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1.
J Org Chem ; 85(12): 8271-8278, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32425047

RESUMO

A total synthesis of polyoxamic acid has been achieved. The key feature of the synthetic route is a visible-light-mediated ß-scission and carbon-to-carbon 1,5-hydrogen atom transfer (1,5-HAT) to provide the functionalized alditol under mild conditions. This type of carbon-to-carbon 1,5-HAT initiated by C(sp3)-centered radicals has been scarcely reported. Furthermore, the reaction was adapted for flow chemistry, facilitating the total synthesis of polyoxamic acid.

2.
Org Lett ; 21(14): 5485-5490, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31287325

RESUMO

We describe the development of a strategy for the construction of the quaternary carbon stereocenter of α-tertiary amines. This strategy highlights a site-selective C-H functionalization involving an alkoxy-radical-triggered 1,5-hydrogen transfer (1,5-HAT) reaction of a conformationally fixed spiro-compound derived from trishydroxymethylaminomethane (Tris). The utilization of this strategy enabled an enantioselective total synthesis of myriocin, a naturally occurring sphingosine analog that displays potent immunosuppressive activity.


Assuntos
Aminas/química , Carbono/química , Ácidos Graxos Monoinsaturados/química , Ácidos Graxos Monoinsaturados/síntese química , Trometamina/química , Catálise , Técnicas de Química Sintética , Estereoisomerismo
3.
Chem Pharm Bull (Tokyo) ; 66(9): 866-872, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30175743

RESUMO

Sphingosine kinases (SphKs) are key enzymes that regulate sphingosine 1-phosphate production levels, and are involved in a range of cellular processes. Focusing on a hydrophilic residue in the hydrophobic binding pocket of SphKs, we designed and synthesized 4-epi-jaspine B derivatives containing a polar functional group in the lipid tail. A biological evaluation revealed that the introduction of ether groups to the lipid tail of 4-epi-jaspine B modulated its isoform selectivity toward SphKs.


Assuntos
Lipídeos/química , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Inibidores de Proteínas Quinases/síntese química , Esfingosina/análogos & derivados , Sítios de Ligação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Isoenzimas/antagonistas & inibidores , Conformação Molecular , Simulação de Acoplamento Molecular , Ligação Proteica , Esfingosina/síntese química , Estereoisomerismo , Relação Estrutura-Atividade
4.
Heart Vessels ; 28(5): 559-65, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22968851

RESUMO

Despite the positive impact of percutaneous coronary intervention (PCI) on reducing mortality, a small percentage of patients experience poor myocardial reperfusion following PCI. However, factors associated with no-reflow remain unclear. We investigated clinical factors associated with no-reflow following PCI for coronary artery disease (CAD). We retrospectively analyzed 1622 consecutive CAD patients who underwent PCI over a 5-year period at our institution. Patients were divided into two groups according to the presence (n = 31) or absence (n = 1591) of no-reflow, defined as Thrombolysis in Myocardial Infarction flow grade <3 after PCI. No significant differences in patient characteristics or PCI strategy were seen between the no-reflow and normal flow groups. The incidence of no-reflow was significantly lower in the left circumflex artery (LCx) than in the left anterior descending artery (LAD) (P = 0.0015), with no differences in characteristics or PCI strategy between these two target vessels. Multivariate analysis revealed that involvement of the LCx was an independent protective factor against no-reflow (odds ratio 0.14, 95 % confidence interval 0.02-0.98, P = 0.044). In conclusion, LCx as the target vessel was protective against no-reflow compared with LAD following PCI for CAD. Our results suggest that embolic protection devices may be unnecessary in CAD patients with involvement of LCx.


Assuntos
Doença da Artéria Coronariana/terapia , Circulação Coronária , Vasos Coronários/fisiopatologia , Fenômeno de não Refluxo/prevenção & controle , Intervenção Coronária Percutânea/efeitos adversos , Idoso , Distribuição de Qui-Quadrado , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/fisiopatologia , Feminino , Mortalidade Hospitalar , Humanos , Incidência , Japão/epidemiologia , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fenômeno de não Refluxo/epidemiologia , Fenômeno de não Refluxo/mortalidade , Fenômeno de não Refluxo/fisiopatologia , Razão de Chances , Intervenção Coronária Percutânea/mortalidade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
5.
Artigo em Japonês | MEDLINE | ID: mdl-22186202

RESUMO

Our study was involved with entrance surface dose reduction and irradiation field by the filter use of PCI, and insertion in place of an effective compensating filter to maximize entrance surface dose reduction, which we verified. The radiation dosimetry put a 6cc ion chamber on the back side of the thorax phantom, and changed the filter of the four corners (a: upper left, b: upper right, c: lower right, d: lower left) of the monitor confirmed with fluoroscopy [(0) no filter, (1) one filter, (2) two filters]. The angle of C arm was assumed to be eight directions and 0 degrees adopted by this hospital. It was compared with a corrective rate of which one was no filter. Next, the presence of filter and irradiation field overlaps on the area in monitor in the angle of C arm was verified by this hospital's classic example. As for corrective rate, (1) becomes 0.41 and (2) become 0.25 at fluoroscopy, (1) becomes 0.26 and (2) become 0.16 at exposure. Irradiation field overlaps on the area (+) compensating filter (-) was many with d of RAO/CAU, a of RAO and c of CAU at left CAG, c of LAO at right CAG, b of LAO/CRA (left CAG), b of CRA (right CAG) and a and d of RAO (right CAG) at both CAG. Irradiation field overlaps on the area (+) compensating filter (+) was many with b of CRA at left CAG, a of LAO/CRA at right CAG, b of CRA (left CAG) and b of RAO (right CAG) at both CAG. When the compensating filter is used the entrance surface dose reduction effect was great. If automatic exposure control protects the part of irradiation field overlaps on the area in the range without operating excessively, the radiological risk can be reduced, and it is conceivable as useful clinical setting.


Assuntos
Angioplastia Coronária com Balão , Filtração , Doses de Radiação , Proteção Radiológica/métodos , Pele/efeitos da radiação , Humanos , Comportamento de Redução do Risco
6.
Aviat Space Environ Med ; 81(6): 593-6, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20540453

RESUMO

Ventricular fibrillation diagnoses such as Brugada syndrome pose a risk of sudden incapacitation or death in aircrew. This case report presents a 44-yr-old male fighter pilot who unexpectedly developed ventricular fibrillation (VF) during an electrophysiological study (EPS) prior to therapy for non-sustained ventricular tachycardia (nsVT). The initial aeromedical disposition for this case was "qualified for flying duties". with the restriction that he must fly with another pilot due to repeatedly observed nsVT. This pilot wanted to return to flight duty in single-seat aircraft without any restrictions. Therefore, this patient decided to undergo catheter therapy for nsVT. Unexpectedly, not VT but VF was induced by catheter manipulation during EPS. Pilsicainide-induced coved-type ST wave elevation consistent with Brugada syndrome was noted in this patient's electrocardiogram. He was ultimately disqualified due to the diagnosis of VF. This report suggests EPS on rare occasions may uncover another severe disease similar to this case report.


Assuntos
Síndrome de Brugada/diagnóstico , Saúde Ocupacional , Taquicardia Ventricular/diagnóstico , Fibrilação Ventricular/diagnóstico , Adulto , Antiarrítmicos/uso terapêutico , Eletrocardiografia , Humanos , Japão , Lidocaína/análogos & derivados , Lidocaína/uso terapêutico , Masculino , Taquicardia Ventricular/fisiopatologia , Fatores de Tempo , Fibrilação Ventricular/fisiopatologia
7.
J Nat Prod ; 72(8): 1507-11, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19594141

RESUMO

A screening study for TRAIL resistance-overcoming activity was carried out, and activity-guided fractionations of Thevetia peruviana and Sapindus emarginatus led to the isolation of four cardenolide glycosides (1-4) and four triterpenoid saponins (5-8), respectively. In particular, cardenolide glycosides (1 and 2) from T. peruviana were shown to have a significant reversal effect on TRAIL resistance in human gastric adenocarcinoma cells, and real-time PCR showed that thevefolin (2) enhanced mRNA expression of death receptor 4 (DR4) and DR5. In addition, 1H and 13C NMR characterizations are shown for thevefolin (2) for the first time.


Assuntos
Cardenolídeos/isolamento & purificação , Cardenolídeos/farmacologia , Plantas Medicinais/química , Sapindus/química , Saponinas/isolamento & purificação , Saponinas/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/efeitos dos fármacos , Thevetia/química , Sequência de Bases , Cardenolídeos/química , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Saponinas/química , Neoplasias Gástricas/metabolismo , Tailândia , Células Tumorais Cultivadas
8.
Aviat Space Environ Med ; 80(2): 139-43, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19198201

RESUMO

INTRODUCTION: Cardiovascular diseases can cause sudden incapacitation in aircrew. Cardiological diagnosis and therapy have changed a great deal in recent decades, as with coronary revascularization, including percutaneous coronary intervention and coronary artery bypass grafting for coronary artery disease, and electrophysiological studies and radiofrequency catheter ablation (RFCA) for sustained arrhythmias. Physicians need to be able to make appropriate, objective recommendations regarding cardiovascular diseases in an aeromedical waiver system. METHODS: We analyzed all 95 waiver cases regarding cardiovascular diseases in the Japan Air Self-Defense Force (JASDF), 1980-2007, and compared them to policies in the United States Air Force (USAF). RESULTS: The JASDF and the USAF handle most conditions similarly, although there are differences regarding coronary revascularization, atrial fibrillation, non-sustained ventricular tachycardia (nsVT), and hypertrophic cardiomyopathy. The JASDF used RFCA more commonly for the treatment of aircrew with atrial fibrillation and nsVT Although routine follow-up with electrophysiological studies is no longer indicated for Wolff-Parkinson-White and atrioventricular node reentrant tachycardia in USAF policy, the JASDF still conducts reevaluation for all RFCA cases. CONCLUSION: This study made recommendations to improve the JASDF waiver system for cardiovascular diseases.


Assuntos
Medicina Aeroespacial , Doenças Cardiovasculares , Militares , Doenças Profissionais , Inabilitação Profissional/legislação & jurisprudência , Adulto , Tomada de Decisões , Avaliação da Deficiência , Humanos , Japão , Estados Unidos
9.
J Nat Prod ; 71(5): 918-21, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18351742

RESUMO

Two new acylated triterpenoid saponins were isolated from the branches of Schima noronhae by bioassay-guided purification. Their chemical structures were established on the basis of spectroscopic analysis and chemical means as 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl 22-O-angeloyl-A1-barrigenol (1) and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl 22-O-angeloylerythrodiol (2). Compounds 1 and 2 showed cell growth inhibitory activity against both HeLa and DLD1 cells at a concentration of less than 10 microM.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Plantas Medicinais/química , Saponinas/isolamento & purificação , Saponinas/farmacologia , Theaceae/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Saponinas/química , Tailândia , Triterpenos/química
10.
In Vivo ; 21(5): 715-20, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18019403

RESUMO

The relationship between the structure and cytotoxic activity of azulenequinones and trihaloacetylazulenes was investigated based on theoretical calculations. Four different dipole moments (mu(G), mu(ESP-G), mu(W) and mu(ESP-W)) and heats of formation (DeltaH(f)) of the azulenequinones [1-27] and trihaloacetylazulenes [28a,b-40a,b] were separately calculated in gas phase and aqueous solution using the conductor-like screening model/parametric method 3 (COSMO/PM3) method. The cytotoxic activity of azulenequinones was well correlated to DeltaDeltaH(f) HOMO energy and mu(ESP-w). The cytotoxic activity of trihaloacetylazulenes was correlated to DeltaDeltaH(f) LUMO energy and mu(ESP-W). QSAR may be applicable to predict the cytotoxicity of azulenequinones and trihaloacetylazulenes.


Assuntos
Azulenos/química , Azulenos/toxicidade , Elétrons , Quinonas/química , Quinonas/toxicidade , Acetilação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Simulação por Computador , Halogenação , Humanos , Relação Quantitativa Estrutura-Atividade
11.
J Phys Chem B ; 111(34): 10079-87, 2007 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-17676792

RESUMO

The dielectric relaxation process of water was investigated for polymer/water mixtures containing poly(vinyl methyl ether), poly(ethyleneimine), poly(vinyl alcohol), and poly(vinylpyrrolidone) with a polymer concentration of up to 40 wt % at frequencies between 10 MHz and 10 GHz in subzero temperatures down to -55 degrees C. These polymer/water mixtures have a crystallization temperature TC of water at -10 to -2 degrees C. Below TC, part of the water crystallized and another part of the water, uncrystallized water (UCW), remained in a liquid state with the polymer in an uncrystallized phase. The dielectric relaxation process of UCW was observed, and reliable dielectric relaxation parameters of UCW were obtained at temperatures of -26 to -2 degrees C. At TC, the relaxation strength, relaxation time, and relaxation time distribution change abruptly, and their subsequent changes with decreasing temperature are larger than those above TC. The relaxation strength of UCW decreases, and the relaxation time and dynamic heterogeneity (distribution of relaxation time) increase with decreasing temperature. These large temperature dependences below TC can be explained by the increase in polymer concentration in the uncrystallized phase C(p,UCP) with decreasing temperature. C(p,UCP) is independent of the initial polymer concentration. In contrast to the relaxation times above TC, which vary with the chemical structure of the polymer and its concentration, the relaxation times of UCW are independent of both of them. This indicates that the factor determining whether the water forms ice crystals or stays as UCW is the mobility of the water molecules.


Assuntos
Polímeros/química , Água/química , Cristalização , Eletroquímica , Análise Espectral
12.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 60(2): 255-63, 2004 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-15054314

RESUMO

To investigate proper radiographic contrast and latitude based on density perception of the high-density areas of X-ray films, we studied the human characteristics of darkness perception for those areas. Magnitude estimation was used to provide a numerical estimate of the sensory magnitudes for contrast. Experimental figures that imitated the head were imaged on X-ray films. Magnitude estimation of darkness in the surrounding fields showed greater misperception or darker perception. When the density of the background field was high, the larger the density difference between the background and surrounding field, the darker the surrounding field was perceived. This implies that the lighter field is assimilated into the darker field. Since assimilation reduces the perceived density difference between soft tissue and the area around it, using high contrast film is less effective for attempting to increase the physical density difference between such areas. We concluded that psychological assimilation of darkness on contrast perception had a detrimental influence on the density perception of high-density areas on head radiographs.


Assuntos
Variações Dependentes do Observador , Percepção Visual/fisiologia , Filme para Raios X , Humanos , Imagens de Fantasmas
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