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1.
Signal Transduct Target Ther ; 6(1): 414, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873151

RESUMO

Azvudine (FNC) is a nucleoside analog that inhibits HIV-1 RNA-dependent RNA polymerase (RdRp). Recently, we discovered FNC an agent against SARS-CoV-2, and have taken it into Phase III trial for COVID-19 patients. FNC monophosphate analog inhibited SARS-CoV-2 and HCoV-OC43 coronavirus with an EC50 between 1.2 and 4.3 µM, depending on viruses or cells, and selective index (SI) in 15-83 range. Oral administration of FNC in rats revealed a substantial thymus-homing feature, with FNC triphosphate (the active form) concentrated in the thymus and peripheral blood mononuclear cells (PBMC). Treating SARS-CoV-2 infected rhesus macaques with FNC (0.07 mg/kg, qd, orally) reduced viral load, recuperated the thymus, improved lymphocyte profiles, alleviated inflammation and organ damage, and lessened ground-glass opacities in chest X-ray. Single-cell sequencing suggested the promotion of thymus function by FNC. A randomized, single-arm clinical trial of FNC on compassionate use (n = 31) showed that oral FNC (5 mg, qd) cured all COVID-19 patients, with 100% viral ribonucleic acid negative conversion in 3.29 ± 2.22 days (range: 1-9 days) and 100% hospital discharge rate in 9.00 ± 4.93 days (range: 2-25 days). The side-effect of FNC is minor and transient dizziness and nausea in 16.12% (5/31) patients. Thus, FNC might cure COVID-19 through its anti-SARS-CoV-2 activity concentrated in the thymus, followed by promoted immunity.

2.
Front Microbiol ; 12: 771463, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956132

RESUMO

Atrazine, a triazine herbicide, is widely used around the world. The residue of atrazine due to its application in the fore-rotating crop maize has caused phytotoxicity to the following crop sweet potato in China. Bioaugmentation of atrazine-contaminated soil with atrazine-degrading strains is considered as the most potential method to remove atrazine from soil. Nevertheless, the feasibility of bioaugmentation and its effect on soil microbiome still need investigation. In this study, Paenarthrobacter sp. AT-5, an atrazine-degrading strain, was inoculated into agricultural soils contaminated with atrazine to investigate the bioaugmentation process and the reassembly of the soil microbiome. It was found that 95.9% of 5 mg kg-1 atrazine was removed from the soils when inoculated with strain AT-5 with 7 days, and the phytotoxicity of sweet potato caused by atrazine was significantly alleviated. qRT-PCR analysis revealed that the inoculated strain AT-5 survived well in the soils and maintained a relatively high abundance. The inoculation of strain AT-5 significantly affected the community structure of the soil microbiome, and the abundances of bacteria associated with atrazine degradation were improved.

3.
J Pharm Anal ; 11(5): 628-637, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34765276

RESUMO

Berberine (BBR) is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes, hyperlipidemia and inflammation. Due to the low oral bioavailability of BBR, its mechanism of action is closely related to the gut microbiota. This study focused on the CYP51 enzyme of intestinal bacteria to elucidate a new mechanism of BBR transformation by demethylation in the gut microbiota through multiple analytical techniques. First, the docking of BBR and CYP51 was performed; then, the pharmacokinetics of BBR was determined in ICR mice in vivo, and the metabolism of BBR in the liver, kidney, gut microbiota and single bacterial strains was examined in vitro. Moreover, 16S rRNA analysis of ICR mouse feces indicated the relationship between BBR and the gut microbiota. Finally, recombinant E. coli containing cyp51 gene was constructed and the CYP51 enzyme lysate was induced to express. The metabolic characteristics of BBR were analyzed in the CYP51 enzyme lysate system. The results showed that CYP51 in the gut microbiota could bind stably with BBR, and the addition of voriconazole (a specific inhibitor of CYP51) slowed down the metabolism of BBR, which prevented the production of the demethylated metabolites thalifendine and berberrubine. This study demonstrated that CYP51 promoted the demethylation of BBR and enhanced its intestinal absorption, providing a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo.

4.
Eur J Med Chem ; : 113979, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34802838

RESUMO

The shortage of new antibiotics makes infections caused by gram-negative (G-) bacteria a significant clinical problem. The key enzymes involved in folate biosynthesis represent important targets for drug discovery, and new antifolates with novel mechanisms are urgently needed. By targeting to dihydrofolate reductase (DHFR), a series of 1,3-diamino-7H-pyrrol[3,2-f]quinazoline (PQZ) compounds were designed, and exhibited potent antibacterial activities in vitro, especially against multi-drug resistant G- strains. Multiple experiments indicated that PQZ compounds contain a different molecular mechanism against the typical DHFR inhibitor, trimethoprim (TMP), and the thymidylate synthase (TS) was identified as another potential but a relatively weak target. A significant synergism between the representative compound, OYYF-175, and sulfamethoxazole (SMZ) was observed with a strong cumulative and significantly bactericidal effect at extremely low concentrations (2 µg/mL for SMZ and 0.03 pg/mL for OYYF-175), which could be resulted from the simultaneous inhibition of dihydropteroate synthase (DHPS), DHFR and TS. PQZ compounds exhibited therapeutic effects in a mouse model of intraperitoneal infections caused by Escherichia coli (E. coli). The co-crystal structure of OYYF-175-DHFR was solved and the detailed interactions were provided. The inhibitors reported represent innovative chemical structures with novel molecular mechanism of action, which will benefit the generation of new, efficacious bactericidal compounds.

5.
Eur J Med Chem ; : 113974, 2021 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34772528

RESUMO

GYH2-18 is a type II HBV CAM with 6,7-dihydropyrazolo[1,5-a]pyrazine-5(4H)-carboxamine (DPPC) skeleton discovered by Roche INC. A series of GYH2-18 derivatives were designed, synthesized and evaluated for their anti-HBV activity. Two compounds 2f and 3k exhibited excellent anti-HBV activity, low cytotoxicity and accepted oral PK profiles. Chiral separation of 2f and 3k was conducted successfully, and (6S)-cyclopropyl DPPC isomers 2f-1, 2f-3, 3k-1 and 3k-3 were identified to be much more active than the corresponding (6R)-ones. The preliminary structure-activity relationship, particle gel assay and molecular modeling studies were also discussed, which provide useful indications for guiding the further rational design of new (6S)-cyclopropyl DPPC analogues.

6.
Front Pharmacol ; 12: 679207, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630077

RESUMO

Introduction: Immune checkpoint inhibitors (ICIs) have substantially improved the clinical outcomes of various malignancies. However, the adverse event of tumor lysis syndrome (TLS) has not been included in the National Comprehensive Cancer Network guidelines or drug inserts. In this study, we aimed to establish the relationship between ICI therapies and TLS events using data from a real-world pharmacovigilance database. Methods: The MedDRA terms of TLS and both generic and brand names of ICIs were retrieved from the FDA Adverse Event Reporting System. Four frequentist algorithms were employed to confirm the association between the TLS and the ICI regimens, involving anti-cytotoxic T lymphocyte antigen-4 (anti-CTLA-4), anti-programmed death receptor-1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1), and anti-(CTLA-4 + PD-1). A descriptive and statistical analysis was performed according to the case information. Results: One hundred sixty-four TLS cases, where patients underwent anti-CTLA-4 (n = 14), anti-(PD-1)/(PD-L1) (n = 113), or anti-(CTLA-4 + PD-1) (n = 37) therapies, were collected between the first quarter of 2004 and the fourth quarter of 2020. The most coverage-reporting year, age-group, sex, reporter, region, country, and indication were 2020 (n = 62), 60-74 years (n = 65), males (n = 105), physician (n = 66), Asia (n = 80), Japan (n = 67), and lung and thymus malignancies (n = 40), respectively. The median TLS onset time associated with anti-CTLA-4, anti-(PD-1)/(PD-L1), and anti-(CTLA-4 + PD-1) therapies was 6 (IQR: 2-39.5), 9 (IQR: 2-40), and 20 (IQR: 7.5-37.75) days, respectively. Mortality distribution of 71 reported death outcomes among three groups was statistically significant. All four algorithm signal values of anti-(CTLA-4 + PD-1) were higher than those of anti-CTLA-4 and anti-(PD-1)/(PD-L1). Conclusion: Elderly male patients with lung and thymus malignancies are frequently predisposed to TLS. ICI therapies could induce TLS in both solid and hematological malignancies. The rapid onset time and poor outcomes of patients prompt caution from health-care professionals.

7.
Front Pharmacol ; 12: 734603, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690771

RESUMO

Background: Berberine (BBR), a natural product, was reported to inhibit platelet aggregation; however, the molecular mechanisms remain unclear. This study aims to investigate the effects and mechanisms of BBR in inhibiting platelet activation and thrombus formation. Methods: Flow cytometry, immunofluorescence, and Western blot were used to determine the inhibitory effects and mechanisms of BBR and its main metabolite berberrubine (M2) on platelet activation in vitro and ex vivo. Purified integrin αIIbß3, class I PI3K kit, and molecular docking were used to identify the possible targets of BBR and M2. A carrageenan-induced mouse thrombosis model was used to evaluate the effects of BBR on thrombus formation in vivo. Results: In vitro, BBR and M2 significantly inhibited ADP-induced integrin αIIbß3 activation, reduced the level of P-selectin on the platelet membrane, and suppressed the binding of fibrinogen to the platelets. In this process, BBR and M2 greatly suppressed the PI3K/Akt pathway and inhibited Rasa3 membrane translocation and Rap1 activation. Furthermore, BBR and M2 selectively inhibited class I PI3Kß, perhaps through binding to its active site. The activities of BBR were stronger than those of M2. After oral administration, BBR significantly inhibited the PI3K/Akt pathway and Rap1 activation and suppressed ADP-induced platelet activation and carrageenan-induced thrombosis in mice without prolonging bleeding time. Conclusions: We reveal for the first time the possible targets and mechanisms of BBR and M2 in inhibiting platelet activation. Our research may support the future clinical application of BBR as an antiplatelet drug in the prevention or treatment of thrombotic diseases.

8.
Front Microbiol ; 12: 757914, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707597

RESUMO

Tuberculosis (TB) is still a threat to humans worldwide. The rise of drug-resistant TB strains has escalated the need for developing effective anti-TB agents. Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) is essential for thymidylate biosynthesis to maintain the DNA integrity. In Mycobacterium tuberculosis, dUTPase provides the sole source for thymidylate biosynthesis, which also has the specific five-residue loop and the binding pockets absent in human dUTPase. Therefore, dUTPase has been regarded as a promising anti-TB drug target. Herein, we used a luminescence-based dUTPase assay to search for the inhibitors target M. tuberculosis dUTPase (Mt-dUTPase) and identified compound F0414 as a potent Mt-dUTPase inhibitor with an IC50 of 0.80 ± 0.09 µM. F0414 exhibited anti-TB activity with low cytotoxicity. Molecular docking model and site-directed mutation experiments revealed that P79 was the key residue in the interaction of Mt-dUTPase and F0414. Moreover, F0414 was shown to have stronger binding with Mt-dUTPase than with Mt-P79A-dUTPase by surface plasmon resonance (SPR) detection. Interestingly, F0414 exhibited insensitivity and weak directly binding on human dUTPase compared with that on Mt-dUTPase. All the results highlight that F0414 is the first compound reported to have anti-TB activity by inhibiting Mt-dUTPase, which indicates the potential application in anti-TB therapy.

9.
Sheng Wu Gong Cheng Xue Bao ; 37(10): 3475-3486, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34708605

RESUMO

A plethora of organic pollutants such as pesticides, polycyclic and halogenated aromatic hydrocarbons, and emerging pollutants, such as flame retardants, is continuously being released into the environment. This poses a huge threat to the society in terms of environmental pollution, agricultural product quality, and general safety. Therefore, effective removal of organic pollutants from the environment has become an important challenge to be addressed. As a consequence of the recent and rapid developments in additive manufacturing, 3D bioprinting technology is playing an important role in the pharmaceutical industry. At the same time, an increasing number of microorganisms suitable for the production of biomaterials with complex structures and functions using 3D bioprinting technology, have been identified. This article briefly discusses the principles, advantages, and disadvantages of different 3D bioprinting technologies for pollutant removal. Furthermore, the feasibility and challenges of developing bioremediation technologies based on 3D bioprinting have also been discussed.


Assuntos
Bioimpressão , Poluentes Ambientais , Materiais Biocompatíveis , Biodegradação Ambiental , Tecnologia , Engenharia Tecidual
10.
Microorganisms ; 9(9)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34576734

RESUMO

The study of microbial activity can be viewed as a triangle with three sides: environment (dominant resources in a specific habitat), community (species dictating a repertoire of metabolic conversions) and function (production and/or utilization of resources and compounds). Advances in metagenomics enable a high-resolution description of complex microbial communities in their natural environments and support a systematic study of environment-community-function associations. NetCom is a web-tool for predicting metabolic activities of microbial communities based on network-based interpretation of assembled and annotated metagenomics data. The algorithm takes as an input, lists of differentially abundant enzymatic reactions and generates the following outputs: (i) pathway associations of differently abundant enzymes; (ii) prediction of environmental resources that are unique to each treatment, and their pathway associations; (iii) prediction of compounds that are produced by the microbial community, and pathway association of compounds that are treatment-specific; (iv) network visualization of enzymes, environmental resources and produced compounds, that are treatment specific (2 and 3D). The tool is demonstrated on metagenomic data from rhizosphere and bulk soil samples. By predicting root-specific activities, we illustrate the relevance of our framework for forecasting the impact of soil amendments on the corresponding microbial communities. NetCom is available online.

11.
Appl Environ Microbiol ; 87(22): e0156221, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34524896

RESUMO

rac-Dichlorprop, a commonly used phenoxyalkanoic acid herbicide, is frequently detected in environments and poses threats to environmental safety and human health. Microbial consortia are thought to play key roles in rac-dichlorprop degradation. However, the compositions of the microbial consortia involved in rac-dichlorprop degradation remain largely unknown. In this study, DNA stable isotope probing (SIP) and metagenomic analysis were integrated to reveal the key microbial consortium responsible for rac-dichlorprop degradation in a rac-dichlorprop-degrading enrichment. OTU340 (Sphingobium sp.) and OTU348 (Sphingopyxis sp.) were significantly enriched in the rac-[13C]dichlorprop-labeled heavy DNA fractions. A rac-dichlorprop degrader, Sphingobium sp. strain L3, was isolated from the enrichment by a traditional enrichment method but with additional supplementation of the antibiotic ciprofloxacin, which was instructed by metagenomic analysis of the associations between rac-dichlorprop degraders and antibiotic resistance genes. As revealed by functional profiling of the metagenomes of the heavy DNA, the genes rdpA and sdpA, involved in the initial degradation of the (R)- and (S)-enantiomers of dichlorprop, respectively, were mostly taxonomically assigned to Sphingobium species, indicating that Sphingopyxis species might harbor novel dichlorprop-degrading genes. In addition, taxonomically diverse bacterial genera such as Dyella, Sphingomonas, Pseudomonas, and Achromobacter were presumed to synergistically cooperate with the key degraders Sphingobium/Sphingopyxis for enhanced degradation of rac-dichlorprop. IMPORTANCE Understanding of the key microbial consortium involved in the degradation of the phenoxyalkanoic acid herbicide rac-dichlorprop is pivotal for design of synergistic consortia used for enhanced bioremediation of herbicide-contaminated sites. However, the composition of the microbial consortium and the interactions between community members during the biodegradation of rac-dichlorprop are unclear. In this study, DNA-SIP and metagenomic analysis were integrated to reveal that the metabolite 2,4-dichlorophenol degraders Dyella, Sphingomonas, Pseudomonas, and Achromobacter synergistically cooperated with the key degraders Sphingobium/Sphingopyxis for enhanced degradation of rac-dichlorprop. Our study provides new insights into the synergistic degradation of rac-dichlorprop at the community level and implies the existence of novel degrading genes for rac-dichlorprop in nature.

12.
Anticancer Drugs ; 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34538863

RESUMO

Arrhythmias associated with antibody-drug conjugates (ADCs) are rare but potentially life-threatening adverse events (AEs). No study has systemically compared arrhythmias associations for various marketed ADCs. This needs to be clarified to guide antitumor therapies. We extracted data of patients treated with ADCs registered between 2004 q1 and 2020 q3 from the US Food and Drug Administration adverse event reporting system (FAERS). The medical dictionary for regulatory activities was used to identify arrhythmias cases. Disproportionality analysis was performed by calculating the reporting odds ratios (ROR) with corresponding 95% confidence intervals (95% CI). Clinical characteristics of patients with ADCs-associated arrhythmias and the time to onset of arrhythmias following different ADCs were collected. A total of 140 reports were considered after inclusion criteria were used. Exposure to gemtuzumab ozogamicin (2.23, 1.67-2.97; 48 cases) and brentuximab vedotin (1.27, 1.00-1.61; 67 cases) were associated with a positive signal of arrhythmia. The highest number of arrhythmia reports was for brentuximab vedotin (n = 67). Also 88.00% of arrhythmia occurred within 60 days for all these ADCs. Arrhythmia was commonly reported in patients with hematologic tumors and breast cancer. In the time to onset of adverse events after administration, brentuximab vedotin was significantly earlier than gemtuzumab ozogamicin (38.21 vs. 40.50 days; P = 0.0093), and gemtuzumab ozogamicin was significantly earlier than trastuzumab emtansine (40.50 vs. 147.50 days; P = 0.0035). We reviewed arrhythmia adverse drug reactions associated with ADCs from the FAERS database. This study is practical for clinicians to enhance the management of arrhythmia associated with ADCs and improve ADCs treatment safety.

13.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202717

RESUMO

Timosaponin BII is one of the most abundant Anemarrhena saponins and is in a phase II clinical trial for the treatment of dementia. However, the pharmacological activity of timosaponin BII does not match its low bioavailability. In this study, we aimed to determine the effects of gut microbiota on timosaponin BII metabolism. We found that intestinal flora had a strong metabolic effect on timosaponin BII by HPLC-MS/MS. At the same time, seven potential metabolites (M1-M7) produced by rat intestinal flora were identified using HPLC/MS-Q-TOF. Among them, three structures identified are reported in gut microbiota for the first time. A comparison of rat liver homogenate and a rat liver microsome incubation system revealed that the metabolic behavior of timosaponin BII was unique to the gut microbiota system. Finally, a quantitative method for the three representative metabolites was established by HPLC-MS/MS, and the temporal relationship among the metabolites was initially clarified. In summary, it is suggested that the metabolic characteristics of gut microbiota may be an important indicator of the pharmacological activity of timosaponin BII, which can be applied to guide its application and clinical use in the future.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Saponinas/farmacocinética , Esteroides/farmacocinética , Animais , Biotransformação , Masculino , Ratos , Ratos Sprague-Dawley , Saponinas/farmacologia , Esteroides/farmacologia
14.
15.
Nat Prod Res ; : 1-7, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34121549

RESUMO

Two new prenylaromadendrane-type diterpenoids, and three known analogues, were isolated from the ethanol extract of the gum resin of B. sacra Flueck. The structures of the new compounds were elucidated using 1 D and 2 D NMR spectroscopic analyses, mass spectrometric data, circular dichroism spectra, and comparison with the other compounds in the literature. One diterpenoid represents the first example of an acetoxyl-substituted prenylaromadendranoid in frankincense. All compounds exhibited notable cytotoxicity against human malignant glioma (U87-MG) cell line, with inhibitory rates exceeding that of the positive control 5-fluorouracil. However, nitric oxide inhibition induced by lipopolysaccarides was not observed in primary mouse peritoneal macrophages.

16.
Eur J Med Chem ; 222: 113591, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34126455

RESUMO

JNJ4796, a small molecule fuse inhibitor targeting the conserved stem region of hemagglutinin, effectively neutralized a broad spectrum of group 1 influenza A virus (IAV), and protected mice against lethal and sublethal influenza challenge after oral administration. In this study, we reported the modification and structure-activity relationship (SAR) of C (piperazine ring) and E (phenyl ring) rings of JNJ4796. Compound (R)-2c was identified to show excellent in vitro activity against IAV H1N1 and Oseltamivir-resistant IAV H1N1 stains (IC50: 0.03-0.06 µM), low cytotoxicity (CC50 > 200 µM), accepted oral PK profiles and low inhibition rate of hERG (13.2%, at 10 µM). Evaluation for the in vivo anti-IAV efficacy of (R)-2c will begin soon.


Assuntos
Antivirais/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Piperazina/farmacologia , Piperazinas/farmacologia , Piridinas/farmacologia , Tetrazóis/farmacologia , Antivirais/síntese química , Antivirais/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piperazina/síntese química , Piperazina/química , Piperazinas/síntese química , Piperazinas/química , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , Tetrazóis/síntese química , Tetrazóis/química
17.
J Agric Food Chem ; 69(26): 7324-7333, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34167301

RESUMO

Chlorpyrifos (CPF) is one of the most critical insecticides in the world. However, many countries are gradually banning its use due to its reported hazardous impacts on humans. This study explored the possibility of reducing the environmental risk of CPF through appropriate agricultural management practices. Results showed that the environmental risk of CPF is lower under drainage conditions because there is more mineralization and less bound residues (BRs) than under submerged conditions. Bioaugmentation significantly enhanced the CPF mineralization and inhibited the formation of CPF-BRs. Biochar adsorbed CPF and thus reduced its bioavailability, but it could not completely eliminate the toxicity of CPF. In addition, bioaugmentation did not significantly affect the native microbial community of CPF-contaminated soil, suggesting its safety in reducing the environmental risk of CPF. The study indicated that the environmental risk of CPF could be reduced by appropriate agricultural management such as water management, bioaugmentation, soil biochar amendment, and selecting suitable soil types.


Assuntos
Clorpirifos , Inseticidas , Agricultura , Radioisótopos de Carbono , Clorpirifos/toxicidade , Humanos , Inseticidas/análise , Inseticidas/toxicidade
18.
Phytochemistry ; 187: 112761, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33933827

RESUMO

Seven previously unidentified polycyclic polyprenylated acylphloroglucinol (PPAP) derivatives hypseudohenrins A-G, along with six known analogs, were isolated from the aerial portion of Hypericum pseudohenryi. Their structures were determined by NMR, ECD and X-ray crystallographic spectroscopy. These compounds were screened for anti-inflammatory activity, and hypseudohenrins B and G (at the concentration of 10 µM) showed NO production inhibition ratios of 52.56% and 54.01%, respectively, which imply good anti-inflammatory activity. In particular, uraloidin A exhibited an NO inhibition ratio of 90.61%, while that ratio of the positive control compound dexamethasone was 94.88%. Additionally, anti-cancer and neural-protective activities were screened, but none of these compounds showed desirable activity.


Assuntos
Hypericum , Anti-Inflamatórios/farmacologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Floroglucinol/farmacologia
19.
Environ Res ; 198: 111216, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33971135

RESUMO

The environmental fates of chlorinated 4-nitrophenols, 2,6-dichloro-4-nitrophenol (2,6-DCNP) and 2-chloro-4-nitrophenol (2C4NP), mediated via microbial catabolism have attracted great attention due to their high toxicity and persistence in the environment. In this study, a strain of Ensifer sp. 22-1 that was capable of degrading both 2,6-DCNP and 2C4NP was isolated from a halogenated aromatic-contaminated soil sample. A gene cluster cnpBADCERM was predicted to be involved in the catabolism of 2,6-DCNP and 2C4NP based on genome sequence analysis. A two-component monooxygenase CnpAB, composed of an oxygenase component (CnpA) and a reductase component (CnpB), was confirmed to catalyze the continuous denitration and dechlorination of 2,6-DCNP and 2C4NP to 6-chlorohydroxyquinol (6-CHQ) and hydroxyquinol (HQ), respectively. Knockout of cnpA resulted in the complete loss of the capacity for strain 22-1 to degrade 2,6-DCNP and 2C4NP. Homologous modeling and docking showed that Val155~Ala159, Phe206~Pro209 and Phe446~Arg461 of CnpA participated in the formation of the FAD-binding pocket, and Arg101, Val155 and Asn447 formed hydrogen bonds with 2,6-DCNP/2C4NP in the substrate-binding pocket. This work characterized a new two-component monooxygenase for 2,6-DCNP and 2C4NP, and enriched our understanding of the degradation mechanism of chlorinated nitrophenols (CNPs) by microorganisms.


Assuntos
Oxigenases de Função Mista , Nitrofenóis , Biodegradação Ambiental
20.
Front Cell Infect Microbiol ; 11: 665379, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33898335

RESUMO

The recurring outbreak of Zika virus (ZIKV) worldwide makes an emergent demand for novel, safe and efficacious anti-ZIKV agents. ZIKV non-structural protein 5 (NS5) methyltransferase (MTase), which is essential for viral replication, is regarded as a potential drug target. In our study, a luminescence-based methyltransferase assay was used to establish the ZIKV NS5 MTase inhibitor screening model. Through screening a natural product library, we found theaflavin, a polyphenol derived from tea, could inhibit ZIKV NS5 MTase activity with a 50% inhibitory concentration (IC50) of 10.10 µM. Molecular docking and site-directed mutagenesis analyses identified D146 as the key amino acid in the interaction between ZIKV NS5 MTase and theaflavin. The SPR assay indicated that theaflavin had a stronger binding activity with ZIKV NS5 wild-type (WT)-MTase than it with D146A-MTase. Moreover, theaflavin exhibited a dose dependent inhibitory effect on ZIKV replication with a 50% effective concentration (EC50) of 8.19 µM. All these results indicate that theaflavin is likely to be a promising lead compound against ZIKV.


Assuntos
Preparações Farmacêuticas , Infecção por Zika virus , Zika virus , Humanos , Metiltransferases/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Proteínas não Estruturais Virais/metabolismo , Replicação Viral
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