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1.
Rapid Commun Mass Spectrom ; 38(6): e9693, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38356085

RESUMO

RATIONALE: The volatile organic compounds (VOCs) of Lonicerae Japonicae flos (LJF) and Lonicera flos (LF) play a pivotal role in determining their sensory characteristics, medicinal properties, and subsequent impact on market pricing and consumer preferences. However, the differences and specificity of these VOCs remain obscure. Hence, it is crucial to conduct a comprehensive characterization of the VOCs in LJF and LF and pinpoint their potential differential VOCs. METHODS: In this study, headspace gas chromatography-ion mobility spectrometry (HS-GC/IMS) and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) were employed to comprehensively investigate the compositional characteristics and distinctions in VOCs between LJF and LF. Multivariate statistical analysis was used to identify candidate differential VOCs of LJF and LF samples. RESULTS: A total of 54 and 88 VOCs were identified using HS-GC/IMS and HS-SPME-GC/MS analysis, respectively. Primary VOCs detected in LJF include leaf alcohol, (E)-2-hexen-1-ol dimer, 2-octyn-1-ol, and (E)-3-hexen-1-ol. Key VOCs prevalent in LF encompass farnesol, heptanoic acid, octanoic acid, and valeric acid. Multivariate statistical analysis indicates that compounds such as phenethyl alcohol and leaf alcohol were selected as potential VOCs for distinguishing between LJF and LF. CONCLUSION: This research conducted a comprehensive analysis of the fundamental volatile components in both LJF and LF. It subsequently elucidated the distinctions and specificities within their respective VOC profiles. And this study enables differentiation between LJF and LF through the analysis of VOCs, offering valuable insights for enhancing the quality control of both LJF and LF.


Assuntos
Lonicera , Extratos Vegetais , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/análise , Microextração em Fase Sólida/métodos , Espectrometria de Mobilidade Iônica , Etanol
2.
Molecules ; 29(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38338347

RESUMO

The flower buds of three Panax species (PGF: P. ginseng; PQF: P. quinquefolius; PNF: P. notoginseng) widely consumed as health tea are easily confused in market circulation. We aimed to develop a green, fast, and easy analysis strategy to distinguish PGF, PQF, and PNF. In this work, fast gas chromatography electronic nose (fast GC e-nose), headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were utilized to comprehensively analyze the volatile organic components (VOCs) of three flowers. Meanwhile, a principal component analysis (PCA) and heatmap were applied to distinguish the VOCs identified in PGF, PQF, and PNF. A random forest (RF) analysis was used to screen key factors affecting the discrimination. As a result, 39, 68, and 78 VOCs were identified in three flowers using fast GC e-nose, HS-GC-IMS, and HS-SPME-GC-MS. Nine VOCs were selected as potential chemical markers based on a model of RF for distinguishing these three species. Conclusively, a complete VOC analysis strategy was created to provide a methodological reference for the rapid, simple, and environmentally friendly detection and identification of food products (tea, oil, honey, etc.) and herbs with flavor characteristics and to provide a basis for further specification of their quality and base sources.


Assuntos
Panax , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Nariz Eletrônico , Microextração em Fase Sólida/métodos , Panax/química , Espectrometria de Mobilidade Iônica , Compostos Orgânicos Voláteis/análise , Flores/química , Chá
3.
Biochem Biophys Res Commun ; 668: 90-95, 2023 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-37245294

RESUMO

Antimicrobial resistance (AMR) crisis urges the development of new antibiotics. In the present work, we for the first time used bio-affinity ultrafiltration combined with HPLC-MS (UF-HPLC-MS) to examine the interaction between the outer membrane ß-barrel proteins and natural products. Our results showed that natural product licochalcone A from licorice interacts with BamA and BamD with the enrichment factor of 6.38 ± 1.46 and 4.80 ± 1.23, respectively. The interaction was further confirmed by use of biacore analysis, which demonstrated that the Kd value between BamA/D and licochalcone was 6.63/28.27 µM, suggesting a good affinity. To examine the effect of licochalcone A on BamA/D function, the developed versatile in vitro reconstitution assay was used and the results showed that 128 µg/mL licochalcone A could reduce the outer membrane protein A integration efficiency to 20%. Although licochalcone A alone can not inhibit the growth of E. coli, but it can affect the membrane permeability, suggesting that licochalcone A holds the potential to be used as a sensitizer to combat AMR.


Assuntos
Chalconas , Proteínas de Escherichia coli , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Chalconas/farmacologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Dobramento de Proteína
4.
Rapid Commun Mass Spectrom ; 37(7): e9479, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36690334

RESUMO

RATIONALE: Shuang-Huang-Lian powder injection (SHLPI) is a well-known modern traditional Chinese medicine formula preparation (TCMFP) widely used to treat acute upper respiratory infections. However, SHLPI is extracted from pure Chinese medicine and administered through an injection, and many adverse reactions have been reported clinically. Therefore, it is necessary to characterize in depth the chemical composition of SHLPI and quantitatively analyze its potential allergenic components. METHODS: In this study, the samples were analyzed using ion mobility ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS) combined with a self-built database. Furthermore, the parallel reaction monitoring (PRM) model of ultra-high-performance liquid chromatography-quadrupole-Orbitrap-mass spectrometry (UHPLC-Q-Orbitrap-MS) was used to successfully quantify 10 representative bioactive components. RESULTS: Using this strategy 90 compounds were identified, the fragmentation pathways of five representative compounds in the five main components of SHLPI were summarized, and 10 components (neochlorogenic acid, chlorogenic acid, sweroside, forsythiaside A, luteoloside, isochlorogenic acid B, isochlorogenic acid C, baicalin, phillyrin, and baicalein) were determine as the quality markers of SHLPI based on UPLC-Q-Orbitrap-MS. CONCLUSIONS: This work comprehensively characterized the material basis of SHLPI, summarized the cracking laws of representative substances, and quantitatively analyzed 10 potential allergenic components. Therefore, this study could provide a basis for the quality control of SHLPI and the clinical rational use of drugs to reduce its adverse reactions.


Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão/métodos , Pós , Medicamentos de Ervas Chinesas/química , Espectrometria de Massas
5.
Rapid Commun Mass Spectrom ; 36(20): e9363, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-35902380

RESUMO

RATIONALE: Many methods have been reported for the production of rare ginsenosides, including heat treatment, acid hydrolysis, alkaline hydrolysis, enzymatic hydrolysis, and microbial transformation. However, the conversion of original ginsenosides to rare ginsenosides under the dual conditions of citric acid and high-pressure steam sterilization has rarely been reported. METHODS: In this study, a method involving ultrahigh-performance liquid chromatography coupled to ion mobility quadrupole time-of-flight mass spectrometry was developed for analysis of chemical transformation of protopanaxatriol (PPT)-type ginsenosides Rg1 and Re, protopanaxadiol (PPD)-type ginsenoside Rb1 , and total ginsenosides in the dual conditions of citric acid and high-pressure steam sterilization. An internal ginsenoside database containing 126 known ginsenosides and 18 ginsenoside reference compounds was established to identify the transformation products and explore possible transformation pathways and mechanisms. RESULTS: A total of 54 ginsenosides have been preliminarily identified in the transformation products of PPD-type ginsenosides Rg1 and Re, PPD-type ginsenoside Rb1 , and total ginsenosides, and the possible transformation pathways were as follows: Rg1 , Re → 20(S)-Rh12 , 20(R)-Rh12 ; Rg1 , Re → 20(S)-Rh1 , 20(R)-Rh1 → Rk3 , Rh4 , Rh5 ; Rb1 → gypenoside LXXV; Rb1 → 20(S)-Rg3 , 20(R)-Rg3 → Rk1 , Rg5 ; Re → 20(S)-Rg2 , 20(R)-Rg2 → 20(S)-Rf2 , 20(R)-Rf2 , Rg4 , F4 . CONCLUSIONS: The results elucidated the possible transformation pathways and mechanisms of ginsenosides in the dual conditions of citric acid and high-pressure steam sterilization, which were helpful for revealing the mechanisms of ginsenosides and enhanced safety and quality control of pharmaceuticals and nutraceuticals. Meanwhile, a simple, efficient, and practical method was developed for the production of rare ginsenosides, which has the potential to produce diverse rare ginsenosides on an industrial scale.


Assuntos
Ginsenosídeos , Panax , Cromatografia Líquida , Ácido Cítrico , Ginsenosídeos/química , Espectrometria de Massas , Panax/química , Saponinas , Vapor/análise , Triterpenos
6.
Molecules ; 27(14)2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35889268

RESUMO

Volatile organic compounds (VOCs) are the main chemical components of Schizonepetae Spica (SS), which have positive effects on the quality evaluation of SS. In this study, HS-SPME-GC-MS (headspace solid-phase microextraction-gas chromatography-mass spectrometry) and HS-GC-IMS (headspace-gas chromatography-ion mobility spectrometry) were performed to characterize the VOCs of SS from six different regions. A total of 82 VOCs were identified. In addition, this work compared the suitability of two instruments to distinguish SS from different habitats. The regional classification using orthogonal partial least squares discriminant analysis (OPLS-DA) shows that the HS-GC-IMS method can classify samples better than the HS-SPME-GC-MS. This study provided a reference method for identification of the SS from different origins.


Assuntos
Microextração em Fase Sólida , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Mobilidade Iônica , Análise dos Mínimos Quadrados , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/análise
7.
Rapid Commun Mass Spectrom ; 35(21): e9174, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34350664

RESUMO

RATIONALE: Kaixin San (KXS) is a prescription traditional Chinese medicine (TCM) with the effects of "tonifying the kidney and brain" and "improving memory". The volatile organic compounds (VOCs) in KXS could effectively improve senile dementia and depression, but only few studies have focused on the overall characterization of VOCs in KXS and the quantitative study of the main active components. METHODS: We have developed a strategy to correlate the results from headspace gas chromatography/ion mobility spectrometry (HS-GC/IMS) and headspace gas chromatography/mass spectrometry (HS-GC/MS) for the comprehensive characterization of VOCs in KXS and the quantitative analysis of the main pharmacodynamic substances. RESULTS: A totsal of 68 low molecular weight VOCs were identified in KXS by HS-GC/IMS at room temperature and atmospheric pressure; 117 VOCs were identified and 10 components (isocalamenediol, α-asarone, ß-asarone, methyl eugenol, isoeugenol methyl ether, camphor, anethol, 2,4-di-tert-butylphol, linalool, asarylaldehyde) as the quality markers of KXS based on HS-GC/MS. CONCLUSIONS: This results from this study provide a foundation for quality control, pharmacodynamic mechanism research and further development of KXS, and provides more convincing data supporting the VOCs of other natural products.


Assuntos
Medicamentos de Ervas Chinesas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Mobilidade Iônica/métodos , Compostos Orgânicos Voláteis/análise , Controle de Qualidade
8.
Opt Express ; 28(9): 13616-13624, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32403832

RESUMO

Ga-free InAs/InAsSb type-II superlattices (T2SLs) are emerging as candidate materials for high temperature operation of mid-infrared photodetectors, which are critical for infrared technology with an aim to provide low-cost and compact detection systems. In this work, by utilizing upside-down device structure, a closely lattice-matched Al0.83Ga0.17AsSb quaternary alloy as electron barrier was pre-grown before the growth of InAs/InAsSb T2SLs absorber in a nBn device. Based on this design, we have demonstrated 5-µm cut-off mid-wavelength infrared (MWIR) photodetectors that exhibited a dark current density of 1.55 × 10-4 A/cm2 at an operation bias 400mV at 150K. A saturated quantum efficiency at ∼4.0 µm reaches 37.5% with a 2 µm absorber and the peak responsivity reaches 1.2 A/W, which yields a peak specific detectivity as high as ∼1.82 × 1011 cm·H z1/2/W at a forward bias of 400mV.

9.
Anal Chem ; 91(23): 15308-15316, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31691562

RESUMO

Exosomes are cell-secreted membrane-coated vesicles with their sizes variable from 30 to 150 nm. So far, there is no simple, fast, and economical way to evaluate the sizes of exosomes in living systems. Here, we put forward a hypothesis in which the sphere sizes (resulting in different curvature) may affect the local mobility/viscosity of exosome membranes. Based on this hypothesis, we propose a novel method to evaluate the exosome sizes by quantifying the membrane viscosity. For this sake, we design a membrane-targeting molecular rotor with its fluorescence lifetime sensitive to viscosity and use it under a fluorescence lifetime imaging microscope (FLIM). Through a multiple-step ultrafiltration technique, we isolate three individual size distributions (10-50, 50-100, and 100-220 nm) with exosomes from HeLa and MCF-7 cell culture media and then perform the FLIM assay on the above two groups. In both cases, we indeed find a regular pattern in which the membrane viscosity reflected by lifetime decreases with exosome sizes. We then perform the assay on exosomes from cancer cells, corresponding normal tissue cells, and serum of breast cancer patients. We find that exosomes from cancer cells have a fluorescence lifetime (larger viscosity) longer than that of normal tissue cells. The average fluorescence lifetime of exosomes from a triple-negative breast cancer patient is longer (or the viscosity is larger) than that of a HER2 positive one. Therefore, our new and simple method may hold application prospects in future cancer diagnosis.


Assuntos
Membrana Celular/química , Exossomos/química , Imagem Óptica , Humanos , Microscopia de Fluorescência , Tamanho da Partícula , Propriedades de Superfície , Células Tumorais Cultivadas , Viscosidade
10.
J Asian Nat Prod Res ; 21(10): 970-976, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29947250

RESUMO

A phytochemical study on the seeds of Cassia obtusifolia was carried out, which finally led to obtain two naphthalenes (1 and 2), two naphthopyrans (3 and 4) and twelve anthraquinones (5-16). The structures of all compounds were established mainly by NMR and MS experiments as well as the necessary chemical evidence. Among them, 1 and 2 (obtusinaphthalensides A and B) were identified to be new naphthalene glycosides.


Assuntos
Cassia/química , Naftalenos/isolamento & purificação , Sementes/química , Antraquinonas/química , Hidrólise , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Extratos Vegetais/química
11.
J Pharmacol Sci ; 137(4): 324-332, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30150145

RESUMO

Glycyrrhiza Uralensis Polysaccharide (GCP), as a macromolecular polysaccharide extracted from the Traditional Chinese Medicine (TCM) - Licorice has been proved to inhibit tumor growth in vitro and in vivo; however, the specific anti-tumor mechanism of GCP needs to be further investigated. In this study, we explore the anti-tumor mechanism of GCP from the angle of gut microbiota. Colon carcinoma cells (CT-26) were used to set up a tumor-bearing mouse model. After 14 days of GCP treatment, the weights of tumors were significantly reduced. In addition, HE staining of tissue sections reflected that GCP could effectively inhibit tumor metastasis. 16SrRNA high-throughput sequencing of fecal samples showed a significant change between the model group and GCP group in the composition of gut microbiota. Subsequently, gut microbiota depletion and fecal transplantation experiments further confirmed the relationship between the anti-tumor effects of GCP and gut microbiota. Following depletion of gut microbiota, GCP cannot inhibit tumor growth. Fecal transplantation experiments found that transplanting the feces of GCP-treated mice, to a certain extent, could inhibit tumor growth and metastasis. These results indicate that Glycyrrhiza Polysaccharides exert anti-tumor effects by affecting gut microbiota composition.


Assuntos
Antineoplásicos Fitogênicos , Transformação Celular Neoplásica/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Glycyrrhiza uralensis/química , Fitoterapia , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Transplante de Microbiota Fecal , Masculino , Camundongos Endogâmicos BALB C
12.
Chembiochem ; 18(17): 1762-1769, 2017 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-28632960

RESUMO

Genetically encoded technologies provide methods for the specific labeling and imaging of proteins, which is essential to understand the subcellular localization of these proteins and their function. Herein, we employed naphthalimide, an efficient two-photon fluorophore, to develop O6 -benzylguanine (BG) derivatives for specific labeling of subcellular proteins and fluorescent imaging through the SNAP-tag. Three naphthalimide-BG derivatives, TNI-BG, QNI-BG, and ONI-BG, were conveniently synthesized through modular "click chemistry" in high yields. All of them showed high labeling efficiency with SNAP-tag in solution (≈1-2×103  s-1 m-1 ) and in bacteria. Among them, ONI-BG showed high specificity to diffused, histone H2B and mitochondria COX8A targeted SNAP-tag in mammalian cells. The protein-labeled naphthalimides exhibited high two-photon absorption cross-sections, which indicated their potential application in protein-specific two-photon fluorescent imaging, such as two-photon fluorescent lifetime imaging and two-photon multicolor imaging. Therefore, ONI-BG is a versatile tool that can be used to track subcellular proteins through multiple fluorescent techniques.


Assuntos
Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Corantes Fluorescentes/química , Naftalimidas/química , Proteínas Supressoras de Tumor/metabolismo , Animais , Células COS , Chlorocebus aethiops , Química Click , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Histonas/química , Histonas/metabolismo , Humanos , Microscopia de Fluorescência por Excitação Multifotônica , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteínas Supressoras de Tumor/genética
13.
Org Biomol Chem ; 15(38): 8091-8101, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28905964

RESUMO

Near-infrared (NIR) fluorescent probes are advantageous over visible ones, for they can avoid the interference from the short-wavelength background emission in biological systems. However, there are a very limited number of NIR probes that can specifically label target proteins in living cells. In this work, a series of long-wavelength dyes (N-NIR, S-NIR, and K-NIR) analogous to the novel Changsha NIR family are synthesized conveniently through a new approach that is different from the previously reported one. These three dyes have similar conjugation structures but exhibit tunable photophysical properties. N-NIR and S-NIR have large extinction coefficients over 100 000, and high fluorescence quantum yields. Although NIR absorption and emission of K-NIR are inferior to the former two, it emits in a much longer wavelength region. And all the three dyes can easily pass through the cell membranes to obtain the high-resolution NIR fluorescence images. Furthermore, N-NIR is chosen as the NIR fluorophore to develop a protein-labeling reagent PYBG-D, since it demonstrates the highest fluorescence quantum yield of up to 0.4 (in methanol). PYBG-D is efficiently synthesized through Sonogashira coupling between bromo-substituted N-NIR and alkyne-substituted benzylguanine (PYBG). The conjugate PYBG-D proves to be a specific and efficient label for O6-alkylguanine-DNA alkyltransferase (SNAP-tag) that fused to target proteins in living cells, which contributes to high resolution NIR fluorescence images under a laser confocal microscope.


Assuntos
Corantes Fluorescentes/química , Animais , Técnicas Biossensoriais , Linhagem Celular , Membrana Celular , Sobrevivência Celular , Humanos , Modelos Moleculares , Estrutura Molecular , Conformação Proteica , Espectrofotometria Infravermelho
14.
J Pharmacol Sci ; 133(4): 268-275, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28433565

RESUMO

Extract of pine nodules (matsufushi) formed by bark proliferation on the surface of trees of Pinus tabulaeformis or Pinus massoniana has been used as an analgesic for joint pain, rheumatism, neuralgia, dysmenorrhea and other complaints in Chinese traditional medicine. Here we report the effects of matsufushi extract and its components on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. We found that matsufushi extract (0.0003-0.005%) and its component, SJ-2 (5-hydroxy-3-methoxy-trans-stilbene) (0.3-100 µM), but not the other three, concentration-dependently inhibited catecholamine secretion induced by acetylcholine, a physiological secretagogue. Matsufushi extract (0.0003-0.005%) and SJ-2 (0.3-100 µM) also inhibited 45Ca2+ influx induced by acetylcholine in a concentration-dependent manner, similar to its effect on catecholamine secretion. They also suppressed 14C-catecholamine synthesis and tyrosine hydroxylase activity induced by acetylcholine. In Xenopus oocytes expressing α3ß4 nicotinic acetylcholine receptors, matsufushi extract (0.00003-0.001%) and SJ-2 (1-100 µM) directly inhibited the current evoked by acetylcholine. The present findings suggest that SJ-2, as well as matsufushi extract, inhibits acetylcholine-induced catecholamine secretion and synthesis by suppression of nicotinic acetylcholine receptor-ion channels in bovine adrenal medullary cells.


Assuntos
Acetilcolina/farmacologia , Medula Suprarrenal/citologia , Medula Suprarrenal/metabolismo , Catecolaminas/biossíntese , Catecolaminas/metabolismo , Pinus/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Estilbenos/farmacologia , Acetilcolina/antagonistas & inibidores , Animais , Cálcio/metabolismo , Bovinos , Células Cultivadas , Relação Dose-Resposta a Droga , Antagonistas Nicotínicos , Extratos Vegetais/isolamento & purificação , Receptores Nicotínicos/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Xenopus
15.
Molecules ; 22(4)2017 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-28425969

RESUMO

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular degeneration (AMD), age-related cataract (ARC), cognition diseases, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis and diabetic retinopathy. The mechanism by which they are involved in the prevention of eye diseases may be due their physical blue light filtration properties and local antioxidant activity. In addition to their protective roles against light-induced oxidative damage, there are increasing evidences that L and Z may also improve normal ocular function by enhancing contrast sensitivity and by reducing glare disability. Surveys about L and Z supplementation have indicated that moderate intakes of L and Z are associated with decreased AMD risk and less visual impairment. Furthermore, this review discusses the appropriate consumption quantities, the consumption safety of L, side effects and future research directions.


Assuntos
Transtornos Cognitivos/prevenção & controle , Luteína/farmacologia , Transtornos da Visão/prevenção & controle , Zeaxantinas/farmacologia , Fatores Etários , Animais , Cognição/efeitos dos fármacos , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/metabolismo , Suplementos Nutricionais , Humanos , Luteína/administração & dosagem , Luteína/química , Degeneração Macular/diagnóstico , Degeneração Macular/etiologia , Degeneração Macular/metabolismo , Degeneração Macular/prevenção & controle , Estrutura Molecular , Transtornos da Visão/diagnóstico , Transtornos da Visão/etiologia , Transtornos da Visão/metabolismo , Zeaxantinas/administração & dosagem , Zeaxantinas/química
16.
Opt Lett ; 41(4): 816-9, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26872196

RESUMO

The terahertz (THz) modulators, as an essential component of the THz system, have been developed by many efforts until now. However, the development of flexible THz modulators is hindered due to the lack of flexible THz modulating materials. Herein, for the first time to the best of our knowledge, we demonstrated the feasibility of flexible THz modulators based on the coplanar-gate field-effect transistor (FET) structure of ion-gel/graphene/polyethylene terephthalate. The THz transmittance through this THz graphene modulator can be well controlled with a modulation depth up to 22% by tuning the carrier concentration of graphene via electrical gating. Furthermore, because of the integration of high flexibilities of graphene, ion-gel, and polyethylene terephthalate (PET), the proposed THz graphene modulator shows superior flexible performance, where the modulation properties can be maintained almost unchanged, not only under bending deformations, but also before and after bending 1000 times. In addition, due to the unique structure of ion-gel/graphene/PET, the flexible THz graphene modulator has a low insertion loss (1.2 dB). Therefore, this Letter is expected to be beneficial for the potential applications, ranging from the traditional compact THz system to a new flexible THz technology.


Assuntos
Grafite , Radiação Terahertz , Transistores Eletrônicos , Fenômenos Mecânicos
17.
Nanotechnology ; 27(30): 30LT01, 2016 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-27320289

RESUMO

The reported flexible and transparent triboelectric generator (FTTG) can only output ultralow power density (∼2 µW cm(-2)), which has seriously hindered its further development and application. The low power density of FTTG is mainly limited by the transparent material and the electrode structure. Herein, for the first time, a FTTG with a superior power density of 60.7 µW cm(-2) has been fabricated by designing asymmetric electrodes where graphene and indium tin oxide (ITO) act as top and bottom electrodes respectively. Moreover, the performance of FTTG with graphene/ITO (G/I) asymmetric electrodes (GI-FTTG) almost remains unchanged even after 700 cycles, indicating excellent mechanical stability. The excellent performance of GI-FTTG can be attributed to the suitable materials and unique asymmetric electrode structure: the extraordinary flexibility of the graphene top electrode ensures the GI-FTTG excellent mechanical robustness and stability even after longer cycles, and the bottom electrode with very low sheet resistance guarantees lower internal resistance and higher production rate of induction charges to obtain higher output power density. It shows that light-emitting diodes (LED) can be easily powered by GI-FTTG, which demonstrates that the GI-FTTG is very promising for harvesting electrical energy from human activities by using flexible and transparent devices.

18.
Molecules ; 21(4): 429, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-27043512

RESUMO

Twelve new steroidal saponins, including eleven furostanol saponins, terrestrinin J-T (1-11), and one spirostanol saponin, terrestrinin U (12), together with seven known steroidal saponins 13-19 were isolated from T. terrestris. The structures of the new compounds were established on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS, and comparisons with published data.


Assuntos
Extratos Vegetais/química , Saponinas/química , Espirostanos/química , Esteróis/química , Tribulus/química , Medicamentos de Ervas Chinesas/química , Estrutura Molecular , Saponinas/isolamento & purificação , Espirostanos/isolamento & purificação , Esteróis/isolamento & purificação
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(4): 1056-61, 2015 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-26197602

RESUMO

Five samples of Cistanches Herba from different places were analyzed by HPLC-ESI-MS and FTIR methods. The effective compositions in Cistanches Herba including cistanoside A, echinacoside, acteoside , isoacteoside, 2'-actylacteoside, cistanoside C and tubluoside B were determined by HPLC-MS. The common peak ratio and variant peak ratio were calculated by FTIR spectroscopy of the five samples and the dual index sequence of common peak ratio and variant peak ratio were established. The results showed that the evaluation results of the samples by the two methods were the same. The general fake plant Cynomorii Herba could be identified by FTIR. HPLC-ESI-MS, which has high sensitivity and rapid determination procedure, can be used to evaluate quality of Cistanches Herba by quantitative analysis of the primary compositions. FTIR is a non-destructive analysis method. without complicated extraction and separation procedures to the samples. The absorption strength and the absorption shape were the synergistic effect of the functional groups and the nestification of the components in Cistanches Herba. The provided method has some advantages such as rapid analysis process, good reproducibility, non-destructive, small quantity of sample, simple treatment, good specificity, low-cost and environment-friendly. The method meets the trend of complex analysis and whole analysis for the Chinese medicines. Combination of FTIR and HPLC-ESI-MS was a good method for identification and evaluation of quality of Chinese medicines.


Assuntos
Cistanche/classificação , Medicamentos de Ervas Chinesas/análise , Catecóis , Cromatografia Líquida de Alta Pressão , Glucosídeos , Glicosídeos , Espectrometria de Massas , Fenóis , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Zhong Yao Cai ; 38(10): 2105-8, 2015 Oct.
Artigo em Zh | MEDLINE | ID: mdl-27254925

RESUMO

OBJECTIVE: To establish an assay method for simultaneous determination of peimine, peiminine, peimissine and hupehenine and to make a comparative analysis of the content of four alkaloids in Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea for the first time. METHODS: A Unitary C18 column(250 mm x 4.6 mm, 5 µm) was chosen with acetonitrile-water (containing 0.05% diethylamine) as mobile phase in a gradient program. The column temperature was 35 degrees C and the flow-rate was 1.0 mL/min. RESULTS: There was high content of peiminine and the content of peimissine was inferior to peiminine in Fritillaria hupehensis. Relatively speaking, peimine and hupehenine were much lower than the other two ingredients. Fritillaria ebeiensis var. purpurea also contained high levels of peiminine, the minimum content of peimine and equivalent content of peimissine comparing with Fritillaria hupehensis. In addition, it didn't contain hupehenine in Fritillaria ebeiensis var. purpurea. CONCLUSION: This method is simple and fast, and it has good separation, reproducibility and reliable results. Also, it can be used as basis for the quality evaluation of Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea.


Assuntos
Alcaloides/isolamento & purificação , Cevanas/isolamento & purificação , Fritillaria/química , Reprodutibilidade dos Testes , Fritillaria/classificação , Plantas Medicinais/química
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