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1.
Nano Lett ; 24(15): 4618-4624, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38588453

RESUMO

Extracting osmotic energy from waste organic solutions via reverse electrodialysis represents a promising approach to reuse such industrial wastes and helps to mitigate the ever-growing energy needs. Herein, a molecularly thin membrane of covalent organic frameworks is engineered via interfacial polymerization to investigate its ion transport behavior in organic solutions. Interestingly, a significant deviation from linearity between ion conductance and reciprocal viscosity is observed, attributed to the nanoscale confinement effect on intermolecular interactions. This finding suggests a potential strategy to modulate the influence of apprarent viscosity on transmembrane transport. The osmotic energy harvesting of the ultrathin membrane in organic systems was studied, achieving an unprecedented output power density of over 84.5 W m-2 at a 1000-fold salinity gradient with a benign conversion efficiency and excellent stability. These findings provide a meaningful stepping stone for future studies seeking to fully leverage the potentials of organic systems in energy harvesting applications.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38720416

RESUMO

Although a series of studies confirm the bioactivities of hederagenin and its glycosides, their synergistic effects and potential mechanisms are still worthy of further exploration. This work investigated the synergistic cytotoxicity and in vitro antioxidant activity of hederagenin and hederagenin 28-O-ß-d-glucopyranoside (28-Glc-hederagenin). Hederagenin and 28-Glc-hederagenin inhibited HeLa cell growth and their combination further strengthened this effect. The combination of hederagenin and 28-Glc-hederagenin significantly increased the rate of apoptotic cells, suggesting the presence of a synergistic effect between the two substances. This combination also enhanced in vitro antioxidant activity compared with individual treatments. A network pharmacology and molecular docking-based approach was performed to explore the underlying mechanisms of hederagenin and 28-Glc-hederagenin against cervical cancer and oxidant damage. This work identified 18 related Kyoto Encyclopedia of Genes and Genome pathways, 202 related biological process terms, 17 related CC terms, and 35 related molecular function terms and then revealed 30 nodes and 196 edges. Subsequently, two highly connected clusters and the top four targets were identified. Molecular docking showed potent binding affinity of hederagenin and 28-Glc-hederagenin toward core targets associated with both cervical cancer and oxidant damage. This work may provide scientific basis for the combined use of hederagenin and its glycosides as dietary supplements.

3.
Clin Lab ; 70(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38213199

RESUMO

BACKGROUND: This study aimed to explore the diagnostic value of serum adenosine deaminase (ADA) in patients with myelodysplastic syndromes (MDS) and identify potential risk factors for MDS. METHODS: Eighty patients with MDS and 80 healthy individuals were included. The serum ADA level was found to be significantly higher in patients with MDS compared with that of healthy controls (p = 0.014). RESULTS: The receiver operator characteristic curve (ROC) for ADA had an area under curve (AUC) of 0.807 (p = 0.0018). Serum ADA level of 4.5 U/L had a sensitivity of 71.43% and specificity of 80% for MDS diagnosis. The multivariate analysis showed hemoglobin (Hb, OR = 1.322, 95% CI: 1.035 - 2.323, p = 0.039), prothrombin time (PT, OR = 1.524, 95% CI: 1.156 - 3.280, p = 0.042), fibrinogen (OR = 1.335, 95% CI: 1.022 - 2.775, p = 0.027), calculated international normalized ration (INR, OR = 2.212, 95% CI: 1.320 - 3.085, p = 0.038), D-dimer (OR = 2.043, 95% CI: 1.623 - 4.293, p = 0.038), fibrin degradation product (FDP, OR = 2.525, 95% CI: 1.129 - 3.340, p = 0.029), and serum ADA (OR = 2.057, 95% CI: 1.248 - 3.572, p = 0.033) were independently associated with MDS. CONCLUSIONS: Serum ADA might be a potential biomarker in the diagnosis of MDS. Serum ADA level, Hb level, PT, fibrinogen level, INR, D-dimer, and FDPs were independent risk factors of MDS.


Assuntos
Adenosina Desaminase , Síndromes Mielodisplásicas , Humanos , Curva ROC , Biomarcadores , Síndromes Mielodisplásicas/diagnóstico , Fibrinogênio , Estudos Retrospectivos
4.
Molecules ; 29(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38731476

RESUMO

Although the wide variety of bioactivities of curcumin has been reported by researchers, the clinical application of curcumin is still limited due to its poor aqueous solubility. In view of this, a series of dimethylaminomethyl-substituted curcumin derivatives were designed and synthesized (compounds 1-15). Acetate of these derivatives were prepared (compounds 1a-15a). The Mannich reaction and aldol condensation reaction are the main reactions involved in this study. Compounds 6, 10, 12, 3a, 5a, 6a, 7a, 8a, 10a, 11a, 12a, 13a, 14a, and 15a exhibited better in vitro anti-inflammatory activity compared to curcumin in the RAW264.7 cell line. Compounds 5, 1a, 5a, 8a, and 12a exhibited better in vitro antioxidant activity compared to curcumin in the PC 12 cell line. Compounds 11, 13, 5a, 7a, and 13a exhibited better in vitro radiation protection compared to curcumin in the PC 12 cell line. The aqueous solubilities of all the curcumin derivative acetates were greatly improved compared to curcumin.


Assuntos
Anti-Inflamatórios , Antioxidantes , Curcumina , Protetores contra Radiação , Solubilidade , Curcumina/farmacologia , Curcumina/química , Curcumina/síntese química , Curcumina/análogos & derivados , Animais , Camundongos , Antioxidantes/farmacologia , Antioxidantes/química , Antioxidantes/síntese química , Células RAW 264.7 , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/síntese química , Protetores contra Radiação/farmacologia , Protetores contra Radiação/síntese química , Protetores contra Radiação/química , Desenho de Fármacos , Relação Estrutura-Atividade , Estrutura Molecular , Células PC12 , Ratos , Água/química
5.
Molecules ; 29(6)2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38542949

RESUMO

Orychophragmus violaceus (L.) O. E. Schulz (Brassicaceae) is widely distributed and plentiful in China and has been widely used for its application in ornamental, oil, ecology, foraging, and food. Recent studies have revealed that the main components of Orychophragmus violaceus include flavonoids, alkaloids, phenylpropanoids, phenolic acids, terpenoids, etc., which have pharmacological activities such as antioxidation, antiradiation, antitumor, hepatic protection, antiferroptosis, anti-inflammatory, and antibacterial. In this paper, the nutritional value, chemical compositions, pharmacological activity, and application value of Orychophragmus violaceus are summarized by referring to the relevant domestic and international literature to provide a reference for further research, development, and utilization of Orychophragmus violaceus in the future.


Assuntos
Alcaloides , Brassicaceae , Brassicaceae/química , Alimentos , Fígado , Valor Nutritivo
6.
J Am Chem Soc ; 145(32): 17786-17794, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37537964

RESUMO

Ion transport through nanoconfinement, driven by both electrical and mechanical forces, has drawn ever-increasing attention, due to its high similarity to stress-sensitive ion channels in biological systems. Previous studies have reported only pressure-induced enhancement in ion conductance in low-permeable systems such as nanotubes, nanoslits, or single nanopores. This enhancement is generally explained by the ion accumulation caused by the capacitive effect in low-permeable systems. Here, we fabricate a highly permeable COF monolayer membrane to investigate ion transport behavior driven by both electrical and mechanical forces. Our results show an anomalous conductance reduction activated by external mechanical force, which is contrary to the capacitive effect-dominated conductance enhancement observed in low-permeable nanopores or channels. Through simulations, we uncovered a distinct electrical-mechanical interplay mechanism that depends on the relative rate between the ion diffusion from the boundary layer to the membrane surface and the ion transport through the membrane. The high pore density of the COF monolayer membrane reduces the charge accumulation caused by the capacitive effect, resulting in fewer accumulated ions near the membrane surface. Additionally, the high membrane permeability greatly accelerates the dissipation of the accumulated ions under mechanical pressure, weakening the effect of the capacitive layer on the streaming current. As a result, the ions accumulated on the electrodes, rather than in the capacitive layer, dominating the streaming current and giving rise to a distinct electrical-mechanical interplay mechanism compared to that in low-permeable nanopores or channels. Our study provides new insights into the interplay between electrical and mechanical forces in ultra-permeable systems.

7.
Sensors (Basel) ; 23(21)2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37960412

RESUMO

The return-to-zero error of the resistance strain load cell is most obvious in the first zero-return process during loading and unloading. To improve the accuracy of the load cell, it is necessary to figure out the cause of the error. The influence of the temperature, material, and weld cup were analyzed in this paper. It was concluded that the hysteresis is the main factor affecting the return-to-zero error after the first load. The relationship between hysteresis and zero-return error after first load was obtained by a data fitting algorithm. A method to improve the return-to-zero error after the first load was proposed.

8.
Nano Lett ; 22(21): 8463-8469, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36301844

RESUMO

Efficient hot electron extraction is a promising approach to develop photovoltaic devices that exceed the Shockley-Queisser limit. However, experimental evidence of hot electron harvesting employing an organic-inorganic interface is still elusive. Here, we reveal the hot electron dynamics at a CuPc/MoSe2 interface using steady-state spectroscopy and transient absorption spectroscopy. A hot electron transfer efficiency of greater than 78% from MoSe2 to CuPc is observed, comparable to that achieved in quantum dot hybrid systems. The mechanism is proposed as follows: the photogenerated hot electrons in MoSe2 transfer to CuPc and form singlet charge transfer states, which subsequently transform into triplet charge transfer states assisted by the rapid intersystem crossing, inhibiting back-donation of electrons and facilitating exciton dissociation into CuPc polarons with a nanosecond lifetime. Our results demonstrate that the intersystem crossing of the hybrid electronic state at organic-inorganic interfaces may serve as a scheme to enable efficient hot electron extraction in photovoltaic devices.

9.
Molecules ; 28(9)2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37175238

RESUMO

Alkaloids are a material treasure bestowed on humans by nature owing to their numerous biological activities. Orychophragine D, an alkaloid isolated from the seeds of Orychophragmus violaceus was identified as bearing a novel skeleton and proved to have an excellent radioprotective effect. Different from the common alkaloid structure, the main block of orychophragine D is constructed of an oxotriazine and an oxopiperazine, which are connected in parallel by a C-N bond. In this paper, a preparation method for the novel heterocycle skeleton of orychophragine D is proposed for the first time. N-Boc-L-serine was utilized as the original material to complete the preparation with 11 steps in a 13% overall yield. A hydroxyl group was established on the side chain of the skeleton as the reaction site for researchers to conduct further structural modification or derivatization.


Assuntos
Alcaloides , Antineoplásicos , Humanos , Alcaloides/farmacologia , Alcaloides/química , Sítios de Ligação , Esqueleto , Estrutura Molecular
10.
Plant Foods Hum Nutr ; 78(4): 776-782, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37668768

RESUMO

Phytochemical investigation of 70% EtOH extract of the seeds of Capsella bursa-pastoris led to the isolation of a new cyclobutane organic acid (1), and fourteen known compounds, including two organosulfur compounds (2, 3), two quinonoids (4, 5), five flavonoids (6-10), three sterols (11-13) and two other types (14, 15). The structures of the compounds were elucidated by extensive spectroscopic analyses as well as comparison of their spectroscopic data with those reported in the literature. The antioxidant capacities of all compounds and extractive fractions were evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging test and ferric reducing antioxidant power (FRAP) assay. Then the antioxidative substances were evaluated for their neuroprotective effects against H2O2-induced HT22 cell injury. The results indicated the strong scavenging ability to free radical of the extractive fractions and compounds 1-3, 8-10 and 13, and the ferric reducing antioxidant power of the extractive fractions and compounds 1-3, 8 and 10, which were close to or higher than that of the positive control trolox. The EtOAc fraction, n-BuOH fraction, and compounds 1, 3 and 8 can protect HT-22 cells from oxidative damage.


Assuntos
Antioxidantes , Capsella , Antioxidantes/análise , Peróxido de Hidrogênio , Extratos Vegetais/química , Compostos Fitoquímicos/farmacologia , Sementes/química
11.
J Cell Mol Med ; 26(14): 4113-4123, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35734974

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide with increasing incidence consistent with obesity, type 2 diabetes and cardiovascular diseases. No approved medication was currently available for NAFLD treatment. Molecular hydrogen (H2 ), an anti-oxidative, anti-inflammatory biomedical agent is proved to exhibit therapeutic and preventive effect in various diseases. The purpose of this study was to investigate the effect of hydrogen/oxygen inhalation on NAFLD subjects and explore the mechanism from the perspective of hepatocyte autophagy. We conducted a randomized, placebo-controlled clinical trial of 13-week hydrogen/oxygen inhalation (China Clinical Trial Registry [#ChiCTR-IIR-16009114]) including 43 subjects. We found that inhalation of hydrogen/oxygen improved serum lipid and liver enzymes. Significantly improved liver fat content detected by ultrasound and CT scans after hydrogen/oxygen inhalation was observed in moderate-severe cases. We also performed an animal experiment based on methionine and choline-deficient (MCD) diet-induced mice model to investigate effect of hydrogen on mouse NASH. Hydrogen/oxygen inhalation improved systemic inflammation and liver histology. Promoted autophagy was observed in mice inhaled hydrogen/oxygen and treatment with chloroquine blocked the beneficial effect of hydrogen. Moreover, molecular hydrogen inhibited lipid accumulation in AML-12 cells. Autophagy induced by palmitic acid (PA) incubation was further promoted by 20% hydrogen incubation. Addition of 3-methyladenine (3-MA) partially blocked the inhibitory effect of hydrogen on intracellular lipid accumulation. Collectively, hydrogen/oxygen inhalation alleviated NAFLD in moderate-severe patients. This protective effect of hydrogen was possibly by activating hepatic autophagy.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Animais , Anti-Inflamatórios/farmacologia , Diabetes Mellitus Tipo 2/patologia , Humanos , Hidrogênio/farmacologia , Hidrogênio/uso terapêutico , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologia , Oxigênio/farmacologia , Ácido Palmítico/farmacologia
12.
Org Biomol Chem ; 20(8): 1782, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35156985

RESUMO

Correction for 'Pentacyclic spermidine alkaloids with radioprotective and anti-inflammatory activities from Orychophragmus violaceus' by Zan-Xin Xu et al., Org. Biomol. Chem., 2021, 19, 9844-9848, DOI: 10.1039/D1OB01973B.

13.
Molecules ; 27(19)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36235179

RESUMO

Two new compounds, ardisiapunine B (1) and ardisiapunine C (2), were isolated from Ardisia lindleyana D. Dietr. Their structures were examined using HR-ESI-MS, IR, (1D, 2D) NMR spectroscopic analyses, single-crystal X-ray diffraction, and ECD calculation. It was found that the two new compounds belong to unusual oleanane-type triterpenes, with compound 1 bearing an acetal unit and a C-13-C-18 double bond, and compound 2 bearing a C-28 aldehyde group and a C-18-C-19 double bond. The anti-inflammatory properties of compounds 1 and 2 were tested on NO production and cellular morphology using RAW264.7 cells, and their anti-tumor properties were tested on cytotoxic activities, cellular morphology, cell apoptosis, and cell cycle. The results showed that compound 1 exhibited a potent cytotoxicity against HepG2 cell lines with an IC50 of 12.40 µM. Furthermore, it is possible that compound 1 inhibits cell proliferation by blocking the cell G2/M phase and promoting cell apoptosis. Compound 2 exhibited a potential anti-inflammatory activity by decreasing the production of NO in LPS-stimulated RAW264.7 cells. Comparative analysis of the structures of compounds 1 and 2 revealed that the acetal structure and double bond positions were the main differences between them, and these are presumed to be the main reasons for the extreme differences in their cytotoxicity and anti-inflammatory activities. From these new findings, two promising lead compounds were identified for the future development of potential anti-inflammatory or anti-tumor agents.


Assuntos
Antineoplásicos , Ácido Oleanólico , Triterpenos , Acetais , Aldeídos , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Lipopolissacarídeos/farmacologia , Estrutura Molecular , Ácido Oleanólico/farmacologia , Triterpenos/química , Triterpenos/farmacologia
14.
Med Res Rev ; 41(3): 1798-1811, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33512023

RESUMO

Aconitine (AC) is well-known as the main toxic ingredient and active compound of Aconitum species, of which several aconites are essential herbal medicines of Traditional Chinese Medicine (TCM) and widely applied to treat diverse diseases for their excellent anti-inflammatory, analgesic, and cardiotonic effects. However, the cardiotoxicity and neurotoxicity of AC attracted a lot of attention and made it a favorite botanic poison in history. Nowadays, the narrow therapeutic window of AC limits the clinical application of AC-containing herbal medicines; overdosing on AC always induces ventricular tachyarrhythmia and heart arrest, both of which are potentially lethal. But the underlying cardiotoxic mechanisms remained chaos. Recently, beyond its cardiotoxic effects, emerging evidence shows that low doses of AC or its metabolites could generate cardioprotective effects and are necessary to aconite's clinical efficacy. Consistent with TCM's theory that even toxic substances are powerful medicines, AC thus could not be simply identified as a toxicant or a drug. To prevent cardiotoxicity while digging the unique value of AC in cardiac pharmacology, there exists a huge urge to better know the characteristic of AC being a cardiotoxic agent or a potential heart drug. Here, this article reviews the advances of AC metabolism and focuses on the latest mechanistic findings of cardiac efficacy and toxicity of this aconite alkaloid or its metabolites. We also discuss how to prevent AC-related cardiotoxicity, as well as the issues before the development of AC-based medicines that should be solved, to provide new insight into the paradoxical nature of this ancient poison.


Assuntos
Aconitum , Medicamentos de Ervas Chinesas , Venenos , Aconitina/efeitos adversos , Aconitina/toxicidade , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Venenos/toxicidade
15.
Org Biomol Chem ; 19(45): 9844-9848, 2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34751698

RESUMO

Two pairs of novel pentacyclic spermidine alkaloid enantiomers, (±)-orychoviolines A and B ((±)-1 and (±)-2), were isolated from the seeds of Orychophragmus violaceus and represented the first example of a 2-piperidinone-fused hydrodibenzofuran skeleton, constructed from a 6/5/6/6 tetracyclic system and an 18 atomic ring. The most unexpected novelty was the formation of one more piperidinone ring by a connection between C-6 and N-7. Their structures and absolute configurations were determined by spectroscopic analyses, X-ray crystallography, and ECD analysis. Compared to Ex-RAD (sodium salt of 4-carboxystyryl-4-chlorobenzylsulfone), (-)-1 exhibited a significant radioprotective effect on cell survival and DNA damage. (-)-1 also exhibited remarkable anti-inflammatory activity by inhibiting the production of NO in RAW 264.7 cells activated by lipopolysaccharide with an IC50 value of 20.3 ± 1.58 µM, which was equivalent to that of dexamethasone.


Assuntos
Espermidina
16.
Clin Lab ; 67(9)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34542978

RESUMO

BACKGROUND: Serum thyroid stimulating hormone (TSH) detection is of great clinical significance in monitoring thyroid function. The aim of the present study was to establish reference intervals (RIs) for serum TSH in healthy Han population in Southwest China using data from routine health check-up individuals. METHODS: Healthy subjects (n = 7,116) were enrolled from January 2019 to September 2020. Serum TSH values were determined in the Beckman Coulter UniCel™ DxI 800 Access® immunoassay system. Outliers were identified and removed using Dixon's interactive principle. The 95th percentile range was calculated as RIs for serum TSH. All the statistical analyses were run on R statistical software version 4.0.3. RESULTS: A total of 6,668 (1,324 female and 5,344 male) suitable individuals were included in this study. Serum TSH results showed a non-Gaussian distribution by Kolmogorov-Smirnov test. According to Mann-Whitney U analysis, the serum TSH values for the female group differ from the male group's (p < 0.05). Besides, Spearman's rank correlation test disclosed that no obvious correlation was observed between serum TSH levels and age (r = -0.0039, p > 0.05). Accordingly, the RIs for serum TSH in Southwest China Han population were 0.64 (95% CI: 0.62 to 0.65) to 4.05 (95% CI: 4.02 to 4.09) mIU/L in male and 0.72 (95% CI: 0.67 to 0.77) to 5.66 (95% CI: 5.58 to 5.75) mIU/L in female, respectively. CONCLUSIONS: In this study, the laboratory specific RIs for serum TSH were successfully established by indirect method using the data from health check-up population. It implies that the indirect method is an easy and lowcost pathway for each laboratory to establish its own RIs.


Assuntos
Nível de Saúde , Tireotropina , China , Feminino , Humanos , Imunoensaio , Masculino , Valores de Referência
17.
J Clin Lab Anal ; 35(7): e23830, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34018637

RESUMO

BACKGROUND: It has been widely reported that the prognostic nutritional index (PNI) played a pivotal role in nutritional assessment of surgical patients and tumor prognosis. In order to improve the accuracy of evaluation in Western China, we established reference intervals (RIs) of PNI in healthy controls. METHODS: A retrospective cohort study on healthy ethnic Han adults (18-79 years) was conducted to explore the influences of age, gender, study centers, and instruments on PNI and to establish RIs. The data came from a healthy routine examination center database and laboratory information system (LIS) of four centers in Western China, and there were 200 persons selected randomly for verification of RIs. RESULTS: Five thousand eight hundred and thirty-nine healthy candidates were enrolled. PNI showed a marked gender dependence, and males had significantly higher PNI than females across all ages (p < 0.01). We found that PNI is significantly different between age groups (p < 0.01), the value of PNI tended to decrease with age increasing. There is also an obvious influence of centers and instruments on PNI (p < 0.01). CONCLUSIONS: We established reference intervals of PNI in healthy Han Chinese population in Western China and validated successfully. Further established RIs will lead to better standardizations of PNI for clinical applications.


Assuntos
Saúde , Avaliação Nutricional , Adolescente , Adulto , Idoso , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Adulto Jovem
18.
Molecules ; 26(13)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34209219

RESUMO

Ginkgo biloba L. has always been a popular area of research due to its various active ingredients and pharmacological effects. Ginkgo biloba is rich in ginkgo flavonoids, ginkgolides, and ginkgolic acid, with anti-inflammation, antioxidation, neuroprotection, anti-platelet agglutination, hypolipidemic effect, anti-cancer, and anti-radiation properties. There are many methods to extract and separate the active components of ginkgo. Among them, supercritical carbon dioxide fluid extraction (SFE-CO2) is known for its green, clean, and environment-friendly properties. In this paper, the pharmacological activities, the active components, and structures of different parts of ginkgo, the extraction methods of its effective ingredients, and the application of the SFE-CO2 method for the extraction and separation of active ingredients in Ginkgo biloba from leaves, seeds, pollen, and roots were reviewed, in order to make best use of ginkgo resources, and provide support and references for the development of SFE-CO2 of active components from Ginkgo biloba.


Assuntos
Dióxido de Carbono/química , Ginkgo biloba/química , Ginkgolídeos , Extratos Vegetais/química , Folhas de Planta/química , Ginkgolídeos/química , Ginkgolídeos/isolamento & purificação
19.
J Chem Inf Model ; 60(3): 1700-1708, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32096984

RESUMO

The monofunctional trinuclear platinum complex (MTPC), as a promising antitumor agent, can form MTPC-DNA adducts via bifunctional and trifunctional cross-links. Molecular dynamics simulations were used to investigate DNA structural distortions of the MTPC-DNA adducts. MTPC coordinating to DNA results in the decrease of base-pair thermal stability and DNA structural distortions. It is found that there are more significant DNA structural distortions in the trifunctional cross-link than in the bifunctional cross-link, in the 1,4-GG than in the 1,3-GG cross-link, and in the intrastrand than in the interstrand cross-link with the same spans. The results provide a better understanding of DNA structural distortions induced by MTPC with various cross-links at the nucleotide level and are helpful for exploring novel Pt-based anticancer drugs.


Assuntos
Antineoplásicos , Platina , Antineoplásicos/farmacologia , Reagentes de Ligações Cruzadas , DNA , Adutos de DNA , Simulação de Dinâmica Molecular , Conformação de Ácido Nucleico , Compostos Organoplatínicos/farmacologia
20.
Nanotechnology ; 31(47): 475703, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32885790

RESUMO

Friction measurement via atomic force microscope (AFM) relies on accurate calibration for the torsional spring constant of the AFM cantilever and its lateral deflection sensitivity. Here we describe a method that employs a suspended nanowire (SNW) as a reference beam to quantify the torsional spring constant of AFM cantilevers. Based on the fact that a uniform SNW with cylindrical symmetry has an identical spring constant when bent in any direction perpendicular to its axis, the spring constant of the SNW in a normal direction is determined by an AFM cantilever with a known normal spring constant, and is subsequently used as a force transfer standard to calibrate the torsional spring constant of the AFM cantilever. The lateral deflection sensitivity can be accurately measured by pushing the AFM tip laterally on the groove edge. The calibration result is compared to the well-known diamagnetic lateral force calibrator method and shows an uncertainty of 15% or better. The presented method is applicable for the lateral force calibration of AFM cantilevers in a wide range of instruments including inverted configurations and in an ultrahigh vacuum.

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