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1.
Nat Mater ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594486

RESUMO

DNA origami is capable of spatially organizing molecules into sophisticated geometric patterns with nanometric precision. Here we describe a reconfigurable, two-dimensional DNA origami with geometrically patterned CD95 ligands that regulates immune cell signalling to alleviate rheumatoid arthritis. In response to pH changes, the device reversibly transforms from a closed to an open configuration, displaying a hexagonal pattern of CD95 ligands with ~10 nm intermolecular spacing, precisely mirroring the spatial arrangement of CD95 receptor clusters on the surface of immune cells. In a collagen-induced arthritis mouse model, DNA origami elicits robust and selective activation of CD95 death-inducing signalling in activated immune cells located in inflamed synovial tissues. Such localized immune tolerance ameliorates joint damage with no noticeable side effects. This device allows for the precise spatial control of cellular signalling, expanding our understanding of ligand-receptor interactions and is a promising platform for the development of pharmacological interventions targeting these interactions.

2.
Chem Soc Rev ; 53(7): 3224-3252, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38379286

RESUMO

Neoantigens play a pivotal role in the field of tumour therapy, encompassing the stimulation of anti-tumour immune response and the enhancement of tumour targeting capability. Nonetheless, numerous factors directly influence the effectiveness of neoantigens in bolstering anti-tumour immune responses, including neoantigen quantity and specificity, uptake rates by antigen-presenting cells (APCs), residence duration within the tumour microenvironment (TME), and their ability to facilitate the maturation of APCs for immune response activation. Nanotechnology assumes a significant role in several aspects, including facilitating neoantigen release, promoting neoantigen delivery to antigen-presenting cells, augmenting neoantigen uptake by dendritic cells, shielding neoantigens from protease degradation, and optimizing interactions between neoantigens and the immune system. Consequently, the development of nanotechnology synergistically enhances the efficacy of neoantigens in cancer theranostics. In this review, we provide an overview of neoantigen sources, the mechanisms of neoantigen-induced immune responses, and the evolution of precision neoantigen-based nanomedicine. This encompasses various therapeutic modalities, such as neoantigen-based immunotherapy, phototherapy, radiotherapy, chemotherapy, chemodynamic therapy, and other strategies tailored to augment precision in cancer therapeutics. We also discuss the current challenges and prospects in the application of neoantigen-based precision nanomedicine, aiming to expedite its clinical translation.


Assuntos
Vacinas Anticâncer , Neoplasias , Humanos , Antígenos de Neoplasias , Medicina de Precisão , Neoplasias/diagnóstico , Neoplasias/terapia , Imunoterapia , Nanotecnologia , Microambiente Tumoral
3.
Angew Chem Int Ed Engl ; 63(16): e202319982, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38361437

RESUMO

Enzymes are considered safe and effective therapeutic tools for various diseases. With the increasing integration of biomedicine and nanotechnology, artificial nanozymes offer advanced controllability and functionality in medical design. However, several notable gaps, such as catalytic diversity, specificity and biosafety, still exist between nanozymes and their native counterparts. Here we report a non-metal single-selenium (Se)-atom nanozyme (SeSAE), which exhibits potent nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mimetic activity. This novel single atom nanozyme provides a safe alternative to conventional metal-based catalysts and effectively cuts off the cellular energy and reduction equivalents through its distinctive catalytic function in tumors. In this study, we have demonstrated the substantial efficacy of SeSAE as an antitumor nanomedicine across diverse mouse models without discernible systemic adverse effects. The mechanism of the NADPH oxidase-like activity of the non-metal SeSAE was rationalized by density functional theory calculations. Furthermore, comprehensive elucidation of the biological functions, cell death pathways, and metabolic remodeling effects of the nanozyme was conducted, aiming to provide valuable insights into the development of single atom nanozymes with clinical translation potential.


Assuntos
Nanotecnologia , Neoplasias , Animais , Camundongos , Metais , Catálise , Neoplasias/tratamento farmacológico , Nanomedicina
4.
Small ; 19(30): e2300750, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37058076

RESUMO

Nanomaterials with enzyme-mimicking properties, coined as nanozymes, are a promising alternative to natural enzymes owing to their remarkable advantages, such as high stability, easy preparation, and favorable catalytic performance. Recently, with the rapid development of nanotechnology and characterization techniques, single atom nanozymes (SAzymes) with atomically dispersed active sites, well-defined electronic and geometric structures, tunable coordination environment, and maximum metal atom utilization are developed and exploited. With superior catalytic performance and selectivity, SAzymes have made impressive progress in biomedical applications and are expected to bridge the gap between artificial nanozymes and natural enzymes. Herein, the recent advances in SAzyme preparation methods, catalytic mechanisms, and biomedical applications are systematically summarized. Their biomedical applications in cancer therapy, oxidative stress cytoprotection, antibacterial therapy, and biosensing are discussed in depth. Furthermore, to appreciate these advances, the main challenges, and prospects for the future development of SAzymes are also outlined and highlighted in this review.


Assuntos
Nanoestruturas , Nanoestruturas/química , Catálise , Nanotecnologia
5.
Angew Chem Int Ed Engl ; 62(27): e202304312, 2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-37137872

RESUMO

The metabolic reprogramming of tumors requires high levels of adenosine triphosphate (ATP) to maintain therapeutic resistance, posing a major challenge for photothermal therapy (PTT). Although raising the temperature helps in tumor ablation, it frequently leads to severe side effects. Therefore, improving the therapeutic response and promoting healing are critical considerations in the development of PTT. Here, we proposed a gas-mediated energy remodeling strategy to improve mild PTT efficacy while minimizing side effects. In the proof-of-concept study, a Food and Drug Administration (FDA)-approved drug-based hydrogen sulfide (H2 S) donor was developed to provide a sustained supply of H2 S to tumor sites, serving as an adjuvant to PTT. This approach proved to be highly effective in disrupting the mitochondrial respiratory chain, inhibiting ATP generation, and reducing the overexpression of heat shock protein 90 (HSP90), which ultimately amplified the therapeutic outcome. With the ability to reverse tumor thermotolerance, this strategy delivered a greatly potent antitumor response, achieving complete tumor ablation in a single treatment while minimizing harm to healthy tissues. Thus, it holds great promise to be a universal solution for overcoming the limitations of PTT and may serve as a valuable paradigm for the future clinical translation of photothermal nanoagents.


Assuntos
Nanopartículas , Neoplasias , Humanos , Terapia Fototérmica , Neoplasias/tratamento farmacológico , Temperatura , Linhagem Celular Tumoral , Nanopartículas/uso terapêutico , Fototerapia
6.
J Am Chem Soc ; 142(14): 6822-6832, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32196319

RESUMO

Biocatalytic reactions in living cells involve complex transformations in the spatially confined microenvironments. Inspired by biological transformation processes, we demonstrate effective biocatalytic cascade driven photodynamic therapy in tumor-bearing mice by the integration of an artificial enzyme (ultrasmall Au nanoparticles) with upconversion nanoparticles (NaYF4@NaYb0.92F4:Er0.08@NaYF4)zirconium/iron porphyrin metal-organic framework core-shell nanoparticles (UMOF NPs) which act as biocatalysts and nanoreactors. The construction of core-shell UMOF NPs are realized by using a unique "solvent-assisted self-assembly" method. The integration of ultrasmall AuNPs on the UMOFs matrix leads to glucose depletion, providing Au-mediated cancer therapy via glucose oxidase like catalytic activity. Meanwhile, the UMOF matrix acts as a near-infrared (NIR) light photon-activated singlet oxygen generator through a continuous supply of oxygen via hydrogen peroxide decomposition upon irradiation. Such kinds of biocatalysts offer exciting opportunities for biomedical, catalytical ,and energy applications.


Assuntos
Nanopartículas Metálicas/química , Estruturas Metalorgânicas/metabolismo , Fotoquimioterapia/métodos , Humanos
7.
Adv Funct Mater ; 30(4)2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-33041745

RESUMO

The combination of reactive oxygen species (ROS)-involved photodynamic therapy (PDT) and chemodynamic therapy (CDT) holds great promise for enhancing ROS-mediated cancer treatment. Herein, we reported an in situ polymerized hollow mesoporous organosilica nanoparticle (HMON) biocatalysis nanoreactor to integrate the synergistic effect of PDT/CDT for enhancing ROS-mediated pancreatic ductal adenocarcinoma treatment. HPPH photosensitizer was hybridized within the framework of HMON via an "in situ framework growth" approach. Then, the hollow cavity of HMONs was exploited as a nanoreactor for "in situ polymerization" to synthesize the polymer containing thiol groups, thereby enabling the immobilization of ultrasmall gold nanoparticles, which behave like glucose oxidase-like nanozyme, converting glucose into H2O2 to provide self-supplied H2O2 for CDT. Meanwhile, Cu2+-tannic acid complexes were further deposited on the surface of HMONs (HMON-Au@Cu-TA) to initiate Fenton-like reaction to covert the self-supplied H2O2 into •OH, a highly toxic ROS. Finally, collagenase (Col), which can degrade the collagen I fiber in the extracellular matrix (ECM), was loaded into HMON-Au@Cu-TA to enhance the penetration of HMONs and O2 infiltration for enhanced PDT. This study provides a good paradigm for enhancing ROS-mediated anti-tumor efficacy. Meanwhile, this research offers a new method to broaden the application of silica based nanotheranostics.

8.
Small ; 16(42): e2004016, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32985099

RESUMO

Chemical transformation in cellular environment is critical for regulating biological processes and metabolic pathways. Harnessing biocatalytic cascades to produce chemicals of interest has become a research focus to benefit industrial and pharmaceutic areas. Nanoreactors, which can act as artificial cell-like devices to organize cascade reactions, have been recently proposed for potential therapeutic applications for life-threatening illnesses. Among various types of nanomaterials, there is a growing interest in 2D metal-organic frameworks (MOFs). By virtue of the ultralarge specific surface area, high porosity, and structural diversity, 2D MOF nanosheets hold great promise for a broad spectrum of biomedical use. Herein, a unique planar MOF-based hybrid architecture (GMOF-LA) is introduced by incorporating ultrasmall gold nanoparticles (Au NPs) as nanozyme and l-Arginine (l-Arg) as nitric oxide (NO) donor. The prepared Au NPs enable oxidation of glucose into hydrogen peroxide, which drives biocatalytic cascades to covert l-Arg into NO. Interestingly, the well-designed nanosheets not only possess excellent catalytical activity for NO generation, resulting in gas therapeutic effect, but also serve as a desired photosensitizer for photodynamic therapy. This study establishes a good example of exploring bioinspired nanoreactors for cooperative anticancer effect, which may pave the path for future "bench-to-bedside" design of nanomedicine.


Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Neoplasias , Catálise , Ouro , Humanos , Neoplasias/tratamento farmacológico
9.
Angew Chem Int Ed Engl ; 59(23): 8833-8838, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-31943602

RESUMO

Continuous irradiation during photodynamic therapy (PDT) inevitably induces tumor hypoxia, thereby weakening the PDT effect. In PDT-induced hypoxia, providing singlet oxygen from stored chemical energy may enhance the cell-killing effect and boost the therapeutic effect. Herein, we present a phototheranostic (DPPTPE@PEG-Py NPs) prepared by using a 2-pyridone-based diblock polymer (PEG-Py) to encapsulate a semiconducting, heavy-atom-free pyrrolopyrrolidone-tetraphenylethylene (DPPTPE) with high singlet-oxygen-generation ability both in dichloromethane and water. The PEG-Py can trap the 1 O2 generated from DPPTPE under laser irradiation and form a stable intermediate of endoperoxide, which can then release 1 O2 in the dark, hypoxic tumor microenvironment. Furthermore, fluorescence-imaging-guided phototherapy demonstrates that this phototheranostic could completely inhibit tumor growth with the help of laser irradiation.


Assuntos
Escuridão , Fototerapia/métodos , Oxigênio Singlete/metabolismo , Hipóxia Tumoral/efeitos da radiação , Microambiente Tumoral/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Humanos , Lasers , Imagem Óptica , Polietilenoglicóis/química , Pirrolidinonas/química , Oxigênio Singlete/química , Estilbenos/química
10.
J Am Chem Soc ; 141(37): 14687-14698, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31466436

RESUMO

Phototheranostics refers to advanced photonics-mediated theranostic methods for cancer and includes imaging-guided photothermal/chemotherapy, photothermal/photodynamic therapy, and photodynamic/chemotherapy, which are expected to provide a paradigm of modern precision medicine. In this regard, various phototheranostic drug delivery systems with excellent photonic performance, controlled drug delivery/release, and precise photoimaging guidance have been developed. In this study, we reported a special "in situ framework growth" method to synthesize novel phototheranostic hollow mesoporous nanoparticles by ingenious hybridization of perylene diimide (PDI) within the framework of small-sized hollow mesoporous organosilica (HMO). The marriage of PDI and HMO endowed the phototheranostic silica nanoparticles (HMPDINs) with largely amplified fluorescence and photoacoustic signals, which can be used for enhanced fluorescence and photoacoustic imaging. The organosilica shell can be chemically chelated with isotope 64Cu for positron emission tomography imaging. Moreover, in situ polymer growth was introduced in the hollow structure of the HMPDINs to produce thermosensitive polymer (TP) in the cavity of HMPDINs to increase the loading capacity and prevent unexpected leakage of the hydrophobic drug SN38. Furthermore, the framework-hybridized PDI generated heat under near-infrared laser irradiation to trigger the deformation of TP for controlled drug release in the tumor region. The fabricated hybrid nanomedicine with organic-inorganic characteristic not only increases the cancer theranostic efficacy but also offers an attractive solution for designing powerful theranostic platforms.


Assuntos
Imidas/química , Nanopartículas/química , Compostos de Organossilício/química , Perileno/química , Medicina de Precisão , Nanomedicina Teranóstica , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Nus , Polimerização , Porosidade , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Sensors (Basel) ; 17(3)2017 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-28241492

RESUMO

The longer network lifetime of Wireless Sensor Networks (WSNs) is a goal which is directly related to energy consumption. This energy consumption issue becomes more challenging when the energy load is not properly distributed in the sensing area. The hierarchal clustering architecture is the best choice for these kind of issues. In this paper, we introduce a novel clustering protocol called Markov chain model-based optimal cluster heads (MOCHs) selection for WSNs. In our proposed model, we introduce a simple strategy for the optimal number of cluster heads selection to overcome the problem of uneven energy distribution in the network. The attractiveness of our model is that the BS controls the number of cluster heads while the cluster heads control the cluster members in each cluster in such a restricted manner that a uniform and even load is ensured in each cluster. We perform an extensive range of simulation using five quality measures, namely: the lifetime of the network, stable and unstable region in the lifetime of the network, throughput of the network, the number of cluster heads in the network, and the transmission time of the network to analyze the proposed model. We compare MOCHs against Sleep-awake Energy Efficient Distributed (SEED) clustering, Artificial Bee Colony (ABC), Zone Based Routing (ZBR), and Centralized Energy Efficient Clustering (CEEC) using the above-discussed quality metrics and found that the lifetime of the proposed model is almost 1095, 2630, 3599, and 2045 rounds (time steps) greater than SEED, ABC, ZBR, and CEEC, respectively. The obtained results demonstrate that the MOCHs is better than SEED, ABC, ZBR, and CEEC in terms of energy efficiency and the network throughput.

12.
Zhonghua Nan Ke Xue ; 23(7): 646-651, 2017 Jul.
Artigo em Zh | MEDLINE | ID: mdl-29723460

RESUMO

OBJECTIVE: To observe the synergistic effect of Qilan Capsules in the treatment of the patient with Qi-deficiency blood-stasis type of prostate cancer receiving androgen-deprivation therapy after castration. METHODS: This randomized controlled double-blind study included 246 cases of Qi-deficiency blood-stasis type of prostate cancer after castration, which were randomly divided into an experiment and a control group of equal number to be treated with Qilan Capsules + androgen-deprivation and placebo + androgen-deprivation, respectively. After 6 months of treatment, we compared the International Prostate Symptoms Scores (IPSS), TCM Symptoms Scores (TCMSS), maximal urine flow rate (Qmax), and the level of serum prostate-specific antigen (PSA) between the two groups of patients. RESULTS: Statistically significant differences were observed between the experiment and control groups in the syndrome classification-based efficacy (87.7% vs 67.9%, P <0.05) and total effectiveness rate (86.0% vs 71.6%, P <0.05). Compared with the baseline, the experiment group showed remarkable improvement after treatment in TCMSS (17.1±5.1 vs 8.3±4.0, P <0.05), IPSS (17.7±7.5 vs 11.4±4.6, P <0.05), and Qmax (ï¼»10.9±4.3ï¼½ ml/s vs ï¼»14.7±3.7ï¼½ ml/s, P <0.05), and so did the control group (16.8±5.2 vs 11.5±5.2, 17.8±6.7 vs 14.6±5.8, and ï¼»11.0±4.3ï¼½ ml/s vs ï¼»12.0±4.1ï¼½ ml/s, P <0.05). The above three parameters were even more markedly improved in the former than in the latter group (P <0.05). However, there was no statistically significant difference between the two groups in the improvement of the PSA level after treatment (P >0.05). CONCLUSIONS: Qilan Capsules can significantly enhance the effect of androgen-deprivation therapy in the treatment of Qi-deficiency blood-stasis type of prostate cancer after castration though cannot obviously improve the PSA level.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Orquiectomia , Neoplasias da Próstata/cirurgia , Qi , Cápsulas , Método Duplo-Cego , Quimioterapia Combinada/métodos , Humanos , Masculino , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/irrigação sanguínea , Qualidade de Vida , Resultado do Tratamento
13.
Nanotechnology ; 27(49): 494003, 2016 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-27827342

RESUMO

A laminated structure of Al2O3 and MgO deposited by atomic layer deposition (ALD) is used to realize a thin film encapsulation technology in organic light-emitting diodes (OLEDs). This film was targeted to achieve an excellent barrier performance. As the thickness of MgO layer increased from 0 nm to 20 nm, its physical properties transformed from the amorphous state into a crystalline state. The optimized cyclic ratio of ALD Al2O3 and MgO exhibited much lower water vapor transmission rate (WVTR) of 4.6 × 10-6 gm-2/day evaluated by Calcium (Ca) corrosion at 60 °C&100% RH, owing to the formation of a terrific laminated structure. Top-emitting OLEDs encapsulated with laminated Al2O3/MgO show longer operating lifetime under rigorous environmental conditions. These improvements were attributed to the embedded MgO film that served as a modified layer to establish a laminated structure to obstruct gas permeation, as well as a scavenger to absorb water molecules, thus alleviating the hydrolysis of bulk Al2O3 material.

14.
Zhongguo Zhong Yao Za Zhi ; 41(24): 4568-4571, 2016 Dec.
Artigo em Zh | MEDLINE | ID: mdl-28936839

RESUMO

Secoisolariciresinol dehydrogenase (SDH) is a key enzyme involved in the biosynthetic pathway of podophyllotoxin.In this study, two SDH candidate genes,SO282 and SO1223, were cloned from callus of Dysosma versipellis by homology-based PCR and rapid amplification of cDNA end (RACE).The SDH candidate genes were expressed in Escherichia coli and the subsequent enzyme assay in vitro showed that recombinant SO282 had the SDH activity. These results pave the way to the follow-up investigation of the biosynthetic of podophyllotoxin.


Assuntos
Berberidaceae/enzimologia , Álcool Oxidorredutases Dependentes de NAD(+) e NADP(+)/genética , Proteínas de Plantas/genética , Berberidaceae/genética , Clonagem Molecular , DNA Complementar , Podofilotoxina/biossíntese
15.
Zhongguo Zhong Yao Za Zhi ; 41(1): 87-91, 2016 Jan.
Artigo em Zh | MEDLINE | ID: mdl-28845646

RESUMO

Various chromatographic techniques, including silica gel column chromatography, Sephadex LH-20, preparative thin-layer chromatography, and preparative HPLC, were employed to isolate the chemical constituents from callus cultures of Dysosma versipellis. Structures of the compounds were elucidated based on UV, IR, MS and NMR spectroscopic data analysis. Totally, seven flavonoid glycosides were isolated from the 95% ethanol extract of the callus cultures and identified as kaempferol-3-O-[6″-(3″'-methoxy)-malonyl]-ß-D-glucopyranoside(1), kaempferol-3-O-(6″-O-acetyl)-ß-D-glucopyranoside(2), kaempferide-3-O-ß-D-glucopyranoside(3), kaempferol-3-O-ß-D-glucopyranoside(4), isoquercitrin(5), quercetin-4'-O-ß-D-glucopyranoside(6) and kaempferol-3-(6″-malonyl)-ß-D-glucopyranoside(7), respectively.All these compounds were isolated from callus cultures of D. versipellis for the first time.Compounds 1, 2, 3, 6 and 7 were firstly obtained from plant materials of D. versipellis, and compound 1 was a new compound.


Assuntos
Berberidaceae/química , Flavonoides/análise , Flavonoides/isolamento & purificação , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray
16.
J Biol Chem ; 289(52): 35815-25, 2014 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-25361766

RESUMO

Prenylated flavonoids are attractive specialized metabolites with a wide range of biological activities and are distributed in several plant families. The prenylation catalyzed by prenyltransferases represents a Friedel-Crafts alkylation of the flavonoid skeleton in the biosynthesis of natural prenylated flavonoids and contributes to the structural diversity and biological activities of these compounds. To date, all identified plant flavonoid prenyltransferases (FPTs) have been identified in Leguminosae. In the present study two new FPTs, Morus alba isoliquiritigenin 3'-dimethylallyltransferase (MaIDT) and Cudrania tricuspidata isoliquiritigenin 3'-dimethylallyltransferase (CtIDT), were identified from moraceous plants M. alba and C. tricuspidata, respectively. MaIDT and CtIDT shared low levels of homology with the leguminous FPTs. MaIDT and CtIDT are predicted to be membrane-bound proteins with predicted transit peptides, seven transmembrane regions, and conserved functional domains that are similar to other homogentisate prenyltransferases. Recombinant MaIDT and CtIDT were able to regioselectively introduce dimethylallyl diphosphate into the A ring of three flavonoids with different skeleton types (chalcones, isoflavones, and flavones). Phylogenetic analysis revealed that MaIDT and CtIDT are distantly related to their homologs in Leguminosae, which suggests that FPTs in Moraceae and Leguminosae might have evolved independently. MaIDT and CtIDT represent the first two non-Leguminosae FPTs to be identified in plants and could thus lead to the identification of additional evolutionarily varied FPTs in other non-Leguminosae plants and could elucidate the biosyntheses of prenylated flavonoids in various plants. Furthermore, MaIDT and CtIDT might be used for regiospecific prenylation of flavonoids to produce bioactive compounds for potential therapeutic applications due to their high efficiency and catalytic promiscuity.


Assuntos
Alquil e Aril Transferases/química , Flavonoides/química , Moraceae/enzimologia , Morus/enzimologia , Proteínas de Plantas/química , Alquil e Aril Transferases/genética , Sequência de Aminoácidos , Clonagem Molecular , Sequência Conservada , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Especificidade por Substrato
17.
Chembiochem ; 15(11): 1673-81, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-25044857

RESUMO

GuA6DT, a flavonoid prenyltransferase, was identified from Glycyrrhiza uralensis, and it was found that this enzyme regiospecifically transfers a dimethylallyl moiety to apigenin at the C-6 position. A further substrate specificity investigation indicated that the existence of hydroxyls at both the C-5 and C-7 positions of the flavone skeleton is critical for the prenylation. However, substitutions on the B-ring had negligible influence on the prenylation. A comparison of GuA6DT expression in different organs revealed that mRNA is mainly expressed in the aerial parts. Moreover, the GuA6DT mRNA was found to be regulated at the transcriptional level, because methyl jasmonate induced upregulation in cultured cells. GuA6DT is the first identified flavone prenyltransferase to exhibit strict substrate specificity and regiospecificity.


Assuntos
Biocatálise , Dimetilaliltranstransferase/metabolismo , Flavonas/química , Flavonas/metabolismo , Glycyrrhiza uralensis/enzimologia , Prenilação , Cromatografia Líquida de Alta Pressão , Dimetilaliltranstransferase/química
18.
Yao Xue Xue Bao ; 49(6): 913-20, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25212040

RESUMO

Seven meroterpenoids and five small-molecular precursors were isolated from Penicillium sp., an endophytic fungus from Dysosma versipellis. The structures of new compounds, 11beta-acetoxyisoaustinone (1) and isoberkedienolactone (2) were elucidated based on analysis of the spectral data, and the absolute configuration of 2 was established by TDDFT ECD calculation with satisfactory match to its experimental ECD data. Meroterpenoids originated tetraketide and pentaketide precursors, resepectively, were found to be simultaneously produced in specific fungus of Penicillium species. These compounds showed weak cytotoxicity in vitro against HCT-116, HepG2, BGC-823, NCI-H1650, and A2780 cell lines with IC 50 > 10 micromol x L(-1).


Assuntos
Lactonas/farmacologia , Monoterpenos/farmacologia , Penicillium/química , Berberidaceae/microbiologia , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Lactonas/isolamento & purificação , Monoterpenos/isolamento & purificação
19.
Zhongguo Zhong Yao Za Zhi ; 39(12): 2275-80, 2014 Jun.
Artigo em Zh | MEDLINE | ID: mdl-25244758

RESUMO

Syringin, chlorogenic acid and 1,5-dicaffeoylquinic acid are three main bioactive ingredients in herbs of Saussurea involucrata with various pharmacological properties, while their contents are very low. In this study, the biosynthesis of syringin, chlorogenic acid and 1,5-dicaffeoylquinic acid in the cell suspension cultures of S. involucrata were regulated by feeding carbon sources and precursors, which resulted in a great increase of the contents and yields of the above three bioactive ingredients. After 16 days of fermentation, the yields of syringin, chlorogenic acid and 1,5-dicaffeoylquinic acid reached 339.0, 225.3, 512.7 mg x L(-1), respectively. Meanwhile, their contents increased up to 67.9, 1.9, 10.6 times of wild medicinal material, respectively. The results provided a solid basis for further studies on application of cell suspension cultures of S. involucrata for large-scale production of bioactive compounds syringin, chlorogenic acid and 1,5-dicaffeoylquinic acid.


Assuntos
Ácido Clorogênico/metabolismo , Cinamatos/metabolismo , Glucosídeos/biossíntese , Saussurea/metabolismo , Técnicas de Cultura de Células , Células Cultivadas , Ácido Clorogênico/análise , Cinamatos/análise , Glucosídeos/análise , Fenilpropionatos/análise , Saussurea/química , Saussurea/crescimento & desenvolvimento
20.
Adv Mater ; 36(1): e2304848, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37526997

RESUMO

Molecular fluorophores emitting in the second near-infrared (NIR-II, 1000-1700 nm) window with strong optical harvesting and high quantum yields hold great potential for in vivo deep-tissue bioimaging and high-resolution biosensing. Recently, J-aggregates are harnessed to engineer long-wavelength NIR-II emitters and show unique superiority in tumor detection, vessel mapping, surgical navigation, and phototheranostics due to their bathochromic-shifted optical bands in the required slip-stacked arrangement aggregation state. However, despite the preliminary progress of NIR-II J-aggregates and theoretical study of structure-property relationships, further paradigms of NIR-II J-aggregates remain scarce due to the lack of study on aggregated fluorophores with slip-stacked fashion. In this effort, how to utilize the specific molecular structure to form slip-stacked packing motifs with J-type aggregated exciton coupling is emphatically elucidated. First, several molecular regulating strategies to achieve NIR-II J-aggregates containing intermolecular interactions and external conditions are positively summarized and deeply analyzed. Then, the recent reports on J-aggregates for NIR-II bioimaging and theranostics are systematically summarized to provide a clear reference and direction for promoting the development of NIR-II organic fluorophores. Eventually, the prospective efforts on ameliorating and promoting NIR-II J-aggregates to further clinical practices are outlined.


Assuntos
Corantes Fluorescentes , Imagem Óptica , Estudos Prospectivos , Imagem Óptica/métodos , Corantes Fluorescentes/química
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