著者
二五田 公俊
出版者
日本ビタミン学会
雑誌
ビタミン (ISSN:0006386X)
巻号頁・発行日
vol.48, no.9, pp.453-462, 1974-09-25

A mutant strain of Escherichia coli, O8-442,requiring lipoic acid (LiA) for both aerobic and anaerobic growth in a minimal medium with glucose as a sole carbon source was isolated. The requirment for LiA could be replaceable by either acetate+succinate or acetate+lysine+methionine under aerobic conditions, but anaerobically it grew on either acetate or succinate alone. Pyruvate markedly stimu1ated.the respiration of the mutant cells grown aerobically on LiA and the addition of LiA did not cause a further stimulation. Conversely, results obtained with the cells grown aerobically on acetate+ lysine+methionine was quite different ; the degree of the pyruvate-oxidizing activity was very low but the activity was fully restored by the addition of LiA. In the same system, lipoamide (LiANH_2) was found to have no activity for the respiration of the mutant cells, while it was more active than LiA when extracts prepared from the mutant cells were used. These results suggest that the de novo synthesis of LiA is blocked in the mutant strain. A permeability barrier appears to be involved in the utilization of LiANH_2.
著者
神谷 真太郎
出版者
日本ビタミン学会
雑誌
ビタミン (ISSN:0006386X)
巻号頁・発行日
vol.18, pp.396-400, 1959

In the previous papers, it was reported that L-ascorbic acid decomposing enzymes of bacteria were produced adaptively only in the cells grown in a medium containing L-ascorbic acid, but not in the unadapted cells even when they were in contact with L-ascorbic acid for a long time. In this paper, it was shown that the unadapted cells became able to metabolize L-ascorbic acid when a small quantity of glucose and casein hydrolyzate were given. Both D-araboascorbic acid and D-glucoascorbic acid too were decomposed by L-ascorbic acid decomposing cells, but other reductones such as reductic acid, dihydroxymaleic acid, and 5-methyl-3,4-dihydroxytetrone were not. On the other hand, some properties of L-ascorbic acid oxidase found in the unadapted cells were studied. Its optimum pH was about 5.0 and the optimum concentration of the substrate was 800μM. It was found, too, that endiol compounds such as D-araboascorbic acid, reductic acid and 5-methyl-3,4-dihydroxytetrone, etc. were not decomposed by this enzyme.
著者
阿部 皓一 石橋 恭子 大前 雅彦 河部 靖 勝井 五一郎
出版者
日本ビタミン学会
雑誌
ビタミン (ISSN:0006386X)
巻号頁・発行日
vol.51, no.3, pp.111-117, 1977-03-25
被引用文献数
2

A Method for the determination of ubiquinone homologues (UQ) in serum and liver is described. Serum or liver homogenate was saponified with methanolic alkaline solution after addition of 2,3,6-trimethyl-5-nonaprenyl-1,4-benzoquinone (TQ-9) as an internal standard and then extracted with n-hexane. The n-hexane extract was evaporated under N_2 gas at 30℃, and the residue was dissolved in dioxane. The sample solution was applied to the high-speed liquid chromatography (HSLC) using a Permaphase ODS column and ethanol・water (80 : 20) as a mobile phase. The peaks of UQ and TQ-9 were not disturbed by other fat-soluble substances when an on-line high-sensitive multiple wavelength detector set at 275 nm (absorption maximum of UQ) was used as a detector. The proposed HSLC method was found to be more simple and specific than the other conventional determination methods.
著者
池川 雅哉 木村 美恵子
出版者
日本ビタミン学会
雑誌
ビタミン (ISSN:0006386X)
巻号頁・発行日
vol.83, no.8, pp.453-460, 2009-08-25

Lithium (Li) is the smallest of the alkali metals. Medical application of Li for treating mood disorders was preceded to the studies on its actions for human health. Traces of Li were detected in human organs and fetal tissue. Li is found in variable amounts in our environment and in foods. In some areas, the drinking water also provides significant amounts of the element. Animal experiments on rats and goats maintained on low-lithium rations showed to exhibit higher mortalities as well as reproductive and behavioral abnormalities; however, it is still debatable that Li is essential as an ultra trace nutrient. The biochemical mechanisms of action of Li appear to be multi-factorial and are inter-correlated with the functions of several enzymes, hormones, vitamins and minerals. Here we reviewed lithium occurrence, dietary intakes, and nutritional essentiality as well as pharmacological properties with special references to cancer and stem cell biology.
著者
井上 正康
出版者
日本ビタミン学会
雑誌
ビタミン (ISSN:0006386X)
巻号頁・発行日
vol.78, no.9, pp.458-460, 2004-09-25
被引用文献数
1

通常, "疲労"と言えば"肉体疲労"と"精神疲労"に分類されるが, 風邪や慢性炎症などでも強く疲労を感じ, いずれの場合も"しんどい"と感じる. このことは, 筋肉病態, 感染病態, あるいは精神病態が誘起した変化を同じ病態情報として認識する脳の"疲労検知中枢"が存在することを意味する. UVAは体表組織の葉酸を破壊して成長不良を誘起するが, 遺伝子毒性の強いUVBはコレステロールからビタミンD前駆体を合成してクル病を予防する. アフリカ大地溝帯で産まれた人類の祖先は, 紫外線のプラスとマイナスの効果がちょうど折り合うニッチで, 黒人, 黄色人種および白人として環境に適応分布してきた. しかし, 大航海時代以後, 移動システムの進歩, 植民地政策, 奴隷貿易などにより, 肌の色や紫外線感受性とは無関係に人種の分布が混ざり合ってきた. オーストラリアの珊瑚礁などで1時間ほど太陽光を浴びると皮膚細胞の遺伝子に約10万個もの傷がつきメラノーマが生じる. このため, オーストラリアの70歳以上の白人男性の約半数は皮膚癌に悩まされている. 皮膚をUVBで照射すると日焼けすることは常識であるが, 実は「眼に紫外線を当てても皮膚が黒くなる」という驚くべき現象がみつかった.