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1.
Fitoterapia ; : 104498, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32058053

RESUMO

Three new triterpenoids, mallomacrostins A-C (1-3), and 11 known ones (4-14) were obtained from the twigs and leaves of Mallotus macrostachyus. Mallomacrostin A possessed a new trinor-D:B-friedobaccharane skeleton. The structures of the new compounds were elucidated on the basis of extensive spectroscopic techniques including HR-ESIMS and NMR and the structure of 1 was confirmed by single crystal X-ray diffraction analysis. Spectroscopic data of the known compound 4 were provided for the first time. Compounds 2 and 10 exhibited significant anti-inflammatory activity by inhibiting LPS-induced release of nitric oxide with IC50 of 70.0 µM and 14.0 µM, respectively.

2.
Sci Adv ; 5(11): eaaw9120, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31803831

RESUMO

Two-dimensional synthetic polymers (2DSPs) are sheet-like macromolecules consisting of covalently linked repeat units in two directions. Access to 2DSPs with controlled size and shape and diverse functionality has been limited because of the need for monomers to retain their crystallinity throughout polymerization. Here, we describe a synthetic strategy for 2DSPs that obviates the need for crystallinity, via the free radical copolymerization of amphiphilic gemini monomers and their monomeric derivatives arranged in a bilayer at solid-liquid interfaces. The ease of this strategy allowed the preparation of 2DSPs with well-controlled size and shape and diverse functionality on solid templates composed of various materials with wide-ranging surface curvatures and dimensions. The resulting 2DSPs showed remarkable mechanical strength and have multiple applications, such as nanolithographic resist and antibacterial agent. The broad scope of this approach markedly expands the chemistry, morphology, and functionality of 2DSPs accessible for practical applications.

3.
Chem Commun (Camb) ; 56(2): 217-220, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31803869

RESUMO

Herein, we evaluate the suitablity of polystyrenes with thiol, dithioester and trithiocarbonate end-groups for the synthesis of Al nanocrystals. Both the end-groups and molecular weight of the polymer ligands play important roles for controlling the size and shape of the Al nanocrystals. A general criterion for evaluating polymers as the ligand for the synthesis of Al nanocrystals is proposed.


Assuntos
Nanopartículas/química , Poliestirenos/química , Alumínio/química , Cristalização , Teoria da Densidade Funcional , Ligantes , Modelos Químicos , Peso Molecular , Tamanho da Partícula , Compostos de Sulfidrila/química
4.
Transl Psychiatry ; 9(1): 305, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31740657

RESUMO

Bipolar disorder (BPD) is often confused with major depression, and current diagnostic questionnaires are subjective and time intensive. The aim of this study was to develop a new Bipolar Diagnosis Checklist in Chinese (BDCC) by using machine learning to shorten the Affective Disorder Evaluation scale (ADE) based on an analysis of registered Chinese multisite cohort data. In order to evaluate the importance of each item of the ADE, a case-control study of 360 bipolar disorder (BPD) patients, 255 major depressive disorder (MDD) patients and 228 healthy (no psychiatric diagnosis) controls (HCs) was conducted, spanning 9 Chinese health facilities participating in the Comprehensive Assessment and Follow-up Descriptive Study on Bipolar Disorder (CAFÉ-BD). The BDCC was formed by selected items from the ADE according to their importance as calculated by a random forest machine learning algorithm. Five classical machine learning algorithms, namely, a random forest algorithm, support vector regression (SVR), the least absolute shrinkage and selection operator (LASSO), linear discriminant analysis (LDA) and logistic regression, were used to retrospectively analyze the aforementioned cohort data to shorten the ADE. Regarding the area under the receiver operating characteristic (ROC) curve (AUC), the BDCC had high AUCs of 0.948, 0.921, and 0.923 for the diagnosis of MDD, BPD, and HC, respectively, despite containing only 15% (17/113) of the items from the ADE. Traditional scales can be shortened using machine learning analysis. By shortening the ADE using a random forest algorithm, we generated the BDCC, which can be more easily applied in clinical practice to effectively enhance both BPD and MDD diagnosis.

5.
J Phys Chem B ; 123(48): 10311-10321, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31710227

RESUMO

The ligand shell of a nanoparticle (NP) determines most of the interfacial properties through its composition and structure. Despite widespread study over the years, the factors impacting the ligand shell structures, especially the effects of ligand-adsorption kinetics in solution, are still not clear and even conflict with each other. We have developed an adsorption-migration reaction model to study the dynamic evolution processes of binary ligands on NP surfaces during adsorption reaction. Apparent dependence of the structure of ligand shells on ligand-adsorption and phase-separation rates has been found, which induces the formation of different shell patterns, including Janus, patchy, stripe, and island patterns. The formation process of these patterns accords with different reaction kinetic pathways, depending on the nature of ligands. Further screening the role of the NPs' curvature reveals that it can indirectly influence the ligand-adsorption and phase-separation kinetics. As the NPs' curvature increases, an accelerated ligand-adsorption and phase-separation process on NPs will happen, resulting in the preferential formation of more ordered Janus or stripe patterns. These results suggest that controlling the reaction kinetics is key to effectively regulating the composition and morphology of binary ligands on NPs. They also provide principles for guiding the experimental studies to fabricate novel NPs with a functional surface for use in broad nanoscience fields.

6.
Zhongguo Zhong Yao Za Zhi ; 44(14): 3087-3093, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31602857

RESUMO

Due to lack of reference substances,the content of triterpenoid saponins in traditional Chinese medicines is usually characterized by colorimetric determination of total saponins. However,the specificity of colorimetric method is poor,and the determination result is not accurate enough. So,in this paper,the content determination method of total triterpenoid saponins was studied by taking Akebiae Caulis saponins as an example. The contents of three main saponin aglycones,including arjunolic acid,hederagenin and oleanolic acid,were determined by HPLC method. Referring to the content determination method of total flavonol glycosides in Ginkgo biloba leaves in the 2015 edition of Chinese Pharmacopoeia,the content of Akebiae Caulis saponins was obtained by multiplying the total content of the three above-mentioned aglycones with conversion coefficient. LC-MS/MS analysis results showed that mutongsaponin C and aponin PJIwere the two main triterpene saponins in Akebiae Caulis,and they shared the same molecular formula. So,the average value of the ratios of the molecular weight between mutongsaponin C and the three aglycones was defined as the conversion coefficient.The three aglycones were separated on an ACE Excel 3 C18-AR column( 4. 6 mm×150 mm,3 µm),and methanol-water( containing0. 04% glacial acetic acid and 0. 02% triethylamine) was used as mobile phase with gradient elution. The detection wavelength was set at 210 nm,and the flow rate was 0. 5 m L·min-1. The results showed that there was a good linearity among the ranges of 1. 053-16. 84,0. 200-3. 200 and 1. 515-24. 24 µg for arjunolic acid,hederagenin and oleanolic acid,respectively. Their average recoveries were97. 90%,97. 50% and 100. 5%,with RSD of 2. 0%,2. 9% and 2. 9%,respectively. The results of methodological investigation met the requirements of content determination. The conversion coefficient was 2. 31. This method is simple and reliable,and can be used for the determination of total triterpenoid saponins in Akebiae Caulis. The assay strategy can be used for the determination of total triterpenoid saponins in other traditional Chinese medicines.


Assuntos
Medicamentos de Ervas Chinesas/análise , Ranunculales/química , Saponinas/análise , Triterpenos/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Medicina Tradicional Chinesa , Compostos Fitoquímicos/análise , Espectrometria de Massas em Tandem
7.
Reproduction ; 158(5): 441-452, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31546232

RESUMO

It is well documented that granulosa cell apoptosis is the main reason for follicular atresia and death; however, increasing evidence suggests that autophagy plays an important role in the fate of granulosa cells. miR-21-3p regulates many fundamental biological processes and is pivotal in the autophagy of tumor cells; nevertheless, the autophagy in cattle ovary and how miR-21-3p regulates the follicular cells is unknown. In this study, we aimed to elucidate the autophagy and the role of miR-21-3p in cattle ovary using bovine primary ovarian granulosa cells (BGCs). The results showed the autophagy for the first time in BGCs in large follicle according to autophagic gene transcript of LC3, BECN-1, ATG3, protein expression of LC3, P62 and LC3 puncta, a standard marker for autophagosomes. miR-21-3p was identified as a novel miRNA that repressed BGCs autophagy according to the results from plasmids transfection of miR-21-3p mimics and inhibitor. Meanwhile, VEGFA was confirmed to be a validated target of miR-21-3p in BGCs using luciferase reporter assays and the results of VEGFA expression decreased with transfection of miR-21-3p mimics, while it increased with transfection of miR-21-3p inhibitor. In addition, small interference-mediated knockdown of VEGFA significantly inhibits BGCs autophagy signaling; however, overexpression of VEGFA in BGCs promoted autophagy in the presence of miR-21-3p. Finally, the results of AKT and its phosphorylation suggested that miR-21-3p suppressed VEGFA expression through downregulating AKT phosphorylation signaling. In summary, this study demonstrates that miR-21-3p inhibits BGCs autophagy by targeting VEGFA and attenuating PI3K/AKT signaling.

8.
Bioorg Chem ; 92: 103226, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31491566

RESUMO

Six new compounds, including a new compound with an unusual 2, 4, 6-cycloheptatrien ketone skeleton (1), two new diphenylpropanoid ethers (2, 3), a new protostane-type triterpenoid (4), two new norsesquiterpene (5a, 5b), and two new natural products (6, 7), together with eleven known compounds (8-18) were isolated from the aqueous extract of Alismatis Rhizoma (AR). Their structures were elucidated by a combination of 1D and 2D NMR (1H and 13C NMR, COSY, HSQC, HMBC, and NOESY), HRESIMS spectroscopic data, experimental and calculated electronic circular dichroism (ECD) spectra. Some of the compounds were evaluated for their inhibitory effects on nitric oxide (NO) production in LPS-induced RAW 264.7 cells. Two protostane-type triterpenoids, compounds 4 and 17, exhibited potent inhibitory activities with the IC50 values of 39.3 and 63.9 µM compared with indomethacin. In the meanwhile, their anti-inflammatory effects were also confirmed by acute inflammation model induced by CuSO4 in zebrafish.

9.
Animals (Basel) ; 9(8)2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31412668

RESUMO

Female animals living in the Qinghai-Tibet Plateau have lower ovulation rates because of the hypoxic environment, however, the mechanism of hypoxia on animal follicles is unclear. In this study, the effects of hypoxia on bovine follicles were investigated using an in vitro follicular culture system. The results show that there was a significant decrease in follicular diameter from day 3 to day 6 in both hypoxia and hypoxia with estrogen (E2) and fulvestrant (ICI 182780) (hypoxia + E2 + ICI) groups, when compared with a normoxia group (p < 0.05). We also observed significant downregulation of ERα and FSHR, while upregulation of LHCGR expression in the hypoxia group and hypoxia + E2 + ICI groups compared to the normoxia group (p < 0.05). The expression of IGF1 gene was significantly downregulated in hypoxia + E2 + ICI group when compared to the hypoxia + E2 group (p < 0.05). The expression of HIF1A, ADAMTS1, VEGFA, and EDN2 were upregulated in both hypoxia and hypoxia + E2 + ICI groups in comparison to normoxia group (p < 0.05). Under hypoxic conditions, the addition of E2 resulted in a decrease of HIF1A protein but an increase of ERα protein in cultured bovine follicles (p < 0.05). In summary, hypoxia limits the growth of bovine follicle cultured in vitro through inhibition of ERα.

10.
Acta Neuropsychiatr ; 31(6): 316-324, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31405402

RESUMO

OBJECTIVE: To explore whether and how group cognitive-behavioural therapy (GCBT) plus medication differs from medication alone for the treatment of generalised anxiety disorder (GAD). METHODS: Hundred and seventy patients were randomly assigned to the GCBT plus duloxetine (n=89) or duloxetine group (n=81). The primary outcomes were Hamilton Anxiety Scale (HAMA) response and remission rates. The explorative secondary measures included score reductions from baseline in the HAMA total, psychic, and somatic anxiety subscales (HAMA-PA, HAMA-SA), the Hamilton Depression Scale, the Severity Subscale of Clinical Global Impression Scale, Global Assessment of Functioning, and the 12-item Short-Form Health Survey. Assessments were conducted at baseline, 4-week, 8-week, and 3-month follow-up. RESULTS: At 4 weeks, HAMA response (GCBT group 57.0% vs. control group 24.4%, p=0.000, Cohen's d=0.90) and remission rates (GCBT group 21.5% vs. control group 6.2%, p=0.004; d=0.51), and most secondary outcomes (all p<0.05, d=0.36-0.77) showed that the combined therapy was superior. At 8 weeks, all the primary and secondary significant differences found at 4 weeks were maintained with smaller effect sizes (p<0.05, d=0.32-0.48). At 3-month follow-up, the combined therapy was only significantly superior in the HAMA total (p<0.045, d=0.43) and HAMA-PA score reductions (p<0.001, d=0.77). Logistic regression showed superiority of the combined therapy for HAMA response rates [odds ratio (OR)=2.12, 95% confidence interval (CI) 1.02-4.42, p=0.04] and remission rates (OR=2.80, 95% CI 1.27-6.16, p=0.01). CONCLUSIONS: Compared with duloxetine alone, GCBT plus duloxetine showed significant treatment response for GAD over a shorter period of time, particularly for psychic anxiety symptoms, which may suggest that GCBT was effective in changing cognitive style.

11.
ACS Appl Mater Interfaces ; 11(38): 34766-34776, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31429547

RESUMO

The construction of polymeric nanocomponents into a hierarchical structure poses great importance for subsequent biomedical applications. Herein, we report for the first time the electroassembly of chitin nanoparticles (14 nm ± 3 nm from transmission electron microscopy) to construct thick and freestanding hydrogels, which can be further dried to obtain high porous and tough aerogels for wound healing. The electroassembly is a simple, straightforward, and controllable process, which crucially depends on the pH of the chitin nanoparticle suspension and the degree of deacetylation of chitin. Interestingly, the electroassembly of chitin nanoparticles is completely reversible, suggesting the physical assembly feature of the freestanding hydrogel. By using supercritical CO2 drying and freeze-drying, chitin aerogels and cryogels can be facilely obtained. Because of the intriguing features (i.e., large surface area, interconnected porous structure, and enhanced hydrophilicity), chitin aerogels demonstrate adorable performance to accelerate the healing of wounds.

12.
J Phys Chem Lett ; 10(16): 4505-4510, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31310141

RESUMO

Owing to their excellent surface plasmonic properties, Au nanobranches have drawn increasing attention in various bioapplications, such as contrast agents for photoacoustic imaging, nanomedicines for photothermal therapy, and carriers for drug delivery. The monodispersity and plasmonic bandwidth of Au nanobranches are of great importance for the efficacy of those bioapplications. However, it is still a challenge to accurately synthesize size- and shape-controlled Au nanobranches. Here we report a facile seed-mediated growth method to synthesize monodisperse Au nanotetrapods (NTPs) with tunable and ultranarrow plasmonic bands. The NTPs have a novel D2d symmetry with four arms elongated in four ⟨110⟩ directions. The growth mechanism of NTPs relies on the delicate kinetic control of deposition and diffusion rates of adatoms. Upon laser irradiation, the PEGylated NTPs possess remarkable photothermal conversion efficiencies and photoacoustic imaging properties. The NTPs can be applied as a multifunctional theranostic agent for both photoacoustic imaging and image-guided photothermal therapy.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Nanomedicina Teranóstica , Polietilenoglicóis/química , Temperatura Ambiente
13.
Plant Physiol Biochem ; 141: 20-29, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31125808

RESUMO

Soil salinity is one of the most abiotic stress factors that severely affects the growth and development of many plants, which can ultimately threaten crop yield. Arbuscular mycorrhiza fungi (AMF) has been proven to be effective in mitigating salinity stress by symbiosis in many crops. Asparagus officinalis are perennial plants grown in saline-alkaline soil, however, limited information on their molecular mechanisms has restricted efficient application of AMF to garden asparagus under salinity stress. In this study, we conducted a transcriptome analysis on the leaves of garden asparagus to identify gene expression under salinity stress. Seedlings were grown in 4 treatments, including non-inoculated AMF using distilled water (NI), inoculated AMF using distilled water (AMF), non-inoculated with salinity stress (NI + S), and inoculated with salinity stress (AMF + S). A total of 6019 novel genes were obtained based on the reference-guided assembly of the garden asparagus transcriptome. Results revealed that 455 differentially expressed genes (DEGs) were identified when comparing NI + S to AMF + S. However, among the up-regulated DEGs, 41 DEGs were down-regulated, while 242 DEGs had no differences in their expression levels when comparing NI to NI + S. These DEGs' expression patterns may be key induced by AMF under salinity stress. Additionally, the GO and KEGG enrichment analyses of 455 DEGs revealed that these genes mainly participate in the improvement of the internal environment in plant cells, nitrogen metabolic-related processes, and possible photoprotection mechanisms. These findings provide insight into enhanced salinity stress adaptation by AMF inoculation, as well as salt-tolerant candidate genes for further functional analyses.


Assuntos
Asparagus (Planta)/genética , Micorrizas/fisiologia , Estresse Salino , Transcriptoma , Asparagus (Planta)/microbiologia , DNA Complementar/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Biblioteca Gênica , Genoma de Planta , Metabolômica , Nitrogênio/química , Fotoquímica , Folhas de Planta/genética , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Brotos de Planta/genética , Salinidade , Tolerância ao Sal , Sais/química , Plântula , Análise de Sequência de RNA , Simbiose
14.
Zhongguo Zhong Yao Za Zhi ; 44(4): 730-739, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30989886

RESUMO

To solve the problems of the poor resolution of chromatographic separation,the weak durability of the relative correction factors,and the low accuracy of content determination results in the quantitative analysis of multi-components by single-marker( QAMS) method with andrographolide as the internal reference substance in the existing research of Andrographis Herba,a new QAMS method using dehydroandrographolide as the internal reference substance was established for the first time in this study. This new method can be used to simultaneously determine four diterpene lactones,including andrographolide( A),neoandrographolide( B),14-deoxyandrographolide( C),and dehydroandrographolide( S) through the optimization of chromatographic conditions and systematic investigation of methodology. At the present HPLC chromatographic conditions,four components could be well separated( R > 1. 5),and the methodology validations could satisfy the requirement of quantitative analysis. The relative correction factors( RCFs) of fA/S,fB/S,fC/S were determined as 0. 65,0. 54,0. 78,respectively. The relative standard deviations( RSDs) of their RCFs ranged between 1. 3%-5. 1%,0. 25%-0. 33%,0. 070%-0. 15%,0. 070%-0. 22%,respectively with three brands of HPLC instruments,five brands of C18 column,different flow rates( 0. 9,1. 0,1. 1 m L·min~(-1)),and different column temperatures( 25,30,35 ℃),indicating good durability of the RCFs. The relative retention value( RRV) method was used to locate the chromatographic peak of the components to be determined.The RRVs of rA/S,rB/S,and rC/Swere 0. 44,0. 86,0. 97,respectively. The RSDs of the RRVs ranged between 0. 030%-1. 6% with different HPLC instruments and columns,showing accurate peak location. The present QAMS method and the external standard method( ESM)were both used to determine the contents of four diterpene lactones from Andrographis Herba( 6 batches of medicinal materials and 18 batches of cut crude drugs). The relative errors of the determined content results between two methods were less than 2. 0%. It demonstrated that there was no significant difference in content results between these two methods,indicating good accuracy of the present QAMS method. Therefore,in this study,an accurate and highly durable QAMS method using dehydroandrographolide as the internal reference substance was established for simultaneous determination of four diterpene lactones. This method could be used to effectively control the quality of Andrographis Herba and provide technical basis for the formulation of traditional Chinese medicine industry standard and improvement of the Chinese Pharmacopoeia standard of Andrographis Herba.


Assuntos
Andrographis , Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão , Diterpenos , Controle de Qualidade
15.
Biomater Sci ; 7(6): 2571-2581, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-30977470

RESUMO

Traumatic injury is a major cause of mortality, and poor wound healing affects millions of people. Thus, the development of effective wound dressings is essential for speeding up wound healing and decreasing mortality. In this study, a suspension of carboxylated brown algae cellulose nanofibers (BACNFs) with a high aspect ratio was freeze dried to prepare a sponge. The sponge showed high porosity and water absorption capacity; thus, it can absorb wound exudates when used as a wound dressing. In addition, quaternized ß-chitin (QC) with antibacterial properties was intercalated into the interlayer space of the organic rectorite (OREC) via electrostatic interactions to obtain composite suspensions (QCRs) with improved antimicrobial activity compared to that of QC alone. Subsequently, the BACNF sponge was soaked in the QCR suspension to absorb QCRs via electrostatic interactions and hydrogen bonding from which cellulose nanofiber/quaternized chitin/organic rectorite composite (BACNF/QCR) sponges were constructed via freeze-drying. The in vivo animal tests demonstrated that the BACNF/QCR sponges rapidly induced hemostasis in a rat tail amputation test, making them superior to the traditional hemostatic materials. Furthermore, BACNFs/QCRs could substantially promote collagen synthesis and neovascularization, thereby accelerating wound healing 3 days earlier than gauze. This multi-functional biomedical material, fabricated using natural substances, shows great potential to be used for wound healing.


Assuntos
Silicatos de Alumínio/química , Bandagens/microbiologia , Materiais Biocompatíveis/farmacologia , Celulose/química , Quitina/química , Minerais/química , Nanocompostos/química , Nanofibras/química , Animais , Materiais Biocompatíveis/química , Linhagem Celular , Escherichia coli/efeitos dos fármacos , Liofilização , Hemostasia/efeitos dos fármacos , Humanos , Masculino , Teste de Materiais , Ratos , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
16.
Soft Matter ; 15(5): 890-900, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30633294

RESUMO

The effect of different lengths of solvophilic A and C blocks on the assembled configuration of intermediate solvophobic B-blocks in both ABA and ABC polymer brush systems is investigated via dissipative particle dynamics simulations. For the AB diblock copolymer brush with solvophilic A-blocks being grafted to the surface, B-blocks self-assemble into spherical micelle structures that are immersed in a layer formed by the A-blocks. Tethering a very small solvophilic block A(C) at the free end of the polymer brush pulls the B-blocks toward the polymer brush/solvent interface and increases their local density which can significantly change the B-block self-assembled structure from spherical micelles to ripples. By increasing the length of the outermost solvophilic blocks, the lateral density distribution of B-blocks can be further changed, resulting in the domain size of the ripple structure first decreasing and then increasing. Compared to the ABA system, the incompatibility between the A and C blocks can effectively reduce the vertical domain separation caused by the fusion of the upper and lower A blocks. Then, based on an AB diblock copolymer brush system with self-assembled spherical micelles, we introduce extremely short free solvophilic blocks A(C) in dilute solution that can be tethered to the free ends of the polymer brush by using a reaction model [Liu et al., J. Chem. Phys., 2007, 127, 144903]. We find that the micelles' coalescence is mainly affected by the content of tethered reactive solvophilic blocks, and only weakly affected by the reaction rate of the reversible reactions. This strategy of tethering solvophilic blocks to the ends of polymer brushes can be an effective way for the fabrication of stimuli-responsive surfaces and for adjusting nanoscopic surface patterns.

17.
Artigo em Inglês | MEDLINE | ID: mdl-30420891

RESUMO

Xueshuan Xinmaining Tablet (XXT) is a widely used traditional Chinese medicine for the treatment of stroke, chest pain, coronary heart disease, and angina pectoris caused by blood stasis. Having a multiple-component preparation, it is still far from meeting the requirements of modernization and standardization because its detailed chemical basis and action mechanism have not been clarified. In this work, the different batches of XXT samples were analyzed by HPLC and the typical sample was analyzed by UPLC-ESI-Q-TOF/MS to understand its chemical profiling. As a result, 77 chromatographic peaks were detected, among which 63 constituents were identified or tentatively characterized based on the comparison of retention time and UV spectra with authentic compounds as well as by summarized MS fragmentation rules and matching of empirical molecular formula with those of published components. This is the first systematic report on the chemical profiling of the commercial XXT products, which provides the sufficiently chemical evidence for the global quality evaluation of XXT products.

18.
J Am Chem Soc ; 140(45): 15412-15418, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30375861

RESUMO

The challenge of controllable chemical synthesis of aluminum nanocrystals (Al NCs) has been met with only limited success. A major barrier is the absence of effective ligands to control the nucleation and growth of Al NCs. Here we demonstrate the size- and shape-controlled synthesis of monodisperse Al NCs using a polymer ligand, cumyl dithiobenzoate-terminated polystyrene (CDTB-PS). Density functional theory (DFT) calculations indicate that CDTB-PS shows selective absorption on Al{100} facets, inducing the formation of nanocubes and trigonal bipyramids. An excess of CDTB-PS, however, decreases the supersaturation of Al atoms, leading to the formation of {111} facet-terminated octahedral and triangular plates. The concentration of the catalyst, titanium (IV) isopropoxide, determines the size of Al NCs by controlling the number of seeds. Depending on nanoparticle size, the solutions of Al NCs possess distinct colors, a characteristic feature of plasmonic nanomaterials. This robust and controlled chemical synthesis of Al NCs lays a foundation for Al as a sustainable plasmonic material for current and future applications.

19.
Zhongguo Zhong Yao Za Zhi ; 43(14): 2863-2871, 2018 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-30111043

RESUMO

Toad venom (Chansu) is prepared from the dried secretion of parotid gland and skin gland from Bufo bufo gargarizans or B. melanostictus. Up to now, much attention shall be paid to the poor quality of commercial toad venom because of the adulteration. So, it is urgent to establish a scientific and perfect quality control method to improve the quality of toad venom and guarantee its safety and effectiveness in clinical application. The different batches of toad venom samples were assayed by high performance liquid chromatography (HPLC) and the quantitative analysis of multi-components by single marker (QAMS) was used to detect the contents of five bufagenins. As a result, the reference characteristic chromatogram was established, displaying serotonin, gamabufotalin, arenobufagin, hellebrigenin, telocinobufagin, bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin as characteristic peaks. Taking cinobufagin as an internal reference substance, QAMS was verified for the determination of five bufagenins (gamabufotalin, bufotalin, bufalin, cinobufagin, resibufogenin) in toad venom samples. The durability and applicability of the relative correction factor (RCF) were also studied systematically. RCFs of cinobufagin to gamabufotalin, bufotalin, bufalin and resibufogenin were determined as 1.05, 0.895, 1.09 and 0.913, respectively. The characteristic chromatogram and QAMS established in this study could effectively control the quality of toad venom and provide scientific evidence for the improvement of the quality standard of the toad venom to be described in Chinese Pharmacopoeia (2020 edition).


Assuntos
Venenos de Anfíbios/análise , Bufanolídeos , Animais , Cromatografia Líquida de Alta Pressão , Controle de Qualidade
20.
Zhongguo Zhong Yao Za Zhi ; 43(14): 2872-2877, 2018 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-30111044

RESUMO

To systematically identify the related substances in the original materials of breviscapine injection, 18 batches of samples collected from different pharmaceutical companies, its ethanol extract and breviscapine mother liquor concentrate were analyzed by high performance liquid chromatography (HPLC), and their structures were identified by ultra performance liquid chromatography and quadruple/time-of-flight mass spectrometry (UPLC-QTOF-MS). Under the selected chromatographic conditions, scutellarin and related substances have good resolution and 13 related substances were observed. Based on the molecular weight and fragmentation patterns obtained by UPLC-QTOF-MS as well as reference substances, their structures were elucidated as 6-hydroxyapigenin-6-O-glucosyl-7-O-glucuronide (1), 5,7,8,3',4',5'-hexahydroxyflavone-7-O-glucuronide (2), 5,6,7,3',4'-pentahydroxyflavone-7-O-glucuronide(3)and its isomer (4), patuletin-3-O-glucuronide (5), methoxylscutellarin (6), apigenin 7-O-glucuronide (7), isorhamnetin 7-O-glucuronide (8), diosmetin 7-O-glucuronide (9), scutellarein (10), scutellarin methyl ester (11), scutellarin ethyl ester (12), and apigenin (13). This study has clarified related substances in the original materials of breviscapine injection, providing references for the improvement of quality control for breviscapine drug material and its preparations.


Assuntos
Cromatografia Líquida de Alta Pressão , Flavonoides , Espectrometria de Massas
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