Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Asunto de la revista
País de afiliación
Intervalo de año de publicación
1.
Bioorg Chem ; 151: 107631, 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39018800

RESUMEN

UPLC-Q-TOF-MS combined with mass defect filtering strategies were applied for the phytochemical investigation of Harrisonia perforata, leading to the isolation of thirteen undescribed limonoids named haperforatones A-M (1-13) and seventeen known compounds (14-30). Particularly, haperforatones D-E (4-5) have an unprecedented A, B, C, D-seco-6, 7-nor-C-24-limonoid skeleton, structurally stripped of the five-membered lactone ring B and formed a double bond at the C-5 and C-10 positions. Their 2D structures and relative configurations were identified using spectroscopic data. The absolute configurations of 1, 4, and 6 were established via X-ray diffraction crystallography. All 30 compounds were evaluated for anti-inflammatory potential in LPS-induced Raw 264.7 cell lines. Among those tested compounds, the most potent activity against LPS-induced NO generation was demonstrated by haperforatone F (6), with the IC50 value of inhibition NO production of 7.2 µM. Additionally, 6 could significantly inhibit IL-1ß and IL-6 release and markedly downregulate the protein expression level of iNOS in the LPS-stimulated RAW264.7 cells at 10 µM. The possible mechanism of NO inhibition of 6 was also investigated using molecular docking, which revealed the interaction of compound 6 with the iNOS protein.

2.
Bioorg Chem ; 142: 106958, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37979322

RESUMEN

UPLC-TOF-MS/MDF directed phytochemical research of Chloranthus japonicus led to the isolation of 46 lindenane sesquiterpenoid dimers, which included 13 new analogs. Their structures with absolute configurations were elucidated by analysis of spectroscopic data. Fourteen compounds with ester chains significantly decreased PCSK9 protein level in medium of HepG2 cells, especially for compounds 14 and 29 (5 µM) with inhibition rates of 69.0% and 72.8%, respectively. Compound 14 in HepG2 cells was evaluated via DiI-LDL uptake assays and found to increase LDL uptake by upregulating LDLR mRNA and protein level. Meanwhile, 14 decreased the secretion of PCSK9 protein in medium and downregulated intracellular PCSK9 protein and mRNA level. The discovery of these natural small molecule compounds provides a novel structure basis for design PCSK9 regulators, making them a promising lead for development of new lipid-lowering agents.


Asunto(s)
Proproteína Convertasa 9 , Sesquiterpenos , Humanos , Proproteína Convertasa 9/genética , Proproteína Convertasa 9/metabolismo , Células Hep G2 , Sesquiterpenos/química , ARN Mensajero
3.
Phys Rev Lett ; 127(7): 074801, 2021 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-34459641

RESUMEN

Particle accelerators that use electromagnetic fields to increase a charged particle's energy have greatly advanced the development of science and industry since invention. However, the enormous cost and size of conventional radio-frequency accelerators have limited their accessibility. Here, we demonstrate a miniaccelerator powered by terahertz pulses with wavelengths 100 times shorter than radio-frequency pulses. By injecting a short relativistic electron bunch to a 30-mm-long dielectric-lined waveguide and tuning the frequency of a 20-period terahertz pulse to the phase-velocity-matched value, precise and sustained acceleration for nearly 100% of the electrons is achieved with the beam energy spread essentially unchanged. Furthermore, by accurately controlling the phase of two terahertz pulses, the beam is stably accelerated successively in two dielectric waveguides with close to 100% charge coupling efficiency. Our results demonstrate stable and scalable beam acceleration in a multistage miniaccelerator and pave the way for functioning terahertz-driven high-energy accelerators.

4.
Fitoterapia ; 175: 105951, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38583637

RESUMEN

Four undescribed amide alkaloids hongkongensines A-C and 1-(1-oxo-6-hydroxy-2E,4E-dodecadienyl)-piperidine, five known amide alkaloids, and three known neolignans were isolated from the aerial part of Piper hongkongense. The planar structures of these compounds were determined by detailed analyses of HR-ESI-MS and NMR data. The absolute configurations of hongkongensines A-C were elucidated by single-crystal X-ray diffraction analysis and ECD calculations. Moreover, the inhibitory activities of PCSK9 expression in vitro for all compounds were assessed by PCSK9 AlphaLISA screening. Kadsurenone (10) displayed a significant inhibitory activity at 5 µM with an inhibition rate of 51.98%, compared with 55.55% of berberine (BBR 5 µM).


Asunto(s)
Alcaloides , Lignanos , Inhibidores de PCSK9 , Fitoquímicos , Piper , Componentes Aéreos de las Plantas , Piper/química , Estructura Molecular , Alcaloides/farmacología , Alcaloides/aislamiento & purificación , Alcaloides/química , Lignanos/farmacología , Lignanos/aislamiento & purificación , Humanos , Fitoquímicos/farmacología , Fitoquímicos/aislamiento & purificación , Componentes Aéreos de las Plantas/química , Amidas/farmacología , Amidas/aislamiento & purificación , Amidas/química , Proproteína Convertasa 9/metabolismo , China
5.
Fitoterapia ; 174: 105840, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38296167

RESUMEN

The phytochemical investigation of the aerial parts of Isodon japonica var. glaucocalyx afforded four undescribed (glaucocalyxin O-R, 1-4) and six known ent-kauranoids (5-10). Their structures were established using NMR and MS measurements. Compounds 1 and 2 are dimeric ent-kaurane-type diterpenoids. Moreover, the plausible biogenetic pathways for compounds 1 and 2 were proposed as Michael addition between two monomers. Eight compounds were assayed for their anti-inflammatory activity by evaluating NO production in LPS-induced RAW 267.4 cells, and compounds 7, 8 and 9 exhibited relatively remarkable anti-inflammatory activities at 10 µM.


Asunto(s)
Antineoplásicos Fitogénicos , Diterpenos de Tipo Kaurano , Diterpenos , Isodon , Isodon/química , Estructura Molecular , Diterpenos de Tipo Kaurano/farmacología , Diterpenos de Tipo Kaurano/química , Diterpenos/química , Antiinflamatorios/farmacología , Antineoplásicos Fitogénicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales
6.
J Med Chem ; 67(14): 12055-12067, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38959380

RESUMEN

PCSK9 has been recognized as an efficient target for hyperlipidemia and related cardiovascular/cerebrovascular diseases. However, PCSK9 inhibitors in the clinic are all biological products, and no small molecules are available yet. In the current work, we discovered that the crude extract of Euphorbia esula (E. esula) promoted LDL uptake in vitro and then obtained 8 new and 12 known jatrophane diterpenoids by activity-guided isolation. After summarized their structure-activity relationship of PCSK9 inhibition, we selected compound 11 (C11) with potent activity and high abundance to investigate its mechanism and in vivo efficacy. Mechanistically, C11 bound with HNF1α to influence its nuclear distribution and subsequently inhibit PCSK9 transcription, thereby enhancing LDLR and promoting LDL uptake. Moreover, C11 demonstrated obvious lipid-lowering activity in HFD mouse model. In conclusion, we first revealed the novel application of E. esula in the discovery of a lipid-lowering candidate and highlighted the potential of C11 in the treatment of hyperlipidemia.


Asunto(s)
Diterpenos , Euphorbia , Proproteína Convertasa 9 , Euphorbia/química , Diterpenos/farmacología , Diterpenos/química , Diterpenos/aislamiento & purificación , Animales , Proproteína Convertasa 9/metabolismo , Proproteína Convertasa 9/genética , Humanos , Ratones , Relación Estructura-Actividad , Masculino , Hiperlipidemias/tratamiento farmacológico , Hiperlipidemias/metabolismo , Células Hep G2 , Ratones Endogámicos C57BL , Transcripción Genética/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Inhibidores de PCSK9
7.
Phytochemistry ; 226: 114219, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38997098

RESUMEN

Eight previously undescribed sesquiterpene lactones (1-8), together with six known ones (9-14) were isolated from the aerial parts of Tithonia diversifolia (Hemsl.) A. Gray. The absolute configurations of these compounds were elucidated using HRMS, NMR spectroscopy, optical rotation measurements, X-ray crystallography, and ECD. Among them, sesquiterpene lactones 2-4 share a unique carbon skeleton with a rare C-3/C-4 ring-opened structure. Compounds 1 and 8 showed moderate inhibitory effects toward CT26 murine colon carcinoma cells by promoting lipid ROS production, highlighting their potential as ferroptosis inducers.

8.
Phytochemistry ; 219: 113962, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38185394

RESUMEN

Thirteen previously undescribed iridoids (1-13), together with five known iridoids (14-18) were isolated from the roots and rhizomes of Valeriana jatamansi Jones. Their structures with absolute configurations were elucidated by analysis of MS, NMR, optical rotation and their experimental and calculated electronic circular dichroism spectra. All of the isolated compounds were tested for their protective effects against α-hemolysin-induced cell death in A549 cells. Compounds 14, 16 and 17 showed moderate protective effects, and compounds 15 and 18 showed weak protective effects.


Asunto(s)
Nardostachys , Valeriana , Rizoma , Valeriana/química , Proteínas Hemolisinas/análisis , Estructura Molecular , Iridoides/farmacología , Iridoides/química , Raíces de Plantas/química
9.
Rev Sci Instrum ; 91(10): 104703, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33138552

RESUMEN

To achieve the application of a periodic permanent magnet in high power microwave, a compact coaxial cusped periodic permanent magnet (CPPM) focusing system is constructed. The system consists of permanent magnets with different magnetization directions and soft magnets. Taking the required magnetic field performance and the effect of demagnetization into account, NdFeB and FeCoV are selected as the permanent and soft magnet materials. After the system is constructed, the magnetic field is measured. The results show that the guiding magnetic field strength and period of the CPPM are about 0.29 T and 26 mm, respectively, and the magnetic field distribution of measurement shows good agreement with the simulation results. However, there are some differences between the measurement and simulation results, and the differences are compared and analyzed here.

10.
Stem Cells Int ; 2017: 7427606, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28396689

RESUMEN

[This corrects the article DOI: 10.1155/2016/5385137.].

11.
Stem Cells Int ; 2016: 5385137, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27313626

RESUMEN

Bone tissue engineering is the most promising technology for enhancing bone regeneration. Scaffolds loaded with osteogenic factors improve the therapeutic effect. In this study, the bioactive PEI (polyethylenimine)/pBMP2- (bone morphogenetic protein-2 plasmid-) PLGA (poly(D, L-lactic-co-glycolic acid)) core-shell scaffolds were prepared using coaxial electrospinning for a controlled gene delivery to hPDLSCs (human periodontal ligament stem cells). The pBMP2 was encapsulated in the PEI phase as a core and PLGA was employed to control pBMP2 release as a shell. First, the scaffold characterization and mechanical properties were evaluated. Then the gene release behavior was analyzed. Our results showed that pBMP2 was released at high levels in the first few days, with a continuous release behavior in the next 28 days. At the same time, PEI/pBMP2 showed high transfection efficiency. Moreover, the core-shell electrospun scaffold showed BMP2 expression for a much longer time (more than 28 days) compared with the single axial electrospun scaffold, as evaluated by qRT-PCR and western blot after culturing with hPDLSCs. These results suggested that the core-shell PEI/pBMP2-PLGA scaffold fabricated by coaxial electrospinning had a good gene release behavior and showed a prolonged expression time with a high transfection efficiency.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA