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1.
Small ; : e2400915, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38597683

ABSTRACT

Hole transporting layers (HTLs), strategically positioned between electrode and light absorber, play a pivotal role in shaping charge extraction and transport in organic solar cells (OSCs). However, the commonly used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL, with its hygroscopic and acidic nature, undermines the operational durability of OSC devices. Herein, an environmentally friendly approach is developed utilizing nickel acetate tetrahydrate (NiAc·4H2O) and [2-(9H-carbazol-9-yl)ethyl] phosphonic acid (2PACz) as the NiAc·4H2O/2PACz HTL, aiming at overcoming the limitations posed by the conventional PEDOT:PSS one. Encouragingly, a remarkable power conversion efficiency (PCE) of 19.12% is obtained for the OSCs employing NiAc·4H2O/2PACz as the HTL, surpassing that of devices with the PEDOT:PSS HTL (17.59%), which is ranked among the highest ones of OSCs. This improvement is attributed to the appropriate work function, enhanced hole mobility, facilitated exciton dissociation efficiency, and lower recombination loss of NiAc·4H2O/2PACz-based devices. Furthermore, the NiAc·4H2O/2PACz-based OSCs exhibit superior operational stability compared to their PEDOT:PSS-based counterparts. Of significant note, the NiAc·4H2O/2PACz HTL demonstrates a broad generality, boosting the PCE of the PM6:PY-IT and PM6:Y6-based OSCs from 16.47% and 16.79% (with PEDOT:PSS-based analogs as HTLs) to 17.36% and 17.57%, respectively. These findings underscore the substantial potential of the NiAc·4H2O/2PACz HTL in advancing OSCs, offering improved performance and stability, thereby opening avenue for highly efficient and reliable solar energy harvesting technologies.

2.
Article in English | MEDLINE | ID: mdl-38359602

ABSTRACT

Tegillarca granosa can survive intermittent hypoxia for a long-term. We used the clam T. granosa as model to investigate the respiratory, antioxidant and metabolic responses to consecutive hypoxia-reoxygenation (H/R) stress at both physiological and transcriptional levels. The results showed that the clams were able to rapidly regulate oxygen consumption and ammonia excretion during H/R stress, and alleviate oxidative stress during the second-time challenge. The clams also efficiently balanced energy metabolism through the rapid conversion and decomposition of glycogen. According to the transcriptome profile, KEGG pathways of starch and sucrose metabolism, ECM-receptor interaction, and protein processing in endoplasmic reticulum were significantly enriched in H group (the second-time 24 h hypoxia exposure), while pathways associated with lipid metabolism were significantly enriched in h group (the first-time 24 h hypoxia exposure). DEGs including hspa5, birc2/3, and map3k5 might play important roles in alleviating endoplasmic reticulum stress, cpla2 and pla2g16 might mitigate oxidative stress by adjusting the composition of cellular membrane. In conclusions, our findings suggest that rapid adjustment of oxygen consumption, ammonia metabolism, glycogen metabolism, and the ability to adjust the composition of the membrane lipid may be critical for T. granosa in maintaining energy homeostasis and reducing oxidative damage during intermittent H/R exposure. This study preliminarily clarified the response of T. granosa to intermittent hypoxia stress on the physiological and molecular levels, offering insights into the hypoxia-tolerant mechanisms in this species and providing a reference for the following study on the other hypoxic-tolerant species.


Subject(s)
Antioxidants , Transcriptome , Animals , Antioxidants/metabolism , Hypoxia/metabolism , Adaptation, Physiological , Oxidative Stress , Energy Metabolism , Bivalvia/metabolism , Bivalvia/genetics , Oxygen Consumption
3.
CNS Neurosci Ther ; 30(1): e14397, 2024 01.
Article in English | MEDLINE | ID: mdl-37553782

ABSTRACT

BACKGROUND: Necroptosis induced by receptor-interacting protein kinase 3 (RIPK3) is engaged in intracerebral hemorrhage (ICH) pathology. In this study, we explored the impact of RIPK3 activation on neuronal necroptosis and the mechanism of the death domain-associated protein (DAXX)-mediated nuclear necroptosis pathway after ICH. METHODS: Potential molecules linked to the progression of ICH were discovered using RNA sequencing. The level of DAXX was assessed by quantitative real-time PCR, ELISA, and western blotting. DAXX localization was determined by immunofluorescence and immunoprecipitation assays. The RIPK3 inhibitor GSK872 and DAXX knockdown with shRNA-DAXX were used to examine the nuclear necroptosis pathway associated with ICH. Neurobehavioral deficit assessments were performed. RESULTS: DAXX was increased in patients and mice after ICH. In an ICH mouse model, shRNA-DAXX reduced brain water content and alleviated neurologic impairments. GSK872 administration reduced the expression of DAXX. shRNA-DAXX inhibited the expression of p-MLKL. Immunofluorescence and immunoprecipitation assays showed that RIPK3 and AIF translocated into the nucleus and then bound with nuclear DAXX. CONCLUSIONS: RIPK3 revitalization promoted neuronal necroptosis in ICH mice, partially through the DAXX signaling pathway. RIPK3 and AIF interacted with nuclear DAXX to aggravate ICH injury.


Subject(s)
Necroptosis , Protein Kinases , Animals , Humans , Mice , Brain/metabolism , Cerebral Hemorrhage , Co-Repressor Proteins/metabolism , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Protein Kinases/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , RNA, Small Interfering/genetics
4.
Sci Prog ; 106(2): 368504231170302, 2023.
Article in English | MEDLINE | ID: mdl-37198979

ABSTRACT

Bacterial meningitis after percutaneous radiofrequency trigeminal ganglion is a rare but severe complication. In this article, we report a case of meningitis due to Streptococcus parasanguinis and review the related literature. A 62-year-old male patient with uremia and severe trigeminal neuralgia presented to another hospital and was offered to undergo radiofrequency treatment for a trigeminal ganglion lesion (2022.08.05). The next day (2022.08.06), he presented with a headache and right shoulder and back pain. The pain continued to worsen, so he came to our hospital (The First Affiliated Hospital of Wannan Medical College) and received a diagnosis of bacterial meningitis, which was confirmed by a lumbar puncture. The patient was treated with appropriate antibiotics, and subsequently recovered before being discharged. Although this complication is relatively rare, its progression is rapid. Meningitis must be suspected when a patient presents with headache, fever, and other symptoms associated with meningitis within days after undergoing radiofrequency treatment for a trigeminal ganglion lesion, especially if the patient has an underlying disease that causes a decline in immunity. We discuss this case in terms of clinical presentation, time of onset, treatment, prognosis, past history, and sex. Although early detection of this complication is beneficial, it is better to effectively prevent its occurrence.


Subject(s)
Meningitis, Bacterial , Trigeminal Neuralgia , Male , Humans , Middle Aged , Trigeminal Neuralgia/therapy , Trigeminal Neuralgia/complications , Trigeminal Ganglion , Streptococcus , Meningitis, Bacterial/therapy , Meningitis, Bacterial/etiology
5.
Small Methods ; 7(5): e2201614, 2023 05.
Article in English | MEDLINE | ID: mdl-36960933

ABSTRACT

In the past decades, immunotherapy has achieved a series of clinical successes in the field of cancer. However, existing therapeutic options usually show a low immune response to solid tumors caused by immunosuppressive "cold" tumor microenvironment (TME). Several types of proinflammatory regulated cell death (RCD), mainly including ferroptosis and pyroptosis, have been studied recently, which can provide proinflammatory signals and immunogenicity necessary for remodeling TME and activating an antitumor immune response. A variety of chemotherapeutic drugs are proven to be effective in the proinflammatory RCD induction of tumor cells, but several adverse effects and intrinsic drug resistance usually occur in the therapeutic process, greatly hindering their further clinical application. The emerging organic photosensitizer (PS)-based materials open new possibilities to effectively activate proinflammatory RCD through precise spatiotemporal regulation of intracellular reactive oxygen species-associated signaling pathways, which can overcome many challenges encountered in current proinflammatory RCD-mediated immunotherapy. In this review, the recent design strategies of PS probes are detailly summarized and their potential advantages for tumor-specific proinflammatory RCD induction are discussed. Moreover, the representative examples in cancer immunotherapy are highlighted and future perspectives in this emerging field are proposed.


Subject(s)
Ferroptosis , Regulated Cell Death , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Immunotherapy , Cell Death
6.
Mol Immunol ; 146: 1-8, 2022 06.
Article in English | MEDLINE | ID: mdl-35395473

ABSTRACT

Gastric cancer (GC) remains one of the prevalent causes of cancer-related deaths globally. Long non-coding RNAs (lncRNAs) have been associated with different cancers. The polarization of macrophages towards the M2 (alternatively activated) phenotype promotes immunologic tolerance and can induce gastric tumorigenesis. Thus far, lncRNAs have been shown to modulate the differentiation of immune cells. Here, we investigated the biological effects of LINC00665 on the progression of GC and explored the mechanisms underlying its ability to mediate the polarization of macrophages towards the M2 phenotype. We report that the levels of LINC00665 were increased in GC tissues. Furthermore, this increase in LINC00665 expression could be associated with decreased overall survival (OS), progression-free survival (PFS), and post-progression survival (PPS). Using cell-based macrophage polarization models, we demonstrated that LINC00665 upregulation in GC cells facilitated the polarization of macrophages towards the M2 but not M1 (classically activated) phenotype. Furthermore, the loss of LINC00665 prevented the M2 polarization of macrophages. Mechanically, we identified that Wnt1 was the downstream target of LINC00665. Additionally, LINC00665 could directly interact with the transcription factor BTB domain and CNC homology 1 (BACH1). The interaction between LINC00665 and BACH1 resulted in the activation and binding of BACH1 to the Wnt1 promoters. Furthermore, BACH1 silencing could inhibit GC progression, which highlighted a crucial role for BACH1 in LINC00665-mediated Wnt1 activation. In addition, genetic Wnt1 overexpression effectively abolished the repression of Wnt signaling after BACH1 depletion and mediated GC development by supporting M2 macrophage polarization. In conclusion, we report that LINC00665 modulates M2 macrophage polarization and suggest that it may facilitate macrophage-dependent GC progression.


Subject(s)
Basic-Leucine Zipper Transcription Factors , RNA, Long Noncoding , Stomach Neoplasms , Tumor-Associated Macrophages , Basic-Leucine Zipper Transcription Factors/genetics , Humans , Macrophage Activation , RNA, Long Noncoding/genetics , Stomach Neoplasms/metabolism , Tumor-Associated Macrophages/cytology , Wnt1 Protein
7.
Anal Chem ; 94(6): 2901-2911, 2022 02 15.
Article in English | MEDLINE | ID: mdl-34989555

ABSTRACT

Elucidating the intrinsic relationship between mitochondrial pH (pHm) fluctuation and lipid droplets (LDs) formation is vital in cell physiology. The development of small-molecular fluorescent probes for discrimination and simultaneous visualization of pHm fluctuation toward LDs has not yet been reported. In this work, utilizing pH-driven polarity-reversible hemicyanine and rhodamine derivatives, a multifunctional fluorescent probe is developed for selectively identifying mitochondria and LDs under specific pH values via dual-emission channels. This rapid-response probe, Hcy-Rh, has two distinct chemical structures under acidic and alkaline circumstances. In acidic conditions, Hcy-Rh exhibits good hydrophilicity that can target mitochondria and display an intense red fluorescence. Conversely, the probe becomes lipophilic under weakly alkaline conditions and targets LDs, showing a strong blue emission. In this manner, Hcy-Rh can selectively label mitochondria and LDs, exhibiting red and blue fluorescence, respectively. Moreover, this ratiometric probe is applied to map pHm changes in living cells under the stimulus with FCCP, NAC, and H2O2. The interplay of LD-mitochondria under oleic acid treatment and starvation-induced autophagy has been studied using this probe at different pH values. In a word, Hcy-Rh is a potential candidate for further exploring mitochondria-LD interaction mechanisms under pHm fluctuation. Moreover, the polarity-dependent strategy is valuable for designing other functional biological probes in imaging multiple organelles.


Subject(s)
Fluorescent Dyes , Lipid Droplets , Fluorescent Dyes/chemistry , HeLa Cells , Humans , Hydrogen Peroxide/analysis , Hydrogen-Ion Concentration , Lipid Droplets/metabolism , Mitochondria/chemistry
8.
J Stroke Cerebrovasc Dis ; 31(1): 106213, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34837868

ABSTRACT

BACKGROUND: Recent studies have reported that receptor-interacting protein kinase 3 (RIPK3)-dependent necroptosis is related to the pathological process of intracerebral hemorrhage (ICH). Some studies support the view that inhibiting necroptosis is a key mechanism preventing inflammation. Inflammation is a crucial factor contributing to neurological injuries and unfavorable outcomes after ICH. The aim of this study was to clarify the association between necroptosis and monocyte chemoattractant protein-1 (MCP-1)-mediated inflammation and identify a new target for the treatment of ICH. METHODS: An ICH model was established in C57BL/6 mice by injecting collagenase IV into the right basal ganglia. The RIPK3 inhibitor GSK872 was administered through intraventricular injection. Then, we assessed brain edema and neurobehavioral function. Western blotting was employed to detect changes in RIPK3, phospho-mixed lineage kinase domain-like protein (p-MLKL), MCP-1, phospho-c-Jun N-terminal kinase (p-JNK) and interleukin 6 (IL-6) levels in the brain tissue. The localization of RIPK3 and MCP-1 was observed using immunofluorescence staining. Co-immunoprecipitation was performed to determine the interaction between RIPK3 and MCP-1. RESULTS: Compared with the sham group, the levels of RIPK3, p-MLKL, MCP-1, p-JNK and IL-6 were increased post-ICH. GSK872 pretreatment significantly reduced RIPK3, p-MLKL, MCP-1, p-JNK and IL-6 expression, accompanied by mitigated cerebral edema and neurobehavioral defects. RIPK3 and MCP-1 colocalized in the perinuclear region after ICH. We detected the formation of the RIPK3-MCP-1 complex in ICH brain tissue. CONCLUSIONS: There exerted an association between RIPK3 and MCP-1. The inhibition of RIPK3 alleviated MCP-1-mediated inflammation following ICH.


Subject(s)
Cerebral Hemorrhage/complications , Chemokine CCL2 , Inflammation , Necroptosis/drug effects , Receptor-Interacting Protein Serine-Threonine Kinases/antagonists & inhibitors , Animals , Brain Edema/etiology , Interleukin-6 , Mice , Mice, Inbred C57BL , Protein Kinases/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism
9.
J Mater Chem B ; 9(19): 4002-4005, 2021 05 19.
Article in English | MEDLINE | ID: mdl-33904569

ABSTRACT

Hemoglobin-functionalized HKUST-1 as an artificial oxygen carrier has been developed. The new oxygen carrier has excellent oxygen loading capacity and good chemical durability. The sustained electrochemical responses toward H2O2 and O2 make this new material an ideal candidate as a promising artificial blood substitute.


Subject(s)
Blood Substitutes/chemistry , Hemoglobins/chemistry , Metal-Organic Frameworks/chemistry , Oxygen/chemistry , Electrochemical Techniques , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/metabolism , Oxygen/metabolism
10.
Article in English | MEDLINE | ID: mdl-33774729

ABSTRACT

This study aims to explore the mechanism on how aggressive interaction alters reproductive physiology by testing whether aggressive interaction can activate the reproductive neuroendocrine function via the hypothalamus-pituitary-gonadal (HPG) axis in black rockfish (Sebastes schlegelii). The expressions of the androgen receptor gene (ar) and gonadotropin-releasing hormone genes (gnrhs), the concentration of plasma androgens, and GSI (the ratio of testes mass to body mass) were compared between the interaction group (dominant males or subordinate males) and the isolation group in male black rockfish after 3 weeks. A full-length cDNA encoding an androgen receptor (AR) of 766 amino acids was isolated. Transcripts encoding this AR were detected at a high relative abundance in the liver, kidney, testis, ovary, muscle, and intestine tissue. Further evaluation of brain genes transcripts abundance revealed that the mRNA levels of gnrh I and ar genes were significantly different between the interaction group and the isolation group in the hypothalamus. However, no significant difference was detected in testosterone, 11-keto-testosterone, and GSI between these two groups. This study indicates that a long-term aggressive interaction affect the expression of hypothalamic gnrh I and ar but may not change the physiological function of the HPG axis in an all-male condition.


Subject(s)
Aggression , Behavior, Animal , Fish Proteins/genetics , Hypothalamus/metabolism , Perciformes/genetics , Receptors, Androgen/genetics , Animals , Female , Fish Proteins/metabolism , Gene Expression Regulation , Gonadotropin-Releasing Hormone/genetics , Gonadotropin-Releasing Hormone/metabolism , Male , Perciformes/blood , Receptors, Androgen/metabolism , Reproduction , Sex Factors , Testosterone/analogs & derivatives , Testosterone/blood , Time Factors
11.
J Cell Biochem ; 121(3): 2268-2276, 2020 03.
Article in English | MEDLINE | ID: mdl-31736127

ABSTRACT

Long noncoding RNAs (lncRNAs) are recently recognized as noteworthy regulators of different tumors, counting gastric cancer (GC). Lately, long intergenic noncoding RNA (LINC) 00665 has been verified to display significant parts in several cancers. Be that as it may, its role and mechanism in GC movement still stay uninvestigated. As of now, we observed LINC00665 was obviously GC cells (MKN28, BGC-823, SGC7-901, AGS, HGC-27) in comparison to GES-1 cells, which was identified as human normal gastric epithelial cells. Then, LINC00665 was obviously downregulated in GC cells including AGS and BGC-823 cells. Loss of LINC00665 greatly repressed AGS and BGC-823 cell survival and cell expansion. Moreover, GC cell apoptosis was significantly induced by the loss of LINC00665. For another, we found that the GC cell cycle was also captured in G1 and G2 phases. The experiments on cell migration and invasion indicated that knockdown of LINC00665 restrained GC cell migration and invasion. Modifications in Wnt signaling are closely associated with the development of cancers. Here, we found that Wnt signaling was significantly inactivated by the silence of LINC00665 in GC cells. ß-catenin and cyclinD1 were restrained whereas GSK-3ß was induced by the inhibition of LINC00665 in GC cells. Furthermore, we confirmed the impact of LINC00665 in vivo using xenograft models. Taken these together, we indicated that LINC00665 could function as a novel biomarker in GC progression.


Subject(s)
Biomarkers, Tumor/metabolism , Gene Expression Regulation, Neoplastic , Glycogen Synthase Kinase 3 beta/metabolism , RNA, Long Noncoding/genetics , Stomach Neoplasms/pathology , Wnt Signaling Pathway , beta Catenin/metabolism , Animals , Apoptosis , Biomarkers, Tumor/genetics , Cell Cycle , Cell Movement , Cell Proliferation , Epithelial-Mesenchymal Transition , Glycogen Synthase Kinase 3 beta/genetics , Humans , Male , Mice , Mice, Nude , Neoplasm Invasiveness , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor Assays , beta Catenin/genetics
12.
Sci Rep ; 9(1): 20004, 2019 12 27.
Article in English | MEDLINE | ID: mdl-31882847

ABSTRACT

Quantitative real-time PCR (qPCR) is commonly used for deciphering gene functions. For effective qPCR analyses, suitable reference genes are needed for normalization. The objective of this study is to identify the appropriate reference gene(s) for qPCR analyses of the leaves and roots of ramie (Boehmeria nivea L.), an important natural fiber crop. To accomplish this goal, we investigated the expression patterns of eight common plant qPCR reference genes in ramie leaves and roots under five abiotic stresses, five hormonal treatments, and one biotic stress. The relative expression stabilities of the eight genes were evaluated using four common but different approaches: geNorm, NormFinder, BestKeeper, and RefFinder. Across the 11 tested conditions, ACT1 was the most stably expressed among the eight genes while GAPDH displayed the biggest variation. Overall, while variations in the suggested reference genes were found for different tissue x treatment combinations, our analyses revealed that together, genes ACT1, CYP2, and UBQ can provide robust references for gene expression studies of ramie leaves under most conditions, while genes EF-1α, TUB, and ACT1 can be used for similar studies of ramie roots. Our results should help future functional studies of the genes in ramie genome across tissues and environmental conditions.


Subject(s)
Boehmeria/genetics , Gene Expression Regulation, Plant , Plant Leaves/metabolism , Plant Roots/metabolism , Real-Time Polymerase Chain Reaction/methods , Gene Expression Profiling , Reference Standards , Stress, Physiological
13.
Org Lett ; 21(20): 8225-8228, 2019 10 18.
Article in English | MEDLINE | ID: mdl-31556619

ABSTRACT

Macrocyclic peptides are promising scaffolds of bioactive compounds and clinical therapeutics. Herein, we develop a strategy for the macrocyclization of biaryl-bridged peptides through late-stage Pd-catalyzed C(sp2)-H arylation. This method displays broad substrate scope and high efficiency in the synthesis of peptide conjugates with various bioactive molecules. Furthermore, we applied this method to prepare peptide macrocycles with aryl-aryl cross-links. Our results show the effectiveness of backbone amide groups as directing groups in Pd-catalyzed C-H functionalization of peptides.

14.
Org Lett ; 21(15): 5858-5861, 2019 08 02.
Article in English | MEDLINE | ID: mdl-31310555

ABSTRACT

Bioactive peptides are emerging as promising candidates of clinic therapeutics. Here, we report a method for late-stage functionalization of sulfonamide-containing peptides through Pd-catalyzed C(sp3)-H arylation. In this protocol, the backbones of N-sulfonated peptides act as directing groups, which allows site-specific arylation of benzylsulfonamide moiety. This chemistry exhibits broad substrate scope and can be utilized to synthesize peptide-peptide and peptide-amino acid conjugates. Our results highlight the potency of the backbone of peptidomimetics in promoting Pd-catalyzed functionalization.


Subject(s)
Palladium/chemistry , Peptides/chemistry , Sulfonamides/chemistry , Amino Acids/chemistry , Catalysis
15.
Int J Mol Sci ; 20(5)2019 Mar 07.
Article in English | MEDLINE | ID: mdl-30866540

ABSTRACT

Melatonin (MT; N-acetyl-5-methoxytryptamine) is a pleiotropic signaling molecule that has been demonstrated to play an important role in plant growth, development, and regulation of environmental stress responses. Studies have been conducted on the role of the exogenous application of MT in a few species, but the potential mechanisms of MT-mediated stress tolerance under salt stress are still largely unknown. In this study, naked oat seedlings under salt stress (150 mM NaCl) were pretreated with two different concentrations of MT (50 and 100 µM), and the effects of MT on the growth and antioxidant capacity of naked oat seedlings were analyzed to explore the regulatory effect of MT on salt tolerance. The results showed that pretreating with different concentrations of MT promoted the growth of seedlings in response to 150 mM NaCl. Different concentrations of MT reduced hydrogen peroxide, superoxide anion, and malondialdehyde contents. The exogenous application of MT also increased superoxide dismutase, peroxidase, catalase, and ascorbate peroxide activities. Chlorophyll content, leaf area, leaf volume, and proline increased in the leaves of naked oat seedlings under 150 mM NaCl stress. MT upregulated the expression levels of the lipid peroxidase genes lipoxygenase and peroxygenase, a chlorophyll biosynthase gene (ChlG), the mitogen-activated protein kinase genes Asmap1 and Aspk11, and the transcription factor genes (except DREB2), NAC, WRKY1, WRKY3, and MYB in salt-exposed MT-pretreated seedlings when compared with seedlings exposed to salt stress alone. These results demonstrate an important role of MT in the relief of salt stress and, therefore, provide a reference for managing salinity in naked oat.


Subject(s)
Antioxidants/pharmacology , Avena/growth & development , Melatonin/pharmacology , Plant Proteins/genetics , Salt Tolerance , Avena/drug effects , Avena/metabolism , Dose-Response Relationship, Drug , Gene Expression Regulation, Plant/drug effects , Hydrogen Peroxide/metabolism , Malondialdehyde/metabolism , Plant Leaves/drug effects , Plant Leaves/growth & development , Plant Leaves/metabolism , Plant Proteins/metabolism , Seedlings/drug effects , Seedlings/growth & development , Seedlings/metabolism , Superoxides/metabolism
16.
Nat Commun ; 9(1): 3383, 2018 08 23.
Article in English | MEDLINE | ID: mdl-30139997

ABSTRACT

Peptides and peptidomimetics are emerging as an important class of clinic therapeutics. Here we report a peptide-guided method for the functionalization and macrocyclization of bioactive peptidosulfonamides by Pd(II)-catalyzed late-stage C-H activation. In this protocol, peptides act as internal directing groups and enable site-selective olefination of benzylsulfonamides and cyclization of benzosulfonamides to yield benzosultam-peptidomimetics. Our results provide an unusual example of benzosulfonamide cyclization with olefins through a sequential C-H activation, which involves the generation of a reactive palladium-peptide complex. Furthermore, this protocol allows facile self-guided macrocyclization of sulfonamide-containing peptides by intramolecular olefination with acrylates and unactivated alkenes, affording bioactive peptidosulfonamide macrocycles of various sizes. Together, our results highlight the utility of peptides as internal directing groups in facilitating transition metal-catalyzed functionalization of peptidomimetics.


Subject(s)
Palladium/chemistry , Peptides/chemistry , Sulfonamides/chemistry , Alkenes/chemistry , Catalysis , Cell Line, Tumor , Cyclization , Humans
17.
Molecules ; 23(7)2018 06 29.
Article in English | MEDLINE | ID: mdl-29966243

ABSTRACT

Melatonin (N-acetyl-5-methoxytryptamine, MT) is a molecule with pleiotropic effects including antioxidant activity, regulated plant growth, development, and reduced environmental stress in plants. However, only a few studies have analyzed the effect of exogenous MT on drought stress in naked oat seedlings. Therefore, in this study, we studied the effects of exogenous MT on the antioxidant capacity of naked oat under drought stress to understand the possible antioxidant mechanism. The results showed that a pretreatment of 100 µM MT reduced the hydrogen peroxide (H2O2) and superoxide anion (O2−•) contents. MT also enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activities in the leaves of naked oat seedlings under 20% PEG-6000 drought stress. MT upregulated the expression levels of the mitogen-activated protein kinases (MAPKs) Asmap1 and Aspk11, and the transcription factor (TF) genes (except for NAC), WRKY1, DREB2, and MYB increased in drought with MT pretreatment seedlings when compared with seedlings exposed to drought stress alone. These data indicated that the MT-mediated induction of the antioxidant response may require the activation of reactive oxygen species (ROS) and MAPK, followed by triggering a downstream MAPK cascade such as Asmap1 and Aspk11, to regulate the expression of antioxidant-related genes. This study demonstrated that MT could induce the expression of MAPKs and TFs and regulate the expression of downstream stress-responsive genes, thereby increasing the plant's tolerance. This may provide a new idea for MT modulation in the regulation of plant antioxidant defenses. These results provide a theoretical basis for MT to alleviate drought stress in naked oat.


Subject(s)
Antioxidants/pharmacology , Avena/drug effects , Avena/metabolism , Droughts , Melatonin/pharmacology , Seedlings/drug effects , Stress, Physiological/drug effects , Ascorbate Peroxidases/metabolism , Avena/growth & development , Catalase/metabolism , Gene Expression Regulation, Plant , MAP Kinase Signaling System , Malondialdehyde/metabolism , Oxidative Stress/drug effects , Phenotype , Plant Leaves/drug effects , Plant Leaves/metabolism , Reactive Oxygen Species/metabolism , Seedlings/metabolism
18.
J Agric Food Chem ; 60(6): 1555-66, 2012 Feb 15.
Article in English | MEDLINE | ID: mdl-22243478

ABSTRACT

According to the Friedel-Crafts and amination reaction, a series of macroporous adsorption resins (MARs) with novel structures were synthesized and identified by the Brunauer-Emmett-Teller (BET) method and Fourier transform infrared (FTIR) spectra, and corresponding adsorption behaviors for (-)-epigallocatechin gallate (EGCG) and caffeine (CAF) extracted from waste tea were systemically investigated. Based on evaluation of adsorption kinetics, the kinetic data were well fitted by pseudo-second-order kinetics. Langmuir, Freundlich, Temkin-Pyzhev, and Dubinin-Radushkevich isotherms were selected to illustrate the adsorption process of EGCG and CAF on the MARs. Thermodynamic parameters were adopted to explain in-depth information of inherent energetic changes associated with the adsorption process. The effect of temperature on EGCG and CAF adsorption by D101-3 was further expounded. Van der Waals force, hydrogen bonding, and electrostatic interaction were the main driving forces for the adsorption of EGCG and CAF on the MARs. This study might provide a scientific reference point to aid the industrial large-scale separation and enrichment of EGCG from the extracts of waste tea using modified MARs.


Subject(s)
Caffeine/isolation & purification , Catechin/analogs & derivatives , Tea/chemistry , Adsorption , Catechin/isolation & purification , Chemical Phenomena , Indicators and Reagents , Kinetics , Spectroscopy, Fourier Transform Infrared , Thermodynamics
19.
J Agric Food Chem ; 59(17): 9629-36, 2011 Sep 14.
Article in English | MEDLINE | ID: mdl-21800862

ABSTRACT

Preparative separation and purification of rebaudioside A from steviol glycosides using mixed-mode macroporous adsorption resins (MARs) were systematically investigated. Mixed-mode MARs were prepared by a physical blending method. By evaluation of the adsorption/desorption ratio and adsorption/desorption capacity of mixed-mode MARs with different proportions toward RA and ST, the mixed-mode MAR 18 was chosen as the optimum strategy. On the basis of the static tests, it was found that the experimental data fitted best to the pseudosecond-order kinetics and Temkin-Pyzhev isotherm. Furthermore, the dynamic adsorption/desorption experiments were performed on the mini column packed with mixed-mode MAR 18. After one run treatment, the purity of rebaudioside A in purified product increased from 40.77 to 60.53%, with a yield rate of 38.73% (W/W), and that in residual product decreased from 40.77 to 36.17%, with a recovery yield of 57.61% (W/W). The total recovery yield reached 96.34% (W/W). The results showed that this method could be utilized in large-scale production of rebaudioside A from steviol glycosides in industry.


Subject(s)
Diterpenes, Kaurane/chemistry , Diterpenes, Kaurane/isolation & purification , Glycosides/chemistry , Resins, Synthetic , Sweetening Agents , Adsorption , Chromatography, High Pressure Liquid , Thermodynamics
20.
Zhong Yao Cai ; 34(9): 1438-41, 2011 Sep.
Article in Chinese | MEDLINE | ID: mdl-22260014

ABSTRACT

OBJECTIVE: To investigate the optimum ethanol extraction process conditions for the available components in the tea - Catechines (CT) including Epigallo catechin gallate (EGCG) and Caffeine (CF). METHODS: The content of EGCG, CT and CF, extraction rate, DPPH * Free radical scavenging capacity were chosen as the assessment indexes. With the alcohol ratio (A), solid-liquid ratio (B) and reflux time (C) as investigation factors, the optimum ethanol extraction process of the available components from tea was determined by L9 (3(4)) orthogonal experimental design. RESULTS: It would obtain different extraction conditions to analyze the assessment indexes depending on the different extraction purposes. For the purpose of CT, the contents of EGCG and CT, extraction rate and DPPH * Free radical scavenging capacity were chosen as the assessment indexes, the optimum extraction conditions were selected as follows: the ratio of raw material to 75% alcohol was 1: 12, the reflux time was 30 minutes and extraction times were three; For the purpose of CF, the content of CF and extraction rate were chosen as the assessment indexes, the optimum extraction conditions were selected as follows: the ratio of raw material to 60% alcohol was 1: 12, the reflux time was 30 minutes and extraction times were three; For the purpose of integrated extraction, the contents of CT and CF, extraction rate and DPPH * Free radical scavenging capacity were chosen as the assessment indexes, the optimum extraction conditions were selected as follows: the ratio of raw material to 60% alcohol was 1: 8, the reflux time was 30 minutes and extraction times were three. CONCLUSION: The optimum extraction process in order to attain different purposes can give a reference to the research of a new medicine and industry production.


Subject(s)
Caffeine/isolation & purification , Catechin/isolation & purification , Tea/chemistry , Technology, Pharmaceutical/methods , Antioxidants/isolation & purification , Antioxidants/pharmacology , Caffeine/analysis , Caffeine/pharmacology , Catechin/analysis , Catechin/pharmacology , Ethanol , Hydroxyl Radical/metabolism , Solvents/chemistry , Temperature , Time Factors
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