Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
Más filtros










Intervalo de año de publicación
1.
Sci Total Environ ; 946: 174137, 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-38909806

RESUMEN

Poly/perfluoroalkyl substances (PFAS) are persistent organic pollutants and ubiquitous in aquatic environment, which are hazardous to organisms and human health. Several countries and regions have taken actions to regulate or limit the production and emission of some PFAS. Even though a series of water treatment technologies have been developed for removal of PFAS to eliminate their potential adverse effects, the removal and degradation performance are usually unsatisfactory. Photocatalytic degradation of PFAS is considered as one of the most effective approaches due to the mild operation conditions and environmental friendliness. This review systematically summarized the recent advances in photocatalytic degradation of PFAS based on heterogeneous photocatalysts, including TiO2-, Ga2O3-, In2O3-, ZnO-, Bi-based, and others. Overall, two mainly degradation mechanisms were involved, including photo-oxidation (involving the holes and oxidative radicals) and photo-reduction types (by e- and reductive radicals). The band structures of the photocatalysts, degradation pathways, structure-function relationship, and impacting factors were further discussed to elucidate the essential reasons for the enhanced degradation of PFAS. Furthermore, the review identified the major knowledge gaps to solve the issues of photocatalysis in real application. This paper also propounded several strategies to promote the design and optimization of high-efficient photocatalysts, and meet the challenges to remove PFAS through photodegradation technologies.

2.
Angew Chem Int Ed Engl ; 62(32): e202305390, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37261869

RESUMEN

Adsorption-based removal of carbon dioxide (CO2 ) from gas mixtures has demonstrated great potential for solving energy security and environmental sustainability challenges. However, due to similar physicochemical properties between CO2 and other gases as well as the co-adsorption behavior, the selectivity of CO2 is severely limited in currently reported CO2 -selective sorbents. To address the challenge, we create a bioinspired design strategy and report a robust, microporous metal-organic framework (MOF) with unprecedented [Mn86 ] nanocages. Attributed to the existence of unique enzyme-like confined pockets, strong coordination interactions and dipole-dipole interactions are generated for CO2 molecules, resulting in only CO2 molecules fitting in the pocket while other gas molecules are prohibited. Thus, this MOF can selectively remove CO2 from various gas mixtures and show record-high selectivities of CO2 /CH4 and CO2 /N2 mixtures. Highly efficient CO2 /C2 H2 , CO2 /CH4 , and CO2 /N2 separations are achieved, as verified by experimental breakthrough tests. This work paves a new avenue for the fabrication of adsorbents with high CO2 selectivity and provides important guidance for designing highly effective adsorbents for gas separation.

3.
Front Pharmacol ; 14: 1177819, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37188270

RESUMEN

The primary processed product of Panax ginseng C.A. Meyer (P. ginseng) is red ginseng. As technology advances, new products of red ginseng have arisen. Red ginseng products, e.g., traditional red ginseng, sun ginseng, black ginseng, fermented red ginseng, and puffed red ginseng, are commonly used in herbal medicine. Ginsenosides are the major secondary metabolites of P. ginseng. The constituents of P. ginseng are significantly changed during processing, and several pharmacological activities of red ginseng products are dramatically increased compared to white ginseng. In this paper, we aimed to review the ginsenosides and pharmacological activities of various red ginseng products, the transformation law of ginsenosides in processing, and some clinical trials of red ginseng products. This article will help to highlight the diverse pharmacological properties of red ginseng products and aid in the future development of red ginseng industrialization.

4.
Front Aging Neurosci ; 15: 1071391, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36923118

RESUMEN

Background: Alzheimer's Disease (AD) and Type 2 Diabetes Mellitus (DM) have an increased incidence in modern society. Although more and more evidence has supported that DM is prone to AD, the interrelational mechanisms remain fully elucidated. Purpose: The primary purpose of this study is to explore the shared pathophysiological mechanisms of AD and DM. Methods: Download the expression matrix of AD and DM from the Gene Expression Omnibus (GEO) database with sequence numbers GSE97760 and GSE95849, respectively. The common differentially expressed genes (DEGs) were identified by limma package analysis. Then we analyzed the six kinds of module analysis: gene functional annotation, protein-protein interaction (PPI) network, potential drug screening, immune cell infiltration, hub genes identification and validation, and prediction of transcription factors (TFs). Results: The subsequent analyses included 339 common DEGs, and the importance of immunity, hormone, cytokines, neurotransmitters, and insulin in these diseases was underscored by functional analysis. In addition, serotonergic synapse, ovarian steroidogenesis, estrogen signaling pathway, and regulation of lipolysis are closely related to both. DEGs were input into the CMap database to screen small molecule compounds with the potential to reverse AD and DM pathological functions. L-690488, exemestane, and BMS-345541 ranked top three among the screened small molecule compounds. Finally, 10 essential hub genes were identified using cytoHubba, including PTGS2, RAB10, LRRK2, SOS1, EEA1, NF1, RAB14, ADCY5, RAPGEF3, and PRKACG. For the characteristic Aß and Tau pathology of AD, RAPGEF3 was associated significantly positively with AD and NF1 significantly negatively with AD. In addition, we also found ADCY5 and NF1 significant correlations with DM phenotypes. Other datasets verified that NF1, RAB14, ADCY5, and RAPGEF3 could be used as key markers of DM complicated with AD. Meanwhile, the immune cell infiltration score reflects the different cellular immune microenvironments of the two diseases. Conclusion: The common pathogenesis of AD and DM was revealed in our research. These common pathways and hub genes directions for further exploration of the pathogenesis or treatment of these two diseases.

5.
Chinese Journal of Neonatology ; (6): 157-161, 2023.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-990737

RESUMEN

Objective:To study the predictive value of vasoactive-inotropic score (VIS), fluid overload (FO) and lactate level for the outcome of preterm infants with refractory septic shock.Methods:Preterm infants diagnosed with refractory septic shock and required hydrocortisone treatment in our Department from January 2016 to December 2021 were analyzed retrospectively. Preterm infants were assigned into three gestational age groups (<28 weeks, 28-31 weeks, 32-36 weeks). According to the outcome of the disease, the children were further divided into good prognosis group and poor prognosis group. The relationship between the maximum VIS, FO and the mean lactic acid before hydrocortisone and the outcome of refractory septic shock was analyzed by receiver operating characteristic (ROC) curve, the cut-off point of ROC curve was calculated to obtain the predictive efficacy of the three indicators for the outcome of refractory septic shock in preterm infants.Results:A total of 50 preterm infants with refractory septic shock and received hydrocortisone treatment were enrolled, including 20 in the good prognosis group and 30 in the poor prognosis group. There were no significant differences in the maximum VIS, FO and mean lactic acid before hydrocortisone treatment between the two groups of gestational age of <32 weeks ( P> 0.05). The maximum VIS, FO and mean lactic acid of gestational age of 32-36 weeks in the poor prognosis group were higher than those in the good prognosis group, VIS: 56.1±15.7 vs. 37.1±12.9, FO (%): 108.2 (78.6,137.7) vs. 55.5 (10.3, 100.7), and mean lactic acid (mmol/L): 8.3 (4.6, 12.0) vs. 4.8 (-0.8, 10.5), all P<0.05. The area under the ROC curve of the mean lactic acid was the largest, the cut-off value was 4.1 mmol/L, and the Youden index was 1.732. Conclusions:VIS, FO and lactate level are difficult to be used for determining the outcome of refractory septic shock in preterm infants of <32 weeks. While the mean lactic acid has the best predictive performance in preterm infants of 32-36 weeks.

6.
Zhongguo Zhong Yao Za Zhi ; 47(21): 5855-5862, 2022 Nov.
Artículo en Chino | MEDLINE | ID: mdl-36472004

RESUMEN

To comprehensively evaluate the quality of commercial Ginseng Radix et Rhizoma Rubra, 43 batches of commercial Ginseng Radix et Rhizoma Rubra were collected to determine the content of nine ginsenosides Rg_1, Re, Rb_1, Rk_3, Rh_4, 20(S)-Rg_3, 20(R)-Rg_3, Rk_1, and Rg_5 by high performance liquid chromatography(HPLC). The quality of the commercial Ginseng Radix et Rhizoma Rubra was evaluated by correlation analysis, principal component analysis, factor analysis, analysis of variance(ANOVA), and cluster heatmap analysis. The content determination indicated that the content of common ginsenosides in commercial Ginseng Radix et Rhizoma Rubra were higher while that of rare ginsenosides were lower. Multivariate statistical analysis revealed that ginsenosides Rg_1 and Rb_1 were significantly positively correlated with rare ginsenosides, and Rg_1, Rb_1 and rare ginsenosides played an important role in evaluating the quality of commercial Ginseng Radix et Rhizoma Rubra. In combination with the processing principle and current quality situation of Ginseng Radix et Rhizoma Rubra, it is recommended to improve the content limit of Rb_1 in the existing quality standards.


Asunto(s)
Medicamentos Herbarios Chinos , Ginsenósidos , Panax , Ginsenósidos/análisis , Rizoma/química , Raíces de Plantas/química , Cromatografía Líquida de Alta Presión
7.
Chinese Journal of Neonatology ; (6): 499-504, 2022.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-955280

RESUMEN

Objective:To study the threshold of fluid overload (FO) and its risk factors in neonatal septic shock.Methods:From January 2019 to November 2020, clinical data of infants with septic shock hospitalized in the neonatal department of our hospital were reviewed. With poor prognosis as the outcome, ROC curve was drawn based on 24 h (from the beginning of septic shock), 48 h and 72 h FO value. FO cutoff value was determined as area under curve (AUC) reached maximum. Risk factors of FO were analyzed between FO<cutoff value group and FO≥cutoff value group.Results:A total of 152 eligible cases were included and the cutoff value of 48 h FO was determined as 43.3%. 116 cases were in FO<43.3% group and 36 cases were in FO≥43.3% group. FO≥43.3% group had smaller gestational age (GA), birth weight (BW), 1 min Apgar score, 5 min Apgar score and lower PLT, PCT, pH, and ALB level compared with FO<43.3% group. Meanwhile, FO≥43.3% group had significantly higher shock score, bedside septic shock scores (bSSS), lactic acid level, higher incidences of WBC <5×10 9/L and albumin infusion compared with FO<43.3% group. As for prognostic outcome, FO≥43.3% group had significantly higher incidences of neonatal persistent pulmonary hypertension, severe cerebral hemorrhage, periventricular leukomalacia, acute kidney injury, severe brain injury, multiple organ dysfunction syndrome, disseminated intravascular coagulation and 28 d all-cause mortality rate than FO<43.3% group ( P<0.05). Logistic regression analysis showed risk factors associated with FO≥43.3% were BW ( OR=0.998, 95% CI 0.998~0.999, P<0.05), pH ( OR=0.018, 95% CI 0.000~0.990, P<0.05) and bSSS ( OR=1.619, 95% CI 1.134~2.311, P<0.05). The cutoff values were BW 1 830 g, pH 7.15 and bSSS 0.5. Conclusions:The 48 h FO with cutoff value of 43.3% has the highest predictive value for prognostic outcome in neonates with septic shock. FO≥43.3% is associated with more adverse outcomes. Infants with septic shock who have lower BW, lower pH and higher bSSS are more likely to develop FO≥43.3%.

8.
Chinese Journal of Neonatology ; (6): 494-498, 2022.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-955279

RESUMEN

Objective:To study the predictive value of vasoactive-inotropic score (VIS), shock score and lactate level for the outcome of term infants with septic shock.Methods:From January 2019 to October 2020, clinical data of term infants with septic shock admitted to our department were reviewed. According to their clinical outcome, the infants were assigned into the survival group and the deceased group and the differences of the two groups were compared. Logistic regression was used to determine the risk factors of mortality in term infants with septic shock. Receiver operating characteristic curve was used to compare the predictive efficacy of VIS, shock score and lactate level for the outcome of septic shock.Results:Significant differences existed between the survival group and the deceased group in the following: maximum VIS, maximum shock score, maximum lactate level, the mean value of VIS during the second 24 h, the mean value of lactate during the first and second 24 h ( P < 0.05). Meanwhile, maximum VIS ( OR = 1.038, 95% CI 1.014~1.063), maximum shock score ( OR = 2.372, 95% CI 1.126~4.999) and the mean value of lactate during the first 24h ( OR = 2.983, 95% CI 1.132~7.862) were correlated with mortality in the infants ( P < 0.05). The area under the curve of maximum VIS was the most prominent, with 58.5 as cut-off. Conclusions:Among the three indicators, VIS has the best predictive value for mortality outcome in term infants with septic shock, followed by shock score and lactate level.

9.
Chinese Journal of Neonatology ; (6): 133-137, 2022.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-931003

RESUMEN

Objective:To study the efficacy of norepinephrine in the treatment of neonates with septic shock.Methods:A prospective observation study of neonates with septic shock, who received norepinephrine in the neonatal intensive care unit of Guangdong Women and Children's Hospital from January 2019 to November 2020. All infants had functional echocardiography for hemodynamic monitoring before norepinephrine treatment and 1 hour thereafter blood pressure, heart rate, arterial blood gas analyses were recorded at the same time. The intravenous fluid volume and urine volume from the diagnosis of shock to the commencement of norepinephrine therapy (T0) and 24 hours thereafter (T1) were recorded, and the hemodynamic parameters, vasoactive drugs and clinical outcomes were analyzed.Results:A total of 66 newborns were enrolled, including 27 cases of mild shock, 33 cases of moderate shock and 6 cases of severe shock. 48 were male infants, 38 cases were premature infants. The gestational age was (35.2±4.1) weeks and the birth weight was (2 476±909) g. The median time of shock diagnosis was 2 days after birth, and the median shock score was 4 points. The median time from the diagnosis of shock to the start of norepinephrine treatment was 7.5 hours. Compared with that before norepinephrine treatment, stroke volume, stroke volume index, cardiac output, cardiac index, left ventricular ejection fraction, shortening fraction, systolic blood pressure, diastolic blood pressure, mean arterial pressure, blood pH and BE at 1 hour after treatment were increased, heart rate and blood lactic acid were decreased, the differences were statistically significant ( P<0.05). Urine volume was increased 24 hours after treatment ( P<0.05), and fluid overload decreased ( P<0.05). The maximum dopamine dose, the down-regulation time and duration of vasoactive drugs were positively correlated with the time to start norepinephrine therapy ( r=0.325、 r=0.383、 r=0.319, P<0.05). Among the 66 infants, 58 infants with shock had been corrected and 14 infants died within 28 days. Conclusions:Norepinephrine is effective and feasible in the treatment of neonatal septic shock and can significantly improve hemodynamic parameters.

10.
Chem Commun (Camb) ; 57(61): 7537-7540, 2021 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-34236352

RESUMEN

A novel cluster-based MOF with uncommon multicentered ZnI-ZnI bonds {[K1.2Na2.8ZnI8(HL)12]·4H2O}n (HL = tetrazole monoanion) (1) was synthesized, which showed higher stability than the reported ZnI-ZnI bonded compounds. Moreover, 1 can effectively and circularly catalyze the cyclization of CO2 and aziridines or epoxides with five substituent groups. Importantly, this is the first time that the catalytic properties of MOFs with multicentered metal-metal bonded clusters as the catalyst have been studied.

11.
Inorg Chem ; 60(3): 1922-1929, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33449682

RESUMEN

Photocatalytic hydrogen evolution is desired to effectively alleviate the serious crisis of energy and the environment, and the utilization of low-cost photocatalysts, especially cobalt-based MOF catalysts, is meaningful, but rarely investigated. Herein, through a self-assembly strategy, we synthesized a Co clusters-based MOF (Co3-XL) by the ligand N,N'-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxdiimide bi(1,2,4-triazole), containing abundant carbonyl O atoms in the channels of the 3D skeleton, and a large porosity of 50.7%. The as-synthesized MOF can be stable in the pH range of 3-10 and shows a narrow band gap of 1.82 eV. Furthermore, its maximum amount of water absorption can reach 192 cm3/g. Under irradiation of simulated solar light, the rate of hydrogen evolution is 23.05 µmol·h-1·g-1 among 12 h with the presence of co-catalyst Pt and photosensitizer RhB. The reaction mechanism has been probed by the transient photocurrent response and steady-state photoluminescence spectra. Therefore, as a narrow band gap photocatalyst, the cobalt clusters-based MOF (Co3-XL) has potential applications for hydrogen evolution from water.

12.
Neural Regen Res ; 16(9): 1848-1855, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33510092

RESUMEN

High mobility group box 1 (HMGB1) interacts with pattern-recognition receptors of immune cells to activate the inflammatory response. Astrocytes play a positive role in the inflammatory response of the central nervous system by expressing a broad range of pattern-recognition receptors. However, the underlying relationship between HMGB1 and the inflammatory reaction of astrocytes remains unclear. In this study, we established rat models of spinal cord injury via laminectomy at the T8-10 level, and the injured spinal cord was subjected to transcriptome sequencing. Our results showed that the HMGB1/Toll-like receptor 4 (TLR4) axis was involved in the activation of astrocyte inflammatory response through regulation of cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) signaling. Both TLR4 and COX2 were distributed in astrocytes and showed elevated protein levels following spinal cord injury. Stimulation of primary astrocytes with recombinant HMGB1 showed that COX2 and microsomal PGE synthase (mPGES)-1, rather than COX1, mPGES-2, or cytosolic PGE synthase, were significantly upregulated. Accordingly, PGE2 production in astrocytes was remarkably increased in response to recombinant HMGB1 challenges. Pharmacologic blockade of TLR2/4 attenuated HMGB1-mediated activation of the COX2/PGE2 pathway. Interestingly, HMGB1 did not impact the production of tumor necrosis factor-α or interleukin-1ß in astrocytes. Our results suggest that HMGB1 mediates the astrocyte inflammatory response through regulating the COX2/PGE2 signaling pathway. The study was approved by the Laboratory Animal Ethics Committee of Nantong University, China (approval No. 20181204-001) on December 4, 2018.

13.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-908535

RESUMEN

Objective:To study the clinical value of neonatal shock score (NSS) and septic shock score (SSS) in the evaluation of mortality and serious complications of neonatal refractory septic shock.Method:From January 2019 to November 2020, clinical data of neonates with septic shock admitted to Neonatal Department of our hospital were retrospectively reviewed. According to the final outcomes, neonates were assigned into good prognosis group (neonates survived without serious complications) and poor prognosis group (neonates were dead within 28 days after birth and/or had serious complications). The NSS and SSS were calculated according to the worst value of each index during the septic shock course. SSS included computed septic shock score (cSSS) and bedside septic shock score (bSSS). The receiver operating characteristic (ROC) curve was used to analyze the efficacy of each scoring system evaluating the risk of poor prognosis due to septic shock. The correlation of each scoring system with the duration of vasoactive drugs was analyzed using Spearman rank correlation analysis.Result:A total of 72 neonates were enrolled, including 45 in good prognosis group and 27 in poor prognosis group. The vasoactive drug score, serum lactate level, NSS and cSSS in poor prognosis group were significantly higher than good prognosis group ( P<0.05).And bSSS score showed no significant differences between the two groups ( P>0.05). The area under the ROC curve (AUC) of NSS and cSSS predicting the adverse prognosis of neonates with septic shock were 0.644 (95% CI 0.510~0.777, P<0.05) and 0.765 (95% CI 0.654~0.877, P<0.05). The best cut-off values for NSS and cSSS predicting poor prognosis were 4.0 and 80.5, respectively. The positive predictive value (PPV) (81.3% vs. 47.5%) and negative predictive value (NPV) (75.0% vs. 70.6%) of cSSS were higher than NSS. Spearman rank correlation analysis showed that cSSS was positively correlated with the duration of vasoactive drugs( r=0.487, P<0.01). Conclusion:Both shock scoring systems have an evaluation value for the prognosis of neonatal septic shock. The evaluation value of cSSS is better than NSS, and can be used as a main tool for the evaluation of neonatal refractory septic shock.

14.
Nanotoxicology ; 14(3): 289-309, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32193966

RESUMEN

Titanium (Ti) and its alloys are widely used in clinical practice as preferred materials for bone tissue repair and replacement because of their good mechanical properties; however, as Ti lacks biological activity, clinical application has been limited. Herein, we prepared a manganese-titanium dioxide (Mn-TiO2) microporous biotic coating on Ti surfaces by micro-arc oxidation (MAO). The coating showed good surface topography and was uniformly doped with Mn, and the Mn ions were slowly released. In vitro, the Mn-TiO2 microporous biotic coating promoted the adhesion, proliferation, differentiation, and mineralization of MC3T3-E1 osteoblasts. Moreover, in vivo experiments showed that the coating promoted early osseointegration. We also conducted a preliminary investigation to explore the molecular mechanism underlying the regulation of the function of osteoblasts by the coating. Furthermore, we found that the coating could inhibit the growth of Escherichia coli in vitro, demonstrating reliable antibacterial ability. To conclude, Mn-TiO2 microporous biotic coating can improve the biological activity of Ti implants, which can potentially improve their clinical applications.


Asunto(s)
Materiales Biocompatibles Revestidos/farmacología , Manganeso/química , Oseointegración/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Prótesis e Implantes , Titanio/química , Animales , Antibacterianos/farmacología , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular , Iones , Osteoblastos/efectos de los fármacos , Oxidación-Reducción , Porosidad , Conejos , Propiedades de Superficie
15.
Angew Chem Int Ed Engl ; 59(22): 8586-8593, 2020 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-32100927

RESUMEN

The reaction of propargylic amines and CO2 can provide high-value-added chemical products. However, most of catalysts in such reactions employ noble metals to obtain high yield, and it is important to seek eco-friendly noble-metal-free MOFs catalysts. Here, a giant and lantern-like [Zn116 ] nanocage in zinc-tetrazole 3D framework [Zn22 (Trz)8 (OH)12 (H2 O)9 ⋅8 H2 O]n Trz=(C4 N12 O)4- (1) was obtained and structurally characterized. It consists of six [Zn14 O21 ] clusters and eight [Zn4 O4 ] clusters. To our knowledge, this is the highest-nuclearity nanocages constructed by Zn-clusters as building blocks to date. Importantly, catalytic investigations reveal that 1 can efficiently catalyze the cycloaddition of propargylic amines with CO2 , exclusively affording various 2-oxazolidinones under mild conditions. It is the first eco-friendly noble-metal-free MOFs catalyst for the cyclization of propargylic amines with CO2 . DFT calculations uncover that ZnII ions can efficiently activate both C≡C bonds of propargylic amines and CO2 by coordination interaction. NMR and FTIR spectroscopy further prove that Zn-clusters play an important role in activating C≡C bonds of propargylic amines. Furthermore, the electronic properties of related reactants, intermediates and products can help to understand the basic reaction mechanism and crucial role of catalyst 1.

16.
Angew Chem Int Ed Engl ; 58(18): 6022-6027, 2019 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-30793462

RESUMEN

Assembled from [Th48 Ni6 ] nanocages, the first transition-metal (TM)-thorium metal-organic framework (MOF, 1) has been synthesized and structurally characterized. 1 exhibits high solvent and acid/base stability, and resistance to 400 kGy ß irradiation. Notably, 1 captures ReO4 - (an analogue of radioactive 99 TcO4 - , a key species in nuclear wastes) with a maximum capacity of 807 mg g-1 , falling among the largest values known to date. Furthermore, 1 can enrich methylene blue (MB) and can also serve as an effective and recyclable catalyst for CO2 fixation with epoxides; there is no significant loss of catalytic activity after 10 cycles. Theoretical studies with nucleus-independent chemical shifts and natural bond orbital analysis reveal that the [Th6 O8 ] clusters in 1 have a unique stable electronic structure with (d-p)π aromaticity, partially rationalising 1's stability.

17.
Bioorg Med Chem ; 27(2): 442-446, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30579802

RESUMEN

A new flavoalkaloid racemate, leucoflavonine (1), together with its flavonoid precursor pectolinarigenin (2), was isolated from the leaves of Leucosceptrum canum collected from Tibet. Its structure was established by comprehensive spectroscopic analysis. Chrial separation of the enantiomers of 1 was achieved, and their absolute configurations were determined as S-(+)- and R-(-)-leucoflavonines ((+)-1a and (-)-1b) by comparison of their computational and experimental optical rotations. Biological assays indicated that both (+)-1a and (-)-1b exhibited inhibitory activity against acetylchlorinesterase (AChE) in vitro (IC50 = 68.0 ±â€¯8.6 and 18.3 ±â€¯1.8 µM, respectively). Moreover, (-)-1b displayed cytotoxicity against human hepatoma cells HepG2 (IC50 = 52.9 ±â€¯3.6 µM), and inhibited the production of interleukelin-2 (IL-2) in Jurkat cells (IC50 = 16.5 ±â€¯0.9 µM), while (+)-1a showed no obvious activity in these assays.


Asunto(s)
Acetilcolinesterasa/metabolismo , Alcaloides/farmacología , Antineoplásicos Fitogénicos/farmacología , Inhibidores de la Colinesterasa/farmacología , Flavonas/farmacología , Interleucina-2/biosíntesis , Lamiaceae/química , Hojas de la Planta/química , Alcaloides/química , Alcaloides/aislamiento & purificación , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Proliferación Celular/efectos de los fármacos , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Anguilas , Flavonas/química , Células Hep G2 , Humanos , Células Jurkat , Ratones , Estructura Molecular , Células RAW 264.7 , Relación Estructura-Actividad
18.
Chemistry ; 24(41): 10296-10299, 2018 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-29697162

RESUMEN

A new 3D framework {[Eu2 Cu(IN)5 (CO3 )(H2 O)] ⋅3 H2 O}n  (1) was obtained and structurally characterized, containing CuI and an unusual lanthanide duplex chain. The luminescent explorations of compound 1 suggest that 1 could emit the characteristic emission of CuI , and 1 can act as the luminescent sensor of ClO- with the detection limit of 10-5  m. Notably, 1 represents the first example of MOF-based sensor for detecting ClO- .

19.
Dalton Trans ; 47(13): 4545-4553, 2018 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-29509207

RESUMEN

A multifunctional metal-organic framework (1) containing 24-nuclear zinc nanocages shows high solvent- and pH-stability. Compound 1 can be employed as a catalyst for the conversion of CO2 with aziridines or epoxides, which can be reused at least ten times just by a simple and rapid method. The PXRD of compound 1 after ten recyclings remains well consistent with the original one. The inductively coupled plasma measurement of a reaction filtrate revealed that only trace amount leakage of Zn2+ was observed, indicating that the framework did not collapse after recyclings. Compound 1 can effectively catalyze the cycloaddition reaction of CO2 and five aziridines or five epoxides with different substituent groups. To our knowledge, this is the first multifunctional MOF-based catalyst used for the conversion of CO2 with aziridines or epoxides. Furthermore, luminescence investigations reveal that compound 1 can also act as a luminescent probe for chromium(vi) anion species, which is seriously harmful to humans and the environment. After five cycle tests, the PXRD of compound 1 is still in accordance with the original one, indicating that compound 1 can serve as a circulatory luminescent probe for Cr(vi) anions.

20.
Inorg Chem ; 56(15): 9169-9176, 2017 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-28737939

RESUMEN

Tunable structures and magnetocaloric effect (MCE) of seven MOFs with [Gdn] as nodes are explored. The [Gdn] node is realized from mononuclear [Gd] to binuclear paddle-wheel [Gd2], tetranuclear tetrahedral [Gd4], and pentanuclear trigonal bipyramidal [Gd5]. Meanwhile, the magnetic entropy changes from 19.4 to 46.0 J·kg-1·K-1. The results reveal that the effect of magnetic density on MCE plays a dominant role for Gd3+-based compounds, and high spin ground state of Mn2+ (S = 5/2) is more favorable to achieve high MCE than that with Zn2+, Co2+, and Ni2+ (Co2+, S = 3/2; Ni2+, S = 1). To our knowledge, it is the first report that MCE is controlled by various clusters as nodes in MOFs.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...