters under varied conditions was also measured. Although both raised the adsorptions of the three components, the lowered concentration was contributed to mainly by an increase of adsorption by the vented charcoal filters. Regardless of whether the filter was perforated or not, the adsorptions of the three components depended on the volume of the air drawn in at the top of the lighted end of the cigarette.     

Identification of d-Erythro-Dihydroneopterin Triphosphate as a Product of Guanosine Triphosphate Cyclohydrolase from Serratia indica

Guanosine triphosphate cyclohydrolase (EC 3.5.4.16) was previously shown to exist in two forms (GTP cyclohydrolase D-I and D-II) in Serratia indica IFO 3759, and they were homogeneously isolated. The present study deals with the characterization of their reaction products. A fluorescent product formed from guanosine triphosphate by GTP cyclohydrolase D-II was identified as 7,8-dihydroneopterin triphosphate by its absorption spectra, phosphate analysis and gas chromatography-mass spectrometry of the dephosphorylated trimethylsilyl derivative. After oxidation and dephosphorylation, the d-erythro configuration of the side chain was made clear by the elution profile on ECTEOLA-cellulose chromatography, Rf values on thin-layer chromatography and by biological activity to Crithidia fasciculata ATCC 12857. The fluorescent products from GTP cyclohydrolase D-I and D-II were indistinguishable.     

An Improved Assay Method for Antifouling Substances Using the Blue Mussel,Mytilus edulis

The restriction endonuclease AatII was purified from cell-free extracts of Acetobacter aceti IFO 3281 by streptomycin treatment, ammonium sulfate fractionation, combined column chromatographies on DEAE-Toyopearl 650S, heparin-Sepharose CL-6B and DEAE-Sepharose CL-6B and FPLC on Mono Q and on Superose 12 (gel filtration). The purified enzyme was homogeneous on SDS-polyacrylamide gel disk electrophoresis. The relative molecular mass of the purified enzyme was 190,000 daltons by gel filtration. The SDS-polyacrylamide gel disk electrophoresis gave the relative molecular mass of 47,500 daltons. These data indicated that the purified, native enzyme is a tetramer (190,000 daltons) composed of four 47,500-dalton subunits. The isoelectric point of the enzyme was 6.0. The purified enzyme was intensely activated by manganese ion (50-fold increase or more when compared with magnesium ion). The enzyme worked best at 37°C and pH 8.5 in a reaction mixture (50 μl) containing 1.0 μg λDNA, 10 mm Tris-HCl, 7 mm 2-mercaptoethanol, 7 mm MnCl₂ and 50 mm NaCl. The enzyme recognizes the same palindromic hexanucleotide sequence 5′-GACGTC-3′, cuts between T and C and produces a 3′-tetranucleotide extension in the presence of MnCl₂, as it does in the presence of MgCl₂.     

Purification and Properties of a Proteolytic Enzyme,Cathepsin D,from Chicken Muscle

Cathepsin D was isolated from crude extract of chicken muscle by the purification procedures of acid- and heat-treatments, ammonium sulfate fractionation, DEAE-Sephadex A-50 column chromatography and Sephadex G-100 gel filtration. The enzyme was purified about 3700 fold and homogeneous in disc-electrophoretic analysis. The molecular weight was found to be about 36,000 and the isoelectric point to be pH 7.3. The best substrate for this enzyme was 6 m urea-denatured casein, and its activity was maximal at pH 3.5 and 40°C. This enzyme was most stable between pH 4 and 5, and its stability was affected by cupric ion. The enzyme activity was markedly inhibited by sodium laurylsulfate and oxidizing agents such as potassium permanganate, N-bromosuccinimide and iodine, and was slightly activated by hydrogen peroxide. The purified cathepsin D was found to be fairly similar to the acid protease from lotus seed, previously reported by the authors.     

Flavor Activity of Sulfur-containing Compounds Related to Flavor Nucleotides

Substance B, the major component, isolated from rice plant treated with probenzaole and inoculated, having anti-conidial germination activity against blast fungus, was found to be a mixture of fatty acids, including palmitic acid, linoleic acid and linolenic acid. The main compound of substance B was linolenic acid, having strong anti-conidial germination activity. It was determined as α-linolenic acid by gas chromatographic analysis. The minor components showed little or no anti-conidial germination activity.     

Metabolism of Isoxathion,O, O-Diethyl O-(5-Phenyl-3-isoxazolyl) phosphorothioate in the Rats

Excretion, distribution and metabolism of the insecticide, Isoxathion, administered orally in male Wistar-strain rats, were investigated with a carbon-14 labeled chemical. During 96 hr, approximately 85% and 14% of the total radioactivity were excreted in the urine and feces. Distribution of isoxathion after oral administration in the rats was investigated by means of whole-body autoradiographic technique and measurement of radioactivity in the tissues. At least eleven radioactive metabolites were detected, four of which were structurally determined. They were 3-hydroxy-5-phenylisoxazole, 3-(β-d-glucopyranuronosyloxy)-5-phenylisoxazole, 5-phenyl-3-isoxazolyl sulfate and hippuric acid.     

The Chlorinolysis of Methionine Derivatives

The chlorinolysis of l-methionine methyl ester hydrochloride with molecular chlorine was carried out under various conditions, resulting in methyl l-2-amino-4,4,4-trichlorobutanoate and methyl l-2-amino-3,4,4,4-tetrachlorobutanoate which were isolated as N-benzoyl and N-carbobenzoxy derivatives. The chlorinolysis of N-acylmethionine ester and methionine sulfoxide ester proceeded also without cleavage of the N-protecting group to give the same products as above. However, the reaction of methionine sulfone derivative with chlorine did not proceed in the same conditions.

It was proved that the resulting polychloroamino acid derivatives are optically pure. The possible chlorinolysis mechanism was also proposed.