The behavior of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) at the interface between the solution and a gold electrode has been studied by specular reflectivity measurement and cyclic voltammetry in 0.05 M carbonate buffer (pH 10.0). Current-potential (i-E) curves obtained for FMN and FAD showed redox peaks at about -0.5 V (vs. Ag/AgCl), suggesting that the isoalloxazine moieties of these compounds participate in the electron transport. The reflectivity-potential curves for these compounds measured simultaneously with the i-E curves showed a marked decrease in reflectivity in the potential region more positive than about -0.8 V. Such a trend suggests that adsorption of these compounds, as well as of their reduction products, takes place on the electrode surface. In order to obtain information about the adsorbed states of these molecules, the data were analyzed according to the theoretical treatment of McIntyre and Aspnes. The results suggest that both FMN and FAD are adsorbed with their isoalloxazine rings in contact with the electrode surface. In addition, the adenine moiety of FAD appears to come partly into contact with the surface. The reduced forms of FMN and FAD are also observed to lie in essentially the same states as their oxidized forms.

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Hydroxyapatite (HAP) in water exhibited a buffer function in the region from weakly acidic through weakly alkaline pH. Equilibrium pH depends on the amount of HAP added, and on the species and concentration of added electrolyte. This function seems to originate from the ability of HAP to adsorb OH-and/or from the protonation-deprotonation equilibrium of surface phosphate ion. Theoretical calculation of the suspension pH was attempted. The isotherm of OH- adsorption from aqueous solutions of NaOH mixed with NaCl was of Langmuir type. The saturated amount of OH- adsorption was almost constant irrespective of the amount of NaCl added, but the binding constant increased with the amount of added NaCl. The adsorption isotherms, however, formed just one curve irrespective of the amount of NaCl added when they were expressed as a function of the thermodynamic activity of NaOH. On the other hand, the amount of adsorbed OH- increased with the amount of Ca²⁺ added, because Ca²⁺ is adsorbed on the HAP surface and forms a positively charged adsorption site for OH-. An electrophoresis experiment confirmed that HAP particles have positive charges due to adsorbed Ca²⁺ even in solutio at high pH.

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A new compound, pyracrenic acid (1), was isolated from the bark of Pyracantha crenulata ROEM. of Rosaceae by tracing its granulation-suppressive activity by the fertile egg method in the course of an extensive search among crude drugs and plants for anti-inflammatory constituents. Methylation of 1 with diazomethane-ether solution gave methyl O, O-dimethylpyracrenate (6), which was cleaved by hydrolysis into methyl betulinate (7) and O, O-dimethylcaffeic acid (8). Thus, 1 has the structure of 3β-(3, 4-dihydroxycinnamoyl) oxylup-20 (29)-en-28-oic acid. Results obtained by the cotton pellet method showed that 1 potently inhibits the formation of granulation tissue.

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Treatment of quinoline 1-oxide (1a) with α, α'-azobisisobutyronitrile (AIBN) ordimethyl α, α'-azobisisobutyrate in boiling benzene for 5 h affords 2-(1-cyano-1-methylethyl) quinoline (2a) or 2-(1-methoxycarbonyl-1-methylethyl) quinoline (4) in 31.9 or 24.9% yield, respectively, accompanied with a small amount of quinoline in each case. The 1-oxides of lepidine, 3, 2'-diquinolyl and 4-nitroquinoline (1c, 1d and 1e), and isoquinoline 2-oxide (6) similarly react with AIBN to produce the corresponding α-substituted products (2c, 2d, 2e and 7). The reaction of pyridine 1-oxide (8) gives not only the 2-substituted pyridine (9 : 1.5%) but also the 4-substituted one (10 : 3.0%). On the other hand, the reactions of 1a and 6 with phenylazotriphenylmethane in boiling benzene afford the α-phenyl N-oxides (12 : 17.2% and 14 : 34.5%) and their deoxygenated products (13 : 3.5% and 15 : 2.9%).

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5-(Substituted-thiomethyl)-6-carbamoyluracils (IIIa-f and VIa-c) were prepared in two steps from 5-chloromethyl-6-ethoxycarbonyluracil (I). Oxidation of IIIa-c gave the corresponding sulfones (IVa-c). The compounds thus prepared were examined for growth inhibition of L-1210 cells in vitro and some of them exhibited high activity.

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Treatment of β-cellobiose with 2 molar equivalents of trityl chloride in pyridine at 100°C for 1 h afforded three unusual ditritylates (2, 4, and 5) as well as the 6, 6'-ditritylate (3) which was the expected product. The ratios of 2, 4, and 5 to 3 were approximately 2, 2, and 1 : 60, respectively. Each unusual ditritylate was isolated by column chromatography and was crystallized as needles. Their structures were established by the use of ¹H nuclear magnetic resonance (NMR), ¹³C-NMR, optical activity measurements, etc. It was concluded that 2 is trityl 6'-O-trityl-β-cellobioside, 4 is 2, 6'-di-O-tritylcellobiose, and 5 is trityl 6-O-trityl-β-cellobioside.

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The reaction of C₂-substituted 1, 2, 3, 4-tetrahydroquinazolin-4-ones (1) with acetic anhydride and pyridine was carried out in order to elucidate the effect of the C₂-substituent. It was found that the various types of reactions occurred depending on the kind and number of C₂-substituents of 1, 2, 3, 4-tetrahydroquinazolin-4-ones (1).

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