Determination of Hematinic Acid Produced by Oxidative Cleavage of Hemoglobin Heme in Red Blood Cells

Our previous studies on the mechanism of phenylhydrazine-induced hemolytic anemia have shown that hematinic acid, one of oxidative cleavage products of heme, is formed by the reaction of hemoglobin with phenylhydrazine. Develoment of the determination of hematinic acid formed by this reaction in red blood cells (RBC) was required to study the mechanism of the hemolysis. Hemolysates prepared by lysis of fresh human RBC with water was mixed with standard hematinic acid. A solution consisting of hydrochloric acid, methanol, and acetone was added, and most of hemoglobin precipitated was removed by centrifugation. Hematinic acid was derived to the methyl ester by incubation with methanol containing sulfuric acid. The ester was passed to two type of silica gel column to remove interferences, and was analysed on a reversedphase high-performance liquid chromatographic column. Hematinic acid could be determined in the range 1.0-20.0μmol/ml RBC. Recovery from hemolysate was 65.0% ±3.5%. Standard compounds of hematinic acid and its methyl ester were prepared by the oxidation of hemin with hydrogen peroxide, and were comfirmed by elemental analyses and mass spectra.フェニルヒドラジン惹起性溶血貧血機構の著者らの研究において、ヘモグロビンとフェニルヒドラジンとの反応でヘムの酸化的開裂物質の１つであるヘマチン酸が生成することが示された。この反応によって赤血球（RBC）中で生じたヘマチン酸を定量する方法の確立が、溶血機構研究のため必要となった。人のRBCを水で溶血し、ヘマチン酸の標品を加えた。塩酸、メタノール、アセトンの溶液え加え、ほとんどのヘモグロビンを沈殿除去した。メタノールー硫酸溶液で加熱し、ヘマチン酸をメチルエステルに誘導した。夾雑物を２種のシリカゲルカラムを通すことによって除去し、逆相カラムを用いた高速液体クロマトグラフィーで分析した。ヘマチン酸は、1.0-20.0μmol/ml　RBCの範囲で定量でき、回収率は65.0 ±3.5％であった。ヘマチン酸とこのメチルエステルの標品は、ヘミンを過酸化水素酸化することによって合成し、元素分析と質量分析によって確認した

Polycyclic N-Hetero Compounds. XL. Reaction of Cyclic Ketones with Trisformylaminomethane

Reactions of cyclic ketones such as α-tetralone, 1,3-cyclohexanedione, or naphthalenedione with formamide or trisformylaminomethane (TFAM) have shown to form polyclic fused pyrimidines by us. Reactions of terpene ketones like l-menthone, d-camphor, l-carvone with TFAM were performed, and 8-isopropyl-5-methyl-5,6,7,8-tetrahydroquinazoline, borno[2,3-d] pyrimidine, and 5-isopropenyl-8-methyl-5,6-dihydroquinazoline were expectedly obtained from three terpenes. Minor products of 5-isopropenyl-8-methyl-5,6,7,8-tetrahydroquinazoline and 5-isopropenyl-8-methylquinazoline were formed with 5-isopropenyl-8-methyl-5,6-dihydroquinazoline by disproportionation reaction of l-carvone. Furthermore, No-formylmenthylamine, N-formylbornylamine, and N-formylcarvylamine were obtained as the Leuckart-type products terpene ketones in these reactions. The reaction of N-benzyl-4-piperidone with TFAM gave desired 6-benzyl-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine. The reaction of diethyl succinylsuccinate with TFAM afforded tricyclic 4,9-dioxo-3,4,8,9-tetrahydropyrimido[4,5-g]quinazoline. Above compounds were determined by the measurements of their instrumental analyses.α-テトラロン、1,3-シクロヘキサンジオン、ナフタレンジオン等の環式ケトン類とホルムアミド或はトリスホルミルアミノメタン（TFAM）との反応により、多環式縮合ピリミジン誘導体を容易に合成できる事は既に報告した。この反応の一環として環式ケトンにl-メントン、d-カンファ、l-カルボン等の生理活性を有するテルペンケトン及びN-ベンジル-4-ピペリドンとジエチルサクシニルサクシネートを用いてTFAMとの反応を検討した。3種のテルペンケトン類からは予期した縮合ピリミジンとして8-イソプロピル-5-メチル-5,6,7,8-テトラヒドロキナゾリン（Ⅱ）、ボルノ[2,3-d]ピリミジン（Ⅴ）、及び5-イソプロペニル-8-メチル-5,6-ジヒドロキナゾリン（Ⅷ）を得た。Ⅷの分離の際にⅧの不均化合物である5-イソプロペニル-8-メチル-5,6,7,8,-テトラヒドロキナゾリン（Ⅸ）及び5-イソプロペニル-8-メチルキナゾリン（Ⅹ）の生成をGC-MS及びpmrで確認したが、それらの単離には到らなかった。又、テルペンケトン類からLeuckart型反応生成物と考えられるN-ホルミルメンチルアミン（Ⅲ）、N-ホルミルボルニルアミン（Ⅵ）及びN-ホルミルカルビルアミン（ⅩⅠ）を得た。N-ベンジル-4-ピペリドンとTFAMとの反応では、6-ベンジル-5,6,7,8-テトラヒドロピリド[4,3-d]ピリミジン（ⅩⅢ）が得られた。最後に、環式ジケトンジエステルであるジエチルサクシニルサクシネートとTFAMとの反応に於いては一挙に三環性の4,9-ジオキソー3,4,8,9-テトラヒドロピリミド[4,5-g]キナゾリン（ⅩⅤ）を得ることが出来た。得られた化合物の構造はir,mass,pmr,元素記号等で決定した

On correlations and mutual entropy in quantum composed systems

We study the correlations of classical and quantum systems from the information theoretical points of view. We analyze a simple measure of correlations based on entropy (such measure was already investigated as the degree of entanglement by Belavkin, Matsuoka and Ohya). Contrary to naive expectation, it is shown that separable state might possesses stronger correlation than an entangled state

7-Chloro-1,2-dihydro­furo[2,3-c]isoquinolin-5-amine

In the title compound, C11H9ClN2O, the fused-ring system is essentially planar, with a maximum deviation of 0.0323 (16) Å. In the crystal, mol­ecules are connected by N—H⋯O hydrogen bonds forming a zigzag chain along the c axis. Mol­ecules are further stacked along the a axis through weak π–π inter­actions, the shortest distance between ring centroids being 3.6476 (8) Å

Attenuation of regulatory T cell function by type I IFN signaling in an MDA5 gain-of-function mutant mouse model

Melanoma differentiation-associated gene 5 (MDA5) is an essential viral double-stranded RNA sensor to trigger antiviral immune responses, including type I interferon (IFN) induction. Aberrant activation of this viral sensor is known to cause autoimmune diseases designated as type I interferonopathies. However, the cell types responsible for these diseases and the molecular mechanisms behind their onset and development are still largely unknown. In this study, we revealed the attenuation of regulatory T cell (Treg) function by type I IFN signaling in a mouse model expressing a gain-of-function MDA5 G821S mutant. We found that experimental colitis induced by adoptive transfer of naïve T cells in Rag2⁻/⁻ mice was rescued by simultaneous transfer of Tregs from wild-type but not from the MDA5 mutant mice. Type I IFN receptor deficiency in the MDA5 mutant mice recovered the suppressive function of MDA5 mutant Tregs. These results suggest that constitutive MDA5 and type I IFN signaling in Tregs decreases the suppressive function of Tregs, potentially contributing to the onset and exacerbation of autoimmune disorders in interferonopathies

Observation of the FeO2 and FeIVO stretching Raman bands for dioxygen reduction intermediates of cytochrome bo isolated from Escherichia coli

AbstractReaction intermediates in dioxygen reduction by the E. coli cytochrome bo-type ubiquinol oxidase were studied by time-resolved resonance Raman spectroscopy using the artificial cardiovascular system. At 0–20 μs following photolysis of the enzyme—CO adduct in the presence of O2, we observed the FeO2 stretching Raman band at 568 cm−1 which shifted to 535 cm−1 with the 18O2 derivative. These frequencies are remarkably close to those of other oxyhemoproteins including dioxygen-bound hemoglobin and aa3-type cytochrome c oxidase. In the later time range (20–40 μs), other oxygen-isotope-sensitive Raman bands were observed at 788 and 361 cm−1. Since the 781 cm−1 band exhibited a downshift by 37 cm−1 upon 18O2 substitution, we assigned it to the FeIVO stretching mode. This band is considered to arise from the ferryl intermediate, but its appearance was much earlier than the corresponding intermediate of bovine cytochrome c oxidase (> 100 μs). The 361 cm−1 band showed the 16O/18O isotopic frequency shift of 14 cm−1 similar to the case of bovine cytochrome c oxidase reaction