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1.
Acta Pharmacol Sin ; 44(12): 2469-2478, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37580493

RESUMO

Intestinal fibrosis is a common complication of inflammatory bowel disease. There is still a lack of effective drugs for the prevention or treatment of intestinal fibrosis. Heat shock protein 47 (HSP47) plays a key role in the development of intestinal fibrosis. In this study we investigated the therapeutic potential and underlying mechanisms of fraxinellone, a degraded limonoid isolated from the root bark of Dictamnus dasycarpus, in the treatment of intestinal fibrosis. Intestinal fibrosis was induced in mice by dextran sodium sulfate (DSS) treatment. DDS-treated mice were administered fraxinellone (7.5, 15, 30 mg·kg-1·d-1, i.g.) for 45 days. We showed that fraxinellone administration dose-dependently alleviated DSS-induced intestinal impairments, and reduced the production of intestinal fibrosis biomarkers such as α-smooth muscle actin (SMA), collagen I, hydroxyproline, fibronectin and laminin, and cytokines such as TGF-ß, TNF-α and IL-ß. We then established in vitro intestinal fibrosis cell models in SW480 and HT-29 cells, and demonstrated that treatment with fraxinellone (3, 10, 30 µM) significantly relieved TGF-ß-induced fibrosis responses by inhibiting the TGF-ß/Smad2/3 signaling pathway. Molecular docking suggested that the fraxinellone might disrupt the interaction between HSP47 and collagen, which was confirmed by coimmunoprecipitation experiments. SPR analysis showed that fraxinellone had a high affinity for HSP47 with a Kd value of 3.542 × 10-5 M. This study provides a new example of HSP47-collagen intervention by a natural compound and has important implications for the clinical treatment of inflammation-induced issue fibrosis.


Assuntos
Colágeno , Proteínas de Choque Térmico HSP47 , Camundongos , Animais , Proteínas de Choque Térmico HSP47/metabolismo , Simulação de Acoplamento Molecular , Colágeno/metabolismo , Fibrose , Epitélio/metabolismo , Fator de Crescimento Transformador beta
2.
Am J Hematol ; 97(4): 458-469, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35064928

RESUMO

Steroid-refractory (SR) acute graft-versus-host disease (aGVHD) is one of the leading causes of early mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We investigated the efficacy, safety, prognostic factors, and optimal therapeutic protocol for SR-aGVHD patients treated with basiliximab in a real-world setting. Nine hundred and forty SR-aGVHD patients were recruited from 36 hospitals in China, and 3683 doses of basiliximab were administered. Basiliximab was used as monotherapy (n = 642) or in combination with other second-line treatments (n = 298). The cumulative incidence of overall response rate (ORR) at day 28 after basiliximab treatment was 79.4% (95% confidence interval [CI] 76.5%-82.3%). The probabilities of nonrelapse mortality and overall survival at 3 years after basiliximab treatment were 26.8% (95% CI 24.0%-29.6%) and 64.3% (95% CI 61.2%-67.4%), respectively. A 1:1 propensity score matching was performed to compare the efficacy and safety between the monotherapy and combined therapy groups. Combined therapy did not increase the ORR; conversely, it increased the infection rates compared with monotherapy. The multivariate analysis showed that combined therapy, grade III-IV aGVHD, and high-risk refined Minnesota aGVHD risk score before basiliximab treatment were independently associated with the therapeutic response. Hence, we created a prognostic scoring system that could predict the risk of having a decreased likelihood of response after basiliximab treatment. Machine learning was used to develop a protocol that maximized the efficacy of basiliximab while maintaining acceptable levels of infection risk. Thus, real-world data suggest that basiliximab is safe and effective for treating SR-aGVHD.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Doença Aguda , Basiliximab/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Estudos Retrospectivos , Esteroides/uso terapêutico
3.
Phytother Res ; 36(4): 1692-1707, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35129872

RESUMO

Rhamnazin (RN) is a flavonol isolated from the calyxes and fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino, which has been used for treating pulmonary diseases in traditional Chinese medicine. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a therapeutic target for pulmonary diseases. In the present study, the underlying mechanism and pharmacological effect of RN against pulmonary disorders are investigated. Human lung epithelial Beas-2B cell and RAW 264.7 murine macrophage-based cell models, and a cigarette smoke (CS)-induced pulmonary impairment mice model are adopted for investigation in vitro and in vivo. RN is identified to be an Nrf2 activator, which promotes Nrf2 dissociation from Keap1 via reacting with the Cys151 cysteine residue of Keap1, and suppresses Nrf2 ubiquitination. In addition, RN is able to attenuate toxicant-stimulated oxidative stress and inflammatory response in vitro. Importantly, RN significantly relieves CS-induced oxidative insult and inflammation, and RN-induced inhibition of inflammation is related to inhibition of nuclear transcription factor-κB (NF-κB) and induction of cell autophagy. In conclusion, our data indicate that RN is an activator of the Nrf2 pathway and evidently alleviates pulmonary disorders via restricting NF-κB activation and promoting autophagy. RN is a promising candidate for the therapy of pulmonary disorders.


Assuntos
Pneumopatias , Physalis , Animais , Flavonoides , Flavonóis , Inflamação , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo , Physalis/química , Physalis/metabolismo
4.
Sheng Li Xue Bao ; 74(6): 927-938, 2022 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-36594381

RESUMO

Chronic psychological stress can promote vascular diseases, such as hypertension and atherosclerosis. This study aims to explore the effects and mechanism of chronic psychological stress on aortic medial calcification (AMC). Rat arterial calcification model was established by nicotine gavage in combination with vitamin D3 (VitD3) intramuscular injection, and rat model of chronic psychological stress was induced by humid environment. Aortic calcification in rats was evaluated by using Alizarin red staining, aortic calcium content detection, and alkaline phosphatase (ALP) activity assay. The expression levels of the related proteins, including vascular smooth muscle cells (VSMCs) contractile phenotype marker SM22α, osteoblast-like phenotype marker RUNX2, and endoplasmic reticulum stress (ERS) markers (GRP78 and CHOP), were determined by Western blot. The results showed that chronic psychological stress alone induced AMC in rats, further aggravated AMC induced by nicotine in combination with VitD3, promoted the osteoblast-like phenotype transformation of VSMCs and aortic ERS activation, and significantly increased the plasma cortisol levels. The 11ß-hydroxylase inhibitor metyrapone effectively reduced chronic psychological stress-induced plasma cortisol levels and ameliorated AMC and aortic ERS in chronic psychological stress model rats. Conversely, the glucocorticoid receptor agonist dexamethasone induced AMC, promoted AMC induced by nicotine combined with VitD3, and further activated aortic ERS. The above effects of dexamethasone could be inhibited by ERS inhibitor 4-phenylbutyrate. These results suggest that chronic psychological stress can lead to the occurrence and development of AMC by promoting glucocorticoid synthesis, which may provide new strategies and targets for the prevention and control of AMC.


Assuntos
Glucocorticoides , Calcificação Vascular , Ratos , Animais , Glucocorticoides/efeitos adversos , Glucocorticoides/metabolismo , Ratos Sprague-Dawley , Nicotina/efeitos adversos , Nicotina/metabolismo , Hidrocortisona/efeitos adversos , Hidrocortisona/metabolismo , Músculo Liso Vascular , Dexametasona/efeitos adversos , Dexametasona/metabolismo , Calcificação Vascular/induzido quimicamente , Calcificação Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Células Cultivadas
5.
Nucleic Acids Res ; 47(1): 56-68, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30462330

RESUMO

Hepatitis C virus (HCV) infection is a major cause of human chronic liver disease and hepatocellular carcinoma. G-quadruplex (G4) is an important four-stranded secondary structure of nucleic acids. Recently, we discovered that the core gene of HCV contains a G4 RNA structure; however, the interaction between the HCV core RNA G4 and host cellular proteins, and the roles of the HCV core RNA G4 in HCV infection and pathogenesis remain elusive. Here, we identified a cellular protein, nucleolin (NCL), which bound and stabilized the HCV core RNA G4 structure. We demonstrated the direct interaction and colocalization between NCL and wild-type core RNA G4 at both in vitro and in cell physiological conditions of the alive virus; however no significant interaction was found between NCL and G4-modified core RNA. NCL is also associated with HCV particles. HCV infection induced NCL mRNA and protein expression, while NCL suppressed wild-type viral replication and expression, but not G4-modified virus. Silencing of NCL greatly enhanced viral RNA replication. Our findings provide new insights that NCL may act as a host factor for anti-viral innate immunity, and binding of cellular NCL with the viral core RNA G4 structure is involved in suppressing HCV replication.


Assuntos
Quadruplex G , Fosfoproteínas/genética , RNA Viral/genética , Proteínas de Ligação a RNA/genética , Proteínas do Core Viral/química , Regulação Viral da Expressão Gênica/genética , Hepacivirus/genética , Hepacivirus/patogenicidade , Hepatite C/genética , Hepatite C/virologia , Humanos , Fosfoproteínas/química , RNA Viral/química , Proteínas de Ligação a RNA/química , Proteínas do Core Viral/genética , Replicação Viral/genética , Nucleolina
6.
Chem Biodivers ; 18(11): e2100302, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34436820

RESUMO

The rhizome of Ligusticum chuanxiong Hort. has been widely used for the therapy of diabetic nephropathy (DN) in traditional Chinese medicine (TCM). The nuclear transcription factor erythroid 2-related factor (Nrf2) is a potential target for treating DN. The purpose of this research was to study the chemical constituents from the rhizome of L. chuanxiong, evaluate their Nrf2 inducing activity, and find the molecules with potential therapeutic effect against DN. In this study, two new phthalides (1-2) along with twenty-seven known constituents were obtained from the rhizome of L. chuanxiong. Their structures were elucidated through various spectroscopic methods. Twelve constituents, including eight phthalides (2, 5, 6,10-13, 14) and four other compounds (17, 18, 20,28), stimulated NAD(P)H: quinone reductase (QR) activity, suggesting that these bioactive constituents were potential Nrf2 activators. Among the isolated compounds, phthalide levistolide A (LA, 14) upregulated the protein levels of Nrf2, NQO1, and γ-GCS in a dose-dependent manner. Our results implied that the clinical application of the rhizome of L. chuanxiong as an anti-DN drug in TCM might be attributed to the Nrf2 inducing effect of phthalides. Thus, phthalides is a group of promising leading molecules for discovering anti-DN agents.


Assuntos
Benzofuranos/farmacologia , Nefropatias Diabéticas/tratamento farmacológico , Hipoglicemiantes/farmacologia , Ligusticum/química , Fator 2 Relacionado a NF-E2/metabolismo , Rizoma/química , Benzofuranos/química , Benzofuranos/isolamento & purificação , Nefropatias Diabéticas/metabolismo , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Estrutura Molecular
7.
Inorg Chem ; 59(17): 11940-11944, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32856902

RESUMO

Metal-organic frameworks (MOFs) have been explored as crystal sponges (CSs) to organic substrates, but attention had rarely been paid to inorganic substrates. Herein, hierarchical zirconium-based MOFs exhibiting different topological structures had been fabricated by modulating the functional groups of the V-shaped linkers, including a new 4-fold-interpenetrating one, which displays a great performance as a CS applicable to inorganic matter (I2 and ReO4-) even in the extreme conditions.

8.
J Nat Prod ; 83(10): 2817-2830, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33001650

RESUMO

A pair of enantiomeric 15-nordolabellane diterpenoids, (-)- and (+)-caseadolabellols A (1a and 1b), three dolabellane diterpenoids, caseadolabellols B-D (2-4), two dolastane diterpenoids, caseadolastols A and B (5 and 6), 10 clerodane diterpenoids, caseakurzins A-J (7-16), and nine known diterpenoids (17-25) were isolated from the twigs and leaves of Casearia kurzii. The structures of the new compounds were established on the basis of extensive spectroscopic data, and those of compounds 1a, 1b, and 2 were verified by single-crystal X-ray crystallographic analysis. The enantiomers 1a and 1b were separated by chiral-phase HPLC. The absolute configurations were determined by experimental and calculated ECD data, the modified Mosher's method, or literature comparison. Compounds 1a and 5 showed significant quinone reductase-inducing activity in Hepa 1c1c7 cells, while 1b showed moderate activity. Molecular docking studies showed that 1a had greater binding affinity with Nrf2 protein (5FNQ) than 1b. The cytotoxic activity of compounds 1a, 1b, 2-12, 15, and 16 was evaluated, among which compounds 8 and 16 exhibited significant inhibitory activity against the A549 cell line. Compounds 8 and 16 induced the A549 cells to arrest at G2/M and S phases, respectively, and both compounds induced apoptosis in A549 cells.


Assuntos
Casearia/química , Diterpenos Clerodânicos/química , Antineoplásicos Fitogênicos/química , Diterpenos , Ensaios de Seleção de Medicamentos Antitumorais , Simulação de Acoplamento Molecular , Estrutura Molecular , Folhas de Planta/química
9.
J Nat Prod ; 83(4): 1217-1228, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32159343

RESUMO

Environmental toxicant- and oxidant-induced [e.g., cigarette smoke (CS)] respiratory oxidative stress and inflammatory response play a vital role in the onset and progression of COPD. The nuclear factor erythroid 2-related factor 2 (Nrf2) represents an important mechanism for regulating intracellular oxidative stress and inflammatory response and is a promising target for developing agents against COPD. Herein, a bioactivity-guided purification of goldenberry (whole fruits of Physalis peruviana L.) led to the isolation of a novel and potent Nrf2 activator 4ß-hydroxywithanolide E (4ß-HWE). Our study indicated that (i) 4ß-HWE activated the Nrf2-mediated defensive response through interrupting Nrf2-Keap1 protein-protein interaction (PPI) via modification of Cys151 and Cys288 cysteine residues in Keap1 and accordingly suppressing the ubiquitination of Nrf2. (ii) 4ß-HWE enhanced intracellular antioxidant capacity and inhibited oxidative stress in normal human lung epithelial Beas-2B cells and wild-type AB zebrafish. (iii) 4ß-HWE blocked LPS-stimulated inflammatory response and inhibited LPS-stimulated NF-κB activation in RAW 264.7 murine macrophages. (iv) 4ß-HWE effectively suppressed oxidative stress and inflammatory response in a CS-induced mice model of pulmonary injury. Collectively, these results display the feasibility of using 4ß-HWE to prevent or alleviate the pathological progression of COPD and suggest that 4ß-HWE is a candidate or a leading molecule against COPD.


Assuntos
Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Pulmão/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Physalis/química , Vitanolídeos/farmacologia , Animais , Antioxidantes/farmacologia , Células Epiteliais/efeitos dos fármacos , Frutas , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/química , Camundongos , Estrutura Molecular , Fator 2 Relacionado a NF-E2/química , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fumaça , Nicotiana , Vitanolídeos/química , Vitanolídeos/isolamento & purificação
10.
Planta Med ; 86(16): 1191-1203, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32668478

RESUMO

Physalis Calyx seu Fructus, a traditional Chinese medicine consisting of the calyxes and fruits of Physalis alkekengi var. franchetii, has been used as therapy for inflammation-related respiratory diseases such as excessive phlegm, cough, sore throat, and pharyngitis for a long history in China. The aim of the present study was to investigate the chemical constituents of Physalis Calyx seu Fructus and identify the bioactive constituents responsible for its traditional application as therapy for inflammation-related diseases. In the present study, one new phenylpropanoid (1: ), two new steroids (17: and 18: ), together with 55 known constituents have been purified from the EtOH extract of Physalis Calyx seu Fructus. Among them, seven and twelve known constituents were isolated for the first time from Physalis Calyx seu Fructus and the genus Physalis, respectively. Fourteen constituents, including steroids [physalins (5:  - 9, 12:  - 14: , and 15: ) and ergostane (21: )], a sesquiterpenoid (35: ), alkaloids (36: and 37: ), and a flavonoid (44: ), showed inhibitory effects against oxidative stress. Ten constituents, including steroids (5, 6, 8, 13: , and 15: ), sesquiterpenoids (34: and 35: ), alkaloids (37: and 41: ), and a flavonoid (43: ), were found be potential anti-inflammatory constituents of this medicinal plant. The inhibition of oxidative stress and inflammatory response may be related to the regulation of Nrf2 and nuclear factor-κB pathways. The ethnomedical use of Physalis Calyx seu Fructus as a treatment for respiratory diseases might be attributed to the combined inhibitory effects of steroids, alkaloids, sesquiterpenoids, and flavonoids against oxidative stress and inflammatory response.


Assuntos
Physalis , China , Flores , Frutas , Estresse Oxidativo
11.
Int J Mol Sci ; 21(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033098

RESUMO

Salmonella typhimurium (S. typhimurium) is a common foodborne pathogen that not only causes diseases and contaminates food, but also causes considerable economic losses. Therefore, it is necessary to find effective and feasible methods to control S. typhimurium. In this study, changes in S. typhimurium after treatment with benzyl isothiocyanate (BITC) were detected by transcriptomics to explore the antibacterial effect of BITC at subinhibitory concentration. The results showed that, in contrast to the control group (SC), the BITC-treated group (SQ_BITC) had 197 differentially expressed genes (DEGs), of which 115 were downregulated and 82 were upregulated. We screened out eight significantly downregulated virulence-related genes and verified gene expression by quantitative Real-time Polymerase Chain Reaction (qRT-PCR). We also selected motility and biofilm formation to observe the effects of BITC on the other virulence related factors of S. typhimurium. The results showed that both swimming and swarming were significantly inhibited. BITC also had a significant inhibitory effect on biofilm formation, and showed an effect on bacterial morphology. These results will be helpful for understanding the mechanism of the antibacterial action of BITC against S. typhimurium and other foodborne pathogens.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Isotiocianatos/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética , Perfilação da Expressão Gênica/métodos , Testes de Sensibilidade Microbiana/métodos , Salmonella typhimurium/genética , Virulência/efeitos dos fármacos , Virulência/genética , Fatores de Virulência/genética
12.
Angew Chem Int Ed Engl ; 59(45): 19919-19923, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32696611

RESUMO

A divergent synthetic approach to biogenetically related diterpenoids such as ent-kauranes, ent-trachylobanes, ent-beyerane, and ent-atisane has been developed. The unified synthetic route involves the De Mayo reaction to rapidly generate the bicyclo[3.2.1]-octane moiety of ent-kaurane. The key reactions also include bioinspired nucleophilic cyclopropanation generating the [3.2.1.02,7 ]-tricyclic core of ent-trachylobane and regioselective cyclopropane fragmentation furnishing ent-beyerane and ent-atisane through the nucleophilic attack and protonation of the cyclopropane ring. This strategy enables the asymmetric total syntheses of six diterpenoids from the commercially available geraniol.

13.
J Am Chem Soc ; 141(34): 13654-13663, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31398288

RESUMO

Postsynthetic metalation (PSM) has been employed as a robust method for the postsynthetic modification of metal-organic frameworks (MOFs). However, the lack of relevant information that can be obtained for the postsynthetically introduced metallic ions has hindered the development of PSM applications. Thanks to the advancement in single-crystal X-ray diffraction (SCXRD) technology, there have been a few recent examples in which successful postsynthetic introduction of single metal ions into MOFs occurred at the defined chelating sites. These works have provided useful explanations about the complicated host-guest chemistry involved in PSMs. On the other hand, there are only limited examples with crystallographic snapshots of the postsynthetic installation of metal clusters into the pores of MOFs using an ordinary SCXRD due to the loss of crystallinity of parent matrix during the PSM process. Herein, by the careful selection of starting materials and controlling the reaction conditions, we report the first crystallographic visualization of metal clusters inserted into Zr-based MOFs via PSM. The structural advantages of the parent Zr-MOF, which are inherited from the stable Zr6 cluster and triazole-containing dicarboxylate ligand, ensure both the preservation of high crystallinity and the presence of flexible coordination sites for PSM. Furthermore, PSM of metal clusters in a MOF pore space enhances stability of the final samples while also imparting the functionality of a successful catalyst toward ethylene dimerization reaction. The related construction ideas and structural information detailed in this work can help lay the foundation for further advancements using the postmodification of MOFs as well as open new doors for the utilization of SCXRD technology in the field of MOFs.

14.
Biochem Biophys Res Commun ; 518(3): 526-532, 2019 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-31445708

RESUMO

Oxidative stress is one of the main pathogenesis for many human diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway plays a key role in regulating intracellular antioxidant responses, and thus activation of Nrf2/ARE signaling pathway is a potential chemopreventive or therapeutic strategy to treat diseases caused by oxidative damage. In the present study, we have found that treatment of Beas-2B cells with botrysphins D (BD) attenuated sodium arsenite [As (III)]-induced cell death and apoptosis. Meanwhile, BD was able to upregulate protein levels of Nrf2 and its downstream genes NQO1 and γ-GCS through inducing Nrf2 nuclear translocation, enhancing protein stability, and inhibiting ubiquitination. It was also found that BD-induced activation of the Nrf2/ARE pathway was regulated by PI3K, MEK1/2, PKC, and PERK kinases. Collectively, BD is a novel activator of Nrf2/ARE pathway, and is verified to be a potential preventive agent against oxidative stress-induced damage in human lung tissues.


Assuntos
Antioxidantes/farmacologia , Arsenitos/toxicidade , Diterpenos/farmacologia , Células Epiteliais/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Compostos de Sódio/toxicidade , Elementos de Resposta Antioxidante/efeitos dos fármacos , Antioxidantes/química , Arsênio/toxicidade , Ascomicetos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular , Diterpenos/química , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Humanos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/efeitos dos fármacos
15.
J Nat Prod ; 82(6): 1542-1549, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31148449

RESUMO

Three new C21 pregnane steroids, chonemorphols A-C (1, 3, and 4), 11 new C21 steroidal glycosides, chonemorphosides A-K (2 and 5-14), and 11 known compounds (15-25) were obtained from the vines and leaves of Chonemorpha megacalyx Pierre. Their structures were established using extensive spectroscopic data. The X-ray crystallographic data of 1 and 3 permitted definition of their absolute configurations. Notably, 1 and 2 possessed an uncommon 6/5/6/5/5-fused steroidal ring system. Compound 7 displayed significant cytotoxicity against several cancer cell lines with IC50 values of 2.0-3.6 µM.


Assuntos
Apocynaceae/química , Glicosídeos/química , Pregnanos/química , Linhagem Celular Tumoral , Glicosídeos/farmacologia , Glicosídeos/toxicidade , Humanos , Estrutura Molecular , Folhas de Planta , Pregnanos/farmacologia , Pregnanos/toxicidade
16.
J Am Chem Soc ; 140(44): 14581-14585, 2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30347976

RESUMO

Herein, we report the construction of a neutral, radical-rich, cobalt valence tautomeric triangle, which consists of two types of radical groups including tetrazine-based bridges and semiquinone anions at high temperature and has traits of high intensity and density of sensing sites. The mechanism of the Valence Tautomerism process within the triangle has been illustrated as one electron transfer, preceding a two electrons transfer along with the phenomenon of spin flipping.

17.
Inorg Chem ; 57(14): 8639-8645, 2018 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-29962201

RESUMO

Two enantiomeric pairs of new 3d-4f heterometallic clusters have been built from two enantiomer Schiff base derivatives, labeled as R-/ S-H2L, in situ obtained from the condensation reactions with o-vanillin and R-/ S-2-phenylglycinol. The formulas of the series clusters are [Mn6Ln2(µ3-OH)4(µ4-O)(Ac)4(H2O)2( R-L)6]·NO3·OH (Ln = Dy (1R), Gd (2R)), [Mn6Ln2(µ3-OH)4(µ4-O)(Ac)4(H2O)2( S-L)6]·NO3·OH (Ln = Dy (1S), Gd (2S)), whose crystal structures and magnetic properties have been characterized. Structural analysis indicated that the above clusters consisted of a [Mn6Ln2] core, featuring a sandwich configuration. The results of magnetic measurements showed the presence of slow magnetic relaxation with the effective energy barrier of 14.85 K in two Dy derivatives under the condition of zero-dc field, while the significant magnetocaloric effect of Gd analogues was found in a wide temperature range.

18.
Bioorg Med Chem ; 26(18): 5140-5150, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30227999

RESUMO

Continuous overproduction of reactive oxygen species (ROS), termed as oxidative stress, plays a crucial role in the onset and progression of many human diseases. Activation of nuclear transcription factor erythroid 2-related factor (Nrf2) by small molecules could eliminate ROS, and thus block the pathogenesis of oxidative stress-induced diseases. In this study, a natural flavonoid library was established and tested for their potential Nrf2 inducing effects. Based on QR inducing effect of flavonoids, their structure-activity relationship (SAR) on Nrf2 induction was summarized, and twenty flavonoids were firstly identified to be potential activators of Nrf2-mediated defensive response. Then, 7-O-methylbiochanin A (7-MBA) was further investigated for its capability on the Nrf2 activation and prevention against oxidative insults in human lung epithelial cells. Further studies indicated that 7-MBA activated Nrf2 signaling pathway and protected human lung epithelial Beas-2B cells against sodium arsenite [As(III)]-induced cytotoxicity in an Nrf2-dependent manner. Activation of Nrf2 by 7-MBA upregulated intracellular antioxidant capacity, which was produced by enhancement of Nrf2 stabilization, blockage of Nrf2 ubiquitination, as well as Nrf2 phosphorylation by mitogen-activated protein kinase (MAPK), protein kinase C (PKC), protein kinase R-like endoplasmic reticulum kinase (PERK), and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). Taken together, 7-MBA is a novel isoflavone-type Nrf2 activator displaying potential preventive effect against oxidative damages in human lung epithelial cells.


Assuntos
Produtos Biológicos/farmacologia , Descoberta de Drogas , Células Epiteliais/efeitos dos fármacos , Flavonoides/farmacologia , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Arsênio/farmacologia , Produtos Biológicos/síntese química , Produtos Biológicos/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Células Epiteliais/metabolismo , Flavonoides/síntese química , Flavonoides/química , Humanos , Estrutura Molecular , Fator 2 Relacionado a NF-E2/metabolismo , Relação Estrutura-Atividade
19.
J Magn Reson Imaging ; 45(1): 291-302, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27367527

RESUMO

PURPOSE: To investigate the physiopathological effects of low- and iso-osmolar contrast media (CM) on renal function with physiologic MRI and histologic-gene examination. MATERIALS AND METHODS: Forty-eight rats underwent time-course DWI and DCE-MRI at 3.0 Tesla (T) before and 5-15 min after exposure of CM or saline (Iop.370: 370 mgI/mL iopromide; Iod.320: 320 mgI/mL iodixanol; Iod.270: 270 mgI/mL iodixanol; 4 gI/kg body weight). Intrarenal viscosity was reflected by apparent diffusion coefficient (ADC). Renal physiologies were evaluated by DCE-derived glomerular filtration rate (GFR), renal blood flow (RBF), and renal blood volume (RBV). Potential acute kidney injury (AKI) was determined by histology and the expression of kidney injury molecule 1 (Kim-1). RESULTS: Iop.370 mainly increased ADC in inner-medulla (△ADCIM : 12.3 ± 11.1%; P < 0.001). Iod.320 and Iod.270 mainly decreased ADC in outer-medulla (△ADCIM ; Iod.320: 16.8 ± 7.5%; Iod.270: 18.1 ± 9.5%; P < 0.001) and inner-medulla (△ADCIM ; Iod.320: 28.4 ± 9.3%; Iod.270: 30.3 ± 6.3%; P < 0.001). GFR, RBF and RBV were significantly decreased by Iod.320 (△GFR: 45.5 ± 24.1%; △RBF: 44.6 ± 19.0%; △RBV: 35.2 ± 10.1%; P < 0.001) and Iod.270 (33.2 ± 19.0%; 38.1 ± 15.6%; 30.1 ± 10.1%; P < 0.001), while rarely changed by Iop.370 and saline. Formation of vacuoles and increase in Kim-1 expression was prominently detected in group of Iod.320, while rarely in Iod.270 and Iop.370. CONCLUSION: Iso-osmolar iodixanol, given at high-dose, produced prominent AKI in nonhydrated rats. This renal dysfunction could be assessed noninvasively by physiologic MRI. LEVEL OF EVIDENCE: 1 J. Magn. Reson. Imaging 2017;45:291-302.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Meios de Contraste/efeitos adversos , Ácidos Tri-Iodobenzoicos/administração & dosagem , Ácidos Tri-Iodobenzoicos/efeitos adversos , Injúria Renal Aguda/patologia , Animais , Meios de Contraste/química , Relação Dose-Resposta a Droga , Imageamento por Ressonância Magnética/métodos , Masculino , Concentração Osmolar , Ratos , Ratos Sprague-Dawley , Ácidos Tri-Iodobenzoicos/química
20.
J Magn Reson Imaging ; 45(2): 586-596, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27654116

RESUMO

PURPOSE: To assess a magnetic resonance imaging (MRI)-based nomogram in the prediction of prostate cancer (PCa) biochemical recurrence (BCR) within 3 years after prostatectomy. MATERIALS AND METHODS: Between 2009 and 2013, 205 patients with biopsy-confirmed PCa had MRI before prostatectomy. BCR was defined as a PSA failure (>0.2 ng/ml) after prostatectomy. MR features (cancer location, diameter, apparent diffusion coefficients [ADCs], PI-RADS v2 score, dynamic contrast-enhanced [DCE] type, and MR T-stage) were retrospectively evaluated for predicting 3-year BCR based on partial least square regression analysis. Second, imaging features were added to a popularized D'Amico and CAPRA scheme to determine imaging contribution to published nomograms. Lastly, a multivariable Cox regression analysis was employed to determine the independent risk factors of time to BCR. RESULTS: Three-year BCR rate (median follow-up of 44.9 mo) was 25.4% (52/205). The area under receiver operating characteristic (ROC) curve (Az) for MR nomogram (0.909, 95% confidence interval [CI]: 0.861-0.944) was higher than popularized D'Amico (0.793, 95% CI: 0.731-0.846, P = 0.001) and CAPRA (0.809, 95% CI: 0.748-0.860, P = 0.001). The performance of D'Amico (Az: 0.901, 95% CI: 0.852-0.938, P < 0.001) and CAPRA (Az: 0.894, 95% CI: 0.843-0.932, P = 0.004) was significantly improved by adding MR findings. Tumor ADCs (hazard ratio [HR] = 1.747; P = 0.011), PI-RADS score (HR = 4.123; P = 0.039), pathological Gleason score (HR = 3.701; P = 0.004), and surgical-T3b (HR = 6.341; P < 0.001) were independently associated with time to BCR. CONCLUSION: Multiparametric MRI, when converted into a prognostic nomogram, can predict the clinical outcome in patients with PCa after prostatectomy. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:586-596.


Assuntos
Interpretação Estatística de Dados , Imageamento por Ressonância Magnética/estatística & dados numéricos , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/prevenção & controle , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/cirurgia , Idoso , China/epidemiologia , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Incidência , Estudos Longitudinais , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Prognóstico , Prostatectomia , Neoplasias da Próstata/diagnóstico por imagem , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Resultado do Tratamento
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