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2.
Acc Chem Res ; 52(7): 1877-1891, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31264824

RESUMO

The monoterpene indole alkaloids, containing over 3000 known members and more than 40 structural types, represent one of the largest natural product families that have proven to be an important drug source. Their complex chemical structures and significant biological activities have rendered these alkaloids attractive targets in the synthetic community for decades. While chemists have developed many synthetic methodologies and tactics toward this end, general strategies allowing divergent access to a large variety of structural types and members of monoterpene indole alkaloids are still limited and highly desirable. Photoredox catalysis has emerged in recent years as a powerful tool to realize chemical transformations via single electron transfer (SET) processes that would otherwise be inaccessible. In particular, when the radical species generated by the visible light photoinduced approach is involved in well-designed cascade reactions, the formation of multiple chemical bonds and the assembly of structurally complex molecules would be secured in a green and economic manner. This protocol might serve to remodel the way of thinking for the preparation of useful pharmaceuticals and complex natural products. Due to a long-standing interest in the synthesis of diverse indole alkaloids, our group previously developed a cyclopropanation strategy ( Qin , Y. Acc. Chem. Res. 2011 , 44 , 447 ) that was versatile to access several intriguing indole alkaloid molecules. With an idea of developing more general synthetic approaches to as many members of various indole alkaloids as possible, we recently disclosed new radical cascade reactions enabled by photoredox catalysis, leading to the collective asymmetric total synthesis of 42 monoterpene indole alkaloids belonging to 7 structural types. Several important discoveries deserve to be highlighted. First, the use of photocatalytic technology allowed us to achieve an unusual reaction pathway that reversed the conventional reactivity between two nucleophilic amine and enamine groups. Second, a crucial nitrogen-centered radical, directly generated from a sulfonamide N-H bond, triggered three types of cascade reactions to deliver indole alkaloid cores with manifold functionalities and controllable diastereoselectivities. Moreover, expansion of this catalytic, scalable, and general methodology permitted the total synthesis of a large collection of indole alkaloids. In this Account, we wish to provide a complete picture of our studies concerning the original synthetic design, method development, and applications in total synthesis. It is anticipated that the visible-light-driven cascade strategy will find further utility in the realm of natural product synthesis.

3.
Am J Surg Pathol ; 43(7): 995-1004, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31045893

RESUMO

Extranodal natural killer/T-cell lymphoma, nasal-type (ENKTL-N) initially presented in larynx is a rare condition without distinctive clinicopathologic features, with a challenging pathologic diagnosis. This study aimed to evaluate the clinicopathologic features and diagnosis of laryngeal ENKTL-N and spread awareness regarding ENKTL-N. A series of 31 cases of laryngeal ENKTL in one Chinese institution over a 9-year interval was retrospectively analyzed. Median age was 50 years (range, 13 to 77 y) with a male/female ratio of 5.2:1 (26/5). All patients initially presented with hoarseness and/or laryngalgia, and 10 patients (32.3%) experienced B symptoms. The supraglottic region was the most common site of occurrence (58.1%), the glottic area being the rarest site (6.5%). The mucosal squamous epithelium was detected in 26 specimens and pseudoepitheliomatous hyperplasia was observed in 8 cases (8/26, 30.8%). "Keratin-pearls" and a "pseudoinvasive" pattern were observed in 2 cases. Follow-up data were available for 26 patients (83.9%), the median survival duration was 9 months, and the overall survival rate at 5 years was 29.6%. Univariate analysis revealed that patients experiencing B symptoms (P=0.019) and age above 60 years had a significantly low survival (P=0.049) and that combined radiotherapy and chemotherapy prolongs overall survival (P<0.001). Laryngeal ENKTL-N is a rare entity with high aggressiveness and a poor prognosis. Multiple biopsies are usually required owing to secondary infection and massive necrosis. Laryngeal EKTL-N may mimic inflammatory lesions or well-differentiated squamous cell carcinoma. Therefore, clinical vigilance is essential to prevent misdiagnosis or a delayed diagnosis.

4.
J Am Chem Soc ; 141(24): 9712-9718, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31136168

RESUMO

The first total synthesis of an arcutine-type C20-diterpenoid alkaloid arcutinine has been achieved in both racemic and asymmetric forms. Construction of the C4 quaternary center and the pyrrolidine E ring in an early stage proved to be important for achieving the successful synthesis of the target alkaloid. Strategically, an asymmetric conjugate addition/aldol cascade and a decarboxylative allylation reaction allowed the establishment of the vicinal all-carbon quaternary stereocenters at C4 and C5. Furthermore, a sequence consisting of an intramolecular aza-Wacker cyclization, an oxidative dearomatization/intramolecular Diels-Alder cycloaddition cascade, and a ketyl-olefin cyclization enabled the assembly of the core structure and led to the total synthesis of arcutinine.

5.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(1): 27-33, 2019 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31037901

RESUMO

OBJECTIVE: To observe the effect of Guben Zenggu Decoction on the expressions of calmodulin (CaM) and calcium/calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ) mRNA in the hypothalamus, pituitary, spleen, adrenal gland and femur in ovariectomized rats. To explore the mechanism of Guben Zenggu Decoction regulating and controlling osteoporosis through neuro-endocrine-immune (NEI) network. METHODS: The osteoporosis model was established by ovariectomy and randomly divided into model control group, Estradiol valerate group, Guben Zenggu Decoction high, medium and low concentration group. Selected the same age rats as the blank control group, after intervention, 10 rats were randomly selected at the time of 4th, 8th, 12th and 16th weeks from each group, After the success of the model and the successful intervention of Guben Zenggu Decoction for 4, 8, 12 and 16 weeks, the blood were taken from the heart, the serum bone alkaline phosphatase (BALP) levels was measured by the enzyme-linked immunosorbent assay (ELISA), and the thalamus, pituitary, spleen, adrenal, femoral tissue of rats were collected to detected the expressions of CaM and CaMKⅡ mRNA by using real-time fluorescence quantitative polymerase chain reaction (RT-PCR). RESULTS: At different time points (4 weeks, 8 weeks, 12 weeks, 16 weeks), the expressions of serum BALP and CaM and CaMKⅡ mRNA in NEI network in model group were significantly different from those in blank control group ( P<0.05). Compared with the model control group, serum BALP concentration and CaM mRNA expression in hypothalamus and pituitary tissue were significantly increased in estradiol valerate and Guben Zenggu Decoction groups ( P<0.05). However, the expression of CaM mRNA in adrenal gland, spleen and femur and the expression of CaMKⅡ mRNA in hypothalamus, pituitary, adrenal gland, spleen and femur were significantly decreased ( P<0.05); compared with estradiol valerate group, the effect of Guben Zenggu Decoction on the expressions of CaM mRNA and CaMKⅡ mRNA in femoral and adrenal tissues was significantly different ( P<0.05). CONCLUSION: Guben Zenggu Decoction can increase the serum concentration of BALP, regulate the expression of CaM mRNA and CaMKⅡ mRNA in hypothalamus, pituitary, adrenal gland, spleen and femur, thus play a role in prevention and treatment of osteoporosis by regulating NEI network.


Assuntos
Sistema Endócrino , Osteoporose , Fosfatase Alcalina , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Calmodulina , Feminino , RNA Mensageiro , Ratos , Ratos Sprague-Dawley
6.
Viruses ; 11(4)2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022917

RESUMO

Hepatitis C virus (HCV) is a major cause of human chronic liver disease and hepatocellular carcinoma. Our recent studies showed that α1,6-fucosyltransferase (FUT8), a key glycosyltransferase, was the most up-regulated glycosyltransferase after the HCV infection of human hepatocellular carcinoma Huh7.5.1 cells. Here, we further studied the effects and possible mechanism of FUT8 on the proliferation of HCV and chemotherapy-resistance of HCV-infected Huh7.5.1 cells. The effects of FUT8 on the proliferation and drug resistance of HCV-infected Huh7.5.1 cells were analyzed by flow cytometry analysis (FCM), quantitative real-time polymerase chain reaction (qRT-PCR), Western blot analysis and lactate dehydrogenase (LDH) release assay. Results: We found that FUT8 not only promoted Huh7.5.1 proliferation by activating PI3K-AKT-NF-κB signaling, but also stimulated the expression of the drug-resistant proteins P-glycoprotein (P-gp) and multidrug resistance related protein 1 (MRP1) and enhanced the 5-fluorouracil (5-FU) chemo-resistance of Huh7.5.1 cells. Silencing of FUT8 reduced the cell proliferation and increased the 5-FU sensitivity of HCV-infected Huh7.5.1 cells. Inhibition of P-gp and MRP1 increased the 5-FU drug sensitivity in HCV infected Huh7.5.1 cells. HCV-induced FUT8 promotes proliferation and 5-FU resistance of Huh7.5.1 cells. FUT8 may serve as a therapeutic target to reverse chemotherapy resistance in HCV-infected Huh7.5.1 cells.

7.
J Pharmacol Sci ; 139(4): 311-318, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30962089

RESUMO

Diabetic cardiomyopathy (DCM) is characterized by cardiac hypertrophy, fibrosis, oxidative stress and inflammation. Trimetazidine (TMZ), a potent metabolism modulator, has been shown to be cardioprotective in experimental models of ischaemia-reperfusion and type 2 diabetes-induced cardiomyopathy. The present study examined whether TMZ inhibits cardiomyopathy induced by insulin-dependent type 1 diabetes. Wistar rats were randomly divided into control group (vehicle alone), diabetes mellitus (DM; induced by streptozocin (STZ) injection) group and DM treated with TMZ (DM/TMZ) group. Cardiac function, histology, plasma biochemistry and molecular mechanism were assessed. STZ induced diabetes in rats as indicated by hyperglycemia, increased and decreased levels of advanced glycation end products (AGEs) and insulin respectively. Diabetic rats were characterized by left ventricular dysfunction, cardiachypertrophy and fibrosis and signs of inflammation and oxidative stress in the myocardium, which were accompanied by elevated levels of NADPH oxidase 2 (Nox2) and transient receptor potential channel 3 (TRPC3) in the heart. TMZ treatment ameliorated diabetes-associated structural and functional alterations by inhibiting Nox2 and TRPC3 without having any effects on glucose, insulin and AGEs levels. These results suggest that TMZ could be used as a therapy to treat cardiomyopathy associated with type 1 induced diabetes mellitus.

8.
Nat Prod Res ; : 1-7, 2019 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-30835548

RESUMO

One new pentanortriterpenoid, 23,24,25,26,27-pentanorlanost-7,9(11)-dien-3ß,22-diol (1), one new triterpenoid, lanost-8-en-3ß,22S,23S-triol (2), together with the known triterpenoid, 23,24,25,26,27-pentanorlanost-8-en-3ß,22-diol (3), were obtained from culture of the fungus Diplodia cupressi associated with the moss Polytrichum commune. The structures of the new compounds were elucidated by extensive spectroscopic techniques including HR-ESIMS and 1 D and 2 D NMR experiments. The cytotoxicity of these compounds against human cancer cell lines (A549, Hep G2, Hepa 1c1c7, and Hela) was evaluated and compound 2 exhibited weak inhibitory activity with IC50 value of 35.0 ± 2.3 µM against the proliferation of the Hepa 1c1c7 cells.

9.
Artigo em Inglês | MEDLINE | ID: mdl-30927572

RESUMO

Graphene quantum dots (GQDs) are synthesized by the method of high-temperature pyrolysis from marigold granules and subsequently nitrogen-doped graphene quantum dots (N-GQDs) are synthesized from ethylenediamine by hydrothermal treatment, which shows a strong blue emission with 7.84% quantum yield (QY). This will be used in detection of Fe3+ in water environments and the field of bioimaging.

10.
Angew Chem Int Ed Engl ; 58(18): 6059-6063, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-30775833

RESUMO

Strictamine and rhazinoline are representative methanoquinolizidine-containing akuammiline alkaloids that possess different stereochemistry at the C16 position. A unified approach to the enantioselective total syntheses of these two molecules is described. The key steps in this synthesis include a photocatalytic intra/intermolecular type II radical cascade reaction, a Tsuji-Trost allylation, a palladium- or nickel-mediated cyclization, and a late-stage intramolecular N-alkylation reaction.

11.
Nat Prod Res ; : 1-7, 2019 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-30663348

RESUMO

A new 12-membered macrolide, aspergillolide (1), along with nine known compounds (2-10), were isolated from the fungus Aspergillus sp. S-3-75 associated with the sea cucumber Holothuria nobilis Selenka. The structure and absolute stereochemistry of 1 were elucidated on the basis of extensive spectroscopic methods and single crystal X-ray diffraction analysis.

12.
Clin Cardiol ; 42(4): 418-424, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30652336

RESUMO

BACKGROUND: No data exist on comparisons of efficacy, safety, and recurrence risk factors of paroxysmal and persistent atrial fibrillation (AF) ablation using robotic magnetic navigation system (MNS), respectively. METHODS: About 151 AF patients were prospectively enrolled and divided into paroxysmal AF group (n = 102) and persistent AF group (n = 49). Circumferential pulmonary vein antrum isolation (CPVI) was performed in all patients. Linear ablation at the left atrial roof and mitral isthmus was performed in patients with persistent AF in addition to CPVI. The procedural time, X-ray exposure time, acute and long-term success rates of CPVI, and procedure-related complications were analyzed. The AF recurrence rates in the two groups were compared during 1 year, and Cox regression was used to analyze the recurrence risk factors. RESULTS: The acute success rates of CPVI in the two groups were 98.04% and 97.96%, respectively. There were no significant differences in the procedural time, X-ray exposure time, and ablation time between the two groups (P > 0.05). No serious complications appeared in either group. The AF ablation success rates were 70.6% and 57.1% for the paroxysmal and persistent groups respectively at 12-month follow-up (P = 0.102). AF duration and coronary heart disease prior to ablation were associated with the higher AF recurrence in patients with persistent AF. CONCLUSION: Ablation using MNS is effective and safe both in patients with paroxysmal and persistent AF. AF duration and coronary heart disease prior to ablation are two independent risk factors of AF recurrence in patients with persistent AF postoperatively.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Veias Pulmonares/cirurgia , Robótica/instrumentação , Cirurgia Assistida por Computador/métodos , Adolescente , Adulto , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Ecocardiografia , Desenho de Equipamento , Feminino , Seguimentos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Fatores de Risco , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
13.
Org Lett ; 21(1): 252-255, 2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30560668

RESUMO

A synthetic strategy for the catalytic asymmetric total synthesis of (+)-strychnine is disclosed. Key features of this synthesis include an organocatalytic enantioselective Michael addition to establish the chirality of the starting building block, a photoinduced radical cascade reaction to access the Corynanthe alkaloid intermediate, and a bioinspired cascade rearrangement to generate the core of the Strychnos alkaloids.

15.
Artigo em Inglês | MEDLINE | ID: mdl-30472262

RESUMO

Exposure to MNP generates Th2 response-inducing dendritic cells. Transfer of OVA/MNP-primed dendritic cells induces nasal allergy. Inhibition of Bcl2L12 prevents nasal allergy development.

16.
Chem Commun (Camb) ; 54(86): 12258-12261, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30318536

RESUMO

A strategy for synthesizing the highly oxidized bicyclo[3.2.1]octane CD rings of aconitine is reported. The key features of the synthesis include a ring-closing metathesis to form the C-ring as well as the application of a ruthenium-catalysed enyne cycloisomerization to assemble the bridged CD ring system of aconitine.

17.
Gene ; 687: 143-150, 2018 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-30359740

RESUMO

Cholangiocarcinoma (CCA) is a fatal disease with increasing morbidity and poor prognosis due to poor response to conventional chemotherapy or radiotherapy. Neurotensin (NTS) has long been recognized as an important factor in the central nervous system and as an endocrine agent in the peripheral circulation via NTS receptor (NTSR) mediated actions. In recent years, NTS has been implicated in the carcinogenesis of numerous cancers; however, its role in cholangiocarcinoma remains obscure. Here, we observed the expression of NTS in cholangiocarcinoma vs. non-cancerous tissues and found that up-regulation of NTS facilitated cholangiocarcinoma cell metastasis and down-regulation of NTS inhibited their migration ability. Mechanistically, NTS drove cholangiocarcinoma cell metastasis via the EGFR/AKT pathway. Both the PI3-K inhibitor LY294002 or EGFR inhibitor Erlotinib stopped the discrepant metastatic capacity between NTS-depleted cholangiocarcinoma cells and control cells, further confirming that EGFR/AKT was required in NTS-promoted cholangiocarcinoma cell metastasis. More importantly, overexpression of NTS predicted poor prognosis of CCA patients. In summary, NTS could promote cholangiocarcinoma cells metastasis by amplifying EGFR/AKT signaling and may therefore be useful to predict patient prognosis.

18.
Org Lett ; 20(21): 6701-6704, 2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30346782

RESUMO

An asymmetric synthetic approach to a tetracyclic framework of the marine-derived alkaloid (+)-sarain A has been developed. The key steps to constructing the congested diazatricycloundecane core include an asymmetric Diels-Alder cycloaddition, an Ireland-Claisen rearrangement, and an intramolecular aziridination/ring-opening sequence.

19.
Sci Rep ; 8(1): 14792, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30287900

RESUMO

It is well recognized that osteocytes communicate with each other via gap junctions and that connxin43 (Cx43) shows its great potential in gap junction for the contribution enabling transmission of small molecules and operating in an autocrine/a paracrine manner. Fibroblast growth factors (FGFs) play significant roles in new bone formation and adult bone remodeling, and FGF signaling is regulated by the precise spatiotemporal approaches. However, the influence of FGF7 on osteocyte cell processes is not well elucidated. In this study, we aimed to examine the impact of FGF7 on osteocyte cell processes by characterizing the expression of Cx43 and to reveal the underlying mechanism regulating this cell process. We first found that the mRNA level of FGF7 was higher relative to other FGF family members both in osteocytes cell line (MLO-Y4) and bone tissue. We then demonstrated that FGF7 could increase the expression of Cx43 in osteocytes and promote the cell processes in the form of gap junctions between osteocytes. This modulation was due to the FGF7-induced cytoplasmic accumulation and resultant nuclear translocation of ß-catenin. Our results could help us to further understand the importance of FGF7 on bone cell behavior and bone physiology and even pathology.

20.
Opt Lett ; 43(19): 4570-4573, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30272685

RESUMO

The modulation bandwidth of a light-emitting diode is inversely proportional to the carrier lifetime, which changes with varying injected current. However, in conventional implementations of visible light communications, the influence of bias current is always emphasized, while the effects of modulation indices and signal components are ignored. In this Letter, it is the first time, to the best of our knowledge, that the mechanism on how modulated signal components impact modulation bandwidth is clarified. We reveal and interpret this impact by featuring the response at different modulation indices and intensity distributions mathematically and experimentally, proposing a series of theoretical approaches for the insight of modulation at a high index. This Letter donates a novel perspective on deciding appropriate configurations for modulators according to the modulation characteristics at a high index of the input signal.

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