RESUMO
Cytosolic DNA activates cGAS (cytosolic DNA sensor cyclic AMP-GMP synthase)-STING (stimulator of interferon genes) signaling, which triggers interferon and inflammatory responses that help defend against microbial infection and cancer. However, aberrant cytosolic self-DNA in Aicardi-Goutière's syndrome and constituently active gain-of-function mutations in STING in STING-associated vasculopathy with onset in infancy (SAVI) patients lead to excessive type I interferons and proinflammatory cytokines, which cause difficult-to-treat and sometimes fatal autoimmune disease. Here, in silico docking identified a potent STING antagonist SN-011 that binds with higher affinity to the cyclic dinucleotide (CDN)-binding pocket of STING than endogenous 2'3'-cGAMP. SN-011 locks STING in an open inactive conformation, which inhibits interferon and inflammatory cytokine induction activated by 2'3'-cGAMP, herpes simplex virus type 1 infection, Trex1 deficiency, overexpression of cGAS-STING, or SAVI STING mutants. In Trex1-/- mice, SN-011 was well tolerated, strongly inhibited hallmarks of inflammation and autoimmunity disease, and prevented death. Thus, a specific STING inhibitor that binds to the STING CDN-binding pocket is a promising lead compound for STING-driven disease.
Assuntos
Proteínas de Membrana/antagonistas & inibidores , Nucleotídeos Cíclicos/metabolismo , Animais , Sítios de Ligação , Biotinilação , Morte Celular , Exodesoxirribonucleases/deficiência , Humanos , Inflamação/patologia , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Mutação/genética , Fosfoproteínas/deficiência , Domínios Proteicos , Transdução de SinaisRESUMO
The glycoprotein hemagglutinin of influenza virus plays a key role in the initial stage of virus infection, making it a potential target for novel influenza viruses entry inhibitors. Two "privileged fragments", 2-(piperidin-1-yl)ethan-1-amine and 2-(1,3-oxazinan-3-yl)ethan-1-amine were integrated into 3-O-ß-chacotriosyl ursolic acid producing new derivatives 5 and 6 with improved activity against IAVs in vitro. Mechanistically, compound 6 was effective in inhibiting infection of H1-, H3-, and H5-typed influenza A viruses by interfering with the viral hemagglutinin. Furthermore, the docking studies were in agreement with the antiviral data. These results showed that the title compound 6 as a new lead compound was meriting further optimization and development.
Assuntos
Aminas/farmacologia , Antivirais/farmacologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Triterpenos/farmacologia , Células A549 , Aminas/química , Animais , Antivirais/síntese química , Antivirais/química , Cães , Relação Dose-Resposta a Droga , Humanos , Células Madin Darby de Rim Canino , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Triterpenos/química , Internalização do Vírus/efeitos dos fármacos , Ácido UrsólicoRESUMO
Currently, it is in urgent need to develop novel selective PDE4 inhibitors with novel structural scaffolds to overcome the adverse effects and improve the efficacy. Novel 1-phenyl-3,4-dihydroisoquinoline amide derivatives were developed as potential PDE4 inhibitors based on the structure-based drug design and fragment identification strategy. A SARs analysis was performed in substituents attached in the C-3 side chain phenyl ring, indicating that the attachment of methoxy group or halogen atom substitution at the ortho-position of the phenyl ring was helpful to enhance both inhibitory activity toward PDE4B and selectivity. Compound 15 with excellent selectivity, exhibited the most potent inhibition in vitro and in vivo, which is a promising lead for development of a new class of selective PDE4 inhibitors.
Assuntos
Amidas/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Descoberta de Drogas , Isoquinolinas/farmacologia , Inibidores da Fosfodiesterase 4/farmacologia , Amidas/síntese química , Amidas/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Isoquinolinas/síntese química , Isoquinolinas/química , Modelos Moleculares , Estrutura Molecular , Inibidores da Fosfodiesterase 4/síntese química , Inibidores da Fosfodiesterase 4/química , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Currently, entry inhibitors contribute immensely in developing a new generation of anti-influenza virus drugs. Our earlier studies have identified that 3-O-ß-chacotriosyl ursolic acid (1) could inhibit H5N1 pseudovirus by targeting hemagglutinin (HA). In the present study, a series of C-28 modified pentacyclic triterpene saponins via conjugation with a series of amide derivatives were synthesized and their antiviral activities against influenza A/Duck/Guangdong/99 virus (H5N1) in MDCK cells were evaluated. The SARs analysis of these compounds revealed that introduction of certain amide structures at the 17-COOH of ursolic acid could significantly enhance both their antiviral activity and selective index. This study indicated that the attachment of the methoxy group or Cl atom to the phenyl ring at the ortho- or para-position was crucial to improve inhibitory activity. Mechanism studies demonstrated that these title triterpenoids could bind tightly to the viral envelope HA to block the attachment of viruses to host cells, which was consistent with docking studies.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Triterpenos/uso terapêutico , Antineoplásicos Fitogênicos/farmacologia , Humanos , Relação Estrutura-Atividade , Triterpenos/farmacologia , Ácido UrsólicoRESUMO
This paper describes our medicinal chemistry efforts on 7-(cyclopentyloxy)-6-methoxy1,2,3,4-tetrahydroisoquinoline scaffold: design, synthesis and biological evaluation using conformational restriction approach and bioisosteric replacement strategy. Biological data revealed that the majority of the synthesized compounds of this series displayed moderate to potent inhibitory activity against PDE4B and strong inhibition of LPS-induced TNFα release. Among them, compound 19 exhibited the strongest inhibition against PDE4B with an IC50 of 0.88⯵M and 21 times more potent selectivity toward PDE4B over PDE4D when compared to rolipram. A primary structure-activity relationship study showed that the attachment of CH3O group or CF3O group to the phenyl ring at the para-position was helpful to enhance the inhibitory activity against PDE4B. Moreover, sulfonamide group played a key role in improving the inhibitory activity against PDE4B and subtype selectivity. In addition, the attachment of the additional rigid substituents at the C-3 position of 1,2,3,4-tetrahydroisoquinoline ring was favored to subtype selectivity, which was consistent well with the observed docking simulation.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Desenho de Fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Tetra-Hidroisoquinolinas/farmacologia , Relação Dose-Resposta a Droga , Humanos , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Inibidores da Fosfodiesterase 4/síntese química , Inibidores da Fosfodiesterase 4/química , Relação Estrutura-Atividade , Tetra-Hidroisoquinolinas/síntese química , Tetra-Hidroisoquinolinas/química , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Tetrahydroquinoline and tetrahydroisoquinoline derivatives containing 2-phenyl-5-furan moiety were designed and synthesized as phosphodiesterase type 4 (PDE4) inhibitors. The bioassay results showed that title compounds showed good inhibitory activity against PDE4B and blockade of LPS (lipopolysaccharide) induced TNF-α release, which also exhibited considerable in vivo activity in animal models of asthma/COPD (chronic obstructive pulmonary disease) and sepsis induced by LPS. The bioactivity of compounds containing tetrahydroquinoline (series 4) was higher than that of tetrahydroisoquinoline derivatives (series 3). Compound 4â¯m with 4-methoxybenzene moiety exhibited the best potential selective activity against PDE4B. The primary structure-activity relationship study and docking results showed that the tetrahydroquinoline moiety of compound 4â¯m played a key role to form hydrogen bonds and π-π stacking interaction with PDE4B protein while the rest part of the molecule extended into the catalytic domain to block the access of cAMP and formed the foundation for inhibition of PDE4B. Based on LPS induced sepsis model for the measurement of TNF-α inhibition in Swiss Albino mice and neutrophilia inhibition for asthma and COPD in Sprague Dawley rats with the potential molecules, compound 4â¯m would be great promise as a hit inhibitor in the future study.
Assuntos
Inibidores da Fosfodiesterase 4/farmacologia , Quinolinas/química , Quinolinas/farmacologia , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/farmacologia , Animais , Domínio Catalítico , Camundongos , Inibidores da Fosfodiesterase 4/metabolismo , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
Highly pathogenic H5N1 virus (H5N1) entry is a key target for the development of novel anti-influenza agents with new mechanisms of action. In our continuing efforts to identify novel potential anti-H5N1 entry inhibitors, a series of 3-O-ß-chacotriosyl oleanolic acid analogs have been designed, synthesized and evaluated as H5N1 entry inhibitors based on two small molecule inhibitors 1 and 2 previously discovered by us. The anti-H5N1 entry activities were determined based on HA/HIV and VSVG/HIV entry assays. Compound 15 displayed the most promising anti-H5N1 entry activities with average IC50 values of 4.05µM and good selective index (22.9). Detailed structure-activity relationships (SARs) studies suggested that either the introduction of an additional oxo group to position 11 at OA or alteration of the C-3 configuration of OA from 3ß- to 3α-forms can significantly enhance the selective index while maintaining their antiviral activities in vitro. Molecular simulation analysis confirmed that the compounds exert their inhibitory activity through binding tightly to hemagglutinin (HA2) protein near the fusion peptide and prevent virus entry.
Assuntos
Antivirais/farmacologia , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Ácido Oleanólico/farmacologia , Animais , Antivirais/síntese química , Antivirais/química , Cães , Relação Dose-Resposta a Droga , Células Madin Darby de Rim Canino/efeitos dos fármacos , Células Madin Darby de Rim Canino/virologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ácido Oleanólico/síntese química , Ácido Oleanólico/química , Relação Estrutura-AtividadeRESUMO
Improvement of subtype selectivity of an inhibitor's binding activity using the conformational restriction approach has become an effective strategy in drug discovery. In this study, we applied this approach to PDE4 inhibitors and designed a series of novel oxazolidinone-fused 1,2,3,4-tetrahydroisoquinoline derivatives as conformationally restricted analogues of rolipram. The bioassay results demonstrated the oxazolidinone-fused tetrahydroisoquinoline derivatives exhibited moderate to good inhibitory activity against PDE4B and high selectivity for PDE4B/PDE4D. Among these derivatives, compound 12 showed both the strongest inhibition activity (IC50=0.60µM) as well as good selectivity against PDE4B and good in vivo activity in animal models of asthma/COPD and sepsis induced by LPS. The primary SAR study showed that restricting the conformation of the catechol moiety in rolipram with the scaffold of oxazolidinone-fused tetrahydroisoquinoline could lead to an increase in selectivity for PDE4B over PDE4D, which was consistent with the observed docking simulation.
Assuntos
Desenho de Fármacos , Tetra-Hidroisoquinolinas/síntese química , Tetra-Hidroisoquinolinas/farmacologia , Animais , Asma/tratamento farmacológico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Modelos Animais de Doenças , Humanos , Concentração Inibidora 50 , Conformação Molecular , Simulação de Acoplamento Molecular , Inibidores da Fosfodiesterase 4/síntese química , Inibidores da Fosfodiesterase 4/química , Inibidores da Fosfodiesterase 4/farmacologia , Inibidores da Fosfodiesterase 4/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Rolipram/química , Rolipram/farmacologia , Rolipram/uso terapêutico , Sepse/tratamento farmacológico , Relação Estrutura-Atividade , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/uso terapêuticoRESUMO
Oligosaccharides have been used for an environmentally friendly insect control in the agricultural industry. In order to discover novel eco-friendly pesticides, a series of partially acetylated oligorhamnoses mezzettiasides, 2-8, and their analogues, 9-14, with biosurfactant characteristics were designed and synthesized, some of which exhibited comparable to or even stronger aphicidal activity than pymetrozine. Preliminary SAR studies demonstrated that the aphicidal activity of mezzettiasides analogs is highly dependent on their structures, including both the sugar length and the substitutes on the sugar. Among them, trirhamnolipid 9 displayed the strongest aphicidal activity, with an LC50 of 0.019 mmol/L, indicating that the biosurfactant 9 may have potential for use as an environmentally friendly agricultural pesticide.
Assuntos
Glicolipídeos/síntese química , Inseticidas/síntese química , Oligossacarídeos/síntese química , Animais , Afídeos , Humanos , Concentração Inibidora 50 , Controle de Insetos/métodos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Relação Estrutura-Atividade , Triazinas/químicaRESUMO
Two partially acylated oligorhamnoside derivatives 1 and 2 structurally related to the natural product mezzettiaside-6 were synthesized via a '2 + 1 + 1' convergent strategy. The bioassay results showed that the introduction of the acetyl groups to the 2-position of the terminal l-rhamnose was helpful to improve in vitro cytotoxicity. Compound 1 showed both extensive in vitro cytotoxicity in tumor cell lines and potential antimultidrug resistance capability. Preliminary mechanistic studies demonstrated that compound 1 could inhibit cell growth by inducing apoptosis, arresting cell cycle progression at the S phase in K562 cells.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Ramnose/análogos & derivados , Ramnose/farmacologia , Acilação , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Células K562 , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neoplasias/metabolismo , Ramnose/síntese químicaRESUMO
As a novel protein knockdown tool, proteolysis targeting chimeras (PROTACs) can induce potent degradation of target proteins by hijacking E3 ubiquitin ligases. However, the uncontrollable protein disruption of PROTACs is prone to cause "off-target" toxicity after systemic administration. Herein, we designed a photocaged-PROTAC (phoBET1) and loaded it in UCNPs-based mesoporous silica nanoparticles (UMSNs) to construct a NIR light-activatable PROTAC nanocage (UMSNs@phoBET1) for controllable target protein degradation. Upon NIR light (980 nm) irradiation, UMSNs@phoBET1 nanocages could be activated to release active PROTAC via a controlled pattern for degrading bromodomain-containing protein 4 (BRD4) and inducing MV-4-11 cancer cell apoptosis. In vivo experiments demonstrated that UMSNs@phoBET1 nanocages were capable of responding to NIR light in tumor tissues to achieve BRD4 degradation and effectively suppress tumor growth. This NIR light-activatable PROTAC nanoplatform compensates for the current shortcomings of short-wavelength light-controlled PROTACs and presents a paradigm for the precise regulation of PROTACs in living tissues.
Assuntos
Neoplasias , Fatores de Transcrição , Humanos , Proteólise , Fatores de Transcrição/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias/tratamento farmacológico , Proteínas de Ciclo Celular/metabolismoRESUMO
Influenza PAN inhibitors are of particular importance in current efforts to develop a new generation of antiviral drugs due to the growing emergence of highly pathogenic influenza viruses and the resistance to existing antiviral inhibitors. Herein, we design and synthesize a set of 1,3-cis-N-substituted-1,2,3,4-tetrahydroisoquinoline derivatives to enhance their potency by further exploiting the pockets 3 and 4 in the PAN endonuclease based on the hit d,l-laudanosoline. Particularly, the lead compound 35 exhibited potent and broad anti-influenza virus effects with EC50 values ranging from 0.43 to 1.12 µM in vitro and good inhibitory activity in a mouse model. Mechanistic studies demonstrated that 35 could bind tightly to the PAN endonuclease of RNA-dependent RNA polymerase, thus blocking the viral replication to exert antiviral activity. Overall, our study might establish the importance of 1,2,3,4-tetrahydroisoquinoline-6,7-diol-based derivatives for the development of novel PAN inhibitors of influenza viruses.
Assuntos
Influenza Humana , Orthomyxoviridae , Tetra-Hidroisoquinolinas , Animais , Camundongos , Humanos , Tetra-Hidroisoquinolinas/farmacologia , Antivirais/farmacologia , Antivirais/metabolismo , EndonucleasesRESUMO
OBJECTIVES: A specific and sensitive automated chemiluminescent immunoassay (CLIA) was developed to detect neutralizing antibody (NAb) levels. This assay can be used for the diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, treatment and vaccine evaluation. METHODS: The SARS-CoV-2 receptor-binding domain (RBD) and a stabilized version of the spike ectodomain as antigens were detected by CLIA. Sera NAb titers and concentrations from 860 SARS-CoV-2 vaccinees, 232 SARS-CoV-2 convalescent patients and 675 healthy individuals were tested by microneutralization test (MNT) and CLIA, respectively. Mathematical models were established to evaluate the relationship between two variables in different groups. CONCLUSIONS: With the RBD-based CLIA protocol, CLIA can be used to replace MNT to test SARS-CoV-2 NAb. Vaccine effectiveness, protectiveness and durability can be evaluated effectively by mathematical models. It is RESULTS: Analysing the relationship between NAb titers and concentrations, R2 for the decision-making tree was 0.870 and that of progressive linear fitting was 0.821. The receiver operating characteristic curve indicated specificity of 78.1%, sensitivity of 87.4%, cut-off value of 6.43 AU/mL and borderline range of 5.79-7.07 AU/mL for CLIA. Three-quarters (75.4%) of vaccinees were found to be NAb positive, and 5.35% vaccinees had NAb protective capability. The half-life of NAb in vaccinees was 10-11 weeks.for vaccinees to take a NAb assay periodically.
Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , Imunoensaio , Eficácia de VacinasRESUMO
The two proteases, PLpro and Mpro, of SARS-CoV-2 are essential for replication of the virus. Using a structure-based co-pharmacophore screening approach, we developed a novel dual-targeted inhibitor that is equally potent in inhibiting PLpro and Mpro of SARS-CoV-2. The inhibitor contains a novel warhead, which can form a covalent bond with the catalytic cysteine residue of either enzyme. The maximum rate of the covalent inactivation is comparable to that of the most potent inhibitors reported for the viral proteases and covalent inhibitor drugs currently in clinical use. The covalent inhibition appears to be very specific for the viral proteases. The inhibitor has a potent antiviral activity against SARS-CoV-2 and is also well tolerated by mice and rats in toxicity studies. These results suggest that the inhibitor is a promising lead for development of drugs for treatment of COVID-19.
Assuntos
COVID-19 , SARS-CoV-2 , Animais , Camundongos , Ratos , Papaína , Cisteína Endopeptidases/química , Proteínas não Estruturais Virais , Peptídeo Hidrolases , Proteases Virais , Antivirais/farmacologia , Antivirais/química , Inibidores de Proteases/farmacologia , Inibidores de Proteases/uso terapêutico , Inibidores de Proteases/química , Simulação de Acoplamento MolecularRESUMO
Many chemotherapeutic drugs and photosensitizers suffer from poor solubility, unspecific delivery and uncontrollable release, which severely impede their biomedical applications. Herein, we designed a type of ROS-cleavable hydrophilic diselenide nanoparticles through self-assembling of PEG-modified camptothecin (CPT, a hydrophobic drug) and mesotetra (4-carboxyphenyl) porphine (TCPP, a hydrophobic photosensitizer). The TCPP@SeSe-CPT nanomedicine (particle size: 116.5 ± 1.9 nm) has stability for long-time blood circulation. Near-infrared (NIR) laser-triggered generation of ROS from TCPP can efficiently break the ROS-sensitive diselenide bond, which induces the decomposition of TCPP@SeSe-CPT nanomedicine for concurrent release of CPT and TCPP. Moreover, the released amounts of CPT and TCPP can be regulated by adjusting the NIR laser irradiation time. Such NIR-controlled release of CPT and TCPP can give rise to on-demand synergistic chemo-/photodynamic therapeutic effects for maximized tumor growth suppression with minimized side effects. STATEMENT OF SIGNIFICANCE: In this work, a ROS-cleavable diselenide nanoparticle was designed and successfully self-assembled with the hydrophobic drug camptothecin and photosensitizer TCPP into a hydrophilic TCPP@SeSe-CPT nanomedicine. Compared with traditional drug delivery systems, TCPP@SeSe-CPT nanomicelles could reduce premature drug release and co-deliver hydrophobic chemotherapeutic drugs/photosensitizers to tumors, which yielded a NIR-controlled synergistic chemo-/photodynamic therapeutic effect. Since diselenide bond is more sensitive than the traditional disulfide bond, under the 660 nm laser irradiation (300 mW/cm2), ROS generated from laser-excited TCPP in TCPP@SeSe-CPT nanomicelles could break the diselenium bonds to achieve the light-controlled release of CPT. In addition, the photosensitizer TCPP could also be imaged at the tumor site. Due to the photodynamic therapy from laser-excited TCPP and chemotherapy from photocontrolled release of CPT in TCPP@SeSe-CPT, our designed nanomicelles yielded potent antitumor effects both in vitro and in vivo.
Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Liberação Controlada de Fármacos , Fármacos Fotossensibilizantes/química , Espécies Reativas de Oxigênio , Nanomedicina , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/uso terapêutico , Nanopartículas/química , Camptotecina/química , Neoplasias/tratamento farmacológico , Linhagem Celular TumoralRESUMO
Currently, influenza PAN endonuclease has become an attractive target for development of new drugs to treat influenza infections. Herein we report the discovery of new PAN endonuclease inhibitors derived from a chelating agent dopamine moiety. A series of dopamine amide derivatives and their conformationally constrained 1,2,3,4-tetrahydroisoquinoline-6,7-diol-based analogs were elaborated and assayed against influenza virus A/WSN/33 (H1N1). Most compounds exhibited moderate to excellent antiviral activities, generating a preliminary SARs. Among them, compounds 14 and 19 showed stronger anti-IAV activity compared with the reference Peramivir. Moreover, 14 and 19 demonstrated a concentration-dependent inhibition of PAN endonuclease based on both FRET assay and SPR assay. Docking studies were also performed to elucidate the binding mode of 14 and 19 with the PAN protein and to identify amino acids involved in their mechanism of action, which were well consistent with the biological data. This finding was beneficial to laying the foundation for the rational development of more effective PAN endonuclease inhibitors.
Assuntos
Antivirais/farmacologia , Dopamina/análogos & derivados , Dopamina/farmacologia , Endonucleases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Proteínas Virais/antagonistas & inibidores , Antivirais/síntese química , Antivirais/metabolismo , Dopamina/metabolismo , Desenho de Fármacos , Endonucleases/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Vírus da Influenza A Subtipo H1N1/enzimologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Relação Estrutura-Atividade , Proteínas Virais/metabolismoRESUMO
Influenza A viruses (IAV) have been a major public health threat worldwide, and options for antiviral therapy become increasingly limited with the emergence of drug-resisting virus strains. New and effective anti-IAV drugs, especially for highly pathogenic influenza, with different modes of action, are urgently needed. The influenza virus glycoprotein hemagglutinin (HA) plays critical roles in the early stage of virus infection, including receptor binding and membrane fusion, making it a potential target for the development of anti-influenza drugs. In this study, we show that OA-10, a newly synthesized triterpene out of 11 oleanane-type derivatives, exhibited significant antiviral activity against four different subtypes of IAV (H1N1, H5N1, H9N2 and H3N2) replications in A549 cell cultures with EC50 ranging from 6.7 to 19.6 µM and a negligible cytotoxicity (CC50 > 640 µM). It inhibited acid-induced hemolysis in a dose-dependent manner, with an IC50 of 26 µM, and had a weak inhibition on the adsorption of H5 HA to chicken erythrocytes at higher concentrations (≥40 µM). Surface plasmon resonance (SPR) analysis showed that OA-10 interacted with HA in a dose-dependent manner with the equilibrium dissociation constants (KD) of the interaction of 2.98 × 10-12 M. Computer-aided molecular docking analysis suggested that OA-10 might bind to the cavity in HA stem region which is known to undergo significant rearrangement during membrane fusion. Our results demonstrate that OA-10 inhibits H5N1 IAV replication mainly by blocking the conformational changes of HA2 subunit required for virus fusion with endosomal membrane. These findings suggest that OA-10 could serve as a lead for further development of novel virus entry inhibitors to prevent and treat IAV infections.
Assuntos
Antivirais/farmacologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A/efeitos dos fármacos , Ácido Oleanólico/química , Ácido Oleanólico/farmacologia , Internalização do Vírus/efeitos dos fármacos , Células A549 , Animais , Antivirais/química , Galinhas , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H9N2/efeitos dos fármacos , Vírus da Influenza A/fisiologia , Concentração Inibidora 50 , Simulação de Acoplamento MolecularRESUMO
Multidrug resistance (MDR) is a tendency in which cells become resistant to structurally and mechanistically unrelated drugs, which is mediated by P-glycoprotein (P-gp). It is one of the noteworthy problems in cancer therapy. As one of the most important drugs in cancer therapy, doxorubicin has not good effectiveness if used independently. So targeting the P-gp protein is one of the key points to solve the MDR. Three series of furan derivatives containing tetrahydroquinoline or tetrahydroisoquinoline were designed and synthesized as P-gp inhibitors in this paper. Compound 5m containing 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline possessed good potency against P-gp (EC50â¯=â¯0.89⯱â¯0.11⯵M). The preliminary structure-activity relationship and docking studies demonstrated that compound 5m would be great promise as a lead compound for further study. Most worthy of mention is drug combination of doxorubicin and 5m displayed antiproliferative effect of about 97.8%. This study provides highlighted P-gp inhibitor for withstanding malignant tumor cell with multidrug resistance especially doxorubicin resistance setting the basis for further studies.