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1.
J Org Chem ; 85(12): 8271-8278, 2020 06 19.
Article in English | MEDLINE | ID: mdl-32425047

ABSTRACT

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.
Article in English | MEDLINE | ID: mdl-31287325

ABSTRACT

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.


Subject(s)
Amines/chemistry , Carbon/chemistry , Fatty Acids, Monounsaturated/chemistry , Fatty Acids, Monounsaturated/chemical synthesis , Tromethamine/chemistry , Catalysis , Chemistry Techniques, Synthetic , Stereoisomerism
3.
Chem Pharm Bull (Tokyo) ; 66(9): 866-872, 2018.
Article in English | MEDLINE | ID: mdl-30175743

ABSTRACT

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.


Subject(s)
Lipids/chemistry , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Sphingosine/analogs & derivatives , Binding Sites , Humans , Hydrophobic and Hydrophilic Interactions , Isoenzymes/antagonists & inhibitors , Molecular Conformation , Molecular Docking Simulation , Protein Binding , Sphingosine/chemical synthesis , Stereoisomerism , Structure-Activity Relationship
4.
Heart Vessels ; 28(5): 559-65, 2013 Sep.
Article in English | MEDLINE | ID: mdl-22968851

ABSTRACT

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.


Subject(s)
Coronary Artery Disease/therapy , Coronary Circulation , Coronary Vessels/physiopathology , No-Reflow Phenomenon/prevention & control , Percutaneous Coronary Intervention/adverse effects , Aged , Chi-Square Distribution , Coronary Artery Disease/diagnosis , Coronary Artery Disease/epidemiology , Coronary Artery Disease/mortality , Coronary Artery Disease/physiopathology , Female , Hospital Mortality , Humans , Incidence , Japan/epidemiology , Kaplan-Meier Estimate , Logistic Models , Male , Middle Aged , Multivariate Analysis , No-Reflow Phenomenon/epidemiology , No-Reflow Phenomenon/mortality , No-Reflow Phenomenon/physiopathology , Odds Ratio , Percutaneous Coronary Intervention/mortality , Retrospective Studies , Risk Factors , Time Factors , Treatment Outcome
5.
Article in Japanese | MEDLINE | ID: mdl-22186202

ABSTRACT

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.


Subject(s)
Angioplasty, Balloon, Coronary , Filtration , Radiation Dosage , Radiation Protection/methods , Skin/radiation effects , Humans , Risk Reduction Behavior
6.
Aviat Space Environ Med ; 81(6): 593-6, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20540453

ABSTRACT

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.


Subject(s)
Brugada Syndrome/diagnosis , Occupational Health , Tachycardia, Ventricular/diagnosis , Ventricular Fibrillation/diagnosis , Adult , Anti-Arrhythmia Agents/therapeutic use , Electrocardiography , Humans , Japan , Lidocaine/analogs & derivatives , Lidocaine/therapeutic use , Male , Tachycardia, Ventricular/physiopathology , Time Factors , Ventricular Fibrillation/physiopathology
7.
J Nat Prod ; 72(8): 1507-11, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19594141

ABSTRACT

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.


Subject(s)
Cardenolides/isolation & purification , Cardenolides/pharmacology , Plants, Medicinal/chemistry , Sapindus/chemistry , Saponins/isolation & purification , Saponins/pharmacology , TNF-Related Apoptosis-Inducing Ligand/drug effects , Thevetia/chemistry , Base Sequence , Cardenolides/chemistry , Humans , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Receptors, TNF-Related Apoptosis-Inducing Ligand/genetics , Saponins/chemistry , Stomach Neoplasms/metabolism , Thailand , Tumor Cells, Cultured
8.
Aviat Space Environ Med ; 80(2): 139-43, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19198201

ABSTRACT

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.


Subject(s)
Aerospace Medicine , Cardiovascular Diseases , Military Personnel , Occupational Diseases , Professional Impairment/legislation & jurisprudence , Adult , Decision Making , Disability Evaluation , Humans , Japan , United States
9.
J Nat Prod ; 71(5): 918-21, 2008 May.
Article in English | MEDLINE | ID: mdl-18351742

ABSTRACT

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.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Plants, Medicinal/chemistry , Saponins/isolation & purification , Saponins/pharmacology , Theaceae/chemistry , Triterpenes/isolation & purification , Triterpenes/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Saponins/chemistry , Thailand , Triterpenes/chemistry
10.
In Vivo ; 21(5): 715-20, 2007.
Article in English | MEDLINE | ID: mdl-18019403

ABSTRACT

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.


Subject(s)
Azulenes/chemistry , Azulenes/toxicity , Electrons , Quinones/chemistry , Quinones/toxicity , Acetylation , Cell Line, Tumor , Cell Survival/drug effects , Computer Simulation , Halogenation , Humans , Quantitative Structure-Activity Relationship
11.
J Phys Chem B ; 111(34): 10079-87, 2007 Aug 30.
Article in English | MEDLINE | ID: mdl-17676792

ABSTRACT

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.


Subject(s)
Polymers/chemistry , Water/chemistry , Crystallization , Electrochemistry , Spectrum Analysis
12.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 60(2): 255-63, 2004 Feb.
Article in Japanese | MEDLINE | ID: mdl-15054314

ABSTRACT

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.


Subject(s)
Observer Variation , Visual Perception/physiology , X-Ray Film , Humans , Phantoms, Imaging
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