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1.
Inorg Chem ; 62(15): 5920-5930, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37017463

RESUMO

Triplet photovoltaic materials have been rarely investigated in organic solar cells (OSCs) because the role and mechanism of triplet excitons are still unclear. Cyclometalated heavy metal complexes with triplet features are expected to increase exciton diffusion lengths and improve exciton dissociation in OSCs, while the power conversion efficiencies (PCEs) of their bulk-heterojunction (BHJ) OSCs are still limited to <4%. We herein report an octahedral homoleptic tris-Ir(III) complex TBz3Ir as a donor material for BHJ OSCs with a PCE of over 11%. In comparison with the planar organic TBz ligand and heteroleptic TBzIr, TBz3Ir demonstrates the highest PCE and best device stability in both fullerene- and non-fullerene-based devices, owing to the long triplet lifetime, enhanced optical absorption, increased charge transport, and improved film morphology. From transient absorption, triplet excitons were deduced to participate in the photoelectric conversion process. In particular, the more significant 3D structure of TBz3Ir induces an unusual film morphology in TBz3Ir:Y6 blends, showing obviously large domain sizes suitable for triplet excitons. Thus, a high PCE of 11.35% with a high circuit current density of 24.17 mA cm-2 and a fill factor of 0.63 is achieved for small-molecular Ir complex-based BHJ OSCs.

2.
Org Biomol Chem ; 19(24): 5342-5347, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34043743

RESUMO

A practical phosphorylation for generating organophosphates and phosphoramidates via electrochemical dehydrogenative cross-coupling of P(O)H compounds with arenols and anilines is disclosed. This method involves using inorganic iodide salts as both redox catalysts and electrolytes in an undivided cell without the addition of oxidants or bases. A preliminary mechanistic study suggests that radicals are not involved in this process. This method is green and eco-friendly and has good functional group tolerance, high yields and broad substrate scope, with the potential for practical synthesis.

3.
Proc Natl Acad Sci U S A ; 115(11): 2818-2823, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29483275

RESUMO

Seven-carbon-chain-containing sugars exist in several groups of important bacterial natural products. Septacidin represents a group of l-heptopyranoses containing nucleoside antibiotics with antitumor, antifungal, and pain-relief activities. Hygromycin B, an aminoglycoside anthelmintic agent used in swine and poultry farming, represents a group of d-heptopyranoses-containing antibiotics. To date, very little is known about the biosynthesis of these compounds. Here we sequenced the genome of the septacidin producer and identified the septacidin gene cluster by heterologous expression. After determining the boundaries of the septacidin gene cluster, we studied septacidin biosynthesis by in vivo and in vitro experiments and discovered that SepB, SepL, and SepC can convert d-sedoheptulose-7-phosphate (S-7-P) to ADP-l-glycero-ß-d-manno-heptose, exemplifying the involvement of ADP-sugar in microbial natural product biosynthesis. Interestingly, septacidin, a secondary metabolite from a gram-positive bacterium, shares the same ADP-heptose biosynthesis pathway with the gram-negative bacterium LPS. In addition, two acyltransferase-encoding genes sepD and sepH, were proposed to be involved in septacidin side-chain formation according to the intermediates accumulated in their mutants. In hygromycin B biosynthesis, an isomerase HygP can recognize S-7-P and convert it to ADP-d-glycero-ß-d-altro-heptose together with GmhA and HldE, two enzymes from the Escherichia coli LPS heptose biosynthetic pathway, suggesting that the d-heptopyranose moiety of hygromycin B is also derived from S-7-P. Unlike the other S-7-P isomerases, HygP catalyzes consecutive isomerizations and controls the stereochemistry of both C2 and C3 positions.


Assuntos
Escherichia coli/metabolismo , Higromicina B/biossíntese , Fosfatos Açúcares/metabolismo , Vias Biossintéticas , Escherichia coli/enzimologia , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Heptoses/metabolismo , Higromicina B/química , Nucleosídeos de Purina/biossíntese , Nucleosídeos de Purina/química , Fosfatos Açúcares/química
4.
Biochem Biophys Res Commun ; 522(1): 33-39, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31735330

RESUMO

The objective of this study was to assess the role of NETs in BPD of hyperoxia-induced rat model and the effect of heparin on alveolarization and vascular development in BPD. The neonatal rats exposed to 90% oxygen continuously for 7 days to mimic BPD, meanwhile, the rats were injected by different doses of histones to evaluate the impact on lung injury. The newborn rats exposed to hyperoxia were injected by different doses of heparin (250 U/kg, 500 U/kg) or anti-H4 antibody to evaluate the effect of heparin. Histones and hyperoxia impaired alveolarization with the increase of mean linear intercept (MLI) and the decrease of radial alveolar count (RAC), decreased lung angiogenesis with the decrease expression of VEGF, and increased the expression of NETs, histones and pro-inflammatory factor. However, low dose heparin (250U/kg) administration enhanced survival, improved alveolarization and vascular development in hyperoxia-induced BPD, as well as reduced expression of NETs, histones and pro-inflammatory factor. We concluded that heparin improves alveolarization and vascularization in BPD by inhibiting NETs.


Assuntos
Displasia Broncopulmonar/metabolismo , Armadilhas Extracelulares/metabolismo , Heparina/farmacologia , Hiperóxia/metabolismo , Alvéolos Pulmonares/metabolismo , Animais , Animais Recém-Nascidos , Displasia Broncopulmonar/patologia , Feminino , Histonas/metabolismo , Inflamação , Pulmão/patologia , Neovascularização Fisiológica , Oxigênio/metabolismo , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
J Clin Lab Anal ; 34(5): e23158, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31821607

RESUMO

BACKGROUND: Early diagnosis decreases the mortality of hepatocellular carcinoma (HCC). We aimed to investigate the usefulness of PIVKA-II, AFP, AFP-L3, CEA, and their combinations in the diagnosis of primary and metastatic HCC. METHODS: One hundred and twenty patients with primary HCC (PHC), 115 with metastatic HCC (MHC), 89 with chronic liver disease (CLD), and 116 healthy volunteers were included. The diagnostic values of each marker and their combinations for HCC diagnosis were represented by ROC curve analyses. RESULTS: PIVKA-II, AFP, and AFP-L3 levels in PHC group were higher than that in normal control, CLD, and MHC groups. CEA levels in MHC group were higher than that in the other three groups. When the four markers were analyzed individually, PIVKA-II showed the highest positive rate in PHC group (76.7%) and CEA showed the highest positive rate in MHC group (69.6%). PIVKA- II showed the largest area under ROC curve (AUC = 0.835) to discriminate PHC group from CLD group. Combined PIVKA-II with AFP-L3 increased the AUC to 0.910. CEA showed the highest AUC (0.849) to discriminate MHC group from CLD group. Combined CEA with PIVKA-II increased the AUC to 0.866. AFP-L3 alone showed the highest AUC (0.890) to discriminate MHC group from PHC group. Combined PIVKA-II with AFP-L3, and CEA increased the AUC to 0.957. CONCLUSION: PIVKA-II, AFP-L3, AFP, and CEA are effective biomarkers for the diagnosis of PHC and MHC. Their combinations could improve the diagnostic performance compared with each marker used alone in detecting PHC and MHC.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/patologia , Adulto , Idoso , Biomarcadores/sangue , Antígeno Carcinoembrionário/sangue , Estudos de Casos e Controles , Feminino , Humanos , Hepatopatias/sangue , Masculino , Pessoa de Meia-Idade , Precursores de Proteínas/sangue , Protrombina
6.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(4): 449-451, 2020 Apr 10.
Artigo em Zh | MEDLINE | ID: mdl-32219834

RESUMO

OBJECTIVE: To detect pathogenic variant in a neonate suspected for Cornelia de Lange syndrome (CdLS). METHODS: Potential mutations of CdLS-related genes (NIPBL, SMC1A, SMC3, RAD21 and HDAC8) were detected by high-throughput target region capture and next-generation sequencing. Suspected variants was verified by Sanger sequencing. RESULTS: The child was found to harbor a heterozygous splice site variant, c.6109-1G>A, of the NIPBL gene. Sanger sequencing suggested that neither parent has carried the same variant, suggesting that it was de novo. The variant was unreported by HGMD and ExAC database, and was predicted to alter an acceptor splicing site. No pathogenic variants of SMC1A, SMC3, RAD21 and HDAC8 genes were detected. CONCLUSION: The heterozygous c.6109-1G>A splicing variant of the NIPBL gene may underlie the disease in this child. Above finding has expanded the variant spectrum of the NIPBL gene.


Assuntos
Proteínas de Ciclo Celular/genética , Síndrome de Cornélia de Lange/genética , Variação Genética , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Recém-Nascido , Mutação , Fenótipo
7.
Med Sci Monit ; 25: 6074-6084, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31411185

RESUMO

BACKGROUND Bronchopulmonary dysplasia (BPD) is a major complication of extreme prematurity, characterized by alveolar simplification and pulmonary malfunction. Hyperoxia-induced lung injury in neonatal rats has been used as a model of BPD, as indicated by lung architectural change and alveolar simplification that resembles clinical feature of BPD. ß-defensin-2 (BD2) plays an important role in lung diseases by inhibiting inflammation response. However, little is known about its role in BPD. The aim of this study was to determine the effect of human BD2 (hBD2) gene on hyperoxia-induced animal model of BPD. MATERIAL AND METHODS The neonatal rats were exposed to 90% oxygen (O2) continuously for 14 days to mimic the BPD-like lung injury. These rats were then randomly assigned to the following four groups: in room air (air), in 90% O2, in 90% O2 with null adenovirus vector infection (O2+Ad), and in 90% O2 with gene therapy through adenovirus transfected hBD2 (O2+Ad-hBD2). Morphology of lungs, pulmonary function and expression of inflammatory cytokines on P7, P10, P14, and P21 were documented and compared across the 4 groups. RESULTS The overexpression of hBD2 mediated by the adenovirus vector was successfully constructed. hBD2 gene therapy increased hBD2 mRNA expression, increased radial alveolar count (RAC), lung volume and compliance, decreased mean linear intercept (MLI), tissue damping, and elastance. Furthermore, pro-inflammatory cytokines IL-1ß, IL-6, and TNF-alpha were inhibited and anti-inflammatory cytokines IL-10 was increased in the lungs of rats in O2+Ad-hBD2 group. CONCLUSIONS In hyperoxia-induced rat models of BPD, hBD2 promotes alveolarization and improves pulmonary function. The mechanism may contribute in alleviating inflammation response and inhibiting pro-inflammatory factors including IL-1ß, IL-6, and TNF-alpha.


Assuntos
Lesão Pulmonar/terapia , beta-Defensinas/metabolismo , Animais , Animais Recém-Nascidos , Displasia Broncopulmonar/fisiopatologia , Modelos Animais de Doenças , Feminino , Humanos , Hiperóxia/complicações , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Pulmão/fisiopatologia , Lesão Pulmonar/etiologia , Oxigênio/metabolismo , Gravidez , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo , beta-Defensinas/fisiologia
9.
Org Biomol Chem ; 16(33): 5999-6005, 2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30083694

RESUMO

Flavone selenide or sulfur-containing derivatives are pretty valuable in drug discovery due to their diversity of important bioactivities. Here, two simple Cu-catalyzed methods of constructing C-Se and C-S bonds on flavone skeletal structures via C-H functionalization are reported, which regioselectively afford flavone selenide and sulfide derivatives in good yields using cheap KSeCN or KSCN salts as selenium and sulfur agents. These methods further enrich the current C-Se and C-S bond construction methods.

10.
Phys Chem Chem Phys ; 20(14): 9516-9522, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29570204

RESUMO

Recent years have witnessed the progress of lanthanide-doped materials from fundamental material synthesis to targeted practical applications such as optical applications in photodetection, anti-counterfeiting, volumetric display, optical communication, as well as biological imaging. The unique compositions and structures of well-designed lanthanide ion-doped materials could expand and strengthen their application performances. Herein, we report dual-mode luminescent crystalline microrods that spatially confine upconversion and downconversion photophysical process within defined regions using the specially designed heterogeneous structure. Through an epitaxial growth procedure, downconversion tips have been conjugated with the parent upconversion microrods in oriented directions. This spatially confined structure can effectively depress the deleterious energy depletion in lanthanide ions homogeneously doped materials, and as a result, the red, green, and blue upconversion intensities have been enhanced by 334, 225, and 22 times, respectively. Moreover, the induced tips hardly disturb the upconversion process of the microrod seeds. Upon 980 nm laser or ultraviolet lamp excitation, tunable emission colors were realized in the single tip-modified microrod, indicating potential applications of these microrods for high-level dual-mode anti-counterfeiting.

11.
J Org Chem ; 82(19): 10617-10622, 2017 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-28850226

RESUMO

The method for constructing C-S bonds is very important in organic synthesis. Here a new sulfenylation method to generate flavone thioether derivatives was developed by employing aromatic or alkyl halides, S powder and Na2S2O3 as reactants. Good yields of regioselective Calkyl-S and Caryl-S-substituted flavones were generated under relatively environmentally friendly and simple conditions. This method might be potentially applicable to large scale production, and it enriches current sulfenylation methods.

12.
BMC Infect Dis ; 17(1): 59, 2017 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-28077075

RESUMO

BACKGROUND: Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite with a broad host range including most warm-blooded animals, including humans. T. gondii surface antigen 1 (SAG1) is a well-characterized T. gondii antigen. T. gondii expresses five nonmitochondrial rhomboid intramembrane proteases, TgROM1-5. TgROM4 is uniformly distributed on the surface of T. gondii and involved in regulating MIC2, MIC3, MIC6, and AMA1 during T. gondii invasion of host cells. Bioinformatics have predicted ROM4 B-cell and T-cell epitopes. Immunization strategy is also a key factor in determining the effectiveness of the immune response and has gained increasing attention in T. gondii vaccine research. In this study, we used a DNA prime-peptide boost vaccination regimen to assess the protective efficacy of various vaccination strategies using TgROM4. METHODS: We identified a polypeptide (YALLGALIPYCVEYWKSIPR) using a bioinformatics approach, and immunized mice using a DNA-prime and polypeptide-boost regimen. BALB/c mice were randomly divided into six groups, including three experimental groups (peptide, pROM4 and pROM4/peptide) and three control groups (PBS, pEGFP-C1 and pSAG1). Mice were then immunized intramuscularly four times. After immunization, IgG and cytokine productions were determined using enzyme-linked immunosorbent assays. The survival time of mice was evaluated after challenge with tachyzoites of T. gondii RH strain. Additionally, the number of cysts in the brain was determined after intragastric challenge with cysts of T. gondii PRU strain. RESULTS: Mice vaccinated with different immunization regimens (peptide, pROM4 and pROM4/peptide) elicited specific humoral and cellular responses, with high levels of IgG, IgG2a, and interferon (IFN)-γ. Moreover, IgG, IgG2a and IFN-γ levels were highest in the pROM4/peptide group. Immunized mice, especially those in the pROM4/peptide group, had prolonged survival times after challenge with tachyzoites and reduced numbers of brain cysts after infection compared with negative controls. CONCLUSION: A DNA prime-peptide boost regimen based on ROM4 elicited the highest level of humoral and cellular immune responses among immunization regimens, and may be a promising approach to increase the efficacy of DNA immunization.


Assuntos
Antígenos de Protozoários/imunologia , Imunoglobulina G/efeitos dos fármacos , Interferon gama/efeitos dos fármacos , Peptídeo Hidrolases/genética , Peptídeos/imunologia , Proteínas de Protozoários/genética , Vacinas Protozoárias/farmacologia , Toxoplasmose Animal/prevenção & controle , Vacinas de DNA/farmacologia , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Imunoglobulina G/imunologia , Injeções Intramusculares , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Peptídeo Hidrolases/imunologia , Proteínas de Protozoários/imunologia , Toxoplasma/imunologia , Vacinação
13.
BMC Infect Dis ; 17(1): 19, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28056837

RESUMO

BACKGROUND: A widely prevalent disease, toxoplasmosis poses serious health threats to both humans and animals; therefore, development of an ideal DNA vaccine against Toxoplasma gondii is needed eagerly. The purpose of the present study is to assess the protective efficacy of a DNA vaccine encoding the T. gondii toxofilin gene (pEGFP-toxofilin). In addition, toxofilin DNA vaccine combined with the individual adjuvants, alum or monophosphoryl lipid A (MPLA), or a mixture of alum-MPLA adjuvant were screened for their ability to enhance antibody responses. METHODS: Using bioinformatics, we analyzed the gene and amino acid sequences of the toxofilin protein, recognizing and identifying several potential linear B and T helper (Th)-1 cell epitopes. BALB/c mice were immunized three times with either toxofilin DNA vaccine alone or in combination with the adjuvants such as alum, MPLA or an alum-MPLA mixture. The systemic immune response was evaluated by cytokine, the percentage of CD4 (+) and CD8 (+) T cells and specific antibody measurement. Two weeks after the last immunization, protective efficacy was evaluated by challenging intraperitoneally with 1 × 104 tachyzoites of T. gondii or intragastrically with 20 cysts of T. gondii PRU strain. RESULTS: All experimentally immunized mice developed strong humoral and cellular immune responses compared with the control groups. Moreover, by comparison with the non-adjuvant toxofilin DNA vaccine group, adding alum adjuvant to toxofilin DNA vaccine resulted in an increase in humoral response and a skewed Th2 response. However, the MPLA adjuvant with toxofilin DNA vaccine induced significantly enhanced humoral and Th1-biased immune responses. Importantly, the co-administration of alum-MPLA adjuvant in combination with the toxofilin DNA vaccine shifted the Th2 immune response to a Th1 response compared with the alum-toxofilin group, and elicited the strongest humoral and Th1 responses among all the groups. At the same time, a longer survival time and less cyst amounts against T. gondii infection were also observed in the alum-MPLA-toxofilin group in comparison with single or no adjuvant groups. CONCLUSIONS: Toxoplasma gondii toxofilin is a promising vaccine candidate that warrants further development. Co-administration of the alum-MPLA adjuvant mixture with DNA vaccine could effectively enhance immunogenicity and strongly skew the cellular immune response towards a Th1 phenotype.


Assuntos
Proteínas de Capeamento de Actina/genética , Adjuvantes Imunológicos/farmacologia , Lipídeo A/análogos & derivados , Proteínas de Protozoários/genética , Vacinas Protozoárias/farmacologia , Toxoplasmose/imunologia , Proteínas de Capeamento de Actina/imunologia , Compostos de Alúmen/farmacologia , Animais , Formação de Anticorpos/efeitos dos fármacos , Feminino , Imunidade Celular , Lipídeo A/imunologia , Lipídeo A/farmacologia , Camundongos Endogâmicos BALB C , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/imunologia , Toxoplasma/imunologia , Toxoplasma/patogenicidade , Toxoplasmose/prevenção & controle , Vacinas de DNA/imunologia , Vacinas de DNA/farmacologia
14.
Pediatr Cardiol ; 38(6): 1169-1174, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28534241

RESUMO

Congenital heart disease (CHD) is one of the most common birth anomalies worldwide. Folate deficiency is an independent risk factor for CHD. Genome-wide association studies (GWAS) revealed that human folate level could be significantly influenced by fidgetin (FIGN), methylenetetrahydrofolate reductase (MTHFR), prickle homolog 2 (PRICKLE2), synaptotagmin 9 (SYT9), gamma-aminobutyric acid B receptor 2 (GABBR2), and alkaline phosphatase (ALPL) genes. The association between the above-mentioned six variants and CHD was examined in the two independent case-control studies in a total of 868 CHD patients and 931 healthy controls. Our results showed that the G > C (rs2119289) variant in intron 4 of FIGN led to a significant reduction of CHD susceptibility in both the separate and combined case-control studies (allele distribution P < 0.001, genotype distribution P < 0.001). Specifically, by analyzing the combined samples, we observed that the risks of CHD in individuals carrying the heterozygous G/C and homozygous C/C genotypes were reduced by 45% (adjusted OR 0.55, 95% CI 0.47-0.67) and 66% (adjusted OR 0.34, 95% CI 0.23-0.50), respectively, in comparison with individuals carrying the wild-type G/G genotype. Our findings have demonstrated that the C allele of variant rs2119289 of FIGN gene is an important genetic marker for decreased CHD risk. Considering that the rs2119289 of FIGN gene is related to the appropriate folate level, FIGN might play an important role in CHD by upregulating plasma folate concentration during embryo heart development. This work provides a new insight for risk assessment of CHD.


Assuntos
Adenosina Trifosfatases/genética , Cardiopatias Congênitas/genética , ATPases Associadas a Diversas Atividades Celulares , Povo Asiático/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Proteínas Associadas aos Microtúbulos , Polimorfismo de Nucleotídeo Único , Fatores de Risco
15.
Korean J Parasitol ; 55(5): 505-512, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29103265

RESUMO

Toxoplasma gondii cathepsin C proteases (TgCPC1, 2, and 3) are important for the growth and survival of T. gondii. In the present study, B-cell and T-cell epitopes of TgCPC1 were predicted using DNAstar and the Immune Epitope Database. A TgCPC1 DNA vaccine was constructed, and its ability to induce protective immune responses against toxoplasmosis in BALB/c mice was evaluated in the presence or absence of the adjuvant α-GalCer. As results, TgCPC1 DNA vaccine with or without adjuvant α-GalCer showed higher levels of IgG and IgG2a in the serum, as well as IL-2 and IFN-γ in the spleen compared to controls (PBS, pEGFP-C1, and α-Galcer). Upon challenge infection with tachyzoites of T. gondii (RH), pCPC1/α-Galcer immunized mice showed the longest survival among all the groups. Mice vaccinated with DNA vaccine without adjuvant (pCPC1) showed better protective immunity compared to other controls (PBS, pEGFP-C1, and α-Galcer). These results indicate that a DNA vaccine encoding TgCPC1 is a potential vaccine candidate against toxoplasmosis.


Assuntos
Cisteína Endopeptidases/genética , Cisteína Endopeptidases/imunologia , DNA de Protozoário/genética , DNA de Protozoário/imunologia , Toxoplasma/genética , Toxoplasma/imunologia , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/prevenção & controle , Vacinas de DNA/imunologia , Animais , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos BALB C
16.
Org Biomol Chem ; 14(4): 1428-31, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26676565

RESUMO

A novel ammonium iodide-induced sulfenylation method of flavones, indole and arylimidazo[1,2-a]pyridines using stable and odorless sodium benzenesulfinates as sulfur sources was developed, generating regioselective derivatives in good yields. This method has enriched current thioether-producing methods and provided a good example of using ammonium iodide as a reaction inducer instead of iodine to make thioethers under environmentally friendly and odorless conditions.

17.
Chemistry ; 21(29): 10278-88, 2015 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-25858775

RESUMO

Fluorenes are a commonly encountered structural motif in materials science, pharmaceutical chemistry, and organic synthesis. Among various strategies towards the synthesis of this unique structure, transition metal-catalyzed functionalization has emerged as one of the most efficient methods. This Minireview presents an overview of the recent advances in this emerging area by highlighting the reactions' specificity and applicability and, where possible, provides a mechanistic rationale.

18.
Biomacromolecules ; 16(7): 1978-86, 2015 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-25996799

RESUMO

In this study, galactose-based nanogels were prepared by reversible addition-fragmentation chain transfer process to facilitate the targeted delivery of iodoazomycin arabinofuranoside (IAZA), a clinical drug for imaging solid hypoxic tumors, and evaluate its role in hypoxia-selective (radio)theranostic (therapy + diagnostic) management of therapy-resistant cancer cells. The nanogels have a cross-linked temperature-responsive core and a dense carbohydrate shell. Their thermoresponsive nature allowed the controlled encapsulation of IAZA drug for targeted delivery and release in hypoxic hepatocellular carcinoma via asialoglycoprotein receptor-mediated uptake. The synthesized nanogel-IAZA delivery systems demonstrated a stable, nonburst release of IAZA over 10 h with up to 0.6 mM loading capacity of IAZA within the nanogel. The cytotoxicity evaluations of the nanogels demonstrated that they are relatively nontoxic in multiple cell lines. The radiosensitization studies indicated that IAZA in encapsulated form offers a superior radiosensitization of hypoxic cells (sensitizer enhancement ratio for IAZA alone, 1.33; 1.62 for nanogel encapsulated IAZA). These studies suggest that galactose-based nanogels may serve as a versatile drug delivery system for IAZA (and other azomycin-based agents) and enable its hypoxia-selective multimodal theranostic applications to manage hypoxic solid (hepatocellular) tumors by facilitating position/single photon emission tomography-based imaging, external beam radiation therapy, and in situ molecular radiotherapy.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Galactose/química , Neoplasias Hepáticas/diagnóstico , Nitroimidazóis/farmacologia , Polietilenoglicóis/síntese química , Polietilenoimina/síntese química , Radiossensibilizantes/farmacologia , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Células HeLa , Células Hep G2 , Humanos , Células MCF-7 , Nanogéis , Nitroimidazóis/química , Polietilenoglicóis/química , Polietilenoimina/química , Radiossensibilizantes/química , Temperatura , Nanomedicina Teranóstica/métodos
19.
J Org Chem ; 80(18): 9167-75, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26291122

RESUMO

A novel and highly regioselective ammonium iodide-induced nonradical sulfenylation method for the construction of a C-S bond was developed via C-H functionalization. With DMSO or R(1)SO2NHNH2 as a sulfenylating agent, MeS- and R(1)S-substituted flavone derivatives were obtained in good yields. This method enriches current C-S bond formation chemistry, making it a highly valuable and practical method in pharmaceutical industry.


Assuntos
Flavonas/química , Compostos de Amônio Quaternário/química , Compostos de Sulfidrila/química , Compostos de Amônio , Catálise , Ligação de Hidrogênio , Estrutura Molecular
20.
J Org Chem ; 80(14): 7251-7, 2015 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-26053358

RESUMO

Coumarin and flavone derivatives are highly valuable molecules in drug discovery. Here, two new regioselective cross-dehydrogenation couplings of coumarins and flavones with different ethers via C(sp(3))-H functionalization processes were developed, generating new ether-substituted derivatives not previously reported. These reactions proceeded well via radical mechanisms and provided the corresponding products in good yields.


Assuntos
Cumarínicos/química , Éteres/síntese química , Flavonas/química , Catálise , Descoberta de Drogas , Éteres/química
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