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1.
J Sep Sci ; 47(14): e2400288, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39034832

RESUMO

Dalbergia odorifera is a natural product rich in pharmacological ingredients, but the comprehensive characterization and rapid profiling of active components remain a challenge. Thus, an integrated data mining and identification strategy was exploited to efficiently identify the chemical constituents and screen acetylcholinesterase inhibitors (AChEIs) through affinity ultrafiltration and ultra-high-performance liquid chromatography-mass spectrometry (AUF-UHPLC-MS). As a result, polygonal mass defect filtering, diagnostic product ions, and neutral loss rules were created for rapid structural classification and component identification. A total of 140 flavonoids were tentatively characterized, including 41 isoflavonoids, 23 flavanones, 21 isoflavans, 19 flavones and flavonols, 13 neoflavonoids, 11 isoflavanones, seven flavone glycosides, and five chalcones. Subsequently, six natural AChEIs including tectorigenin, fisetin, dalbergin, pterostilbene, isoliquiritigenin, and biochanin A were screened out using AUF-UHPLC-MS and molecular docking. Meanwhile, the AChE inhibitory activities of the six compounds were assessed in vitro, tectorigenin, fisetinand, and dalbergin have moderate inhibitory activity. In conclusion, a novel strategy for systematic characterization and further screening of active compounds in natural products was established, which provides a material basis for quality control of Dalbergia odorifera.


Assuntos
Inibidores da Colinesterase , Dalbergia , Espectrometria de Massas em Tandem , Ultrafiltração , Inibidores da Colinesterase/química , Inibidores da Colinesterase/análise , Dalbergia/química , Cromatografia Líquida de Alta Pressão , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Simulação de Acoplamento Molecular , Flavonoides/química , Flavonoides/análise , Estrutura Molecular , Extratos Vegetais/química
2.
J Phys D Appl Phys ; 57(30)2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38800708

RESUMO

Surface acoustic wave (SAW)-enabled acoustofluidic technologies have recently atttracted increasing attention for applications in biology, chemistry, biophysics, and medicine. Most SAW acoustofluidic devices generate acoustic energy which is then transmitted into custom microfabricated polymer-based channels. There are limited studies on delivering this acoustic energy into convenient commercially-available glass tubes for manipulating particles and fluids. Herein, we have constructed a capillary-based SAW acoustofluidic device for multifunctional fluidic and particle manipulation. This device integrates a converging interdigitated transducer to generate focused SAWs on a piezoelectric chip, as well as a glass capillary that transports particles and fluids. To understand the actuation mechanisms underlying this device, we performed finite element simulations by considering piezoelectric, solid mechanic, and pressure acoustic physics. This experimental study shows that the capillary-based SAW acoustofluidic device can perform multiple functions including enriching particles, patterning particles, transporting particles and fluids, as well as generating droplets with controlled sizes. Given the usefulness of these functions, we expect that this acoustofluidic device can be useful in applications such as pharmaceutical manufacturing, biofabrication, and bioanalysis.

3.
Nat Mater ; 21(5): 540-546, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35332292

RESUMO

Precise and selective manipulation of colloids and biological cells has long been motivated by applications in materials science, physics and the life sciences. Here we introduce our harmonic acoustics for a non-contact, dynamic, selective (HANDS) particle manipulation platform, which enables the reversible assembly of colloidal crystals or cells via the modulation of acoustic trapping positions with subwavelength resolution. We compose Fourier-synthesized harmonic waves to create soft acoustic lattices and colloidal crystals without using surface treatment or modifying their material properties. We have achieved active control of the lattice constant to dynamically modulate the interparticle distance in a high-throughput (>100 pairs), precise, selective and reversible manner. Furthermore, we apply this HANDS platform to quantify the intercellular adhesion forces among various cancer cell lines. Our biocompatible HANDS platform provides a highly versatile particle manipulation method that can handle soft matter and measure the interaction forces between living cells with high sensitivity.


Assuntos
Acústica , Coloides , Coloides/química , Ciência dos Materiais
4.
Langmuir ; 39(49): 18011-18021, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38016011

RESUMO

Porous structure design and reversible regulation of pore size during adsorption-desorption are crucial to the removal of pollutants in water such as Cr(VI). In this paper, micropores and switchable mesopores were constructed on MCM-41 to further improve adsorption-desorption performance of Cr(VI) via the confinement effect of micropores and opening and closing of mesopores. 2-Vinylpyridine was introduced and polymerized into the pores and on the pore mouth of MCM41 modified by C═C group (AM41) under the irradiation of ultraviolet light. The obtained samples (PM41) possessed mesopores (2.73 nm) and micropores (1.36 nm), where mesopores could open or close under different pH and micropores showed the confinement effect because their pore size is close to Cr(VI) diameter (0.87 nm). Compared with MCM-41, the introduction of poly(2-vinylpyridine) enhanced obviously its adsorptive ability and it trapped most of the Cr(VI) (99%) in solution, 12 times higher than that of the parent sample. The change of pore size is favorable to the cycle performance, and after 3 times recycling, the removal rate of Cr(VI) by PM41-20 remained above 88%. Langmuir isotherm showed a better data correlation than the Freundlich model. Cr(VI) in solution was removed by electrostatic interaction between the pyridine group and Cr(VI) and the confinement effect from micropores.

5.
Proc Natl Acad Sci U S A ; 117(20): 10976-10982, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32358194

RESUMO

Advances in gene editing are leading to new medical interventions where patients' own cells are used for stem cell therapies and immunotherapies. One of the key limitations to translating these treatments to the clinic is the need for scalable technologies for engineering cells efficiently and safely. Toward this goal, microfluidic strategies to induce membrane pores and permeability have emerged as promising techniques to deliver biomolecular cargo into cells. As these technologies continue to mature, there is a need to achieve efficient, safe, nontoxic, fast, and economical processing of clinically relevant cell types. We demonstrate an acoustofluidic sonoporation method to deliver plasmids to immortalized and primary human cell types, based on pore formation and permeabilization of cell membranes with acoustic waves. This acoustofluidic-mediated approach achieves fast and efficient intracellular delivery of an enhanced green fluorescent protein-expressing plasmid to cells at a scalable throughput of 200,000 cells/min in a single channel. Analyses of intracellular delivery and nuclear membrane rupture revealed mechanisms underlying acoustofluidic delivery and successful gene expression. Our studies show that acoustofluidic technologies are promising platforms for gene delivery and a useful tool for investigating membrane repair.


Assuntos
Técnicas de Transferência de Genes , Terapia Genética/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Sistema Hematopoético , Células-Tronco , Sobrevivência Celular , Citoplasma , Expressão Gênica , Técnicas de Transferência de Genes/instrumentação , Terapia Genética/instrumentação , Proteínas de Fluorescência Verde/genética , Humanos , Células Jurkat , Plasmídeos , Som
6.
Phytother Res ; 37(12): 5991-6005, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37752617

RESUMO

Hypertension is a progressive metabolic disease characterized by circadian regulation of lipid metabolism disorder. Identifying specific lipid components and maintaining circadian homeostasis of lipid metabolism might be a promising therapeutic strategy for hypertension. Isorhynchophylline (IRP) can regulate lipid metabolism; however, the underlying mechanism of IRP in improving lipid metabolism rhythm disorder is still unclear. The lipid circadian biomarkers and abnormal metabolic pathways intervened by IRP were investigated using diurnal lipidomic research methods. The 24-h circadian changes in mRNA and protein expression levels of circadian genes, including Bmal1, Clock, Cry1, Cry2, Per1, and Per2, and lipid metabolism-related factors (PPARα and LPL) were determined using RT-PCR and western blot analyses, respectively. The underlying mechanisms were intensively investigated by inhibiting Bmal1. Molecular docking and drug affinity responsive target stability analyses were performed to assess the binding affinity of IRP and Bmal1. IRP treatment could effectively improve 24-h blood pressure, ameliorate the lipid metabolic rhythm disorder, reverse the expression levels of circadian rhythm genes, and regulate lipid metabolism-related genes (PPARα and LPL) by mediating Bmal1. This study highlighted the potential effects of IRP in maintaining the circadian homeostasis of lipid metabolism and the treatment of hypertension.


Assuntos
Hipertensão , Transtornos do Metabolismo dos Lipídeos , Ratos , Animais , Ratos Endogâmicos SHR , Metabolismo dos Lipídeos , Simulação de Acoplamento Molecular , PPAR alfa/genética , Ritmo Circadiano/genética , Hipertensão/tratamento farmacológico , Hipertensão/genética , Lipídeos
7.
Molecules ; 27(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35335376

RESUMO

As an important source of cholinesterase inhibitors, alkaloids in natural products have high potential value in terms of exerting pharmacological activities. In this study, a strategy for targeted preparation of cholinesterase inhibitors in Uncaria rhynchophlly (Miq.) Miq. ex Havil (UR) by high-speed counter-current chromatography was provided. In the method, a two-phase polar solvent system composed of ethyl acetate/n-butanol/water (1:4:5, v/v/v) was used, which isolated five alkaloids from the UR extract for the first time. All alkaloids were identified by HR-ESI-MS and NMR as 7-epi-javaniside (1), vincosamide (2), strictosamide (3), cadambine (4), and 3α-dihydrocadambine (5). The poorly resolved compounds 2 and 3 were separated by preparative HPLC (prep-HPLC). Among them, compounds 1, 4, and 5 were firstly obtained from UR. The purity of these plant isolates was 98.8%, 98.7%, 99.2%, 95.7%, and 98.5%, respectively. Compounds 1-5 exhibited an inhibitory effect on acetyl-cholinesterase and butyryl-cholinesterase with an IC50 from 1.47 to 23.24 µg/mL and 1.01 to 18.24 µg/mL. Molecular docking and inhibitory activities indicated that compound 1 showed stronger inhibitory activity on acetyl-cholinesterase and butyryl-cholinesterase.


Assuntos
Uncaria , Inibidores da Colinesterase/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Distribuição Contracorrente/métodos , Simulação de Acoplamento Molecular , Uncaria/química
8.
J Sep Sci ; 44(19): 3540-3550, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34329528

RESUMO

Two new three-phase solvent systems combined with elution-extrusion counter-current chromatography mode were used to study the chemical constituents in Bidens pilosa Linn. var. radiata Sch. Bip. The first novel solvent system consisted of n-hexane, acetonitrile, chloroform, and water in a ratio of 5:5:1:5, which was selected for elution-extrusion counter-current chromatography to separate the n-hexane extraction part. A total of six constituents were obtained from this part in the up phase as the stationary phase and the middle phase as the mobile phase. The second novel solvent system, composed of n-hexane-butyl acetate-acetonitrile-water (3:1:4:3, v/v/v/v), was used for separating ethyl acetate extract of Bidens pilosa Linn. var. radiata Sch. Bip. Eight compounds were successfully isolated using elution-extrusion counter-current chromatography elution-extrusion mode. Fourteen chemical constituents were identified as 2-ß-D-glucopyranosytoxy-1-hydroxy-5(E)-tridecene-7,9,11-triyne (Y1), 3-ß-D-glucopyranosyloxy -1-hydroxy-6(E)-tetradecene-8,10,12-triyne (Y2), 1, 2-dihydroxy-5(E)-tridecene-7,9, 11-triyne (Y3), isorhamnetin (Y4), kaempferol (Y5), icthyothereolacetate (Y6), quercetin-3-O-ß-D- galactopyranosyl-7-O-ß-D-glucopyranoside (W1), quercetin 3-O-ß-L-rhamnopyranoside (W2), neosperidin dihydrochalcone (W3), quercetin (W4), quercetagetin-3,6,4' -trimethoxyl- 7-O-ß-D-glucopyranoside (W5), taxifolin (W6), luteolin (W7), and apigenin (W8) by spectra of 1 H-NMR and 13 C-NMR data. Among them, compounds Y1, Y2, Y3, and Y6 belong to polyacetylene compounds, and the rest were flavonoids. In addition, counter-current chromatography has been used to separate polyacetylene compounds for the first time. All compounds in this method were isolated from Bidens pilosa Linn. var. radiata Sch. Bip. for the first time.


Assuntos
Bidens/química , Distribuição Contracorrente/métodos , Compostos Fitoquímicos , Extratos Vegetais/química , Acetatos/química , Hexanos/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Solventes/química
9.
Horm Metab Res ; 52(10): 712-717, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32365399

RESUMO

Although subacute thyroiditis (SAT) is thought to be a self-limited inflammatory thyroid disease, the recurrence rate of SAT is approximately 10-20%. It is difficult for these patients to stop glucocorticoid treatment, and they are usually bothered with recurrent pain and the side effects of glucocorticoids for more than several months. We describe three cases who were diagnosed with recurrent subacute thyroiditis after a reduction in prednisolone (PSL) dose, either immediately upon the cessation of PSL or shortly thereafter. Their symptoms, including the adverse effects of PSL, severely impacted their quality of life. After a complete assessment, we administered colchicine at 1 mg per day for 1-2 months to control the recurrence of SAT and monitored their routine blood parameters every two weeks. All 3 patients were successfully tapered off of PSL treatment and were free of frequently recurrent SAT. Colchicine may be therapeutic in patients with prednisolone-refractory, recurrent SAT. However, a large-scale, double-blind, controlled, prospective multicenter study is required to provide a solid body of evidence.


Assuntos
Colchicina/uso terapêutico , Resistência a Medicamentos/efeitos dos fármacos , Glucocorticoides/uso terapêutico , Supressores da Gota/uso terapêutico , Terapia de Salvação , Tireoidite Subaguda/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Recidiva , Tireoidite Subaguda/patologia
10.
Adv Funct Mater ; 29(13)2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-31123431

RESUMO

Metasurfaces open up unprecedented potential for wave engineering using subwavelength sheets. However, a severe limitation of current acoustic metasurfaces is their poor reconfigurability to achieve distinct functions on demand. Here a programmable acoustic metasurface that contains an array of tunable subwavelength unit cells to break the limitation and realize versatile two-dimensional wave manipulation functions is reported. Each unit cell of the metasurface is composed of a straight channel and five shunted Helmholtz resonators, whose effective mass can be tuned by a robust fluidic system. The phase and amplitude of acoustic waves transmitting through each unit cell can be modulated dynamically and continuously. Based on such mechanism, the metasurface is able to achieve versatile wave manipulation functions, by engineering the phase and amplitude of transmission waves in the subwavelength scale. Through acoustic field scanning experiments, multiple wave manipulation functions, including steering acoustic waves, engineering acoustic beams, and switching on/off acoustic energy flow by using one design of metasurface are visually demonstrated. This work extends the metasurface research and holds great potential for a wide range of applications including acoustic imaging, communication, levitation, and tweezers.

11.
Bioorg Med Chem ; 26(8): 2061-2072, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29571653

RESUMO

Based on the co-crystal structures of tubulin with plinabulin and Compound 1 (a derivative of plinabulin), a total of 18 novel plinabulin derivatives were designed and synthesized. Their biological activities were evaluated against human pancreatic cancer BxPC-3 cell lines. Two novel Compounds 13d and 13e exhibited potent activities with IC50 at 1.56 and 1.72 nM, respectively. The tubulin polymerization assay indicated that these derivatives could inhibit microtubule polymerization. Furthermore, the interaction between tubulin and these compounds were elucidated by molecular docking. The binding modes of Compounds 13d and 13e were similar to the co-crystal structure of Compound 1. H-π interaction was observed between the aromatic hydrogen of thiophene moiety with Phe20, which could enhance their binding affinities.


Assuntos
Antineoplásicos/síntese química , Dicetopiperazinas/química , Desenho de Fármacos , Moduladores de Tubulina/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Dicetopiperazinas/metabolismo , Dicetopiperazinas/farmacologia , Humanos , Simulação de Acoplamento Molecular , Neoplasias Pancreáticas/patologia , Estrutura Terciária de Proteína , Solubilidade , Relação Estrutura-Atividade , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologia
12.
J Biol Chem ; 291(10): 5406-17, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26750095

RESUMO

Chlorothricin, isolated from Streptomyces antibioticus, is a parent member of spirotetronate family of antibiotics that have long been appreciated for their remarkable biological activities. ChlF1 plays bifunctional roles in chlorothricin biosynthesis by binding to its target genes (chlJ, chlF1, chlG, and chlK). The dissociation constants of ChlF1 to these genes are ∼ 102-140 nm. A consensus sequence, 5'-GTAANNATTTAC-3', was found in these binding sites. ChlF1 represses the transcription of chlF1, chlG, and chlK but activates chlJ, which encodes a key enzyme acyl-CoA carboxyl transferase involved in the chlorothricin biosynthesis. We demonstrate that the end product chlorothricin and likewise its biosynthetic intermediates (demethylsalicycloyl chlorothricin and deschloro-chlorothricin) can act as signaling molecules to modulate the binding of ChlF1 to its target genes. Intriguingly, a correlation between the antibacterial activity and binding ability of signaling molecules to the regulator ChlF1 is clearly observed. These features of the signaling molecules are associated with the glycosylation of spirotetronate macrolide aglycone. The findings provide new insights into the TetR family regulators responding to special structure of signaling molecules, and we reveal the regulatory mini-network mediated by ChlF1 in chlorothricin biosynthesis for the first time.


Assuntos
Aminoglicosídeos/biossíntese , Antibacterianos/biossíntese , Produtos Finais de Glicação Avançada/metabolismo , Streptomyces antibioticus/metabolismo , Aminoglicosídeos/metabolismo , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transdução de Sinais , Streptomyces antibioticus/genética
13.
Nat Chem Biol ; 11(4): 259-65, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25730548

RESUMO

The [4+2] cycloaddition remains one of the most intriguing transformations in synthetic and natural products chemistry. In nature, however, there are remarkably few enzymes known to have this activity. We herein report an unprecedented enzymatic [4+2] cyclization cascade that has a central role in the biosynthesis of pyrroindomycins, which are pentacyclic spirotetramate natural products. Beginning with a linear intermediate that contains two pairs of 1,3-diene and alkene groups, the dedicated cyclases PyrE3 and PyrI4 act in tandem to catalyze the formation of two cyclohexene rings in the dialkyldecalin system and the tetramate spiro-conjugate of the molecules. The two cyclizations are completely enzyme dependent and proceed in a regio- and stereoselective manner to establish the enantiomerically pure pentacyclic core. Analysis of a related spirotetronate pathway confirms that homologs are functionally exchangeable, establishing the generality of these findings and explaining how nature creates diverse active molecules with similar rigid scaffolds.


Assuntos
Química/métodos , Liases Intramoleculares/química , Macrolídeos/síntese química , Pirrolidinonas/química , Alcenos/química , Produtos Biológicos/química , Catálise , Ciclização , Cicloexenos/química , DNA Bacteriano/química , Liases Intramoleculares/síntese química , Macrolídeos/química , Modelos Químicos , Estrutura Molecular , Mutação , Plasmídeos/metabolismo , Pirrolidinonas/síntese química , Proteínas Recombinantes/química , Estereoisomerismo , Streptomyces/metabolismo
14.
Org Biomol Chem ; 15(1): 88-91, 2016 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-27942669

RESUMO

We herein report the isolation and characterization of a key linear intermediate in the biosynthetic pathway of pyrroindomycins, the potent spirotetramate natural products produced by Streptomyces rugosporus. This polyene intermediate bears a γ-hydroxymethyl group that is exocyclic to the tetramate moiety, indicating that a serine residue serves as the three-carbon unit for tetramate formation and chain-elongation termination. The further conversion involves an acetylation-elimination of the exocyclic γ-hydroxymethyl group to generate a γ-methylene group, which is indispensable for intramolecular [4 + 2] cross-bridging to construct the characteristic pentacyclic core. The findings presented in this study provide new insights into the biosynthesis of pyrroindomycins, and thus suggest a common paradigm for both spirotetramates and spirotetronates in processing the exocyclic γ-hydroxymethyl group of the five-membered heterocycle.


Assuntos
Macrolídeos/metabolismo , Streptomyces/metabolismo , Acetilação , Produtos Biológicos/metabolismo , Vias Biossintéticas , Metano/análogos & derivados , Metano/metabolismo , Metilação
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(1): 151-6, 2016 Jan.
Artigo em Zh | MEDLINE | ID: mdl-27228759

RESUMO

Due to the intrinsic fluorescence characteristic of tyrosine (Tyr) and phenylalanine (Phe), synchronization fluorescence spectrum technology which adopted the constant wavelength difference (Δλ = 15 nm) was selected to investigate the effects of collagen-based surfactant (CBS) concentration, pH, NaCt concentration and temperature on the aggregation state of CBS molecules in aqueous solutions. Meanwhile, temperature-dependent two-dimensional (2D) synchronization fluorescence correlation analyses was used to investigate the variation order of Tyr and Phe residues in CBS molecules with the change of temperature. The results showed that the characteristic absorption peaks located at 261 and 282 nm were attributed to Phe and Tyr, respectively. With the increase of CBS concentration, the amount of Phe and Tyr residues increased gradually which resulted in the increase of aggregate degree of CBS molecules and then led to the increase of fluorescence intensity. When the pH value (pH 5.0) of CBS solutions was close to the isoelectric point of CBS, the aggregate degree of CBS molecules increased due to the increase of the hydrophobic interaction and the formation ability of hydrogen bond. Additionally, with the increase of NaCl concentration, the repulsion force for inter/intra-molecules of CBS decreased, which helped to improve the aggregation behavior of CBS molecules. However, with the increase of temperature, the aggregation state of CBS was changed to be monomolecular state, and then resulted in the decrease of the fluorescence intensity gradually due to the quenching, the denaturation and the decrease of hydrogen bond formation ability. Furthermore, temperature-dependent 2D synchronization fluorescence correlation spectroscopy demonstrated that at lower temperature (10-40 degrees C), the aggregate state of CBS changed to be loose state and then Phe residues located in the inside of the aggregate varied before Tyr residues; while in the heating process of 45-70 degrees C, the monomolecular state of CBS changed to be random coil conformation, the separation distance between Tyr residues increased and the hydrogen bond formation ability reduced strongly, which led to Tyr residues changed before Phe residues.


Assuntos
Colágeno/química , Espectrometria de Fluorescência , Tensoativos/química
17.
Connect Tissue Res ; 56(3): 244-52, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25689166

RESUMO

Collagen gels from Southern catfish (Silurus meridionalis Chen) skins were prepared via the self-assembly of collagen molecules and simultaneous cross-linking with the N-hydroxysuccinimide adipic acid derivative (NHS-AA). The doses of NHS-AA were converted to [NHS-AA]/[NH2] ratios (0.025-1.6, calculated by the [active ester group] of NHS-AA and [ε-NH2] of lysine and hydroxylysine residues of collagen). When the ratio < 0.05, collagen gels were formed by collagen molecule self-assembly, resulting in the opalescent appearance of collagen gels and the characteristic D-periodicity of partial collagen fibrils, the collagen gel ([NHS-AA]/[NH2] = 0.05) displayed a small increase in denaturation temperature (Td, 42.8 °C), remaining weight (12.59%), specific water content (SWC 233.7) and elastic modulus (G' 128.4 Pa) compared with uncross-linked collagen gel (39.1 °C, 9.12%, 222.4 and 85.4 Pa, respectively). As the ratio > 0.05, disappearance of D-periodicity and a gradual change in appearance from opalescent to transparent suggested that the inhibition of NHS-AA in the self-assembly of collagen molecules was more obvious. As a result, the collagen gel ([NHS-AA]/[NH2] = 0.2) had the lowest Td (35.8 °C), remaining weight (7.96%), SWC (130.9) and G' (31.9 Pa). When the ratio was 1.6, the collagen molecule self-assembly was markedly suppressed and the formation of collagen gel was predominantly via the covalent cross-linking bonds which led to the transparent appearance, and the maximum values of Td (47.0 °C), remaining weight (45.92%) and G' (420.7 Pa) of collagen gel. These results indicated that collagen gels with different properties can be prepared using different NHS-AA doses.


Assuntos
Adipatos/farmacologia , Materiais Biocompatíveis/metabolismo , Colágeno/metabolismo , Reagentes de Ligações Cruzadas/farmacologia , Succinimidas/química , Adipatos/química , Animais , Materiais Biocompatíveis/química , Fenômenos Químicos , Colágeno/química , Reagentes de Ligações Cruzadas/química , Módulo de Elasticidade/efeitos dos fármacos , Matriz Extracelular/metabolismo , Peixes , Géis/química , Temperatura
18.
Connect Tissue Res ; 55(3): 239-47, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24564765

RESUMO

The physicochemical properties of collagen solutions (5 mg/ml) cross-linked by various amounts of glutaraldehyde (GTA) [GTA/collagen (w/w) = 0-0.5] under acidic condition (pH 4.00) were examined. Based on the results of the determination of residual amino group content, sodium dodecyl sulphate-polyacrylamide gel electrophoresis, dynamic rheological measurements, differential scanning calorimetry and atomic force microscopy (AFM), it was proved that the collagen solutions possessed strikingly different physicochemical properties depending on the amount of GTA. At low GTA amounts [GTA/collagen (w/w) ≤ 0.1], the residual amino group contents of the cross-linked collagens decreased largely from 100% to 32.76%, accompanied by an increase in the molecular weight. Additionally, increases of the fiber diameter and the values of G', G″ and η* were measured, while the thermal denaturation temperature (Td) did not change visibly and the fluidity of collagen samples was still retained with increasing the GTA amount. When the ratio of GTA to collagen exceeded 0.1, although the residual amino group content only decreased by ~8.2%, the cross-linked collagen solution [GTA/collagen (w/w) = 0.3] displayed a clear loss of flow and a sudden rise (~2.0 °C) of the Td value compared to the uncross-linked collagen solution, probably illustrating that the collagen solution was converted into a gel with mature network structure-containing nuclei observed in AFM image. It was conjectured that the physicochemical properties of the collagen solutions might be in connection with the cross-linking between collagen molecules from the same aggregate or different aggregates.


Assuntos
Materiais Biocompatíveis/química , Fenômenos Químicos , Colágeno/química , Reagentes de Ligações Cruzadas/química , Glutaral/química , Animais , Varredura Diferencial de Calorimetria/métodos , Géis , Peso Molecular , Agregados Proteicos/fisiologia , Soluções
19.
Nat Prod Res ; : 1-6, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557255

RESUMO

A new compound named raphanised A (1), along with two known methylsulfinyl -butanyl derivatives (2-3) and seven known indole derivatives (4-10), were isolated from the Raphani Semen. Among the indole derivatives, 5 was identified as a new natural product, and 4, 6, 7, 8, 9, 10 were isolated from the genus of Raphanus for the first time. Their structures were elucidated based on the NMR and HR-EI-MS analysis. Additionally, the inhibitory activity of methylsulfinyl-butanyl derivatives 1-3 on SARS CoV-2 3CL protease was evaluated. The results showed that 1-3 exhibited inhibition of SARS-CoV-2 3CL protease activity at concentrations ranging from 3.3 to 30 µM.

20.
Food Funct ; 15(10): 5627-5640, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38722076

RESUMO

Hawthorn fruits have a sweet and sour taste, besides having beneficial therapeutic effects on hyperlipidemia, hypertension, and coronary heart disease, making them widely used in food and clinical medicine. However, their hypotensive effects and potential mechanisms of anti-hypertension still need to be elucidated. This study aims to explore the antihypertensive effect of hawthorn and its monomer hyperoside on spontaneously hypertensive rats through pharmacodynamics, serum metabolomics, and in vivo mechanism studies. After 7 weeks of intervention with hawthorn extract and hyperoside, the blood pressure was significantly reduced. Aortic vascular staining results showed that the injury was significantly improved after intervention with hawthorn extract and hyperoside. According to the serum metabolomics study, the main metabolic pathway regulating blood pressure in hawthorn extract and hyperoside groups was the primary bile acid biosynthesis pathway. Quantitative experiments confirmed that the level of bile acid in the model group was significantly different from that in the normal group, while that in the hawthorn group and the hyperoside group was close to that in the normal group. Based on the prediction of bile acid-hypertension related targets and the literature, nine genes involved in bile acid metabolism and inflammatory pathways were selected for further study. The FXR, TGR5, ET-1, NOS3, Akt1, TNF-α, Ptgs2, ACE2 and Kdr mRNA expression levels in the hawthorn extract and hyperoside groups were significantly different from those in the model groups. In summary, hawthorn extract and hyperoside have a hypotensive effect on spontaneously hypertensive rats through bile acid and inflammation related targets. Hence, hawthorn extract has the potential to become a functional food or an alternative therapy for hypertension.


Assuntos
Anti-Hipertensivos , Pressão Sanguínea , Crataegus , Frutas , Hipertensão , Extratos Vegetais , Quercetina , Ratos Endogâmicos SHR , Animais , Crataegus/química , Ratos , Masculino , Anti-Hipertensivos/farmacologia , Frutas/química , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Extratos Vegetais/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Quercetina/farmacologia , Quercetina/análogos & derivados , Humanos
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