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1.
Artigo em Inglês | MEDLINE | ID: mdl-33405153

RESUMO

Mount of embodied carbon emissions flow along industrial chains and form a complex network. In order to reveal the structure and evolution characteristics of embodied carbon emission flow network among China's industrial sectors, this study applies a complex network theory to construct six embodied carbon emission flow networks with 30 sectors on the basis of China's input-output tables from 2002 to 2015. Through the analysis of complex network technology indicators, the overall structural characteristics of the network, the key sectors, and the key flow paths are analyzed. Main results show that six embodied carbon emission flow networks all have the small-world characteristics; there is an industrial cluster phenomenon in the network. During the study period, construction, manufacturing, and service-related industry community are the absorption sites for embodied carbon emissions. Coal- and petroleum-related industry communities are the divergent sites for embodied carbon emissions; moreover, electric and heat power and fuel processing are the important "suppliers" of embodied carbon emissions; construction and other service are the important "consumers" of embodied carbon emissions. Non-metallic products are the important "transmitters" of embodied carbon emissions. Metal smelting and chemical industry are at the core of the network because of their high weighted degree and betweenness centrality. The central effect of key sectors continues to increase over time; furthermore, the distribution of embodied carbon emission flows in the six networks all have long-tail characteristics, and this characteristic became more prominent over time. There are key edge-weights in the networks. About 11 to 15% of the edges carry 80% of the embodied carbon emissions. Further based on edge-weight analysis, this study identifies the key paths of embodied carbon emission flow in the six networks, and most key paths pass through construction. Thus, such key sectors and key flow paths should receive more attention when making carbon emission reduction policies.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33475878

RESUMO

PURPOSE: The purpose of this review is to clarify the association of body composition with breast cancer risk and treatment, including physiological mechanisms, and to elucidate strategies for overcoming unfavorable body composition changes that relate to breast cancer progression. METHODS: We have summarized updated knowledge regarding the mechanism of the negative association of altered body composition with breast cancer risk and treatment. We also review strategies for reversing unfavorable body composition based on the latest clinical trial results. RESULTS: Body composition changes in patients with breast cancer typically occur during menopause or as a result of chemotherapy or endocrine therapy. Dysfunction of visceral adipose tissue (VAT) in the setting of obesity underlies insulin resistance and chronic inflammation, which can lead to breast cancer development and progression. Insulin resistance and chronic inflammation are also observed in patients with breast cancer who have sarcopenia or sarcopenic obesity. Nutritional support and a personalized exercise program are the fundamental interventions for reversing unfavorable body composition. Other interventions that have been explored in specific situations include metformin, testosterone, emerging agents that directly target the adipocyte microenvironment, and bariatric surgery. CONCLUSIONS: A better understanding of the biology of body composition phenotypes is key to determining the best intervention program for patients with breast cancer.

3.
Med Sci Monit ; 27: e927624, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33436534

RESUMO

BACKGROUND Traditional Chinese medicine has widely used Bolbostemma paniculatum to treat diseases, including cancer, but its underlying mechanisms remain unclear. The present study aimed to elucidate the potential pharmacological mechanisms of "Tu Bei Mu" (TBM), the Chinese name for Bolbostemmatis Rhizoma, the dry tuber of B. paniculatum, for the treatment of hepatocellular carcinoma (HCC). MATERIAL AND METHODS The active components and putative therapeutic targets of TBM were explored using SwissTargetPrediction, Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and Search Tool for Interactions of Chemicals (STITCH). The HCC-related target database was built using DrugBank, DisGeNet, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Database (TTD). A protein-protein interaction network of the common targets was constructed, based on the matches between TBM potential targets and HCC-related targets, using Cytoscape software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of the cluster networks were used to elucidate the biological functions of TBM. RESULTS Pharmacological network diagrams of the TBM compound-target network and HCC-related target network were successfully constructed. A total of 22 active components, 191 predicted biological targets of TBM, and 3775 HCC-related targets were identified. Through construction of an HCC-related target database and a protein-protein interaction network of the common targets, TBM was predicted to be effective in treating HCC mainly through the PI3K-Akt, HIF-1, p53, and PPAR signaling pathways. CONCLUSIONS The PI3K/Akt, HIF1, p53, and PPAR pathways may play vital roles in TBM treatment of HCC. Also, the potential anti-cancer effect of TBM on HCC appears to stem from the synergetic effect of multiple targets and mechanisms.

4.
Commun Biol ; 4(1): 72, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33452400

RESUMO

Inflammatory breast cancer (IBC) is a clinically distinct and highly aggressive form of breast cancer with rapid onset and a strong propensity to metastasize. The molecular mechanisms underlying the aggressiveness and metastatic propensity of IBC are largely unknown. Herein, we report that decorin (DCN), a small leucine-rich extracellular matrix proteoglycan, is downregulated in tumors from patients with IBC. Overexpression of DCN in IBC cells markedly decreased migration, invasion, and cancer stem cells in vitro and inhibited tumor growth and metastasis in IBC xenograft mouse models. Mechanistically, DCN functioned as a suppressor of invasion and tumor growth in IBC by destabilizing E-cadherin and inhibiting EGFR/ERK signaling. DCN physically binds E-cadherin in IBC cells and accelerates its degradation through an autophagy-linked lysosomal pathway. We established that DCN inhibits tumorigenesis and metastasis in IBC cells by negatively regulating the E-cadherin/EGFR/ERK axis. Our findings offer a potential therapeutic strategy for IBC, and provide a novel mechanism for IBC pathobiology.

5.
Ecotoxicol Environ Saf ; 208: 111582, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396105

RESUMO

In recent years, heavy metal pollution has caused immeasurable harm to the environment. As an emerging technology, phytoremediation technology has gained a place in the treatment of heavy metal pollution with its unique advantages. This study analyzes the toxic effects of mulberry (Morus alba) seeds, seedling growth and silkworm under heavy metal stress of lead (Pb) and cadmium (Cd), and explore the accumulation and migration of Pb and Cd in the soil-mulberry tree-silkworm system. The main results were as follows: (1) Seed germination and potted seedling experiments were conducted under heavy metal Pb and Cd stresses, and it was found that Pb and Cd had inhibitory effects on mulberry seed germination, growth and photosynthesis of mulberry seedlings, and as the concentration of heavy metals increased, the stronger the inhibitory effect. Moreover, Pb and Cd have a synergistic effect under compound stress. (2) The accumulation and transfer rules of Pb and Cd ions in mulberry were different. The content of Pb in mulberry was root > leaf > stem and the content of Cd was root > stem > leaf. The combined stress promoted the transfer of Pb and Cd from the underground part to the aerial portion of mulberry. (3) The silkworm feeds on mulberry leaves contaminated with heavy metals in this experiment and found that: with the increase of silkworm feeding, the heavy metal content in the silkworm body increased significantly, but the content remained in the silkworm body was less, most of it was excreted with silkworm excrement. Combined stress has no significant effect on the detoxification mechanism of silkworm. It is indispensable to think of the synergistic effect of heavy metals on plants germination when seeds are used for phytoremediation.


Assuntos
Bombyx/fisiologia , Cádmio/toxicidade , Cadeia Alimentar , Chumbo/toxicidade , Morus/fisiologia , Poluentes do Solo/toxicidade , Solo/química , Animais , Biodegradação Ambiental , Cádmio/análise , Cádmio/metabolismo , Frutas/química , Metais Pesados/análise , Fotossíntese , Folhas de Planta/química , Plântula/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
6.
J Ethnopharmacol ; 266: 113404, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32976970

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Danqi Pill, composed of the root of Salvia miltiorrhiza Bunge and the root of Panax notoginseng, is effective in the clinical treatment of myocardial ischemia in coronary heart diseases. A number of studies have shown that autophagy plays an essential role in cardiac function and energy metabolism, and disordered autophagy is associated with the progression of heart failure. However, the effect and mechanism of Danqi pill on autophagy have not been reported yet. AIM OF THE STUDY: This study aims to elucidate whether Danqi pill restores autophagy to protect against HF and its potential mechanism. MATERIALS AND METHODS: Left anterior descending ligation was established to induce an HF rat model, H2O2-stimulated H9C2 cells model was conducted to clarify the effects and potential mechanism of Danqi pill. In vivo, Danqi pill (1.5 g/kg) were orally administered for four weeks and Fenofibrate (10 mg/kg) was selected as a positive group. In vitro, Danqi pill (10-200 µg/mL) was pre-cultured for 24 h and co-cultured with H2O2 stimulation for 4 h. Importantly, transmission electron microscopy and fluorescence GPF-mRFP-LC3 reporter system were combined to monitor autophagy flux. Furtherly, we utilized Compound C, a specific AMPK inhibitor, to validate whether the autophagy was mediated by AMPK-TSC2-mTOR pathway. RESULTS: Danqi pill significantly improved cardiac function and myocardial injury in HF rats. Intriguingly, Danqi pill potently regulated autophagy mainly by promoting the formation of autophagosomes in vivo. Further results demonstrated that expressions of p-AMPK (P < 0.001) and p-TSC2 (P < 0.001) in cardiac tissue were upregulated by Danqi pill, accompanied with downregulation of p-mTOR (P < 0.01) and p-ULK1(P < 0.01). In parallel with the vivo experiment, in vitro study indicated that Danqi pill dramatically restored autophagy flux and regulated expressions of critical autophagy-related molecules. Finally, utilization of Compound C abrogated the effects of Danqi pill on autophagy flux and the expressions of p-TSC2 (P < 0.05), p-mTOR (P < 0.01) and p-ULK1 (P < 0.05). CONCLUSION: Danqi pill could improve cardiac function and protect against cardiomyocytes injury by restoring autophagy via regulating the AMPK-TSC2-mTOR signaling pathway.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33314677

RESUMO

During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (Tb ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.

9.
Plant Physiol Biochem ; 159: 80-88, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33341082

RESUMO

The natural fluorescence of tree peony is short. Forcing culture, mainly by defoliation and gibberellin (GA) treatment, is frequently used for its industrial production. We previously found forcing culture to be coordinated by non-structural carbohydrates (NSCs). Herein, we further revealed the specific role of NSCs during this process. We observed that both defoliation and GA treatment increased the photosynthesis in the bracts, and defoliation had a greater effect on NSC assimilation. We further determined the NSC content and PsSWEETs expression in the bracts, and the results indicated that GA may contribute more to NSC allocation by inducing PsSWEET7. Furthermore, we determined the trehalose-6-phosphate (T6P) content and sugar signaling-related gene (PsTPS1, PsSnRK1, and PsHXK1) expression in both the petals and bracts and found that both defoliation and GA treatment induced T6P levels as well as PsTPS1 expression in both tissues. This indicated that the sugar signaling pathway may also be involved in NSC-coordinated tree peony flowering. In particular, PsSnRK1 was more rapidly induced in the bracts (as an energy shortage response) in the control plants and was completely prohibited by defoliation and GA treatment, indicating the key role of the bracts in sugar signaling. In conclusion, NSCs induced tree peony flowering both as an energy substrate and sugar signaling trigger, with the bracts playing an essential role. These results may provide further evidence on the mechanism of NSC-coordinated flower opening in tree peony under forcing culture conditions, which may also provide a foundation for improving this technology.

10.
J Ethnopharmacol ; : 113571, 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33181282

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Sparganii Rhizoma (SR), a traditional Chinese medicine (TCM), is the rhizome of Sparganium stoloniferum Buch.-Ham. mainly distributed in East Asia. It has been used for eliminating blood stasis, promoting the flow of Qi, removing the retention of undigested food and relieving pain in China for hundreds of years. AIM OF THE REVIEW: This review summarizes comprehensive information in traditional clinical application, processing, phytochemistry, pharmacology, quality control and toxicity of SR, in exploring future scientific and therapeutic potentials. MATERIALS AND METHODS: Pertinent information was systematically collected from several electronic scientific databases (e.g., Web of Science, PubMed, China Knowledge Resource Integrated, Springer, Elsevier, ScienceDirect, and Google Scholar), PhD and MS dissertations, and classic Chinese medical books. RESULTS: SR is a gynecological drug which is often used to treat dysmenorrhea, mass in the abdomen, amenorrhea due to blood stasis, and abdominal distension in TCM. Two kinds of processed products of SR are included in Chinese Pharmacopoeia, which have better pharmacological effects than the crude herb. Approximately 180 compounds have been identified from SR, including phenylpropanoids, flavonoids, anthraquinones, organic acids, alkaloids, steroids, volatile oils, diarylheptanes, etc. The crude extracts and isolated components of SR have been reported to have anti-tumor, antithrombotic, estrogen antagonistic , anti-inflammatory, analgesic, antioxidant, anti organ fibrosis and other pharmacological activities. SR also has reproductive toxicity. CONCLUSIONS: As an important TCM, SR has been demonstrated by modern pharmacological researches to have significant bioactivities, especially on anti-tumor, antithrombotic, and estrogen antagonistic activities. These activities provide prospects for the development of new drugs and therapeutics for future applications. Nevertheless, quality control and evaluation, in-depth pharmacological mechanism, and toxicological effect of SR require further detailed research.

11.
Bioorg Chem ; 105: 104388, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33130343

RESUMO

A phytochemical investigation on the stems and leaves of Wikstroemia chuii resulted in the isolation of three new daphnane diterpenes, wikstroechuins A-C (1-3), together with eight known analogues (4-11). The structures of new daphnane diterpenes (1-3) were determined on the basis of extensive spectroscopic methods and the known daphnane diterpenes (4-11) were identified by comparing their observable spectroscopic data with those reported spectral data in the literature. The anti-inflammatory effects as well as anti-HIV activities in vitro of all isolated daphnane diterpenes 1-11 were assessed. As a consequence, daphnane diterpenes 1-11 displayed remarkable inhibitory activities on NO (nitric oxide) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells showing IC50 values in the range of 0.12 ± 0.03 to 10.58 ± 0.16 µM. Meanwhile, daphnane diterpenes 1-11 displayed significant anti-HIV-1 reverse transcriptase (RT) effects showing EC50 values ranging from 0.09509 to 8.62356 µM. These research results indicated that the discovery of these new daphnane diterpenes with remarkable anti-inflammatory and anti-HIV activities from W. chuii, especially these new ones, could be extremely meaningful to the discovery of new anti-inflammatory agents and anti-HIV drugs as well as their potential practical values in the health and pharmaceutical products.

12.
Front Neurosci ; 14: 573633, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33041766

RESUMO

Background: Neuropathological studies have revealed copper and iron accumulation in the deep gray matter (DGM) nuclei of patients with Wilson's disease (WD). However, the association between metal accumulation and neurodegeneration in WD has not been well studied in vivo. The study was aimed to investigate whether metal accumulation in the DGM was associated with the structural and functional changes of DGM in neurological WD patients. Methods: Seventeen neurological WD patients and 20 healthy controls were recruited for the study. Mean bulk susceptibility values and volumes of DGM were obtained from quantitative susceptibility mapping (QSM). Regions of interest including the head of the caudate nucleus, globus pallidus, putamen, thalamus, substantia nigra, red nucleus, and dentate nucleus were manually segmented. The susceptibility values and volumes of DGM in different groups were compared using a linear regression model. Correlations between susceptibility values and volumes of DGM and Unified Wilson's Disease Rating Scale (UWDRS) neurological subscores were investigated. Results: The susceptibility values of all examined DGM in WD patients were higher than those in healthy controls (P < 0.05). Volume reductions were observed in the head of the caudate nucleus, globus pallidus, putamen, thalamus, and substantia nigra of WD patients (P < 0.001). Susceptibility values were negatively correlated with the volumes of the head of the caudate nucleus (r p = -0.657, P = 0.037), putamen (r p = -0.667, P = 0.037), and thalamus (r p = -0.613, P = 0.046) in WD patients. UWDRS neurological subscores were positively correlated with the susceptibility values of all examined DGM. The susceptibility values of putamen, head of the caudate nucleus, and dentate nucleus could well predict UWDRS neurological subscores. Conclusion: Our study provided in vivo evidence that paramagnetic metal accumulation in the DGM was associated with DGM atrophy and neurological impairment. The susceptibility of DGM could be used as a biomarker to assess the severity of neurodegeneration in WD.

13.
Front Psychiatry ; 11: 559729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33101081

RESUMO

Objective: Decreased homotopic connectivity of brain networks such as the cortico-striato-thalamo-cortical (CSTC) circuits may contribute to the pathophysiology of obsessive-compulsive disorder (OCD). However, little is known about interhemispheric functional connectivity (FC) at rest in OCD. In this study, the voxel-mirrored homotopic connectivity (VMHC) method was applied to explore interhemispheric coordination at rest in OCD. Methods: Forty medication-free patients with OCD and 38 sex-, age-, and education level-matched healthy controls (HCs) underwent a resting-state functional magnetic resonance imaging. The VMHC and support vector machine (SVM) methods were used to analyze the data. Results: Patients with OCD had remarkably decreased VMHC values in the orbitofrontal cortex, thalamus, middle occipital gyrus, and precentral and postcentral gyri compared with HCs. A combination of the VMHC values in the thalamus and postcentral gyrus could optimally distinguish patients with OCD from HCs. Conclusions: Our findings highlight the contribution of decreased interhemispheric FC within and outside the CSTC circuits in OCD and provide evidence to the pathophysiology of OCD.

15.
Parkinsons Dis ; 2020: 1216568, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33062247

RESUMO

Introduction: This study investigated the influence of lockdown during the 2019 coronavirus disease (COVID-19) pandemic on the quality of life of patients with Parkinson's disease (PD). Methods: We conducted a questionnaire survey involving 113 patients with PD from Xihu District, Hangzhou, Zhejiang. During the epidemic prevention and control period (February 1 to March 31, 2020), patients enrolled were asked to fill out questionnaires, including the "COVID-19 Questionnaire for PD Patients during the Period of Epidemic Prevention and Control" and "39-item Parkinson's Disease Questionnaire (PDQ-39)." During the phase of gradual release of epidemic prevention and control (April 1 to April 30, 2020), all patients were followed up again, and PDQ-39 questionnaires were completed. Results: The quality of life for patients during the period of epidemic prevention and control was worse than that after epidemic prevention and control (P < 0.001). The biggest problem that they faced was that they could not receive their doctor's advice or guidance regularly. The quality of life of patients who had difficulty getting doctors' guidance or those who changed their routine medication due to lockdown was even worse. Telemedicine was quite effective and efficient for patients to get doctors' guidance during lockdown. Conclusions: The inconvenient treatment during the pandemic directly caused the aggravation of patients' symptoms and the decline in their quality of life. It is suggested that social media (such as WeChat or Tencent QQ) are used for regular interactions and follow-up appointments for patients with inconvenient medical treatment.

16.
Stem Cell Res ; 49: 102050, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33096383

RESUMO

Induced pluripotent stem cell (iPSC) line, THSJTUi001-A, was generated from a 26-year-old Chinese male patient with Wilson's disease carrying a homozygous Arg778Leu mutation in ATP7B gene, using non-integrated episomal reprogramming vectors. This cell line had normal karyotype, expressed pluripotency markers and could differentiate into the three germ layers in vivo.

17.
Artigo em Inglês | MEDLINE | ID: mdl-33063211

RESUMO

It is important for China's green innovation productivity and sustainable development to study the effect of heterogeneous environmental regulation on microenterprise innovation activities. Based on the panel data of high-tech enterprises in China from 2012 to 2017, the article studies the incentive effect of heterogeneous environmental regulation on technological innovation and the mediation of innovation input and explores whether different types of environmental regulations have interactive effects on enterprise innovation. The results reveal that compared with the command-controlled environmental regulation, the incentive effect of market-incentive environmental regulation and voluntary environmental regulation on enterprise innovation is more significant, where the innovation input fully plays its role as a mediating effect. Further research finds that there is an interactive effect between command-controlled environmental regulation and other two regulatory tools, but no interactive effect between market-incentive environmental regulation and voluntary environmental regulation, which shows that the control-based regulatory tools and more flexible regulatory tools have a complementary effect on enterprise innovation. Through revealing the internal mechanism of environmental regulation on enterprise innovation, the article displays the process of technological innovation, and it also finds that flexible regulation tools and the combination of rigid and flexible tools are more conducive to encourage enterprises to carry out innovation activities.

18.
Environ Pollut ; 268(Pt A): 115906, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33120333

RESUMO

Fluorescence spectroscopy is a commonly used technique to analyze dissolved organic matter in aquatic environments. Given the high sensitivity and non-destructive analysis, fluorescence has recently been used to study water-soluble organic carbon (WSOC) in atmospheric aerosols, which have substantial abundance, various sources and play an important role in climate change. Yet, current research on WSOC characterization is rather sparse and limited to a few isolated sites, making it challenging to draw fundamental and mechanistic conclusions. Here we presented a review of the fluorescence properties of atmospheric WSOC reported in various field and laboratory studies, to discuss the current advances and limitations of fluorescence applications. We highlighted that photochemical reactions and relevant aging processes have profound impacts on fluorescence properties of atmospheric WSOC, which were previously unnoticed for organic matter in aquatic environments. Furthermore, we discussed the differences in sources and chemical compositions of fluorescent components between the atmosphere and hydrosphere. We concluded that the commonly used fluorescence characteristics derived from aquatic environments may not be applicable as references for atmospheric WSOC. We emphasized that there is a need for more systematic studies on the fluorescence properties of atmospheric WSOC and to establish a more robust reference and dataset for fluorescence studies in atmosphere based on extensive source-specific experiments.

19.
J Agric Food Chem ; 68(44): 12326-12335, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33107299

RESUMO

Toona sinensis, popularly known as Chinese toon or Chinese mahogany, is a perennial deciduous arbor belonging to the genus Toona in the Meliaceae family, which is widely distributed and cultivated in eastern and southeastern Asia. Its fresh young leaves and buds have been consumed as a very popular nutritious vegetable in China and confirmed to display a wide variety of biological activities. To investigate the chemical constituents and their potential health benefits from the fresh young leaves and buds of T. sinensis, a phytochemical study on its fresh young leaves and buds was therefore undertaken. In our current investigation, 16 limonoids (1-16), including four new limonoids, toonasinenoids A-D (1-4), and a new naturally occurring limonoid, toonasinenoid E (5), were isolated and characterized from the fresh young leaves and buds of T. sinensis. The chemical structures and absolute configurations of limonoids 1-5 were elucidated by comprehensive spectroscopic data analyses. All known limonoids (6-16) were identified via comparing their experimental spectral data containing mass spectrometry data, 1H and 13C nuclear magnetic resonance data, and optical rotation values to the data reported in the literature. All known limonoids (6-16) were isolated from T. sinensis for the first time. Furthermore, the neuroprotective effects of all isolated limonoids 1-16 against 6-hydroxydopamine-induced cell death in human neuroblastoma SH-SY5Y cells were assessed in vitro. Limonoids 1-16 exhibited notable neuroprotective activities, with EC50 values in the range from 0.27 ± 0.03 to 17.28 ± 0.16 µM. These results suggest that regular consumption of the fresh young leaves and buds of T. sinensis might prevent the occurrence and development of Parkinson's disease (PD). Moreover, the isolation and characterization of these limonoids that exhibit notable neuroprotective activities from the fresh young leaves and buds of T. sinensis could be very significant for researching and developing new neuroprotective drugs used for the prevention and treatment of PD.

20.
Artigo em Inglês | MEDLINE | ID: mdl-33089632

RESUMO

Buried salt bridges widely exist in protein structures but are rarely used in synthetic systems for molecular recognition in water. By mimicking the binding pocket of bioreceptors, we designed and synthesized a pair of endo-functionalized macrocyclic hosts with secondary ammonium groups in a hydrophobic cavity. We found that these macrocycles are able to selectively recognize carboxylic acids in water through salt bridges and the hydrophobic effect. Moreover, it was demonstrated that these macrocyclic receptors can be used in circular-dichroism-based optical chirality sensing of chiral carboxylic acids and fluorescent sensing of phenylpyruvic acid-a biomarker for phenylketonuria. This research showcases that buried salt bridges can be effectively used by endo-functionalized macrocyclic hosts for molecular recognition in water, where solvent screening on polar noncovalent interactions is high.

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