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Phospholipids are major components of biological membranes and play structural and regulatory roles in various biological processes. To determine the biological significance of phospholipids, the use of chemical inhibitors of phospholipid metabolism offers an effective approach; however, the availability of such compounds is limited. In this study, we performed a chemical-genetic screening using yeast and identified small molecules capable of inhibiting phosphatidylcholine (PC) biogenesis, which we designated PC inhibitors 1, 2, 3, and 4 (PCiB-1, 2, 3, and 4). Biochemical analyses indicated that PCiB-2, 3, and 4 inhibited the phosphatidylethanolamine (PE) methyltransferase activity of Cho2, whereas PCiB-1 may inhibit PE transport from mitochondria to the endoplasmic reticulum (ER). Interestingly, we found that PCiB treatment resulted in mitochondrial fragmentation, which was suppressed by expression of a dominant-negative mutant of the mitochondrial division factor Dnm1. These results provide evidence that normal PC biogenesis is important for the regulation of mitochondrial division.
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Palladium-catalyzed ipso-borylation of aryl halides, well-known as Miyaura borylation, is one of the reliable synthetic methods for organoborons. This reaction involves base-mediated nucleophilic activation of diboron that enables transmetalation of an aryl(halo)palladium(II) intermediate with a diboron. As an alternative, herein, we have established Lewis acid-mediated conditions for borylating (pseudo)haloarenes that require no external base. The electrophilic activation of the aryl(halo)palladium(II) intermediate via dehalogenation with Lewis acidic zinc complexes promotes the borylation.
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A concise route for dibenzoazacyclooctynes (DIBACs) synthesis was developed based on Pictet-Spengler reaction and a novel cobalt decomplexation method established for dibenzo-fused cyclooctyne-cobalt complexes. The method allowed for the facile preparation of functionalized DIBACs, including bisDIBAC, which served as an efficient bisreactive linker for protein modification via the double-click reaction.
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The iridium-catalyzed azide-thioalkyne cycloaddition was found to proceed much faster with benzyl azide than with phenyl azide. The high azido-type selectivity was also observed in other combinations of azides with different steric environments. This finding enabled the efficient assembly of three azidophilic molecules to triazido platforms by three sequential triazole-forming reactions.
Assuntos
Azidas , Irídio , Alcinos , Catálise , Cobre , Reação de Cicloadição , TriazóisRESUMO
Background: Middle-aged and older individuals with spinal cord injury (SCI) often require long-term care even after receiving rehabilitation treatment, making it difficult for them to return home. We retrospectively investigated our active rehabilitation treatment for patients with SCI. Case: Included in this case series were ten patients with SCI who were admitted to our general hospital (located in the southern part of Wakayama Prefecture) and who underwent active rehabilitation treatment. The participants were investigated retrospectively by access to electronic medical records. The Barthel index scores for discharged patients were determined at an outpatient clinic, and the community phase of rehabilitation management was recorded. The average age of the 10 patients was 67.4 ± 13.4 years, and the average period from onset to transfer to our hospital was 102.6 ± 69.9 days. The Barthel index scores significantly improved from 39.0 ± 30.9 at admission to 65.0 ± 28.2 at discharge (P<0.05). Among the seven patients who were discharged to their homes, six had cervical SCI. Some patients with American Spinal Injury Association impairment scale grades A and B at admission could be discharged home, and their Barthel index scores were maintained after discharge. Discussion: : Even in a remote rural hospital, the activities of daily living of patients with SCI improved, and seven of the ten patients were discharged home. The activities of daily living of the discharged patients were maintained. To achieve these results, active rehabilitation treatment conducted by rehabilitation specialists is important.
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BACKGROUND: Blood volume (BV) is a critical factor for physical endurance in chronic stroke patients, while hypervolemia can worsen hypertension in these patients. This prospective study assessed whether rehabilitation combined with protein supplementation immediately after each exercise for 3 weeks would improve plasma volume (PV) and BV as well as physical endurance without worsening hypertension. METHODS: Ambulatory patients with chronic cerebrovascular disease who received a 3-week rehabilitation program with high protein jelly (intervention group [PG]; n = 8; 10-g protein) or protein-free jelly (control group [CG]; n = 8) consumed within 30 min after each exercise. PV and BV were assessed while measuring the 6-min walking distance (6MWD), peak oxygen consumption (VO2peak), strength of knee extension, and resting blood pressure before and after the intervention. Two-way ANOVA was used to determine whether there was an interaction of time × group. The difference between before and after intervention or between the groups by post-hoc test (Tukey's test) at the level of P < 0.05. RESULTS: The 6MWD increased only in the PG (P = 0.001; an interaction of Group and Time, P = 0.037). PV and BV increased only in the PG (P < 0.05). VO2peak and strength of knee extension in the paralysed limb increased in both groups (P < 0.05). The resting blood pressure did not worsen after the intervention. CONCLUSIONS: In chronic post-stroke patients, 3-week rehabilitation combined with protein intake immediately after exercise increased 6MWD simultaneously with increased PV and BV, but it did not increase resting blood pressure. The present regimen is acceptable and effective for ambulatory patients with chronic cerebrovascular disease. Name of the registry Examining effects of protein supplementation on functional improvement during rehabilitation intervention in chronic stroke patients Trial registration number UMIN000028009; date of registration: 30/06/2017. This study was registered prospectively.
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We report a Buchwald-Hartwig amination compatible with azido functionality. Treatment of azidoaryl iodides and amines with fourth-generation Buchwald precatalyst coordinated by CPhos and sodium tert-butoxide in 1,4-dioxane at 50 °C afforded the corresponding azidoanilines while leaving the azido groups intact. The method showed a broad substrate scope and was applicable to the synthesis of diazido compounds as photoaffinity probe candidates of pharmaceutical amines and multiazido platform molecules.
Assuntos
Aminas , AminaçãoRESUMO
An efficient method to synthesize diaryl sulfides with structural diversity is disclosed. Demethylative hydrothiolation of aryne intermediates generated from o-iodoaryl triflates with methylthio-substituted o-silylaryl triflates and further aryne reactions afford diverse diaryl sulfides.
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Efficient consecutive 1,2,3-triazole formations using multiazide platforms are disclosed. On the basis of unique clickability of the 1-adamantyl azido group, a four-step synthesis of tetrakis(triazole)s was achieved from a tetraazide platform molecule. This method was applied to a convergent synthesis of tetrafunctionalized probes in a modular synthetic manner.
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An efficient preparation method of functionalized phosphines by copper-catalyzed azide-alkyne cycloaddition (CuAAC) through the transient protection of phosphine from the Staudinger reaction is disclosed. Diverse phosphines were prepared from phosphinyl alkynes and azides by the click reaction at the ethynyl group without damaging the phosphinyl group. Double- and triple-click assemblies of azides were accomplished by triazole formations and robust azaylide formation.
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An efficient synthetic method of benzopyran derivatives involving coumarins is disclosed. Gold-catalyzed benzopyran formation and subsequent aryne reactions enabled us to prepare a wide range of benzopyran derivatives by virtue of their good functional group tolerance and versatile transformability of aryne intermediates. The synthetic utility was showcased by a diarylnaphthopyran synthesis through this method and consecutive cross-coupling reactions.
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A protection method for cycloalkynes by the formation of (hexafluoroacetylacetonato)copper(i)-cycloalkyne complexes is disclosed. Various complexes having functional groups were efficiently prepared, which are easily purified by silica-gel column chromatography. Selective click reactions were realized through the complexation of cycloalkynes with copper.
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Complexation of bicyclo[6.1.0]nonynes with a cationic silver or gold salt results in protection from a click reaction with azides. The cycloalkyne protection using the silver or gold salt enables selective strain-promoted azide-alkyne cycloadditions of diynes keeping the bicyclo[6.1.0]nonyne moiety unreacted.
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An efficient synthetic method of seven- and six-membered cycloalkenes through the generation of strained cycloalkynes and following carbomagnesiation is described. Further bond formations of the resulting cycloalkenylmagnesium intermediates with a wide variety of electrophiles enabled us to prepare diverse cycloalkene derivatives including benzoxepine analogs having a fully substituted alkene structure.
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Pholasin is classified as a photoprotein and comprises apoPholasin (an apoprotein of pholasin) and an unknown prosthetic group as the light-emitting source. The luminescence reaction of pholasin is triggered by reactive oxygen species. Recombinant apoPholasin was recently expressed as a fusion protein of glutathione S-transferase (GST-apoPholasin) and purified from E. coli cells. By incubating non-fluorescent dehydrocoelenterazine (dCTZ, dehydrogenated form of CTZ) with GST-apoPholasin, the complex of GST-apoPholasin and dCTZ (GST-apoPholasin/dCTZ complex) was formed immediately and showed bright yellow fluorescence (λmax = 539 nm, excited at 430 nm). Unexpectedly, the fluorescent chromophore of the GST-apoPholasin/dCTZ complex was identified as non-fluorescent dCTZ. The luminescence intensity of the GST-apoPholasin/dCTZ complex was increased in a catalase-H2O2 system, but not in sodium hypochlorite.
Assuntos
Apoproteínas/metabolismo , Luciferina de Vaga-Lumes/metabolismo , Imidazóis/metabolismo , Proteínas Luminescentes/metabolismo , Pirazinas/metabolismo , Apoproteínas/biossíntese , Apoproteínas/química , Escherichia coli/metabolismo , Luciferina de Vaga-Lumes/química , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Imidazóis/química , Medições Luminescentes , Proteínas Luminescentes/biossíntese , Proteínas Luminescentes/química , Pirazinas/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismoRESUMO
An efficient method to assemble three cycloalkyne-modules onto a platform compound bearing a thiophene S,S-dioxide moiety and two azido groups has been developed. The sequential reactions without catalysis or additives enabled the facile preparation of trifunctional molecules by a simple procedure. One-pot assembly was also achieved using the platform and three cycloalkynes.
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A novel cascade reaction consisting of a five-membered ring selective Prins cyclization and a subsequent Friedel-Crafts cyclization is reported. Treatment of homocinnamyl alcohols and aromatic aldehydes with BF3·OEt2 in CH2Cl2 afforded hydrocyclopentafurans. Also hydrocyclopentafurans underwent the same cascade reaction after its furan ring cleavage upon treatment with BF3·OEt2 at room temperature. Various combinations of hydropentafurans and aromatic aldehydes or indole aldehydes permitted divergent synthesis of diquinane-furans stuck in aromatic rings.
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A series of Sodium 4-[(4-butoxyphenyl)thio]-2'-substituted-1,1'-biphenyl-3- sulfonates were identified as functional sphingosine-1-phosphate (S1P) antagonists with selectivity for the S1P(1) receptor subtype starting from chemical lead 2, which was found while screening our in-house compound library. We performed chemical modifications on each regional structure of compound 2, for example, on the three ring compartments, the benzyl substituents, and the long alkyl chain part. The introduction of a biphenyl skeletal structure and the installation of a hydroxyl group onto the terminal carbon in the side-chain region resulted in the potent derivative 35c, which showed >500-fold more potent S1P(1) inhibitory activity than lead compound 2. We report herein the synthesis and structure-activity relationships of structurally novel S1P(1) receptor antagonists.