RESUMEN
OBJECTIVES: Studies on cancer incidence and mortality in patients with schizophrenia have reported inconsistent findings. In this study, we simultaneously investigated cancer incidence and mortality in patients with schizophrenia and evaluated the cancer mortality-to-incidence ratio (MIR), which is rare in the literature. METHODS: From the Taiwan National Health Insurance Database, we collected the data of 107,489 patients who received a diagnosis of schizophrenia between 2000 and 2019. Data regarding cancer incidence and mortality were obtained from the Taiwan Cancer Registry and National Mortality Database, respectively. In total, 3881 incident cancer cases and 2288 cancer mortality cases were identified. Standardized incidence ratios (SIRs), mortality rate ratios (MRRs), and MIRs were compared between patients with schizophrenia and the general population. RESULTS: The overall rate of cancer incidence was slightly lower (SIR: 0.95; 95% confidence interval [CI]: 0.92-0.98; p < 0.001) and that of cancer mortality was higher (MRR: 1.29; 95% CI: 1.23-1.3; p < 0.001) in patients with schizophrenia than in the general population. The MIR for overall cancer was significantly higher in the patients with schizophrenia. The relative MIR (MIR of patients with schizophrenia divided by that of the general population) was 1.36 (95% CI: 1.30-1.42). CONCLUSION: The MIR was significantly higher in the patients with schizophrenia than in the general population, indicating the possible presence of healthcare disparities. Additional studies are required to investigate the potential association between the significantly higher MIR in patients with schizophrenia and healthcare disparities.
Asunto(s)
Neoplasias , Esquizofrenia , Humanos , Esquizofrenia/epidemiología , Estudios de Cohortes , Incidencia , Taiwán/epidemiología , Bases de Datos Factuales , Neoplasias/epidemiologíaRESUMEN
The ability to accurately identify SNPs or low-abundance mutations is important for early clinical diagnosis of diseases, but the existing high-throughput sequencing platforms are limited in terms of their accuracy. Here, we propose a correctable decoding sequencing strategy that may be used for high-throughput sequencing platforms. This strategy is based on adding a mixture of two types of mononucleotides, natural nucleotide and cyclic reversible termination (CRT), for cyclic sequencing. Using the synthetic characteristic of CRTs, about 75% of the calls are unambiguous for a single sequencing run, and the remaining ambiguous sequence can be accurately deduced by two parallel sequencing runs. We demonstrate the feasibility of this strategy, and its cycle efficiency can reach approximately 99.3%. This strategy is proved to be effective for correcting errors and identifying whether the sequencing information is correct or not. And its conservative theoretical error rate was determined to be 0.0009%, which is lower than that of Sanger sequencing. In addition, we establish that the information of only a single sequencing run can be used to detect samples with known mutation sites. We apply this strategy to accurately identify a mutation site in mitochondrial DNA from human cells.
Asunto(s)
ADN Mitocondrial , Técnicas de Genotipaje , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Genotipo , Mutación , Análisis de Secuencia de ADN , ADN Mitocondrial/genéticaRESUMEN
Antimicrobial peptides are small, cationic, and amphiphilic peptides found in most organisms, and many of these peptides have broad antimicrobial activity against Gram-negative, -positive bacteria and fungi. In the present study, a derivative of antimicrobial peptide Tatritin, 6His-Tatritin, was designed and expressed by Pichia pastoris using a constitutive vector pGAPZαA with the promoter of pGAP. The 6His-Tatritin had a broad-spectrum antibacterial activity based on the Oxford cup method and the micro broth dilution test. In addition, to explore the role of 6His-Tatritin in vivo, grass carps (Ctenopharyngodon idellus) were infected with Aeromonas hydrophila after they were fed with 6His-Tatritin as feed additives for 28 days. The results revealed that 6His-Tatritin could significantly up-regulate the expression levels of Hepcidin, Leap-2b, Nrf-2, CuZn-SOD and LZM (P < 0.05). In addition, 6His-Tatritin could significantly reduce the mortality (P < 0.05) and the intestinal injury of grass carps infected with bacteria. The 16S sequencing analysis showed that the structure of microbial community in intestine of fish was more diversified compared with control after treatment with 6His-Tatritin. In summary, the peptide of 6His-Tatritin could promote antimicrobial defense via regulating immune ability and intestinal microbial community in grass carp. This study provides an effective method and approach for the application of antimicrobial peptide Tatritin in aquaculture, and also provides insights into the function of antimicrobial peptides in immunity against pathogens in fish.
Asunto(s)
Antiinfecciosos , Carpas , Enfermedades de los Peces , Infecciones por Bacterias Gramnegativas , Animales , Transducción de Señal , Suplementos Dietéticos/análisis , Dieta/veterinaria , FN-kappa B/metabolismo , Carpas/genética , Carpas/metabolismo , Intestinos , Antiinfecciosos/farmacología , Péptidos Antimicrobianos , Aeromonas hydrophila/fisiología , Alimentación Animal/análisisRESUMEN
BsYetJ is a bacterial homolog of transmembrane BAX inhibitor-1 motif-containing 6 (TMBIM6) membrane protein that plays a key role in the control of calcium homeostasis. However, the BsYetJ (or TMBIM6) structure embedded in a lipid bilayer is uncharacterized, let alone the molecular mechanism of the calcium transport activity. Herein, we report structures of BsYetJ in lipid nanodiscs identified by double electron-electron resonance spectroscopy. Our results reveal that BsYetJ in lipid nanodiscs is structurally different from those crystallized in detergents. We show that BsYetJ conformation is pH-sensitive in apo state (lacking calcium), whereas in a calcium-containing solution it is stuck in an intermediate, inert to pH changes. Only when the transmembrane calcium gradient is established can the calcium-release activity of holo-BsYetJ occur and be mediated by pH-dependent conformational changes, suggesting a dual gating mechanism. Conformational substates involved in the process and a key residue D171 relevant to the gating of calcium are identified. Our study suggests that BsYetJ/TMBIM6 is a pH-dependent, voltage-gated calcium channel.
Asunto(s)
Bacillus subtilis/metabolismo , Canales de Calcio/química , Canales de Calcio/metabolismo , Membrana Dobles de Lípidos/química , Nanoestructuras/química , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Calcio/metabolismo , Secuencia Conservada , Concentración de Iones de Hidrógeno , Modelos Moleculares , Conformación Proteica , Reproducibilidad de los Resultados , Marcadores de SpinRESUMEN
Osteoporosis is a serious health issue among aging postmenopausal women. The majority of postmenopausal women with osteoporosis have bone loss related to estrogen deficiency. The rapid bone loss results from an increase in bone turnover with an imbalance between bone resorption and bone formation. Osteoporosis can also result from excessive glucocorticoid usage, which induces bone demineralization with significant changes of spatial heterogeneities of bone at microscale, indicating potential risk of fracture. This review is a summary of current literature about the molecular mechanisms of actions, the risk factors, and treatment of estrogen deficiency related osteoporosis (EDOP) and glucocorticoid induced osteoporosis (GIOP). Estrogen binds with estrogen receptor to promote the expression of osteoprotegerin (OPG), and to suppress the action of nuclear factor-κß ligand (RANKL), thus inhibiting osteoclast formation and bone resorptive activity. It can also activate Wnt/ß-catenin signaling to increase osteogenesis, and upregulate BMP signaling to promote mesenchymal stem cell differentiation from pre-osteoblasts to osteoblasts, rather than adipocytes. The lack of estrogen will alter the expression of estrogen target genes, increasing the secretion of IL-1, IL-6, and tumor necrosis factor (TNF). On the other hand, excessive glucocorticoids interfere the canonical BMP pathway and inhibit Wnt protein production, causing mesenchymal progenitor cells to differentiate toward adipocytes rather than osteoblasts. It can also increase RANKL/OPG ratio to promote bone resorption by enhancing the maturation and activation of osteoclast. Moreover, excess glucocorticoids are associated with osteoblast and osteocyte apoptosis, resulting in declined bone formation. The main focuses of treatment for EDOP and GIOP are somewhat different. Avoiding excessive glucocorticoid use is mandatory in patients with GIOP. In contrast, appropriate estrogen supplement is deemed the primary treatment for females with EDOP of various causes. Other pharmacological treatments include bisphosphonate, teriparatide, and RANKL inhibitors. Nevertheless, more detailed actions of EDOP and GIOP along with the safety and effectiveness of medications for treating osteoporosis warrant further investigation.
Asunto(s)
Estrógenos/deficiencia , Osteoporosis/etiología , Osteoporosis/metabolismo , Remodelación Ósea/efectos de los fármacos , Resorción Ósea/metabolismo , Diferenciación Celular/efectos de los fármacos , Estrógenos/metabolismo , Femenino , Glucocorticoides/farmacología , Humanos , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteocitos/metabolismo , Osteogénesis/efectos de los fármacos , Posmenopausia/fisiología , Ligando RANK/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The electrochemical preparation of 2-aminothiazoles has been achieved by the reaction of active methylene ketones with thioureas assisted by á´ Ê-alanine using NH4I as a redox mediator. The electrochemical protocol proceeds in an undivided cell equipped with graphite plate electrodes under constant current conditions. Various active methylene ketones, including ß-keto ester, ß-keto amide, ß-keto nitrile, ß-keto sulfone and 1,3-diketones, can be converted to the corresponding 2-aminothiazoles. Mechanistically, the in situ generated α-iodoketone was proposed to be the key active species.
RESUMEN
The COVID-19 pandemic caused by the SARS-CoV-2 virus, which first emerged in December 2019, represents an ongoing global public health emergency. Here, we developed an improved and highly sensitive approach to SARS-CoV-2 detection via coupling bioluminescence in real-time (BART) and reverse-transcriptase loop-mediated amplification (RT-LAMP) protocols (RT-LAMP-BART) and was also compatible with a digital LAMP system (Rainsuit), which did not allow for real-time quantification but did, nonetheless, facilitate absolute quantification with a comparable detection limit of 104 copies/mL. Through improving RNA availability in samples to ensure the target RNA present in reaction, we additionally developed a simulated digital RT-LAMP approach using this same principle to enlarge the overall reaction volume and to achieve real-time detection with a limit of detection of 10 copies/mL, and with further improvements in the overall dynamic range of this assay system being achieved through additional optimization.
Asunto(s)
COVID-19/virología , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , SARS-CoV-2/genética , Proteínas Virales/genética , Humanos , Límite de Detección , Mediciones Luminiscentes/métodos , Poliproteínas/genética , ARN Viral/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Transcripción ReversaRESUMEN
Epidermal growth factor receptor (EGFR) specific therapeutics is of great importance in cancer treatment. Fcy-hEGF fusion protein, composed of yeast cytosine deaminase (Fcy) and human EGF (hEGF), is capable of binding to EGFR and enzymatically convert 5-fluorocytosine (5-FC) to 1000-fold toxic 5-fluorocuracil (5-FU), thereby inhibiting the growth of EGFR-expressing tumor cells. To develop EGFR-specific therapy, 188Re-liposome-Fcy-hEGF was constructed by insertion of Fcy-hEGF fusion protein onto the surface of liposomes encapsulating of 188Re. Western blotting, MALDI-TOF, column size exclusion and flow cytometry were used to confirm the conjugation and bio-activity of 188Re-liposome-Fcy-hEGF. Cell lines with EGFR expression were subjected to treat with 188Re-liposome-Fcy-hEGF/5-FC in the presence of 5-FC. The 188Re-liposome-Fcy-hEGF/5-FC revealed a better cytotoxic effect for cancer cells than the treatment of liposome-Fcy-hEGF/5-FC or 188Re-liposome-Fcy-hEGF alone. The therapeutics has radio- and chemo-toxicity simultaneously and specifically target to EGFR-expression tumor cells, thereby achieving synergistic anticancer activity.
Asunto(s)
Citosina Desaminasa/metabolismo , Factor de Crecimiento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Fluorouracilo/farmacología , Neoplasias/metabolismo , Radiofármacos/farmacología , Antimetabolitos Antineoplásicos/metabolismo , Antimetabolitos Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Citosina Desaminasa/química , Factor de Crecimiento Epidérmico/química , Flucitosina/metabolismo , Fluorouracilo/metabolismo , Humanos , Liposomas/química , Células MCF-7 , Neoplasias/patología , Unión Proteica , Radioisótopos/química , Radiofármacos/química , Renio/químicaRESUMEN
Porcine circovirus type 2 (PCV2) is a pathogenic virus that causes high rates of porcine death, resulting in severe economic losses to the swine industry. In recent years, the prevalence of PCV2d genotype infection in pigs has increased, but most commercially available vaccines were developed against the PCV2a strain and do not ensure complete protection from PCV2d. Here, we first constructed an expression vector for the antigenic ORF2-encoded capsid protein of PCV2d (pLp3050-His6-tag-capsid). We then utilized Lactobacillus plantarum to express the protein at mucosal sites in orally vaccinated mice. After transducing L. plantarum with pLp3050-His6-tag-capsid, the expressed protein could be found in cell wall and cell-free supernatant fractions by Western blotting. Using flow cytometry, we found that L. plantarum cells with surface-displayed capsid protein increased with time after SppIP induction. Finally, mice that were orally immunized 18 times with capsid-expressing L. plantarum showed increased levels of capsid-specific sIgA and virus neutralizing activity at mucosal sites, suggesting mucosal immunity had been stimulated by the vaccine. Overall, our findings demonstrate the feasibility and utility of a PCV2d-based vaccine, which may be of great value in porcine agriculture.
RESUMEN
Zirconia-based limiting current oxygen sensor gains considerable attention, due to its high-performance in improving the combustion efficiency of fossil fuels and reducing the emission of exhaust gases. Nevertheless, the Pt electrode is frequently used in the oxygen sensor, therefore, it restrains the broader application due to the high cost. Quite recently, La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) has been reported to be highly active to catalyze oxygen reduction. Herein, with the intention of replacing the frequently used Pt, we studied the practicability of adapting the LSCM to zirconia-based limiting current oxygen sensor. Through comparing the electrocatalytic activity of LSCM and Pt, it is confirmed that LSCM gave analogous oxygen reactivity with that of the Pt. Then, limiting the current oxygen sensors comprised of LSCM or Pt are fabricated and their sensing behavior to oxygen in the range of 2â»25% is evaluated. Conclusively, quick response/recovery rate (within 7s), linear relationship, and high selectivity (against 5% CO2 and H2O) in sensing oxygen are observed for the sensors, regardless of the sensing materials (LSCM or Pt) that are used in the sensor. Particularly, identical sensing characteristics are observed for the sensors consisting of LSCM or Pt, indicating the practicability of replacing the Pt electrode by adapting the LSCM electrode to future zirconia-based oxygen sensors.
RESUMEN
An efficient electrocatalytic functionalization of N-arylglycine esters is reported. The protocol proceeds in an undivided cell under constant current conditions employing the simple, cheap and readily available n-Bu4NI as the mediator. In addition, it is demonstrated that the mediated process is superior to the direct electrochemical functionalization.
RESUMEN
Human diabetic polyneuropathy (DPN) is a progressive complication of chronic diabetes mellitus. Preliminary evidence has suggested that intranasal insulin, in doses insufficient to alter hyperglycemia, suppresses the development of DPN. In this work we confirm this finding, but demonstrate that its impact is modified by sex and deletion of RAGE, the receptor for advanced glycosylation end products. We serially evaluated experimental DPN in male and female wild-type mice and male RAGE null (RN) mice, each with nondiabetic controls, during 16 wk of diabetes, the final 8 wk including groups given intranasal insulin. Age-matched nondiabetic female mice had higher motor and sensory conduction velocities than their male counterparts and had lesser conduction slowing from chronic diabetes. Intranasal insulin improved slowing in both sexes. In male RN mice, there was less conduction slowing with chronic diabetes, and intranasal insulin provided limited benefits. Rotarod testing and hindpaw grip power offered less consistent impacts. Mechanical sensitivity and thermal sensitivity were respectively but disparately changed and improved with insulin in wild-type female and male mice but not RN male mice. These studies confirm that intranasal insulin improves indexes of experimental DPN but indicates that females with DPN may differ in their underlying phenotype. RN mice had partial but incomplete protection from underlying DPN and lesser impacts from insulin. We also identify an important role for sex in the development of DPN and report evidence that insulin and AGE-RAGE pathways in its pathogenesis may overlap.
Asunto(s)
Neuropatías Diabéticas/tratamiento farmacológico , Neuropatías Diabéticas/fisiopatología , Modelos Animales de Enfermedad , Insulina/administración & dosificación , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Administración Intranasal , Animales , Enfermedad Crónica , Progresión de la Enfermedad , Femenino , Hipoglucemiantes/administración & dosificación , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor para Productos Finales de Glicación Avanzada/genética , Caracteres Sexuales , Resultado del TratamientoRESUMEN
BACKGROUND: Olfactory ensheathing cells (OEC), specialized glia that ensheathe bundles of olfactory nerves, have been reported as a favorable substrate for axonal regeneration. Grafting OEC to injured spinal cord appears to facilitate axonal regeneration although the functional recovery is limited. In an attempt to improve the growth-promoting properties of OEC, we transduced prostacyclin synthase (PGIS) to OEC via adenoviral (Ad) gene transfer and examined the effect of OEC with enhanced prostacyclin synthesis in co-culture and in vivo. Prostacyclin is a vasodilator, platelet anti-aggregatory and cytoprotective agent. RESULTS: Cultured OEC expressed high level of cyclooxygneases, but not PGIS. Infection of AdPGIS to OEC could selectively augument prostacyclin synthesis. When cocultured with either OEC or AdPGIS-OEC, neuronal cells were resistant to OGD-induced damage. The resulted OEC were further transplanted to the transected cavity of thoracic spinal cord injured (SCI) rats. By 6 weeks post-surgery, significant functional recovery in hind limbs occurred in OEC or AdPGIS-OEC transplanted SCI rats compared with nontreated SCI rats. At 10-12 weeks postgraft, AdPGIS-OEC transplanted SCI rats showed significantly better motor restoration than OEC transplanted SCI rats. Futhermore, regenerating fiber tracts in the distal spinal cord stump were found in 40-60% of AdPGIS-OEC transplanted SCI rats. CONCLUSIONS: Enhanced synthesis of prostacyclin in grafted OEC improved fiber tract regeneration and functional restoration in spinal cord injured rats. These results suggest an important potential of prostacyclin in stimulating OEC therapeutic properties that are relevant for neural transplant therapies.
Asunto(s)
Sistema Enzimático del Citocromo P-450/genética , Expresión Génica , Oxidorreductasas Intramoleculares/genética , Neuroglía/fisiología , Nervio Olfatorio/fisiología , Regeneración de la Medula Espinal , Animales , Células Cultivadas , Sistema Enzimático del Citocromo P-450/metabolismo , Oxidorreductasas Intramoleculares/metabolismo , Ratas , Ratas Sprague-Dawley , Recuperación de la FunciónRESUMEN
OBJECTIVE: The study was conducted to evaluate the stability of commercial coated lipase (CT-LIP) in vitro. METHODS: The capsules were tested under different conditions with a range of temperature, pH, dry heat treatment and steaming treatment, simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) in this work, respectively. Free lipase (uncoated lipase, UC-LIP) was the control group. Lipase relative activities measured in various treatments were used as a reference frame to characterize the stability. RESULTS: The lipase activities were decreased with increasing temperatures (p<0.05), and there was a markedly decline (p<0.01) in lipase comparative activities of UC-LIP at 80°C compared with CT-LIP group. Higher relative activities of lipase were observed in CT-LIP group compared with the free one under acidic ambient (pH 3 to 7) and an alkaline medium (pH 8 to 12). Residual lipase activities of CT-LIP group were increased (p<0.05) by 5.67% and 35.60% in dry heat and hydrothermal treatments, respectively. The lipase relative activity profile of CT-LIP was raised at first and dropped subsequently (p<0.05) compared with constantly reduced tendency of UC-LIP exposed to both SGF and SIF. CONCLUSION: The results suggest that the CT-LIP possesses relatively higher stability in comparison with the UC-LIP in vitro. The CT-LIP could retain the potential property to provide sustained release of lipase and thus improved its bioavailability in the gastrointestinal tract.
RESUMEN
An efficient electrochemical protocol for the synthesis of α-amino ketones via the oxidative cross-dehydrogenative coupling of ketones and secondary amines has been developed. The electrochemistry performs in a simple undivided cell using NH4I as a redox catalyst and a cheap graphite plate as electrodes under constant current conditions. Gram-scale reaction demonstrates the practicality of the protocol. The reaction is proposed to procced through an initial α-iodination of ketone, followed by a nucleophilic substitution of amines.
RESUMEN
An efficient protocol for the synthesis of sulfonamides via the electrochemical oxidative amination of sodium sulfinates has been developed. The chemistry proceeds in a simple undivided cell employing a substoichiometric amount of NH4I that serves both as a redox catalyst and a supporting electrolyte; in this manner additional conducting salt is not required. A wide range of substrates, including aliphatic or aromatic secondary and primary amines, as well as aqueous ammonia, proved to be compatible with the protocol. Scale-up was possible, thereby demonstrating the practicality of the approach. The electrolytic process avoids the utilization of external oxidants or corrosive molecular iodine and therefore represents an environmentally benign means by which to achieve the transformation.
RESUMEN
Perineuronal satellite cells have an intimate anatomical relationship with sensory neurons that suggests close functional collaboration and mutual support. We examined several facets of this relationship in adult sensory dorsal root ganglia (DRG). Collaboration included the support of process outgrowth by clustering of satellite cells, induction of distal branching behavior by soma signaling, the capacity of satellite cells to respond to distal axon injury of its neighboring neurons, and evidence of direct neuron-satellite cell exchange. In vitro, closely adherent coharvested satellite cells routinely clustered around new outgrowing processes and groups of satellite cells attracted neurite processes. Similar clustering was encountered in the pseudounipolar processes of intact sensory neurons within intact DRG in vivo. While short term exposure of distal growth cones of unselected adult sensory neurons to transient gradients of a PTEN inhibitor had negligible impacts on their behavior, exposure of the soma induced early and substantial growth of their distant neurites and branches, an example of local soma signaling. In turn, satellite cells sensed when distal neuronal axons were injured by enlarging and proliferating. We also observed that satellite cells were capable of internalizing and expressing a neuron fluorochrome label, diamidino yellow, applied remotely to distal injured axons of the neuron and retrogradely transported to dorsal root ganglia sensory neurons. The findings illustrate a robust interaction between intranganglionic neurons and glial cells that involve two way signals, features that may be critical for both regenerative responses and ongoing maintenance.
Asunto(s)
Células Satélites Perineuronales/fisiología , Células Receptoras Sensoriales/fisiología , Animales , Transporte Axonal , Axones/metabolismo , Axones/fisiología , Células Cultivadas , Ganglios Espinales/citología , Ganglios Espinales/fisiología , Conos de Crecimiento/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Células Receptoras Sensoriales/metabolismoRESUMEN
We have previously developed the enabling techniques for sulfoglycomics based on mass spectrometry (MS) analysis of permethylated glycans, which preserves the attractive features of more reliable MS/MS sequencing compared with that performed on native glycans, while providing an easy way to separate and hence enrich the sulfated glycans. Unlike LC-MS/MS analysis of native glycans in negative ion mode that has been more widely in use, the characteristics and potential benefits of similar applications based on permethylated sulfated glycans have not been fully investigated. We report here the important features of reverse phase-based nanoLC-MS/MS analysis of permethylated sulfated glycans in negative ion mode and demonstrate that complementary sets of diagnostic fragment ions afforded can allow rapid identification of various fucosylated, sialylated, sulfated glycotopes and definitive determination of the location of sulfate in a way difficult to achieve by other means. A parallel acquisition of both higher collision energy and trap-based MS(2) coupled with a product dependent MS(3) is conceivably the most productive sulfoglycomic workflow currently possible and the manually curated fragmentation characteristics presented here will allow future developments in automating data analysis.
Asunto(s)
Nanotecnología , Polisacáridos/análisis , Sulfatos/química , Cromatografía Líquida de Alta Presión , Iones/química , Espectrometría de Masas en TándemRESUMEN
An effective Friedel-Crafts alkylation reaction of electron-rich aromatics with N-vinylamides, induced by electrochemically in situ-generated TBPA radical cation, has been developed; the resulting adducts are produced in good to excellent yields. In the "ex-cell" type electrolysis, TBPA is transformed to its oxidized form in situ and subsequently employed as an electron transfer reagent to initiate a cationic chain reaction. An easily recoverable and reusable polymeric ionic liquid-carbon black (PIL-CB) composite was also utilized as a supporting electrolyte for the electrochemical generation of TBPA cation radical, without sacrificing efficiency or stability after four electrolyses. Cyclic voltammetry analysis and the results of control experiments demonstrate that the reaction of electron-rich aromatics and N-vinylamides occurs via a cationic chain reaction, which takes place though an oxidative activation of a C-H bond of electron-rich aromatics instead of oxidation of the N-vinylamide as previously assumed.
RESUMEN
The indirect anodic oxidation of chalcone epoxides in the presence of electron-rich heteroarenes mediated by a triarylimidazole (Med) was investigated by cyclic voltammetry (CV) and controlled potential electrolysis. The CV results indicate that a homogeneous electron transfer between Medâ¢+ and chalcone epoxides is facilitated by an electron-rich heteroarene that serves as an arylation reagent. The preparative scale electrolysis generated epoxide-ring-opened/FriedelCrafts arylation products in moderate to good yields. The fact that only a catalytic amount of charge was required suggests that Medâ¢+ initiates a chain reaction. In addition, overoxidation of the products is avoided even though their oxidation potential is less than that of the starting chalcone epoxides.