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1.
Chem Commun (Camb) ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31960844

RESUMO

We report a modularized sample purification system (MSPS) fabricated by 3D printing for rapid and high-throughput MALDI-MS analysis of various small-volume biological samples. The MSPS presents distinct advantages such as customizability, portability, expandability, simple operation and high throughput and also keeps the flexibility of being customized with more functional modules in future applications.

2.
Medicine (Baltimore) ; 99(2): e18367, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914015

RESUMO

Little is known about the decay kinetics of interferon (IFN)-γ response and its influencing factors in tuberculous pleurisy. We enrolled thirty-two patients with tuberculous pleurisy prospectively and followed up at month 0, 6, and 9, at which time peripheral venous blood was drawn for interferon gamma release assay (IGRA) by means of QuantiFERON-TB Gold In-Tube (QFT-GIT). Demographic and clinical data were captured. To identify significant predictive factors influencing the IFN-γ response, multiple linear regression analyses were performed. Percentage of CD4+, CD8+, Vγ2Vδ2 T cells and Treg cells were measured by flow cytometry. The percentage of QFT-GIT-positive patients at baseline, month 6 and month 9 were 96.9% (30/32), 90.6% (29/32) and 84.4% (27/32), respectively. Quantitative IFN-γ response at baseline were significantly correlated with symptom duration (P = .003, R = 0.261) and age (P = .041, R = 0.132). Besides, the decreases of the IFN-γ response at month 6 and month 9 were positively correlated with the IFN-γ level at baseline. The dynamic tendency of the percentages of Treg cells was similar to the IFN-γ responses at each time-point. Quantitative IFN-γ response could be influenced by host immune status, instead of disease burden and anti-tuberculosis treatment. IGRA is probably not a useful biomarker of treatment efficacy in tuberculous pleurisy.


Assuntos
Testes de Liberação de Interferon-gama/métodos , Interferon gama/imunologia , Tuberculose Pleural/sangue , Adulto , Antituberculosos/administração & dosagem , Antituberculosos/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Feminino , Citometria de Fluxo/métodos , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Linfócitos T/imunologia , Tuberculose Pleural/diagnóstico , Tuberculose Pleural/tratamento farmacológico , Tuberculose Pleural/metabolismo
3.
J Med Virol ; 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900950

RESUMO

Citrullinated histone H3 (H3Cit) is the product of the conversion of peptidylarginine to citrulline in histone H3. We evaluated the H3Cit level in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) tissues and assessed its association with Beclin1 messenger RNA (mRNA) (a key autophagic regulator). The level of H3Cit was detected by a capture enzyme-linked immunosorbent assay, while Beclin1 mRNA was determined by real-time polymerase chain reaction in 80 HBV-related patients with HCC. We found that the mean level of H3Cit was 72.25 ng/mg in HCC and 44.02 ng/mg in nontumor tissues. The mean HCC/nontumor ratio of Beclin1 mRNA was higher (0.096) in tumor samples than in nontumor specimens (0.056). Specifically, Beclin1 mRNA was elevated in 51 HCC cases (63.75%) and decreased in 29 cases (36.25%). Moreover, the levels of H3Cit and Beclin1 mRNA were significantly associated with vascular invasion and serum AFP levels. A shorter survival (19 months) was associated with a high H3Cit level. We also found increased levels of Beclin1 mRNA in the H3Cit (high) group compared with the H3Cit (low) group. The results implied that elevated histone H3 citrullination is associated with increased Beclin1 expression during the development of HBV-related HCC.

4.
Clin Sci (Lond) ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31967309

RESUMO

G protein-coupled receptor kinase 2 (GRK2), a type of cytosolic enzyme, transiently translocates to the plasma membrane upon G protein-coupled receptors (GPCRs) activation, and it also binds to extracellular signal-regulated kinase (ERK) to inhibit the activation of ERK. GRK2 deficiency in endothelial cells (ECs) leads to increased pro-inflammatory signaling and promotes recruitment of leukocytes to activated ECs. However, the role of GRK2 in regulating angiogenesis remains unclear. Here, we show that GRK2 is a novel regulatory molecule on migration and tube formation of ECs, vessel sprouting ex vivo and angiogenesis in vivo. We identify that EP4/AC/cAMP/PKA-mediated GRK2 translocation to cells membrane decreases the binding of GRK2 and ERK1/2 to inhibit ERK1/2 activation, which promotes PGE2-induced angiogenesis. GRK2 siRNA inhibits the increase of PGE2-induced HUVECs migration and tube formation. In vivo, PGE2 increases ECs sprouting from normal murine aortic segments and angiogenesis in mice, but not from GRK2-deficient ones, on Matrigel. Further research found that Lys220 and Ser685 of GRK2 play an important role in angiogenesis by regulating GRK2 translocation. Paeoniflorin-6'-O-benzene sulfonate (CP-25), as a novel ester derivative of paeoniflorin, has therapeutic potential for the treatment of AA and CIA, but the underlying mechanism of CP-25 on angiogenesis has not been elucidated. In our study, CP-25 inhibits the migration and tube formation of HUVECs, and angiogenesis in mice by down-regulating GRK2 translocation activation without affecting GRK2 total expression. Taken together, the present results revealed that CP-25 down-regulates EP4/AC/cAMP/PKA-mediated GRK2 translocation, restoring the inhibition of GRK2 for ERK1/2, thereby inhibiting PGE2-stimulated angiogenesis.

5.
Plant Physiol ; 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937682

RESUMO

Nitrate is the preferred form of nitrogen for most plants, acting both as a nutrient and a signaling molecule. However, the components and regulatory factors governing nitrate uptake in bread wheat (Triticum aestivum), one of the world's most important crop species, have remained unclear, largely due to the complexity of its hexaploid genome. Here, based on recently released whole-genome information for bread wheat, the high-affinity nitrate transporter 2 (NRT2) and the nitrate-assimilation-related (NAR) gene family are characterized. We show that ABA-GE deconjugation is stimulated in bread wheat roots by nitrate resupply following nitrate withdrawal, leading to enhanced root-tissue ABA accumulation, and that this enhancement, in turn, affects the expression of root-type NRT2/NAR genes. TaANR1 is shown to regulate nitrate-mediated ABA accumulation by directly activating TaBG1, while TaWabi5 is involved in ABA-mediated NO3- induction of NRT2/NAR genes. Building on previous evidence establishing ABA involvement in the developmental response to high-nitrate stress, our study suggests that ABA also contributes to the optimisation of nitrate uptake by regulating the expression of NRT2/NAR genes under limited nitrate supply, offering a new target for improvement of nitrate absorption in crops.

6.
Int J Biol Sci ; 16(2): 309-319, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929758

RESUMO

Osteoporosis is a disease characterized by abnormally increased formation and function of osteoclasts. Anti-RANKL treatment using natural medicine is a potential therapy for osteoporosis. Here, we studied the effect of fangchinoline, which is extracted from the root of Stephania tetrandra S. Moore, on osteoclast formation and function. We found that fangchinoline inhibited osteoclastogenesis at doses of 0.5 and 1 µM. In addition, we also examined the mechanism of the inhibitory effect of fangchinoline on osteoclasts. We found that fangchinoline down regulated NFATc1 activity and expression. However, fangchinoline did not affect IκBα degradation and MAPK pathways. In addition, we also found that fangchinoline could protect against bone loss in OVX mice. Taken together, fangchinoline may be a potential compound for osteoporosis.

7.
J Orthop Res ; 2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31930553

RESUMO

Flexor tendon injuries and tendinopathy are very common but remain challenging in clinical treatment. Exosomes-based cell-free therapy appears to be a promising strategy for tendon healing, while limited studies have evaluated its impacts on tenocyte biology. The objective of this study was to characterize a novel purified exosome product (PEP) derived from plasma, as well as to explore its cellular effects on canine tenocyte biology. The transmission electron microscope revealed that exosomes of PEP present cup-shaped structures with the diameters ranged from 80 to 141 nm, and the NanoSight report presented that their size mainly concentrated around 100 nm. The enzyme-linked immunosorbent assay kits analysis showed that PEP was positive for CD63 and AChE expression, and the cellular uptake of exosomes internalized into tenocyte cytoplasm was observed. The cell growth assays displayed that tenocyte proliferation ability was enhanced by PEP solution in a dose-dependent manner. Tenogenic phenotype was preserved as is evident by that tendon-related genes expression (SCX, COL1A, COL3A1, TNMD, DCN, and MKX) were expressed insistently in a high level, while tenocytes were treated with 5% PEP solution. Furthermore, migration capability was maintained and total collagen deposition was increased. More interesting, dexamethasone-induced cellular apoptosis was attenuated during the incubation of tenocytes with a 5% PEP solution. These findings will provide the basic understandings about the PEP, and support the potential use of this biological strategy for tendon healing.

8.
Life Sci ; : 117336, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31972206

RESUMO

AIMS: Postmenopausal osteoporosis and other osteolytic bone diseases are often caused by the elevation in osteoclastogenesis and/or increased osteoclastic bone resorption, leading to excessive bone loss. Hederagenin (Hed) is a pentacyclic triterpenoid saponin extracted from various natural medicinal plants and exhibits numerous biological activities and may offer benefits against bone-related conditions. We evaluated the effects of Hed on osteoclast formation and bone resorption in vitro and the in vivo therapeutic benefits in the mouse model of ovariectomy (OVX)-induced bone loss. MAIN METHODS: In vitro, osteoclast formation were determined by TRAP staining assessed; bone resorption were examined using Hydroxyapatite resorption assay and Podosomal actin belt formation assay; Related molecular mechanisms were determined by western blot assay. Construction of ovx mice by bilateral oophorectomy to simulate bone loss in vivo. KEY FINDINGS: In vitro cellular assays showed that Hed inhibited RANKL-induced osteoclast formation and osteoclast bone (hydroxyapatite) resorption as well as marker gene expression from BMM culture. Mechanistically, Hed attenuated RANKL-induced intracellular reactive oxygen species (ROS) production, and MAPK signaling pathway (ERK and p38) activation which curbed the downstream induction of c-Fos and NFATc1. Consistent with the in vitro findings, Hed administration effectively protected OVX mice from bone loss by reducing osteoclast number and activity on bone surface. SIGNIFICANCE: Our data provided promising evidence for the potential use of Hederagenin in the treatment of osteoclast-mediated osteolytic bone diseases such as postmenopausal osteoporosis.

9.
Circulation ; 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31893939

RESUMO

Background: Blood pressure (BP) often rises with aging, but exact mechanisms are still not completely understood. With aging, the level of pro-inflammatory cytokines increases in T lymphocyte. Prostaglandin (PG) D2, a pro-resolution mediator, suppresses Th1 cytokines through D-prostanoid receptor 1 (DP1). In this study, we aimed to investigate the role of PGD2/DP1 axis in T cells on age-related hypertension. Methods: To clarify the physiological and pathophysiological roles of DP1 in T cells with aging, peripheral blood samples were collected from young and older male participants and CD4+ T cells were sorted for gene expression, PG production and western bot assays. Mice BP was quantified by invasive telemetric monitor. Results: PGD2/DP1 axis was down-regulated in CD4+ T cells from older humans and aged mice, DP1 deletion in CD4+ T cells (TDP1KO) augmented age-related hypertension in aged male mice by enhancing Th1 cytokine secretion, vascular remodeling and CD4+ T cells infiltration, superoxide production in vasculature and kidneys. Conversely, forced expression of exogenous DP1 in T cells retarded age-associated hypertension in mice by reducing Th1 cytokine secretion. TNFα neutralization or IFNγ deletion ameliorated the age-related hypertension in TDP1KO mice. Mechanistically, DP1 inhibited Th1 activity via the Gαs/PKA/p-Sp1/NEDD4L pathway-mediated T-bet ubiquitination. T-bet deletion or forced NEDD4L expression in CD4+ T cell attenuated age-related hypertension in TDP1KO mice. DP1 receptor activation by BW245C prevented age-associated BP elevation and reduced vascular/renal superoxide production in male mice. Conclusions: PGD2/DP1 axis suppresses age-related Th1 activation and subsequent hypertensive response in male mice through increase of NEDD4L-mediated T-bet degradation by ubiquitination. Therefore, the T cell DP1 receptor may be an attractive therapeutic target for age-related hypertension in males.

10.
Oral Dis ; 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31901146

RESUMO

OBJECTIVE: The temporomandibular joint (TMJ) displays a high remodelling capability in response to occlusion changes. The purpose of the current study was to investigate the responses of TMJ condyles of growing mice to the installation of a unilateral anterior crossbite (UAC) prosthesis and the replacement of the UAC prothesis with a bilateral anterior elevation (BAE) prosthesis. MATERIALS AND METHODS: C57BL/6J mice were randomly assigned to the blank control and experimental groups. Mice in the experimental groups, UAC was created, while in others, BAE was created after the creation of UAC or removal of UAC. Changes in TMJ condylar cartilage and subchondral bone were assessed. RESULTS: The degradation of condylar cartilage induced by UAC was reversed by BAE, as evaluated by cartilage histochemical changes, collagen II-positive area, collagen X-positive chondrocytes, and expression levels of Adamts-5, Mmp13, Tnf-α and Il-1ß. Subchondral bone was assessed based on the subchondral bone volume, the number of TRAP-positive cells and the Opg/Rankl ratio. CONCLUSION: The growing mouse TMJ condyle displays a high remodelling capability, which can be degenerative or rehabilitative in response to the creation of UAC and the replacement of UAC with BAE. Early correction of occlusion is beneficial for the recovery of degenerative condyles.

11.
Vet Microbiol ; 240: 108511, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31902508

RESUMO

Since late 2010, highly virulent PEDV G2-genotype strains have emerged globally extracting heavy losses on the pork industries of numerous countries. We investigated the characteristics of a field strain of PEDV (PEDV strain SH) isolated from a piglet with severe diarrhea on a farm in Shanghai China. Whole genome sequencing and analysis revealed that the SH strain belonged to subtype G2b and has a unique 12-aa deletion (aa 399-410) including the antigenic epitope NEP-1C9 (aa 398-406) of the N protein. PEDV SH strain is highly pathogenic to challenged newborn piglets, resulting in 100 % morbidity and mortality. Pathological examination revealed significant villus atrophy in the jejuna of infected piglets. Mice inoculated with inactivated PEDV SH produced antibodies against the N protein, but no antibodies against the deletions. These results illustrated that deletion of the NEP-1C9 epitope had no effect on the immunogenicity or pathogenicity of PEDV, providing evidence of the necessity to monitor the genetic diversity of the virus. Our study also contributes to development of candidate for vaccines and diagnostics that could differentiate pigs seropositive due to vaccination by conventional strains from wild virus infection.

12.
Elife ; 92020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31976859

RESUMO

The Bcl-2 family BH3 protein Bim promotes apoptosis at mitochondria by activating the pore-forming proteins Bax and Bak and by inhibiting the anti-apoptotic proteins Bcl-XL, Bcl-2 and Mcl-1. Bim binds to these proteins via its BH3 domain and to the mitochondrial membrane by a carboxyl-terminal sequence (CTS). In cells killed by Bim, the expression of a Bim mutant in which the CTS was deleted (BimL-dCTS) triggered apoptosis that correlated with inhibition of anti-apoptotic proteins being sufficient to permeabilize mitochondria isolated from the same cells. Detailed analysis of the molecular mechanism demonstrated that BimL-dCTS inhibited Bcl-XL but did not activate Bax. Examination of additional point mutants unexpectedly revealed that the CTS of Bim directly interacts with Bax, is required for physiological concentrations of Bim to activate Bax and that different residues in the CTS enable Bax activation and binding to membranes.

13.
Anal Chem ; 92(2): 1948-1955, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31876141

RESUMO

Detection and quantification of carbon nanomaterials are extremely challenging, especially under the background interference of carbon. Here, we propose a new label-free method to quantify, track, and in situ image graphene and graphene oxide (GO) in plants based on their inherent metallic impurities as fingerprints. We show the ubiquity and high stability of inherent metallic fingerprints of graphene and GO obtained from different exposure routes under the natural environments, which enables the materials to be easily quantified and in situ imaged by high-sensitivity (laser ablation) inductively coupled plasma mass spectrometry. The method was applied to investigate the uptake and spatial distribution of graphene and GO in soybean plants. The plants were cultivated in graphene or GO solutions for 7 days, and the indicative elements (Ni or Mn) in different parts of plants were monitored and imaged. We found that graphene and GO showed different distribution patterns in plants (the highest uptake percentages in root up to 14.4% for graphene and 47.8% for GO), and high concentration of material exposure might cause excessive accumulation of materials in roots which blocked their further transport to the other parts of plants. The present method is more straightforward, accessible, and economical than normally used isotopic or metal-labeling methods. It also avoids the uncertainties or alterations of properties caused by the labeling process and thus has great promise in analysis and risk assessment of carbon nanomaterials.

14.
Chem Commun (Camb) ; 56(7): 1074-1077, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31872824

RESUMO

Electrochemical N2 reduction is an environmentally friendly and sustainable approach for NH3 synthesis under mild conditions, while an efficient electrocatalyst is crucial for the N2 reduction reaction (NRR). Herein, we report Ti3+ self-doped TiO2-x nanowires on Ti mesh (Ti3+-TiO2-x/TM) as an efficient non-noble-metal NRR electrocatalyst with excellent selectivity. In 0.1 M Na2SO4, the Ti3+-TiO2-x/TM achieves a high faradaic efficiency of 14.62% with a NH3 yield of 3.51 × 10-11 mol s-1 cm-2 at -0.55 V vs. the reversible hydrogen electrode. Density functional theory calculations further reveal that introducing Ti3+ decreases the reaction energy barrier and increases the number of active sites on the TiO2 surface for the NRR.

15.
Cell Host Microbe ; 27(1): 68-78.e5, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31866425

RESUMO

The composition of the human microbiome profoundly impacts human well-being. However, the mechanisms underlying microbiome maturation are poorly understood. The nasal microbiome is of particular importance as a source of many respiratory infections. Here, we performed a large sequencing and culture-based analysis of the human nasal microbiota from different age groups. We observed a significant decline of pathogenic bacteria before adulthood, with an increase of the commensal Staphylococcus epidermidis. In seniors, this effect was partially reversed. In vitro, many S. epidermidis isolates stimulated nasal epithelia to produce antimicrobial peptides, killing pathogenic competitors, while S. epidermidis itself proved highly resistant owing to its exceptional capacity to form biofilms. Furthermore, S. epidermidis isolates with high antimicrobial peptide-inducing and biofilm-forming capacities outcompeted pathogenic bacteria during nasal colonization in vivo. Our study identifies a pivotal role of S. epidermidis in healthy maturation of the nasal microbiome, which is achieved at least in part by symbiotic cooperation with innate host defense.

16.
Chem Commun (Camb) ; 56(5): 731-734, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31840689

RESUMO

Fe-enabled high-performance ambient electrochemical N2 reduction still remains a big challenge. Here, we report the unusual role of phosphorous in modulating the electrochemical N2 reduction activity of an Fe catalyst. An FeP2 nanoparticle-reduced graphene oxide hybrid (FeP2-rGO) attains a large NH3 yield of 35.26 µg h-1 mgcat.-1 (7.06 µg h-1 cm-2) and a high faradaic efficiency of 21.99% at -0.40 V vs. reversible hydrogen electrode in 0.5 M LiClO4, outperforming the FeP-rGO hybrid (17.13 µg h-1 mgcat.-1; 8.57%). Theoretical calculations reveal that FeP2 possesses decreased catalytic activity for the hydrogen evolution reaction, higher N2 adsorption energy, and a larger number of active sites than FeP.

17.
Clin Exp Pharmacol Physiol ; 47(1): 158-167, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31574178

RESUMO

MicroRNA-520e (miR-520e) is increasingly being recognized as a cancer-related miRNA in multiple cancer types; however, little is known about its role in colorectal cancer. In this study, we determined the specific role of miR-520e in colorectal cancer. Expression of miR-520e was lower in colorectal cancer tissues compared to normal tissues. Overexpression of miR-520e significantly decreased the proliferation, colony formation and invasion of colorectal cancer cells, while inhibition of miR-520e exhibited the opposite effect. Moreover, miR-520e was found to target the 3'-untranslated region of astrocyte elevated gene-1 (AEG-1) and inhibit AEG-1 expression in colorectal cancer cells. An inverse correlation between miR-520e and AEG-1 expression was confirmed in colorectal cancer tissues. Notably, miR-520e suppressed the phosphorylation of glycogen synthase kinase-3ß and decreased the expression of ß-catenin, leading to inactivation of Wnt/ß-catenin signalling in colorectal cells. A rescue assay confirmed that miR-520e regulates cell proliferation, invasion and Wnt/ß-catenin signalling through targeting AEG-1. Taken together, these results indicate that miR-520e plays a critical role in regulating colorectal cancer cell proliferation and invasion by inhibiting Wnt/ß-catenin signalling via AEG-1. Our study highlights the importance of the miR-520e/AEG-1/Wnt/ß-catenin signalling axis in colorectal cancer, thus targeting miR-520e may represent an effective therapeutic strategy.

18.
Arch Oral Biol ; 109: 104588, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31669922

RESUMO

OBJECTIVE: Dental occlusion are frequently changed in clinic. Molecular responses in jaw muscles to aberrant dental occlusion are changes are attractive, yet remain are obscure. DESIGN: Unilateral anterior crossbite (UAC) prostheses were applied to Sprague-Dawley rats and then ceased after two weeks to detect the reactions of the masseter, a representative jaw elevator, and the lateral pterygoid muscle (LPM), a representative jaw depressor. RESULTS: Two weeks of UAC elicited mild injury of the two muscles. Myogenesis and protective reactions were detected as increases in αB-crystallin expression in the masseter after 3 days and in the LPM after 2 weeks, and increases in desmin expression in both muscles after 2 weeks. A switch in fibre types from IIb to IIx occurred in the LPM but not in the masseter. Inflammatory responses, shown by the infiltration of inflammatory cells and increases in TNF-α mRNA expression, and fibrosis responses, shown by increased mRNA expression of Type I and III collagens, appeared very mild in the two muscles. These responses were partially recovered by the cessation of UAC. During the whole process, no obvious changes were observed in mitochondrial function, as indicated by the levels of proliferator-activated receptor γ coactivator 1α, mitofusin-2 and voltage-dependent anion channel. CONCLUSIONS: UAC causes injury and very limited inflammatory and fibrosis adaption in the masseter and LPM. Both muscles respond with myogenesis and protective activity. The LPM responds also with muscle fibre isoform alternations. These alterations were partially recovered by the cessation of dental stimulation at an early stage.


Assuntos
Implantes Dentários/efeitos adversos , Má Oclusão , Músculo Masseter/fisiopatologia , Músculos Pterigoides/fisiopatologia , Animais , Fibrose , Inflamação , Arcada Osseodentária , Músculo Masseter/lesões , Fibras Musculares Esqueléticas , Músculos Pterigoides/lesões , Ratos , Ratos Sprague-Dawley
19.
J Nat Prod ; 83(1): 99-104, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31867967

RESUMO

Three new meroterpenoids, asperaustins A-C (1-3), and seven known analogues (4-10) were isolated from a marine-derived Aspergillus sp. fungus. The structures and absolute configurations of these new compounds were unequivocally determined by extensive spectroscopic analyses and single-crystal X-ray diffraction analyses. Asperaustin A (1) possesses an unusual spiro[4.5]deca-3,6-dien-2-one moiety with a unique 5/6/6/6/5 pentacyclic skeleton. The absolute configurations of austinoneol A (7) and precalidodehydroaustin (9) were determined by single-crystal X-ray diffraction analyses using Cu Kα radiation for the first time.

20.
Food Chem ; 311: 126018, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31862566

RESUMO

This study investigated the gelling and structural properties of composite gels prepared with myofibrillar protein (MP) and different concentrations of thermo-reversible curdlan gels (TRC) and thermo-irreversible curdlan gels (TIRC). The gel strength, water holding capacity, and whiteness of MP gels were significantly increased with increasing TRC and TIRC content (P < 0.05). Dynamic rheological testing upon temperature sweeping indicated that the G' and G″ values of MP were significantly enhanced with added TRC or TIRC, which were positively related to the lower particle size of composite MP sols. Moreover, the presence of TRC or TIRC changed the secondary structure of MP gels, as well as altered the tertiary structure of MP sols. The micrographs of MP gels indicated that TRC prompted the formation of more dense and stable protein matrix. Our results revealed that TRC or TIRC had distinctive effects on the gelling properties and secondary structure of MP.

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