Chuji Tatsumi

Studies on Kojic Acid and its Related γ-Pyrone Compounds:Part VI. Catalytic Hydrogenation of Kojic Acid

The catalytic hydrogenation of kojic acid in the presence of Raney nickel and noble metals such as platinum or palladium was studied. The hydrogenated products were isolated and identified. By using Raney nickel catalyst, hexahydro kojic acid was obtained in good yield. Allo-maltol, hexahydro kojic acid and hexahydro allo-maltol were produced over platinum catalyst. Also, allomaltol, tetrahydro kojic acid and tetrahydro all maltol were produced over palladium catalyst. The success of the direct conversion from kojic acid to allo-maltol may be emphasized.

Studies on the Reduction of Terpenes with Sodium in Aqueous Ammonia: Part XIII. On the Reduction of p-Mentha-1,3-dien-7-al

The reduction of p-mentha-1,3-dien-7-al (II) with sodium in aqueous ammonia afforded trans- and cis-p-menthan-7-ol via 1-p-menthen-7-al (phellandral) and trans- and cis-p-menthan-7-al, respectively, in which the trans forms were obtained predominantly due to the stereoelectronic requirement.

Studies on Kojic Acid Metabolism by Microorganisms: Part XI. Comenic Aldehyde Dehydrogenase (5-Methoxy Comenic Aldehyde Dehydrogenase)

An enzyme, comenic aldehyde dehydrogenase, which catalyzes the oxidation of comenic aldehyde to comenic acid was partially purified from cell extract of Arthrobacter ureafaciens K-1.The enzyme was purified 31-fold at Sephadex G-100 filtration step, 112-fold at DEAE-Sephadex A-50 fractionation step, and recovery of the activity was 73.3% and 38.5% respectively.NADP and magnesium ion were essential for the oxidation. The enzyme shows optimum activity at pH 7.8. Enzyme activity was extremely sensitive to sulfhydryl reagents such as p-chloromercuribenzoate and monoiodoacetate. l-Cysteine or dithiothreitol protected the enzyme from p-chloromercuribenzoate inhibition. Carbonyl reagents, such as hydroxylamine and semicarbazide, inhibit the enzyme reaction by formation of addition compounds between carbonyl reagents and aldehyde group of the substrate. The enzyme was completely inactivated after heating for 5 min at 40°C The Km for 5-methoxy comenic aldehyde is 2.5×10−6 m, and for NADP is 0.4×1O−6 m. The reaction...

Effect of γ-Radiation on the Fat Production of Rhodotorzaa sp.

The cell of a strain of Rhodotorula sp. (Rh-110) isolated by the authors, contains 10-45 per cent of crude fat and 45-20 per cent of protein. In general, both fatty acid and ergasterol content of the metabolites of the Rh-110 strain is quite constant, being independent from the culture conditions employed.Therefore, it is expected that particular mutant which is to be obtained in irradiation might give specifically varied contents of fatty acids and ergosterol.The present paper reports general characteristics of such mutant strains obtained.

Degradation of Dehydroacetic Acid by Microorganisms Part III

デヒドロ酢酸分解細菌PseudomonasSP.のTAL加水分解酵素を用いてその酵素的性質を検討した. (1) 硫安処理(0.33～0,45飽和), G-75セファデックス処理およびDEAE-セファデックスA-25によるカラムクロマトクラフィーによって約30倍に濃縮された. (2)酵素の性質: i) 最適PH 7.2～8.5,最適温度50～55°Cでかなり高温である. ii) 熱に対しては60°までは安定,80°Cでほとんど失活した.iii)金属イオンとしてMn2+イオンを必要とし,その量は2～4mMである. iv) 各種阻害剤のうちρ-CMBによって完全に阻害され,EDTA,o-フェナンスロリン等で阻害されることから,本酵素はSH基を必要とし,Mn2+イオンを賦活剤とする酵素であると推定した. V) 基質としてアルドノラクトンおよびウロノラクトンには作用しなくてTALのみを水解する. vi) 0～5°Cで約30日間は安定であるが,この温度で貯蔵すると活性を上昇する傾向を示した. (3) 本酵素によるTALの分解生成物をアルカリ性における295mμの変化,アニリンサイトレイト法による脱炭酸量およびo-フェニレンジアミン比色法の3法によって検討した結果から,TALはTAAに分解されるであろうと推定した.

Studies on Kojic Acid and its Related γ-Pyrone Compounds:Part XIV Reactions of Kojic Acid and its Related γ-Pyrones with Hydrazine

The reactions of kojic acid and its related γ-pyrones with anhydrous hydrazine have been investigated. Kojic acid and hydrazine gave 3,6-dihydroxy methyl-4-охо-1,4-dihydro- pyridazine and 3-hydroxymethyl-pyrazolyl-(5)-glycoloyl-hydrazone, respectively, in 65% and 21% yields. The same reaction occured in the case of allomaltol and pyromeconic acid and gave the analogous results. On the other hand, 5-methoxykojic acid was allowed to react with hydrazine and afforded 1-amino-2-hydroxymethyl-5-methoxy-γ-pyridone and α[3-hydroxymethyl-pyrazolyl-(5)]-α-methoxy-acetaldehyde-hydrazone, respectively. The structural elucidation of these products could be fully substantiated by chemical evidences and spectroscopic data. The mechanisms for the reactions are also discussed.

Syntheses of Terpenes by the Condensation of Aliphatic Compounds: Part II. Self-Condensation of Mesityloxide and Structures of Isomeric Isoxylitones

Treatment of mesityloxide with basic condensing agents resulted in formation of isoxylitones-A, B, C and D and isophorone. These compounds were purely isolated and assigned their structures from spectroscopic and chemical evidences. Isoxylitone-A and isoxylitone-B were conformers of 1-acetyl-2, 4, 6, 6-tetramethyl-1, 3-cyclohexadiene separated by the rotational barrier of acetyl group and interconversional barrier of cyclohexadiene ring. Isoxylitone-C was 4-isopropenyl-1, 5, 5-trimethyl-1-cyclohexen-3-one. Isoxylitone-D was 5, 5-dimethyl-3-(1-isobutenyl)-2-cyclohexen-1-one.

Syntheses of Terpenes by the Condensation of Aliphatic Compounds: Part I. Synthesis of Piperitenone by the Condensation of Mesityloxide with 4-Diethylaminobutanone-(2)

The condensation of mesityloxide with 4-diethylaminobutanone-(2) in the presence of potassium t-butoxide gave the products containing piperitenone together with isoxylitones, which were identified by gas chromatography and chemical methods. The effects of the combination of condensing agent, solvent, molar ratio of reagents and reaction temperature on the components in the condensation products were studied. It was found that piperitenone was able to obtain in an yield of 51% on the basis of 4-diethylaminobutanone-(2) by the use of Triton-B as a condensing agent. Also piperitenone can be isolated from the condensation products by the treatment with semicarbazide.

Studies on Kojic Acid and its Related γ-Pyrone Compounds: Part VII. The Alkylation of Kojic Acid and Pyromeconic Acid through their Mannich Base (Synthesis of Maltol-(1))Part VIII. Synthesis of Comenic Acid from Kojic Acid (Synthesis of Maltol (2))

The Mannich reaction of kojic acid in both acidic and basic media was studied. Mono-Mannich derivatives (substitution at position 6) were obtained; the reactivity in basic medium was found to be somewhat greater than in acidic medium. Reduction of the Mannich derivatives with zinc dust and acetic acid gave a 6-methyl kojic acid (6-methyl-5-hydroxy-2-hydroxymethyl-γ-pyrone).Mono-Mannich base of pyromeconic acid was also prepared in a manner similar to that of kojic acid. From this Mannich base, maltol (2-methyl-3-hydroxy-γ-pyrone) was obtained by the reduction with zinc dust and acetic acid.