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Imamura K, Higashi M, Kobayashi Y, Kageyama H, Sato H. Chemical Shift of Solvated Hydride Ion: Comparative Study with Solvated Fluoride Ion. J Phys Chem B 2022; 126:3090-3098. [DOI: 10.1021/acs.jpcb.2c00326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Fuse H, Irie Y, Fuki M, Kobori Y, Kato K, Yamakata A, Higashi M, Mitsunuma H, Kanai M. Identification of a Self-Photosensitizing Hydrogen Atom Transfer Organocatalyst System. J Am Chem Soc 2022; 144:6566-6574. [PMID: 35357152 DOI: 10.1021/jacs.2c01705] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We developed organocatalyst systems to promote the cleavage of stable C-H bonds, such as formyl, α-hydroxy, and benzylic C-H bonds, through a hydrogen atom transfer (HAT) process without the use of exogenous photosensitizers. An electronically tuned thiophosphoric acid, 7,7'-OMe-TPA, was assembled with substrate or co-catalyst N-heteroaromatics through hydrogen bonding and π-π interactions to form electron donor-acceptor (EDA) complexes. Photoirradiation of the EDA complex induced stepwise, sequential single-electron transfer (SET) processes to generate a HAT-active thiyl radical. The first SET was from the electron-rich naphthyl group of 7,7'-OMe-TPA to the protonated N-heteroaromatics and the second proton-coupled SET (PCET) from the thiophosphoric acid moiety of 7,7'-OMe-TPA to the resulting naphthyl radical cation. Spectroscopic studies and theoretical calculations characterized the stepwise SET process mediated by short-lived intermediates. This organocatalytic HAT system was applied to four different carbon-hydrogen (C-H) functionalization reactions, hydroxyalkylation and alkylation of N-heteroaromatics, acceptorless dehydrogenation of alcohols, and benzylation of imines, with high functional group tolerance.
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ZHU ZHE, Higashi M, Saito S. Excited states of chlorophyll a and b in solution by time-dependent density functional theory. J Chem Phys 2022; 156:124111. [DOI: 10.1063/5.0083395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ground state and excited state electronic properties of chlorophyll (Chl) a and Chl b in diethyl ether, acetone, and ethanol solutions are investigated using quantum mechanical and molecular mechanical calculations with density functional theory (DFT) and time-dependent DFT (TDDFT). Although the DFT/TDDFT methods are widely used, the electronic structures of molecules, especially large molecules, calculated with these methods are known to be strongly dependent on the functionals and the parameters used in functionals. Here, we optimize the range-separated parameter, µ, of the CAM-B3LYP functional of Chl a and Chl b to reproduce the experimental excitation energy differences of these Chl molecules in solution. The optimal values of µ for Chl a and Chl b are smaller than the default value of µ and that for bacteriochlorophyll a, indicating the change in electronic distribution, i.e., an increase in electron delocalization, within the molecule. We find that the electronic distribution of Chl b with an extra formyl group is different from that of Chl a. We also find that the polarity of solution and hydrogen bond cause the decrease in the excitation energies and the increase in the widths of excitation energy distributions of Chl a and Chl b. The present results are expected to be useful for understanding the electronic properties of each pigment molecule in a local heterogeneous environment, which will play an important role in the excitation energy transfer in light-harvesting complex II.
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Kitamura T, Komoto R, Oyamada J, Higashi M, Kishikawa Y. Iodine-Mediated Fluorination of Alkenes with an HF Reagent: Regioselective Synthesis of 2-Fluoroalkyl Iodides. J Org Chem 2021; 86:18300-18303. [PMID: 34866387 DOI: 10.1021/acs.joc.1c02422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluorination reaction of alkenes with iodine and HF·pyridine complex (pyr·9HF) was performed under mild conditions in the presence of K2S2O8 or Na2S2O8 as an oxidant. Aliphatic and aromatic alkenes underwent iodofluorination to give the iodofluorinated products with high regioselectivity. The substitution reactions of the iodofluorinated product by nitrogen, sulfur, and oxygen nucleophiles indicated further applications as a building block for synthesis of 2-fluoroalkyl-substituted compounds.
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Marani LO, Costa AFO, Silva FB, Madeira IA, Scheucher PS, Schiavinato JL, Lima ASG, Dorê A, Pagnano KBB, Duarte BK, Kerbauy F, Feliciano JV, Higashi M, Bittencourt R, Nunes EC, Glória ABF, Fagundes E, Fraga ES, Traina F, Rego EM, Freeman S, Figueiredo-Pontes LL. UNRAVELLING THE HIGH INCIDENCE OF ACUTE MYELOID LEUKEMIA WITH MONOCYTIC BLAST DIFFERENTIATION IN A BRAZILIAN MULTICENTER STUDY. Hematol Transfus Cell Ther 2021. [DOI: 10.1016/j.htct.2021.10.312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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31
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Alvarenga BBL, Arca GL, Manzo E, Guerra JO, Guidugli C, Mauad MA, Silva DMSLE, Higashi M, Mattos ER, Moreira LBP. PÚRPURA TROMBOCITOPÊNICA TROMBÓTICA NA ADOLESCÊNCIA: REMISSÃO COMPLETA APÓS TRATAMENTO COM PLASMAFÉRESE E RITUXIMAB. Hematol Transfus Cell Ther 2021. [DOI: 10.1016/j.htct.2021.10.506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Melo IMV, Higashi M, Queiroz LP, Alvarenga BBL, Mattos ER, Santos IPD, Barbosa LGR, Queiroz FFL. MACROGLOBULEMIA DE WALDENSTROM CONCOMITANTE A POLICITEMIA VERA: RELATO DE CASO. Hematol Transfus Cell Ther 2021. [DOI: 10.1016/j.htct.2021.10.233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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33
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Naka K, Sato H, Higashi M. Theoretical study of the mechanism of the solvent dependency of ESIPT in HBT. Phys Chem Chem Phys 2021; 23:20080-20085. [PMID: 34338683 DOI: 10.1039/d0cp06604d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
2-(2'-Hydroxyphenyl)-benzothiazole (HBT) has been widely studied for use as a system for excited-state intramolecular proton transfer. However, the mechanism underlying the solvent dependency of HBT fluorescence spectra remains unclear. In this study, the HBT photochemical process in the S1 state was analysed using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The excited-state intramolecular proton transfer in the enol form of HBT was found to depend on the hydrogen-bond acceptability of the solvent. The twisting of the keto form of HBT is determined by whether HBT acts as a hydrogen-bond acceptor or donor. A specific stacking structure of the enol form of HBT was found to decrease the S1 → S0 transition energy, which corresponds to the experimental fluorescence spectra in a DMSO/H2O solution mixture.
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Nakatani K, Higashi M, Fukuda R, Sato H. An analysis of valence electronic structure from a viewpoint of resonance theory: Tautomerization of formamide and diazadiboretidine. J Comput Chem 2021; 42:1662-1669. [PMID: 34114237 DOI: 10.1002/jcc.26703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/03/2021] [Accepted: 05/27/2021] [Indexed: 01/08/2023]
Abstract
The resonance theory is still very useful in understanding the valence electron structure. However, such a viewpoint is not usually obtained by general-purpose quantum chemical calculations, instead requires rather special treatment such as valence bond methods. In this study, we propose a method based on second quantization to analyze the results obtained by general-purpose quantum chemical calculations from the local point of view of electronic structure and analyze diazadiboretidine and the tautomerization of formamide. This method requires only the "PS"-matrix, consisting of the density matrix (P-matrix) and overlap matrix, and can be computed with a comparable load to that of Mulliken population analysis. A key feature of the method is that, unlike other methods proposed so far, it makes direct use of the results of general-purpose quantum chemical calculations.
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Kimura M, Ito T, Sato H, Higashi M. Theoretical study on isomerization of α-acids: A DFT calculation. Food Chem 2021; 364:130418. [PMID: 34192634 DOI: 10.1016/j.foodchem.2021.130418] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 05/24/2021] [Accepted: 06/17/2021] [Indexed: 11/17/2022]
Abstract
The α-acids contained in hops are one of the ingredients of beer. The isomerization of α-acids produces iso-α-acids, the main source of bitterness in beer. In this study, the isomerization mechanism of the α-acid, cohumulone, was elucidated by using density functional theory in conjunction with the polarizable continuum model or 3D-RISM integral equation theory of liquids. The calculated reaction diagram is consistent with experimental results; the activation free energy difference between the cis and trans isomers is in good agreement with the experimental estimate. The activation energy difference results from solvation energy. Additionally, a calculation of NMR chemical shifts showed that the proton position of isocohumulone is different from that proposed previously. The effect of Mg2+ cation on the isomerization was also investigated. Both the activation and reaction free energy are stabilized by the presence of Mg2+, which is consistent with experimental results. Water solvation reduces the activation free energy.
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Sakai M, Higashi M, Fujiwara T, Uehira T, Shirasaka T, Nakanishi K, Kashiwagi N, Tanaka H, Terada H, Tomiyama N. MRI imaging features of HIV-related central nervous system diseases: diagnosis by pattern recognition in daily practice. Jpn J Radiol 2021; 39:1023-1038. [PMID: 34125369 PMCID: PMC8202053 DOI: 10.1007/s11604-021-01150-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/01/2021] [Indexed: 01/10/2023]
Abstract
With the advent of antiretroviral therapy (ART), the prognosis of people infected with human immunodeficiency virus (HIV) has improved, and the frequency of HIV-related central nervous system (CNS) diseases has decreased. Nevertheless, mortality from HIV-related CNS diseases, including those associated with ART (e.g., immune reconstitution inflammatory syndrome) remains significant. Magnetic resonance imaging (MRI) can improve the outlook for people with HIV through early diagnosis and prompt treatment. For example, HIV encephalopathy shows a diffuse bilateral pattern, whereas progressive multifocal leukoencephalopathy, HIV-related primary CNS lymphoma, and CNS toxoplasmosis show focal patterns on MRI. Among the other diseases caused by opportunistic infections, CNS cryptococcosis and CNS tuberculosis have extremely poor prognoses unless diagnosed early. Immune reconstitution inflammatory syndrome shows distinct MRI findings from the offending opportunistic infections. Although distinguishing between HIV-related CNS diseases based on imaging alone is difficult, in this review, we discuss how pattern recognition approaches can contribute to their early differentiation.
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Yamagishi M, Tamaki N, Akasaka T, Ikeda T, Ueshima K, Uemura S, Otsuji Y, Kihara Y, Kimura K, Kimura T, Kusama Y, Kumita S, Sakuma H, Jinzaki M, Daida H, Takeishi Y, Tada H, Chikamori T, Tsujita K, Teraoka K, Nakajima K, Nakata T, Nakatani S, Nogami A, Node K, Nohara A, Hirayama A, Funabashi N, Miura M, Mochizuki T, Yokoi H, Yoshioka K, Watanabe M, Asanuma T, Ishikawa Y, Ohara T, Kaikita K, Kasai T, Kato E, Kamiyama H, Kawashiri M, Kiso K, Kitagawa K, Kido T, Kinoshita T, Kiriyama T, Kume T, Kurata A, Kurisu S, Kosuge M, Kodani E, Sato A, Shiono Y, Shiomi H, Taki J, Takeuchi M, Tanaka A, Tanaka N, Tanaka R, Nakahashi T, Nakahara T, Nomura A, Hashimoto A, Hayashi K, Higashi M, Hiro T, Fukamachi D, Matsuo H, Matsumoto N, Miyauchi K, Miyagawa M, Yamada Y, Yoshinaga K, Wada H, Watanabe T, Ozaki Y, Kohsaka S, Shimizu W, Yasuda S, Yoshino H. JCS 2018 Guideline on Diagnosis of Chronic Coronary Heart Diseases. Circ J 2021; 85:402-572. [PMID: 33597320 DOI: 10.1253/circj.cj-19-1131] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Higashi M, Sato H, Shibata N, Takeno S, Satoh T, Miura M. A Theoretical Study of Product Selectivity in Rhodium Catalyzed Oxidative Coupling Reaction Caused by the Solvation Effect. HETEROCYCLES 2021. [DOI: 10.3987/com-20-s(k)64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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39
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Pereira L, Barbosa L, Conti-Spilari J, Bertolucci C, Severino A, Teotonio R, Higashi M, Mattos E, Ikoma-Colturato M. PRIMARY CUTANEOUS CD30NEGATIVE ANAPLASTIC LARGE T CELL LYMPHOMA. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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40
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Marotti A, Mascarenhas C, Mattos E, Melo I, Pereira L, Higashi M, Garcia M, Medeiros N. SÍNDROME DE SWEET: RELATO DE CASO. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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41
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Jacovelli G, Costa A, Marani L, Madeira M, Scheucher P, Silva F, Lima A, Duarte B, Pagnano K, Kerbauy F, Feliciano J, Higashi M, Nunes E, Fagundes E, Gloria A, Rego E, Traina F, Figueiredo-Pontes L. HIGH FREQUENCY OF LEUKEMIC STEM CELLS IS ASSOCIATED WITH ADVERSE PROGNOSIS IN A BRAZILIAN COHORT OF ACUTE MYELOID LEUKEMIA WITH NORMAL KARYOTYPE. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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42
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Alvarenga B, Manzo E, Arca G, Higashi M, Mattos E, Melo I, Mascarenhas C, Queiroz L, Moreira L, Ikoma-Colturato M. DISSEMINATED INTRAVASCULAR COAGULATION AND CONCOMITANT CENTRAL NERVOUS SYSTEM BLEEDING IN ACUTE MONOBLASTIC LEUKEMIA: CASE REPORT. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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43
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Queiroz L, Mascarenhas C, Alvarenga B, Melo I, Medeiros N, Souza A, Barbosa L, Mattos E, Higashi M, Marotti A. SARCOMA HISTIOCÍTICO: RELATO DE CASO. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Bonete J, Bertolucci C, Barbosa L, Conte J, Higashi M, Severino A, Teotônio R, Mattos E, Ikoma-Colturato M. MYELOMATOUS PLEURAL EFFUSION IN MULTIPLE MYELOMA DIAGNOSED BY FLOW CYTOMETRY: CASE REPORTS OF A RARE CONDITION. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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45
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Costa A, Marani L, Jacovelli G, Coelho J, Bianco T, Lopes I, Scheucher P, Schiavinato J, Pagnano K, Duarte B, Kerbauy F, Higashi M, Nunes E, Fagundes E, Glória A, Rego E, Traina F, Pontes L. ASSOCIATION OF NATURAL KILLER CELLS FUNCTIONAL SUBTYPES WITH GENETIC RISK STRATIFICATION IN ACUTE MYELOID LEUKEMIA. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Melo I, Mascarenhas C, Alvarenga B, Queiroz L, Medeiros N, Barbosa L, Marotti A, Campoo I, Higashi M, Mattos E. MIELOMA MÚLTIPLO CONCOMITANTE A SÍNDROME MIELODISPLÁSICA: RELATO DE CASO. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Mascarenhas C, Mendes I, Melo I, Queiroz L, Alvarenga B, Medeiros N, Amaru M, Garcia M, Higashi M, Mattos E. UM PONTO FORA DA CURVA: MIELOMA MÚLTIPLO AOS 22 ANOS - RELATO DE CASO. Hematol Transfus Cell Ther 2020. [DOI: 10.1016/j.htct.2020.10.465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Okita T, Entani S, Watanabe K, Higashi M, Hoashi E, Kondo H, Park C, Nakamura MM, Ochiai K, Kasugai A. Verification of accuracy of contact-probe distance meter for lithium target of fusion neutron source. FUSION ENGINEERING AND DESIGN 2020. [DOI: 10.1016/j.fusengdes.2020.111799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kitamura T, Sato R, Morita H, Kitamura D, Oyamada J, Higashi M, Kishikawa Y. Convenient access to stable β-fluorovinyl-substituted 1,2-benziodoxolones. ARKIVOC 2020. [DOI: 10.24820/ark.5550190.p011.291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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50
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Takano M, Higashi M, Baba S, Kawami M, Yumoto R. Transport of ribavirin in human myelogenous leukemia cell line K562. DIE PHARMAZIE 2020; 75:329-334. [PMID: 32635975 DOI: 10.1691/ph.2020.0440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
The anticancer effect of ribavirin, a purine nucleoside analogue, has been studied using cultured cancer cells such as the human myelogenous leukemia cell line K562. In order to exert its pharmacological effect, ribavirin has to enter cancer cells. However, there is little information concerning the transport mechanism of ribavirin into K562 cells. In this study, therefore, we examined the uptake mechanism of ribavirin in K562 cells. The uptake of ribavirin in K562 cells was time- and temperature-dependent, and was saturable with a Km value of 1.5 mM. Ribavirin uptake was inhibited by nucleosides such as adenosine and uridine, and by inhibitors of equilibrative nucleoside transporter 1 (ENT1) such as S-(4-nitrobenzyl)-6-thioinosine and dipyridamole in a concentration-dependent manner. In addition, the expression of ENT1 mRNA in K562 cells was confirmed by real-time PCR. On the other hand, Na+-dependence of ribavirin uptake was not observed, suggesting the involvement of ENT1, but not Na+-dependent concentrative nucleoside transporters, in ribavirin uptake in K562 cells. Treatment of K562 cells with sodium butyrate induced erythroid differentiation, but ribavirin uptake activity and sensitivity of the uptake to various inhibitors were not different between native and differentiated K562 cells. These results suggest that ribavirin uptake into K562 cells is mainly mediated by ENT1, which may have a pivotal role in anticancer effect of ribavirin.
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