Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Brief Bioinform ; 25(4)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38864340

RESUMO

G-protein coupled receptors (GPCRs), crucial in various diseases, are targeted of over 40% of approved drugs. However, the reliable acquisition of experimental GPCRs structures is hindered by their lipid-embedded conformations. Traditional protein-ligand interaction models falter in GPCR-drug interactions, caused by limited and low-quality structures. Generalized models, trained on soluble protein-ligand pairs, are also inadequate. To address these issues, we developed two models, DeepGPCR_BC for binary classification and DeepGPCR_RG for affinity prediction. These models use non-structural GPCR-ligand interaction data, leveraging graph convolutional networks and mol2vec techniques to represent binding pockets and ligands as graphs. This approach significantly speeds up predictions while preserving critical physical-chemical and spatial information. In independent tests, DeepGPCR_BC surpassed Autodock Vina and Schrödinger Dock with an area under the curve of 0.72, accuracy of 0.68 and true positive rate of 0.73, whereas DeepGPCR_RG demonstrated a Pearson correlation of 0.39 and root mean squared error of 1.34. We applied these models to screen drug candidates for GPR35 (Q9HC97), yielding promising results with three (F545-1970, K297-0698, S948-0241) out of eight candidates. Furthermore, we also successfully obtained six active inhibitors for GLP-1R. Our GPCR-specific models pave the way for efficient and accurate large-scale virtual screening, potentially revolutionizing drug discovery in the GPCR field.


Assuntos
Descoberta de Drogas , Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Ligantes , Descoberta de Drogas/métodos , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Sítios de Ligação
2.
Bioorg Chem ; 147: 107387, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38643561

RESUMO

Histamine 4 receptor (H4R), the most recently identified subtype of histamine receptor, primarily induces inflammatory reactions upon activation. Several H4R antagonists have been developed for the treatment of inflammatory bowel disease (IBD) and atopic dermatitis (AD), but their use has been limited by adverse side effects, such as a short half-life and toxicity. Natural products, as an important source of anti-inflammatory agents, offer minimal side effects and reduced toxicity. This work aimed to identify novel H4R antagonists from natural products. An H4R target-pathway model deconvoluted downstream Gi and MAPK signaling pathways was established utilizing cellular label-free integrative pharmacology (CLIP), on which 148 natural products were screened. Cryptotanshinone was identified as selective H4R antagonist, with an IC50 value of 11.68 ± 1.30 µM, which was verified with Fluorescence Imaging Plate Reader (FLIPR) and Cellular Thermal Shift (CTS) assays. The kinetic binding profile revealed the noncompetitive antagonistic property of cryptotanshinone. Two allosteric binding sites of H4R were predicted using SiteMap, Fpocket and CavityPlus. Subsequent molecular docking and dynamics simulation indicated that cryptotanshinone interacts with H4R at a pocket formed by the outward interfaces between TM3/4/5, potentially representing a new allosteric binding site for H4R. Overall, this study introduced cryptotanshinone as a novel H4R antagonist, offering promise as a new hit for drug design of H4R antagonist. Additionally, this study provided a novel screening model for the discovery of H4R antagonists.


Assuntos
Produtos Biológicos , Relação Dose-Resposta a Droga , Descoberta de Drogas , Receptores Histamínicos H4 , Humanos , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Receptores Histamínicos H4/antagonistas & inibidores , Receptores Histamínicos H4/metabolismo , Relação Estrutura-Atividade , Estrutura Molecular , Fenantrenos/farmacologia , Fenantrenos/química , Antagonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores Histamínicos/química , Simulação de Acoplamento Molecular , Fenótipo
3.
Bioorg Chem ; 131: 106308, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36516520

RESUMO

Muscarine acetylcholine receptors (mAChRs) regulate a variety of central and peripheral physiological functions and emerge as important therapeutic targets for a number of diseases including chronic obstructive pulmonary disease (COPD). Inspired by two active natural products, we designed and synthesized a series of 2-(2,2-diarylethyl)-cyclamine derivatives for screening M3 mAChR antagonists. On this skeleton, the structural units including N heterocycle, aryl groups and its substituents on aryl were examined and resulted in a clear structure-activity relationships on the M3 mAChR. In general, these 2-(2,2-diarylethyl)-cyclamine derivatives exhibited good to excellent M3 antagonistic potency and receptor selectivity. The most active 5b-C1 had an IC50 value of 3 nM and the most of compound 6 displayed inactivity against histamine H1 receptor closely related to M3. In in vitro and in vivo evaluations of tracheo-relaxation function, some compounds even showed comparable activity to tiotropium bromide, a known blockbuster drug for COPD. Such excellent properties made these novel compounds potential candidates for COPD drug development.


Assuntos
Antagonistas Muscarínicos , Doença Pulmonar Obstrutiva Crônica , Humanos , Antagonistas Muscarínicos/uso terapêutico , Derivados da Escopolamina/química , Derivados da Escopolamina/uso terapêutico , Receptor Muscarínico M3 , Brometo de Tiotrópio/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico
4.
Bioorg Chem ; 130: 106257, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36375349

RESUMO

Ten new indole alkaloids (1-10) as well as eleven known analogs (11-21) were isolated from the stems and hooks of Uncaria rhynchophylla. Their structure elucidation was based on extensive NMR studies, MS and ECD data, with the essential aid of DFT prediction of ECD spectra. Compound 1 was determined as a 17,19-seco-cadambine-type alkaloid, and compound 3 was confirmed to be a 3,4-seco-tricyclic monoterpene indole alkaloid, which are the first seco-alkaloids possessing such cleavage positions from U. rhynchophylla. All the isolated compounds were evaluated for their bioactivities on dopamine D2 and Mu opioid receptors for discovering natural therapeutic drugs targeting central nervous system (CNS) diseases. Compounds 1, 2, 4, 5, 20 and 21 showed antagonistic bioactivities on the D2 receptor (IC50 0.678-15.200 µM), and compounds 1, 3, 6, 9, 10, 13, 18, 19 and 21 exhibited antagonistic effects on the Mu receptor (IC50 2.243-32.200 µM). Among them, compounds 1 and 21 displayed dual-target activities. Compound 1 showed conspicuous antagonistic activity on D2 and Mu receptors with the IC50 values of 0.678 ± 0.182 µM and 13.520 ± 2.480 µM, respectively. Compound 21 displayed moderate antagonistic activity on the two receptors with the IC50 values at 15.200 ± 1.764 µM and 32.200 ± 5.695 µM, respectively.


Assuntos
Antagonistas dos Receptores de Dopamina D2 , Alcaloides Indólicos , Uncaria , Alcaloides/química , Alcaloides/farmacologia , Dopamina/metabolismo , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/química , Receptores Opioides mu/antagonistas & inibidores , Uncaria/química , Antagonistas dos Receptores de Dopamina D2/química , Antagonistas dos Receptores de Dopamina D2/farmacologia , Antagonistas de Entorpecentes/química , Antagonistas de Entorpecentes/farmacologia
5.
J Sep Sci ; 46(10): e2200704, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36896497

RESUMO

Ziziphi spinosae semen has been widely used to treat insomnia and anxiety. To profile its chemical components, an online comprehensive two-dimensional liquid chromatography-mass spectrometry was developed. In this two-dimensional liquid chromatography system, a novel phthalic anhydride-bonded stationary phase column was combined with a C18 column. As a result, this new stationary phase exhibited remarkable differences in separation selectivity from C18, achieving a good orthogonality of 83.3%. Moreover, this new stationary phase with weaker hydrophobicity than C18 realized solvent compatibility in the online configuration. Coupled with tandem MS, 154 compounds were identified, including 51 unreported compounds. Compared with one-dimensional liquid chromatography-mass spectrometry, this online two-dimensional liquid chromatography-mass spectrometry system exhibited a much higher resolving power in isomer separation. This work provided an effective separation and characterization method for the material basis of Ziziphi spinosae semen. This strategy provides ideas for the material basis research of other traditional Chinese medicines.


Assuntos
Anidridos Ftálicos , Sementes , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Espectrometria de Massas/métodos
6.
Bioorg Chem ; 127: 106027, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35878451

RESUMO

A total of 33 structurally diverse isoquinoline alkaloids were isolated from the rhizomes of Menispermum dauricum, including seventeen benzylisoquinoline analogues (menisperdaurines A-Q, 1-17), five protoberberine analogues (menisperdaurines R-V, 18-22), a quaternary phenanthrene alkaloid (menisperdaurine W, 23) and ten known compounds (24-33). Compound structures, including absolute configurations, were determined by extensive spectroscopic methods, quantum chemical calculations of chemical shifts, and calculated and experimental electronic circular dichroism (ECD) data. Compounds 1-5 were glycosidic benzylisoquinolines with glucose moieties attached at the C-12 position. Compound 8 was the first example that was isolated from the rhizomes of Menispermum dauricum, benzylisoquinoline and an aromatic unit connected by a sugar bridge. Compounds were evaluated for their inhibitory effects on the dopamine D1 receptor. Compounds 1, 8, 21, 24 and 29 showed potent D1 antagonistic activities, with IC50 values ranging from 1.0 to 4.5 µM. Compound 1 exhibited the highest antagonistic activity with an IC50 value of 1.0 ± 0.2 µM.


Assuntos
Alcaloides , Benzilisoquinolinas , Menispermum , Alcaloides/química , Alcaloides/farmacologia , Isoquinolinas/farmacologia , Menispermum/química , Estrutura Molecular , Receptores de Dopamina D1
7.
Int J Mol Sci ; 23(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36142671

RESUMO

ATP citrate lyase (ACLY) is a key enzyme in glucolipid metabolism and its aberrantly high expression is closely associated with various cancers, hyperlipemia and atherosclerotic cardiovascular diseases. Prospects of ACLY inhibitors as treatments of these diseases are excellent. To date, flavonoids have not been extensively reported as ACLY inhibitors. In our study, 138 flavonoids were screened and 21 of them were subjected to concentration-response curves. A remarkable structure-activity relationship (SAR) trend was found: ortho-dihydroxyphenyl and a conjugated system maintained by a pyrone ring were critical for inhibitory activity. Among these flavonoids, herbacetin had a typical structure and showed a non-aggregated state in solution and a high inhibition potency (IC50 = 0.50 ± 0.08 µM), and therefore was selected as a representative for the ligand-protein interaction study. In thermal shift assays, herbacetin improved the thermal stability of ACLY, suggesting a direct interaction with ACLY. Kinetic studies determined that herbacetin was a noncompetitive inhibitor of ACLY, as illustrated by molecular docking and dynamics simulation. Together, this work demonstrated flavonoids as novel and potent ACLY inhibitors with a remarkable SAR trend, which may help design high-potency ACLY inhibitors. In-depth studies of herbacetin deepened our understanding of the interactions between flavonoids and ACLY.


Assuntos
ATP Citrato (pro-S)-Liase , Pironas , ATP Citrato (pro-S)-Liase/metabolismo , Flavonoides/farmacologia , Cinética , Ligantes , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade
8.
Molecules ; 27(22)2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36431815

RESUMO

Curcuma kwangsiensis, one species of Curcumae zedoaria Ros. c, is a commonly used traditional Chinese medicine (TCM) for treating cardiovascular disease, cancer, asthma and inflammation. Polar compounds are abundant in water decoction, which would be responsible for critical pharmacological effects. However, current research on polar compounds in Curcumae zedoaria Ros. c remains scarce. In this study, the polar fraction from Curcuma kwangsiensis was firstly profiled on G protein-coupled receptor 109A (GPR109A), ß2-adrenergic receptor (ß2-AR), neurotensin receptor (NTSR), muscarinic-3 acetylcholine receptor (M3) and G protein-coupled receptor 35 (GPR35), which were involved in its clinical indications and exhibited excellent ß2-AR and GPR109A receptor activities. Then, an offline two-dimensional reversed-phase liquid chromatography (RPLC) coupled with the hydrophilic interaction chromatography (HILIC) method was developed to separate polar compounds. By the combination of a polar-copolymerized XAqua C18 column and an amide-bonded XAmide column, an orthogonality of 47.6% was achieved. As a result of coupling with the mass spectrometry (MS), a four-dimensional data plot was presented in which 373 mass peaks were detected and 22 polar compounds tentatively identified, including the GPR109A agonist niacin. Finally, molecular docking of these 22 identified compounds to ß2-AR, M3, GPR35 and GPR109A receptors was performed to predict potential active ingredients, and compound 9 was predicted to have a similar interaction to the ß2-AR partial agonist salmeterol. These results were supplementary to the material basis of Curcuma kwangsiensis and facilitated the bioactivity research of polar compounds. The integration of RPLC×HILIC-MS and molecular docking can be a powerful tool for characterizing and predicting polar active components in TCM.


Assuntos
Curcuma , Simulação de Acoplamento Molecular , Espécies Reativas de Oxigênio , Cromatografia Líquida/métodos , Espectrometria de Massas
9.
Zhongguo Zhong Yao Za Zhi ; 47(6): 1595-1602, 2022 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-35347958

RESUMO

Bombesin receptor subtype-3(BRS-3) is an orphan receptor in the bombesin receptor family. Its signal transduction mechanism and biological function have attracted much attention. Seeking the ligand for BRS-3 is of great significance for exploring its function. Considering the fact that the activation of BRS-3 receptor can induce the change in intracellular Ca~(2+) concentration, the fluo-rometric imaging plate reader(FLIPR) was utilized for ligand screening at the cellular level. Among more than 400 monomeric compounds isolated from Chinese herbs, yuanhunine from Corydalis Rhizoma and sophoraisoflavanone A and licoriphenone from Glycyrrhizae Radix et Rhizoma antagonized BRS-3 to varying degrees. It was confirmed in HEK293 cells expressing BRS-3 that yuanhunine, sophoraisoflavanone A, and licoriphenone inhibited the calcium current response after the activation of BRS-3 by [D-Phe~6,ß-Ala~(11),Phe~(13),Nle~(14)]bombesin-(6-14) in a dose-dependent manner with the IC_(50) values being 8.58, 4.10, and 2.04 µmol·L~(-1), respectively. Further study indicated that yuanhunine and sophoraisoflavanone A exhibited good selectivity for BRS-3. In this study, it was found for the first time that monomers derived from Chinese herbs had antagonistic activity against orphan receptor BRS-3, which has provided a tool for further study of BRS-3 and also the potential lead compounds for new drug discovery. At the same time, it provides reference for the research and development of innovative drugs based on the active ingredients of Chinese herbs.


Assuntos
Medicamentos de Ervas Chinesas , Receptores da Bombesina , Medicamentos de Ervas Chinesas/química , Células HEK293 , Humanos , Ligantes
10.
Pharmacol Res ; 163: 105173, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33027715

RESUMO

FFA4 is a novel therapeutic target for the treatment of metabolic diseases, such as type II diabetes. However, there are still few ligands with structural diversity, selectivity and high potency, and the signaling pathway downstream of FFA4 remains to be poorly characterized. In this study, a high performance liquid chromatography-corona charged aerosol detector (HPLC-CAD) combined with label-free dynamic mass redistribution (DMR) method was introduced to guide the discovery of FFA4 agonists from Arnebia euchroma (Royle) Johnst. Ten compounds were identified as FFA4 agonists and structure-activity relationship was obtained. Among them, shikonin displayed the most potent activity with pEC50 value of 6.02 ± 0.19. The activity of shikonin was confirmed by FLIPR (fluorometric imaging plate reader) assay. Signaling pathways of FFA4 were explored in HT-29 cells endogenously expressing FFA4 using shikonin and known FFA4 agonists α-linolenic acid (ALA) and TUG891. Multiple pathways included Gq/11-PLC-Ca2+-PKC, RohA, JNK, p38 MAPK, Gi/o and PI3K signaling but may not involve Gs signaling triggered by shikonin, ALA and TUG891. Besides, shikonin, TUG891 and ALA could induce ERK1/2 and AKT phosphorylation in HT-29 cells. Moreover, anti-diabetes effects of shikonin were evaluated on the glucose intolerance in diabetic db/db mice. Shikonin reduced plasma glucose level, suggesting that it had the potential in treatment of type II diabetes. The agonists identified in this study provided structure guidance for FFA4 drug design. This study was also useful for understanding FFA4 pharmacology and its biological function.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Naftoquinonas/uso terapêutico , Receptores Acoplados a Proteínas G/agonistas , Animais , Boraginaceae , Células CHO , Cricetulus , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Células HT29 , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Naftoquinonas/química , Naftoquinonas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Relação Estrutura-Atividade
11.
Bioorg Chem ; 107: 104517, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33280831

RESUMO

Fifteen new bisbenzylisoquinoline alkaloids (1-15) were isolated from the rhizome of Menispermum dauricum DC. Compounds 1-9 were new N-oxides of dauricine-type alkaloids. Compounds 10-14 were rare tail-to-tail quaternary alkaloids. Their structures were characterized by comprehensive analysis of spectroscopic data, and absolute configurations were established from electronic circular dichroism (ECD) data and ECD calculations. Compounds were assayed on analgesic-related G-protein coupled receptors (GPCRs) including dopamine D1 and D2 receptors, opioid Mu receptor and muscarinic M3 receptor. Compound 1 showed high affinity and selective antagonistic activity on the M3 receptor with an IC50 value of 2.2 ± 0.5 µM; compound 15 exhibited the highest antagonistic affinity among the evaluated compounds on Mu (IC50 = 1.1 ± 0.6 µM) and it also acted as a D1 receptor antagonist (IC50 = 8.8 ± 2.9 µM). These findings expanded the existing library of bisbenzylisoquinoline alkaloids and provided new structures for the related future drug design and synthesis.


Assuntos
Analgésicos/farmacologia , Benzilisoquinolinas/farmacologia , Menispermum/química , Rizoma/química , Analgésicos/química , Analgésicos/isolamento & purificação , Benzilisoquinolinas/química , Benzilisoquinolinas/isolamento & purificação , Células HEK293 , Humanos , Estrutura Molecular , Receptor Muscarínico M3/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores Opioides mu/metabolismo
12.
Bioorg Med Chem Lett ; 30(24): 127650, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33127539

RESUMO

Free fatty acid receptor 4 (FFA4) has been recognized as an attractive target in metabolic diseases. To find potent and selective FFA4 agonist, 28 compounds of 3-(4-(phenoxymethyl)phenyl)propanoic acid and N-phenylbenzenesulfonamide derivatives were designed and synthesized, featuring OC and SO2-N linkage. For the OC linkage compounds, 1g showed the most potent FFA4 agonistic activity with a pEC50 of 5.81 ± 0.04 and exhibited at least 64-fold selectivity against FFA1. For SO2-N linkage agonists, 2m had a pEC50 of 5.66 ± 0.04 and displayed>46-fold selectivity against FFA1. Among these two series of compounds, 1g was the most potent agonist at FFA4 and the best selectivity against FFA1, demonstrated by docking simulation. Moreover, 1g showed receptor selectivity on other seven GPCRs. In anti-diabetic evaluation, 1g dose-dependently reduced blood glucose, which was better than a clinical phase III drug TAK875. This study provides guidance for FFA4 ligand design and drug optimization.


Assuntos
Propionatos/química , Propionatos/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Sulfonamidas/química , Sulfonamidas/farmacologia , Humanos , Simulação de Acoplamento Molecular , Propionatos/síntese química , Receptores Acoplados a Proteínas G/metabolismo , Relação Estrutura-Atividade , Sulfonamidas/síntese química
13.
J Sep Sci ; 43(1): 87-104, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31664759

RESUMO

Traditional Chinese medicines have been widely used to prevent and cure diseases for thousands of years. For the purpose of better understanding the extremely complicated traditional Chinese medicines, powerful separation techniques are essential. Two-dimensional liquid chromatography has been proven to be more powerful for the separation of complex traditional Chinese medicines due to its enhanced peak capacity and resolution compared with one-dimensional liquid chromatography. Enormous efforts have been made on the coupling of independent separation mechanisms to improve the resolving power for complex traditional Chinese medicine samples, including the development and introduction of novel stationary phases. This review aims to give an overview on the applications of two-dimensional liquid chromatography in traditional Chinese medicine research since 2008, including comprehensive two-dimensional liquid chromatography, heart-cutting two-dimensional liquid chromatography both in on-line, and off-line mode. Different couplings of separation modes were respectively discussed based on specific studies, with emphasis on the applications of novel stationary phases in the two-dimensional liquid chromatography.


Assuntos
Cromatografia Líquida/métodos , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/química , Medicina Tradicional Chinesa
14.
Entropy (Basel) ; 20(11)2018 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33266552

RESUMO

This paper is dedicated to the study of the geometric average Asian call option pricing under non-extensive statistical mechanics for a time-varying coefficient diffusion model. We employed the non-extensive Tsallis entropy distribution, which can describe the leptokurtosis and fat-tail characteristics of returns, to model the motion of the underlying asset price. Considering that economic variables change over time, we allowed the drift and diffusion terms in our model to be time-varying functions. We used the I t o ^ formula, Feynman-Kac formula, and P a d e ´ ansatz to obtain a closed-form solution of geometric average Asian option pricing with a paying dividend yield for a time-varying model. Moreover, the simulation study shows that the results obtained by our method fit the simulation data better than that of Zhao et al. From the analysis of real data, we identify the best value for q which can fit the real stock data, and the result shows that investors underestimate the risk using the Black-Scholes model compared to our model.

15.
Entropy (Basel) ; 20(1)2018 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33265158

RESUMO

In this paper we consider pricing problems of the geometric average Asian options under a non-Gaussian model, in which the underlying stock price is driven by a process based on non-extensive statistical mechanics. The model can describe the peak and fat tail characteristics of returns. Thus, the description of underlying asset price and the pricing of options are more accurate. Moreover, using the martingale method, we obtain closed form solutions for geometric average Asian options. Furthermore, the numerical analysis shows that the model can avoid underestimating risks relative to the Black-Scholes model.

16.
Entropy (Basel) ; 20(4)2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33265338

RESUMO

To describe the movement of asset prices accurately, we employ the non-extensive statistical mechanics and the semi-Markov process to establish an asset price model. The model can depict the peak and fat tail characteristics of returns and the regime-switching phenomenon of macroeconomic system. Moreover, we use the risk-minimizing method to study the hedging problem of contingent claims and obtain the explicit solutions of the optimal hedging strategies.

17.
Pharmacol Res ; 108: 39-45, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27117668

RESUMO

Neurotensin (NT), an endogenous peptide found in the central nervous system and in peripheral tissues, contributes to the pathophysiology of neurodegenerative and psychiatric diseases, cancer, inflammation, and immunomodulatory disease. NT exerts its physiological effects predominantly through its cognate high-affinity neurotensin receptor-1 (NTS1). NTS1 emerges as a druggable target; however, there are limited numbers of NTS1 active compounds reported to date. Here we reported a label-free cell phenotypic profiling model for screening NTS1 ligands and differentiating their biased agonism. Resonant waveguide grating enabled dynamic mass redistribution (DMR) assay was first optimized against cell confluency and then used to characterize the endogenous NTS1 in HT-29 cell using known agonists and antagonists. Pathway modulators were also used to deconvolute the signaling pathways of endogenous NTS1. Results showed that the NTS1 DMR assay is robust for screening and can differentiate biased agonism; and the activation of NTS1 in HT-29 triggers multiple pathways including Gq signaling and epidermal growth factor receptor transactivation. This study highlighted the power of label-free DMR assay to characterize receptor signaling and pharmacology of distinct classes of ligands for NTS1, G protein-coupled receptors in general.


Assuntos
Técnicas Biossensoriais/métodos , Receptores de Neurotensina/metabolismo , Transdução de Sinais , Avaliação Pré-Clínica de Medicamentos/métodos , Células HT29 , Humanos , Ligantes , Receptores de Neurotensina/agonistas , Receptores de Neurotensina/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
18.
Fitoterapia ; 175: 105956, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38604261

RESUMO

ATP citrate lyase (ACLY) is a key enzyme in glucolipid metabolism, and abnormally high expression of ACLY occurs in many diseases, including cancers, dyslipidemia and cardiovascular diseases. ACLY inhibitors are prospective treatments for these diseases. However, the scaffolds of ACLY inhibitors are insufficient with weak activity. The discovery of inhibitors with structural novelty and high activity continues to be a research hotpot. Acanthopanax senticosus (Rupr. & Maxim.) Harms is used for cardiovascular disease treatment, from which no ACLY inhibitors have ever been found. In this work, we discovered three novel ACLY inhibitors, and the most potent one was isochlorogenic acid C (ICC) with an IC50 value of 0.14 ± 0.04 µM. We found dicaffeoylquinic acids with ortho-dihydroxyphenyl groups were important features for inhibition by studying ten phenolic acids. We further investigated interactions between the highly active compound ICC and ACLY. Thermal shift assay revealed that ICC could directly bind to ACLY and improve its stability in the heating process. Enzymatic kinetic studies indicated ICC was a noncompetitive inhibitor of ACLY. Our work discovered novel ACLY inhibitors, provided valuable structure-activity patterns and deepened knowledge on the interactions between this targe tand its inhibitors.


Assuntos
ATP Citrato (pro-S)-Liase , Eleutherococcus , Eleutherococcus/química , Estrutura Molecular , ATP Citrato (pro-S)-Liase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/química , Ácido Clorogênico/farmacologia , Ácido Clorogênico/isolamento & purificação , Ácido Clorogênico/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/química , Ácido Quínico/análogos & derivados , Ácido Quínico/farmacologia , Ácido Quínico/isolamento & purificação , Ácido Quínico/química , Hidroxibenzoatos/farmacologia , Hidroxibenzoatos/isolamento & purificação , Hidroxibenzoatos/química , Relação Estrutura-Atividade
19.
J Agric Food Chem ; 72(28): 15704-15714, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38976778

RESUMO

Pueraria lobata (Willd.) Ohwi, known as kudzu and used as a "longevity powder" in China, is an edible plant which is rich in flavonoids and believed to be useful for regulating blood sugar and treating diabetes, although the modes of action are unknown. Here, a total of 53 flavonoids including 6 novel compounds were isolated from kudzu using multidimensional preparative liquid chromatography. The flavonoid components were found to lower blood sugar levels, promote urine sugar levels in mice, and reduce the urine volume. Molecular docking and in vitro assays suggested that the antidiabetic effect of kudzu was attributed to at least three targets: sodium-dependent glucose transporter 2 (SGLT2), protein tyrosine phosphatase-1B (PTP1B), and alpha-glucosidase (AG). This study suggests a possible mechanism for the antidiabetic effect that may involve the synergistic action of multiple active compounds from kudzu.


Assuntos
Flavonoides , Hipoglicemiantes , Extratos Vegetais , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Pueraria , Pueraria/química , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Flavonoides/química , Animais , Camundongos , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Simulação de Acoplamento Molecular , Masculino , alfa-Glucosidases/metabolismo , alfa-Glucosidases/química , Glicemia/metabolismo , Plantas Comestíveis/química
20.
J Pharm Biomed Anal ; 248: 116289, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38901158

RESUMO

Traditional Chinese medicines (TCMs) are popular in clinic because of their safety and efficacy. They contain abundant natural active compounds, which are important sources of new drug discovery. However, how to efficiently identify active compounds from complex ingredients remains a challenge. In this study, a method combining UHPLC-MS/MS characterization and in silico screening was developed to discover compounds with dopamine D2 receptor (D2R) activity in Stephania epigaea (S. epigaea). By combining the compounds identified in S. epigaea by UHPLC-MS/MS with reported compounds, a virtual library of 80 compounds was constructed for in silico screening. Potentially active compounds were chosen based on screening scores and subsequently tested for in vitro activity on a transfected cell line CHO-K1-D2 model using label-free cellular phenotypic assay. Three D2R agonists and five D2R antagonists were identified. (-)-Asimilobine, N-nornuciferine and (-)-roemerine were reported for the first time as D2R agonists, with EC50 values of 0.35 ± 0.04 µM, 1.37 ± 0.10 µM and 0.82 ± 0.22 µM, respectively. Their target specificity was validated by desensitization and antagonism assay. (-)-Isocorypalmine, (-)-tetrahydropalmatine, (-)-discretine, (+)-corydaline and (-)-roemeroline showed strong antagonistic activity on D2R with IC50 values of 92 ± 9.9 nM, 1.73 ± 0.13 µM, 0.34 ± 0.02 µM, 2.09 ± 0.22 µM and 0.85 ± 0.08 µM, respectively. Their kinetic binding profiles were characterized using co-stimulation assay and they were both D2R competitive antagonists. We docked these ligands with human D2R crystal structure and analyzed the structure-activity relationship of aporphine-type D2R agonists and protoberberine-type D2R antagonists. These results would help to elucidate the mechanism of action of S. epigaea for its analgesic and sedative efficacy and benefit for D2R drug design. This study demonstrated the potential of integrating UHPLC-MS/MS with in silico and in vitro screening for accelerating the discovery of active compounds from TCMs.


Assuntos
Cricetulus , Receptores de Dopamina D2 , Stephania , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Células CHO , Animais , Cromatografia Líquida de Alta Pressão/métodos , Stephania/química , Receptores de Dopamina D2/metabolismo , Simulação por Computador , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Antagonistas dos Receptores de Dopamina D2/farmacologia , Antagonistas dos Receptores de Dopamina D2/química , Descoberta de Drogas/métodos , Agonistas de Dopamina/farmacologia , Agonistas de Dopamina/química , Humanos , Medicina Tradicional Chinesa/métodos , Espectrometria de Massa com Cromatografia Líquida
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa