著者

平山 晃久 山口 昌史 中田 哲誌 奥村 美和 山崎 智美 渡辺 徹志 福井 昭三

出版者

公益社団法人 日本薬学会

雑誌

衛生化学 (ISSN:0013273X)

巻号頁・発行日

vol.35, no.4, pp.303-306, 1989-08-31 (Released:2008-05-30)

参考文献数

7

被引用文献数

6 7

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0.1% NH2OH (2.5 ml), 5 N HCl (2.5 ml) and 1% m-aminophenol solution (1 ml) were added to unsaturated fatty acid methyl enters (10 mg), and the mixture was heated in a boiling water bath at 100°C for 20 min. The reaction mixtures were measured for their fluorescence intensity at Ex. 356 nm and Em. 505 nm, and the amounts of acrolein formed were determined from its calibration curve. Methyl linolenate oxidized for 20 h at 80°C, 2258.2μg/g of acrolein were formed, whereas 208.1μg/g of malondialdehyde were determined by the thiobarbituric acid method. Thus the determination of acrolein in oxidized lipid may have some fundamental significance for the evaluation of lipid oxidation. It was of interest that acrolein is formed not only from glycerin and triglyceride but also from unsaturated fatty acids by their autoxidation.

著者

平山 晃久 中田 晴美 渡辺 徹志

出版者

The Pharmaceutical Society of Japan

雑誌

衛生化学 (ISSN:0013273X)

巻号頁・発行日

vol.38, no.5, pp.431-436, 1992-10-31 (Released:2008-05-30)

参考文献数

6

被引用文献数

1

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The effect of nicotinamide on 7 kinds of mutagenic alkylating agents was investigated in Salmonella typhimurium TA100 without S9 mix, and its mechanism was studied. The mutagenic potency of alkylating agents other than N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was reduced to less than 50% by the addition of about 50-fold molar ratio of nicotinamide to alkylating agent. The mutagenic potency of MNNG was only reduced to 60-70% by the addition of more than 200-fold molar ratio of nicotinamide. To investigate the mechanism of the suppressive effect of nicotinamide, alkylating agents (1.0 μmol) (methyl methanesulfonate and dimethyl sulfate) were reacted with nicotinamide (1.0 μmol) alone or together with DNA or 5 kinds of nucleotides in phosphate buffer (pH 7.4) at 30°C for 24 h, and the resulting N1-methylnicotinamide (NMN) was analyzed by HPLC with fluorometric detection after derivatization. With the addition of DNA (0.2 molar ratio or more), the amount of NMN by methyl methane-sulfonate was reduced to 80% compared with nicotinamide alone, whereas that by dimethyl sulfate was unchanged. With the addition of nucleotides like guanosine-5'-phosphate, the amount of NMN by methyl methanesulfonate was reduced to 75%, whereas no reducing effect was seen by the other 4 nucleotides. The present results strongly suggest that nicotinamide is more easily alkylated than nucleic bases in DNA or nucleotides by methyl methanesulfonate and dimethyl sulfate, and that nicotinamide scavenged alkyl species derived from them, thereby showing a suppressive effect on the mutagenicity of alkylating agents. In MNNG, nicotinamide did not act as des-mutagen in Salmonella assay.