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1.
Phytochemistry ; 186: 112708, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33857795

RESUMO

Four undescribed piperazine-2,5-dione derivatives designated janthinolides C-F, and an α-pyrone-containing polyketide namely trichopyrone C, were isolated from the extract of the fungus Penicillium griseofulvum along with four known products. Among them, janthinolide C represents the first naturally occured piperazine-2,5-dione analogue featuring a cleavaged piperazinedione ring with an oxime group, while the structure of janthinolide D possesses a rare N-methoxy group in natural products. Their structures and absolute stereochemistry were elucidated based on spectroscopic data, theoretical NMR and ECD calculations, Snatzke's method, and modified Mosher's method. All compounds were evaluated for in vitro immunosuppression activity in murine splenocytes stimulated by anti-CD3/anti-CD28 mAbs, of which janthinolides B and C showed potential inhibitory activity with IC50 values at 9.3 and 1.3 µM, respectively.


Assuntos
Penicillium , Policetídeos , Animais , Imunossupressão , Camundongos , Estrutura Molecular , Piperazina , Pironas/farmacologia
2.
Molecules ; 26(4)2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670784

RESUMO

The fungus strain SCSIO 40433 was isolated from an Arctic-derived glacier sediment sample and characterized as Tolypocladium cylindrosporum. A new compound, cylindromicin (1), and seven known secondary metabolites (2-8) were isolated from this strain. The chemical structures of these compounds were elucidated by comprehensive spectroscopic analyses. Cylindromicin (1) featured a 3,4-dihydro-2H-pyran skeleton. The absolute configuration of compound 1 was assigned via interpretation of key Nuclear Overhauser Effect Spectroscopy (NOESY) correlations and Electronic Circular Dichroism (ECD) calculation. Cylindromicin (1) exhibited significant tyrosinase inhibition activity. This study highlights Polar fungi as a potential resource for new bioactive natural products.


Assuntos
Hypocreales/química , Piranos/isolamento & purificação , Regiões Árticas , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética , Piranos/química , Piranos/farmacologia , Pironas/química , Pironas/farmacologia , Relação Estrutura-Atividade
3.
Food Chem ; 349: 129172, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33545599

RESUMO

Inhibition of tyrosinase activity contributes to the control of food browning and skin pigmentation diseases. Herein, the inhibitory mechanism of epigallocatechin-3-gallate (EGCG) and gallocatechin gallate (GCG) on tyrosinase were investigated. Both EGCG and GCG inhibited tyrosinase in a mixed manner with the IC50 values of 39.4 ± 0.54 µM and 36.8 ± 0.21 µM, and showed a synergism with their combination, while EGCG and GCG combined with kojic acid (IC50 = 19.2 ± 0.26 µM) exhibited antagonism and additive effect, respectively. EGCG and GCG interacted with tyrosinase mainly by hydrogen bonding and hydrophobic interactions and induced a looser conformation of tyrosinase. Molecular docking indicated that EGCG and GCG bound to the active center of tyrosinase and interacted with copper ions and key amino acid residues. Molecular dynamics simulation further characterized the structure and property of EGCG/GCG-tyrosinase complex. This study provides novel insights into the mechanism of catechins as tyrosinase inhibitors.


Assuntos
Catequina/análogos & derivados , Monofenol Mono-Oxigenase/antagonistas & inibidores , Pironas/farmacologia , Catequina/administração & dosagem , Catequina/farmacologia , Sinergismo Farmacológico , Ligação de Hidrogênio , Conformação Molecular , Simulação de Acoplamento Molecular , Pironas/administração & dosagem
4.
Molecules ; 26(3)2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499015

RESUMO

Tyrosinase is an enzyme that plays a crucial role in the melanogenesis of humans and the browning of food products. Thus, tyrosinase inhibitors that are useful to the cosmetic and food industries are required. In this study, we have used evolutionary chemical binding similarity (ECBS) to screen a virtual chemical database for human tyrosinase, which resulted in seven potential tyrosinase inhibitors confirmed through the tyrosinase inhibition assay. The tyrosinase inhibition percentage for three of the new actives was over 90% compared to 61.9% of kojic acid. From the structural analysis through pharmacophore modeling and molecular docking with the human tyrosinase model, the pi-pi interaction of tyrosinase inhibitors with conserved His367 and the polar interactions with Asn364, Glu345, and Glu203 were found to be essential for tyrosinase-ligand interactions. The pharmacophore features and the docking models showed high consistency, revealing the possible essential binding interactions of inhibitors to human tyrosinase. We have also presented the activity cliff analysis that successfully revealed the chemical features related to substantial activity changes found in the new tyrosinase inhibitors. The newly identified inhibitors and their structure-activity relationships presented here will help to identify or design new human tyrosinase inhibitors.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Domínio Catalítico/genética , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Técnicas In Vitro , Ligantes , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/genética , Pironas/química , Pironas/farmacologia , Bibliotecas de Moléculas Pequenas , Homologia Estrutural de Proteína , Relação Estrutura-Atividade , Interface Usuário-Computador
5.
Antivir Chem Chemother ; 28: 2040206620983780, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33353394

RESUMO

BACKGROUND: Gallium has demonstrated strong anti-inflammatory activity in numerous animal studies, and has also demonstrated direct antiviral activity against the influenza A H1N1 virus and the human immunodeficiency virus (HIV). Gallium maltolate (GaM), a small metal-organic coordination complex, has been tested in several Phase 1 clinical trials, in which no dose-limiting or other serious toxicity was reported, even at high daily oral doses for several months at a time. For these reasons, GaM may be considered a potential candidate to treat coronavirus disease 2019 (COVID-19), which is caused by the SARS-CoV-2 virus and can result in severe, sometimes lethal, inflammatory reactions. In this study, we assessed the ability of GaM to inhibit the replication of SARS-CoV-2 in a culture of Vero E6 cells. METHODS: The efficacy of GaM in inhibiting the replication of SARS-CoV-2 was determined in a screening assay using cultured Vero E6 cells. The cytotoxicity of GaM in uninfected cells was determined using the Cell Counting Kit-8 (CCK-8) colorimetric assay. RESULTS: The results showed that GaM inhibits viral replication in a dose-dependent manner, with the concentration that inhibits replication by 50% (EC50) being about 14 µM. No cytotoxicity was observed at concentrations up to at least 200 µM. CONCLUSION: The in vitro activity of GaM against SARS-CoV-2, together with GaM's known anti-inflammatory activity, provide justification for testing GaM in COVID-19 patients.


Assuntos
Anti-Inflamatórios/farmacologia , Antivirais/farmacologia , Compostos Organometálicos/farmacologia , Pironas/farmacologia , /efeitos dos fármacos , Animais , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios/toxicidade , Antivirais/uso terapêutico , Antivirais/toxicidade , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Ferro/metabolismo , Compostos Organometálicos/uso terapêutico , Compostos Organometálicos/toxicidade , Pironas/uso terapêutico , Pironas/toxicidade , Células Vero , Replicação Viral/efeitos dos fármacos
6.
PLoS One ; 15(12): e0244060, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33338048

RESUMO

Ataxia-Telangiectasia (A-T), a pleiotropic chromosomal breakage syndrome, is caused by the loss of the kinase Ataxia-telangiectasia mutated (ATM). ATM is not only involved in the response to DNA damage, but also in sensing and counteracting oxidative stress. Since a disturbed redox balance has been implicated in the pathophysiology of A-T lung disease, we aimed to further explore the interplay between ATM and oxidative stress in lung cells. Using a kinetic trapping approach, we could demonstrate an interaction between the trapping mutant TRX1-CS and ATM upon oxidative stress. We could further show that combined inhibition of thioredoxin reductase (TrxR) and ATM kinase activity, using Auranofin and KU55933 respectively, induced an increase in cellular reactive oxygen species (ROS) levels and protein oxidation in lung cells. Furthermore, ATM inhibition sensitized lung cells to Auranofin-induced cell death that could be rescued by ROS scavengers. As a consequence, targeted reduction of ATM by TRX1 could serve as a regulator of oxidative ATM activation and contribute to the maintenance of the cellular redox homeostasis. These results highlight the importance of the redox-active function of ATM in preventing ROS accumulation and cell death in lung cells.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Auranofina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Células A549 , Animais , Morte Celular/efeitos dos fármacos , Células HEK293 , Humanos , Camundongos , Morfolinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pironas/farmacologia , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Tiorredoxinas/genética , Tiorredoxinas/metabolismo
7.
Life Sci ; 261: 118468, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32961232

RESUMO

AIMS: RacGTPase-mediated proliferation and smooth muscle contraction in the lower urinary tract has been recently suggested and may offer putative targets for treamtment of lower urinary tract symptoms. However, RacGTPase function for proliferation of detrusor smooth muscle cells is unknown and the specificity of Rac inhibitors has been questioned. Here, we examined effects of Rac1 knockdown and of the Rac inhibitors NSC23766 and EHT1864 in human bladder smooth muscle cells (hBSMCs). MAIN METHODS: Rac1 expression was silenced by shRNA expression. Effects of silencing and Rac inhibitors were assessed by CCK-8 assay, EdU staining, RT-PCR, colony formation assay, flow cytometry, and phalloidin staining. KEY FINDINGS: Silencing of Rac1 expression reduced the viability (up to 83% compared to scramble shRNA) and proliferation (virtually completely in proliferation assay), increased apoptosis (124%) and the number of dead cells (51%), and caused breakdown of actin organization (56% reduction of polymerized actin compared to scramble shRNA). Effects on proliferation, viability, and actin organization were mimicked by NSC23766 and EHT1864, while both compounds showed divergent effects on cell death (32-fold increase of dead cells by EHT1864, but not NSC23766). Effects of NSC23766 and EHT1864 on viability of hBSMCs were not altered by Rac1 knockdown. SIGNIFICANCE: Rac1 promotes proliferation, viability, and cytoskeletal organization, and suppresses apoptosis in bladder smooth muscle cells, which may be relevant in overactive bladder or diabetes-related bladder dysfunction. NSC23766 and EHT1864 mimick these effects, but may act Rac1-independently, by shared and divergent effects.


Assuntos
Actinas/metabolismo , Aminoquinolinas/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , Pirimidinas/farmacologia , Pironas/farmacologia , Quinolinas/farmacologia , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Inativação Gênica , Células HEK293 , Humanos , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Bexiga Urinária/citologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo
8.
Pestic Biochem Physiol ; 170: 104683, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980051

RESUMO

Root rot caused by Cylindrocarpon destructans is one of the most devastating diseases of Panax notoginseng, and Trichoderma species are potential agents for the biocontrol of fungal diseases. Thus, we screened a total of 10 Trichoderma isolates against C. destructans and selected Trichoderma atroviride T2 as an antagonistic strain for further research. 6-Pentyl-2H-pyran-2-one (6PP) was identified as an important active metabolite in the fermentation broth of the strain and exhibited antifungal activity against C. destructans. Transcriptome and metabolome analyses showed that 6PP significantly disturbed the metabolic homeostasis of C. destructans, particularly the metabolism of amino acids. By constructing a gene coexpression network, ECHS1 was identified as the hub gene correlated with 6PP stress. 6PP significantly downregulated the expression of ECHS1 at the transcriptional level and combined with the ECHS1 protein. Autophagy occurred in C. destructans cells under 6PP stress. In conclusion, 6PP may induce autophagy in C. destructans by downregulating ECHS1 at the transcriptional level and inhibiting ECHS1 protein activity. 6PP is a potential candidate for the development of new fungicides against C. destructans.


Assuntos
Fungicidas Industriais/farmacologia , Hypocreales , Trichoderma/genética , Pironas/farmacologia
9.
Phytochemistry ; 179: 112505, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32919290

RESUMO

Four undescribed pyrone derivatives, pestalopyrones A-D, containing unusual tricyclic 5/6/6 polycyclic skeletons, were isolated from the ethyl acetate extract of the endophytic fungus Pestalotiopsis neglecta S3 derived from the fresh stems of Rubia podantha Diels (Rubiaceae). Their planar structures were elucidated mainly by NMR and HRESIMS. Pestalopyrones A-D contained six contiguous chiral carbons, and the relative configurations of C-4, C-5, and C-8 in tricyclic 5/6/6 polycyclic skeletons were determined by ROESY spectra. For pestalopyrone B, the absolute configuration of C-16 was determined by the Mosher's method. All isolated compounds were tested for their cytotoxicity against cancer cell lines, antibacterial activity, and inhibitory effect on the lipopolysaccharide (LPS)-induced nitric oxide (NO) production, and the results showed that pestalopyrone A inhibited LPS-induced NO production with an IC50 value of 35.8 µM.


Assuntos
Pironas , Xylariales , Estrutura Molecular , Pironas/farmacologia
10.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32641480

RESUMO

We previously reported that the cellular transcription factor hypoxia-inducible factor 1α (HIF-1α) binds a hypoxia response element (HRE) located within the promoter of Epstein-Barr virus's (EBV's) latent-lytic switch BZLF1 gene, Zp, inducing viral reactivation. In this study, EBV-infected cell lines derived from gastric cancers and Burkitt lymphomas were incubated with HIF-1α-stabilizing drugs: the iron chelator deferoxamine (Desferal [DFO]), a neddylation inhibitor (pevonedistat [MLN-4924]), and a prolyl hydroxylase inhibitor (roxadustat [FG-4592]). DFO and MLN-4924, but not FG-4592, induced accumulation of both lytic EBV proteins and phosphorylated p53 in cell lines that contain a wild-type p53 gene. FG-4592 also failed to activate transcription from Zp in a reporter assay despite inducing accumulation of HIF-1α and transcription from another HRE-containing promoter. Unexpectedly, DFO failed to induce EBV reactivation in cell lines that express mutant or no p53 or when p53 expression was knocked down with short hairpin RNAs (shRNAs). Likewise, HIF-1α failed to activate transcription from Zp when p53 was knocked out by CRISPR-Cas9. Importantly, DFO induced binding of p53 as well as HIF-1α to Zp in chromatin immunoprecipitation (ChIP) assays, but only when the HRE was present. Nutlin-3, a drug known to induce accumulation of phosphorylated p53, synergized with DFO and MLN-4924 in inducing EBV reactivation. Conversely, KU-55933, a drug that inhibits ataxia telangiectasia mutated, thereby preventing p53 phosphorylation, inhibited DFO-induced EBV reactivation. Lastly, activation of Zp transcription by DFO and MLN-4924 mapped to its HRE. Thus, we conclude that induction of BZLF1 gene expression by HIF-1α requires phosphorylated, wild-type p53 as a coactivator, with HIF-1α binding recruiting p53 to Zp.IMPORTANCE EBV, a human herpesvirus, is latently present in most nasopharyngeal carcinomas, Burkitt lymphomas, and some gastric cancers. To develop a lytic-induction therapy for treating patients with EBV-associated cancers, we need a way to efficiently reactivate EBV into lytic replication. EBV's BZLF1 gene product, Zta, usually controls this reactivation switch. We previously showed that HIF-1α binds the BZLF1 gene promoter, inducing Zta synthesis, and HIF-1α-stabilizing drugs can induce EBV reactivation. In this study, we determined which EBV-positive cell lines are reactivated by classes of HIF-1α-stabilizing drugs. We found, unexpectedly, that HIF-1α-stabilizing drugs only induce reactivation when they also induce accumulation of phosphorylated, wild-type p53. Fortunately, p53 phosphorylation can also be provided by drugs such as nutlin-3, leading to synergistic reactivation of EBV. These findings indicate that some HIF-1α-stabilizing drugs may be helpful as part of a lytic-induction therapy for treating patients with EBV-positive malignancies that contain wild-type p53.


Assuntos
Herpesvirus Humano 4/genética , Interações Hospedeiro-Patógeno/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Transativadores/genética , Proteína Supressora de Tumor p53/genética , Linhagem Celular Tumoral , Ciclopentanos/farmacologia , Desferroxamina/farmacologia , Inibidores Enzimáticos/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Regulação da Expressão Gênica , Glicina/análogos & derivados , Glicina/farmacologia , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/crescimento & desenvolvimento , Herpesvirus Humano 4/metabolismo , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/agonistas , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imidazóis/farmacologia , Quelantes de Ferro/farmacologia , Isoquinolinas/farmacologia , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Linfócitos/virologia , Morfolinas/farmacologia , Piperazinas/farmacologia , Inibidores de Prolil-Hidrolase/farmacologia , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacos , Pirimidinas/farmacologia , Pironas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Elementos de Resposta , Transdução de Sinais , Transativadores/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Ativação Viral/efeitos dos fármacos
11.
Am J Physiol Heart Circ Physiol ; 319(1): H203-H212, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32502374

RESUMO

High-altitude (>2,500 m) residence increases the incidence of intrauterine growth restriction (IUGR) due, in part, to reduced uterine artery blood flow and impaired myometrial artery (MA) vasodilator response. A role for the AMP-activated protein kinase (AMPK) pathway in protecting against hypoxia-associated IUGR is suggested by genomic and transcriptomic studies in humans and functional studies in mice. AMPK is a hypoxia-sensitive metabolic sensor with vasodilatory properties. Here we hypothesized that AMPK-dependent vasodilation was increased in MAs from high versus low-altitude (<1,700 m) Colorado women with appropriate for gestational age (AGA) pregnancies and reduced in IUGR pregnancies regardless of altitude. Vasoreactivity studies showed that, in AGA pregnancies, MAs from high-altitude women were more sensitive to vasodilation by activation of AMPK with A769662 due chiefly to increased endothelial nitric oxide production, whereas MA responses to AMPK activation in the low-altitude women were endothelium independent. MAs from IUGR compared with AGA pregnancies had blunted vasodilator responses to acetylcholine at high altitude. We concluded that 1) blunted vasodilator responses in IUGR pregnancies confirm the importance of MA vasodilation for normal fetal growth and 2) the increased sensitivity to AMPK activation in AGA pregnancies at high altitude suggests that AMPK activation helped maintain MA vasodilation and fetal growth. These results highlight a novel mechanism for vasodilation of MAs under conditions of chronic hypoxia and suggest that AMPK activation could provide a therapy for increasing uteroplacental blood flow and improving fetal growth in IUGR pregnancies.NEW & NOTEWORTHY Intrauterine growth restriction (IUGR) impairs infant well- being and increases susceptibility to later-in-life diseases for mother and child. Our study reveals a novel role for AMPK in vasodilating the myometrial artery (MA) from women residing at high altitude (>2,500 m) with appropriate for gestational age pregnancies but not in IUGR pregnancies at any altitude.


Assuntos
Doença da Altitude/metabolismo , Artérias/metabolismo , Retardo do Crescimento Fetal/metabolismo , Miométrio/irrigação sanguínea , Proteínas Quinases/metabolismo , Vasodilatação , Adulto , Doença da Altitude/fisiopatologia , Artérias/efeitos dos fármacos , Artérias/fisiopatologia , Feminino , Retardo do Crescimento Fetal/fisiopatologia , Humanos , Óxido Nítrico/metabolismo , Gravidez , Pironas/farmacologia , Tiofenos/farmacologia
12.
J Cancer Res Clin Oncol ; 146(7): 1801-1811, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32435894

RESUMO

PURPOSE: Oral mucositis is a debilitating inflammatory disorder observed in patients undergoing active cancer treatment, particularly cancer of the head and neck region. A key pathway believed to be involved in the pathogenesis of oral mucositis is the formation of reactive oxygen species (ROS). The identification of compounds that can inhibit this pathway may therefore be of benefit in treating this disorder. The kava plant (Piper methysticum) contains various constituents, including flavokawain A (FKA), flavokawain B (FKB), yangonin, methysticin and kavain. These constituents are known to be biologically active and possess anti-oxidative properties. This study therefore focused on examining these constituents for their effect on ROS formation in an in vitro oral mucositis model. METHODS: Cell proliferation was assessed in normal oral keratinocytes (OKF6) treated with and without kava constituents, namely FKA, FKB, yangonin, methysticin and kavain using an MTS in vitro assay. Oxidative stress was assessed by co-treating and pre-treating OKF6 cells with H2O2. The effects were quantified by analysis of ROS production, using a CM-H2DCFDA assay. RESULTS: Pre-treatment of cells for 24 h with 2.5 µg/ml kavain and 5 µg/ml FKA demonstrated a significant protective anti-oxidative effect. Similarly, FKB at a concentration of 2.5 µg/ml, demonstrated a trend of ROS reduction but was observed to be cytotoxic at concentrations greater than 5 µg/ml. Reduction in ROS production by methysticin and yangonin was compromised by their cell cytotoxicity. CONCLUSION: This was the first study to identify the anti-oxidative effects and safety of FKA and kavain with regard to oral keratinocytes, highlighting their potential use in the development of a preventative treatment for oral mucositis.


Assuntos
Kava/química , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Peróxido de Hidrogênio/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Substâncias Protetoras/química , Piranos/farmacologia , Pironas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Estomatite/tratamento farmacológico , Estomatite/etiologia
13.
Sci Rep ; 10(1): 8193, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424135

RESUMO

Five new chlamydosporol derivatives, named pleospyrones A-E (1-5), together with one known congener (6), were isolated from the culture of the endophytic fungus Pleosporales sp. Sigrf05, obtained from the medicinal plant Siraitia grosvenorii. The structures of the new compounds were elucidated mainly by analysis of the HRESIMS, and (1D, 2D) NMR data, while ECD and optical rotation calculations were used to assign the absolute configurations. The plausible biosynthetic pathway of these compounds were proposed. The isolated compounds were evaluated for their cytotoxicity, antifungal and antibacterial activities. Compounds 1, and 4-6 were cytotoxic against the tested cancer cells with IC50 values of 1.26~47.5 µM. Compounds 1-3 showed moderate antifungal activities against Magnaporthe oryzae, while compound 5 displayed weak antibacterial activity.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Ascomicetos/química , Pironas/química , Pironas/farmacologia , Linhagem Celular Tumoral , Humanos , Modelos Moleculares , Conformação Molecular
14.
Nat Commun ; 11(1): 1830, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286350

RESUMO

A synthetic biology method based on heterologous biosynthesis coupled with genome mining is a promising approach for increasing the opportunities to rationally access natural product with novel structures and biological activities through total biosynthesis and combinatorial biosynthesis. Here, we demonstrate the advantage of the synthetic biology method to explore biological activity-related chemical space through the comprehensive heterologous biosynthesis of fungal decalin-containing diterpenoid pyrones (DDPs). Genome mining reveals putative DDP biosynthetic gene clusters distributed in five fungal genera. In addition, we design extended DDP pathways by combinatorial biosynthesis. In total, ten DDP pathways, including five native pathways, four extended pathways and one shunt pathway, are heterologously reconstituted in a genetically tractable heterologous host, Aspergillus oryzae, resulting in the production of 22 DDPs, including 15 new analogues. We also demonstrate the advantage of expanding the diversity of DDPs to probe various bioactive molecules through a wide range of biological evaluations.


Assuntos
Diterpenos/farmacologia , Fungos/química , Naftalenos/farmacologia , Pironas/farmacologia , Biologia Sintética , Peptídeos beta-Amiloides/metabolismo , Animais , Fármacos Anti-HIV/farmacologia , Aspergillus/química , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Proliferação de Células/efeitos dos fármacos , Diterpenos/química , Drosophila/efeitos dos fármacos , Fungos/genética , Genoma Fúngico , HIV-1/efeitos dos fármacos , Humanos , Células MCF-7 , Naftalenos/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Agregados Proteicos , Pironas/química , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Estereoisomerismo
15.
Sci Rep ; 10(1): 4441, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157166

RESUMO

The DNA damage response after kidney injury induces cell cycle arrest in renal tubular epithelial cells, resulting in the secretion of pro-fibrotic cytokines, thereby promoting interstitial fibrosis in a paracrine manner. Phosphorylation of ataxia-telangiectasia mutated (ATM) is the initial step in the DNA damage response and subsequent cell cycle arrest; however, the effects of ATM inhibition on the injured kidney have not been explored. Pharmacological ATM inhibition by KU55933 in cisplatin-treated mice did not ameliorate, but instead exacerbated cisplatin-induced DNA damage and tubular injury, thereby increasing mortality. Analysis of isolated tubular epithelia by FACS from bigenic SLC34a1-CreERt2; R26tdTomato proximal tubular-specific reporter mice revealed that KU55933 upregulated p53 and subsequent pro-apoptotic signaling in tubular epithelia of cisplatin-treated mice, leading to marked mitochondrial injury and apoptosis. In addition, KU55933 attenuated several DNA repair processes after cisplatin treatment, including single-strand DNA repair and Fanconi anemia pathways, suggesting that DNA repair after dual treatment of cisplatin and KU55933 was not sufficient to prevent the cisplatin-induced tubular injury. Our study suggested that ATM inhibition does not increase DNA repair after cisplatin-induced DNA damage and exacerbates tubular injury through the upregulation of p53-dependent pro-apoptotic signaling. Acute kidney injury must be carefully monitored when ATM inhibitors become available in clinical practice in the future.


Assuntos
Lesão Renal Aguda/etiologia , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Cisplatino/toxicidade , Morfolinas/farmacologia , Proteínas Mutantes/antagonistas & inibidores , Mutação , Pironas/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Lesão Renal Aguda/metabolismo , Lesão Renal Aguda/patologia , Animais , Antineoplásicos/toxicidade , Apoptose , Proteínas Mutadas de Ataxia Telangiectasia/genética , Pontos de Checagem do Ciclo Celular , Reparo do DNA , Camundongos , Fosforilação , Transdução de Sinais , Proteína Supressora de Tumor p53/genética
16.
Biol Pharm Bull ; 43(3): 550-553, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32115514

RESUMO

Equol, an intestinal metabolite of daidzein, inhibited more potently mushroom tyrosinase in vitro than other inhibitors, genistein and kojic acid. We investigated the mechanism underlying tyrosinase inhibition by equol. Treating racemic equol with tyrosinase produced 3'-hydroxyequol. Because the optical activity of the product showed <25% enantiomeric excess, the reaction was not highly stereospecific. Using enzyme-linked immunosorbent assays with an anti-equol monoclonal antibody, we observed that equol bound to pre-coated tyrosinase in a dose-dependent manner. Our results suggested the formation of a stable equol-tyrosinase complex.


Assuntos
Agaricales , Equol/química , Equol/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Genisteína/farmacologia , Pironas/farmacologia
17.
Mol Carcinog ; 59(6): 575-589, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32187756

RESUMO

Dihydromethysticin (DHM), a natural compound derived from Kava, has been reported to be effective against mental disorders and some malignant tumors. However, little is known about the inhibitory effect of DHM on colorectal cancer (CRC). First, we examined the impact of DHM on human colon cancer cell lines, which demonstrated that DHM inhibits proliferation, migration, and invasion and promotes apoptosis and cell cycle arrest in colon cancer cells in vitro. Using small hairpin RNA, we inhibited nucleotide-oligomerization domain-like receptor subfamily C3 (NLRC3)/phosphoinositide 3-kinase (PI3K) pathway to elucidate the partial signaling of DHM-mediated tumor suppression. Additionally, using an ectopic human CRC model, we verified whether DHM inhibits tumor growth and angiogenesis via the NLRC3/PI3K pathway in vivo. Overall, DHM showed an inhibitory effect on CRC by altering cell proliferation, migration, invasion, apoptosis, cell cycle, and angiogenesis, possibly via the NLRC3/PI3K pathway. Thus, DHM may be a promising candidate for CRC therapy.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Kava/química , Fosfatidilinositol 3-Quinases/metabolismo , Pironas/farmacologia , Animais , Apoptose , Ciclo Celular , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Fosfatidilinositol 3-Quinases/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
J Nat Med ; 74(3): 584-590, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32207026

RESUMO

Three new 5,6-dihydro-α-pyrones derivatives, named (S)-rugulactone (1) pulchrinervialactone A (2), and pulchrinervialactone B (4), along with one known pyrone, cryptobrachytone C (3), and three known amide derivatives (5-7) have been isolated from the leaves of Cryptocarya pulchrinervia. The structures of 1-7 were elucidated based on extensive spectroscopic data and comparison with literatures. The configurations of compounds 3 and 4 were established by single crystal X-ray diffraction analysis. This is also the first report in finding (S)-rugulactone (1) as a natural product. In addition, the preliminary cytotoxic activity of the isolated compounds was evaluated against P-388 cells using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. All the pyrones, except compound 4, were active significantly inhibiting the growth of P-388 cells, while the amides derivatives (5-7) showed moderate to weak activities. Therefore, compounds 1-3 could be potentially examined further for anticancer agents.


Assuntos
Antineoplásicos/farmacocinética , Proliferação de Células/efeitos dos fármacos , Cryptocarya/química , Lactonas/farmacologia , Pironas/farmacologia , Animais , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Lactonas/isolamento & purificação , Camundongos , Estrutura Molecular , Neoplasias/tratamento farmacológico , Folhas de Planta/química , Pironas/isolamento & purificação
19.
Nat Commun ; 11(1): 1032, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32098961

RESUMO

The AMP-activated protein kinase (AMPK) is a master sensor of the cellular energy status that is crucial for the adaptive response to limited energy availability. AMPK is implicated in the regulation of many cellular processes, including autophagy. However, the precise mechanisms by which AMPK controls these processes and the identities of relevant substrates are not fully understood. Using protein microarrays, we identify Cyclin Y as an AMPK substrate that is phosphorylated at Serine 326 (S326) both in vitro and in cells. Phosphorylation of Cyclin Y at S326 promotes its interaction with the Cyclin-dependent kinase 16 (CDK16), thereby stimulating its catalytic activity. When expressed in cells, Cyclin Y/CDK16 is sufficient to promote autophagy. Moreover, Cyclin Y/CDK16 is necessary for efficient AMPK-dependent activation of autophagy. This functional interaction is mediated by AMPK phosphorylating S326 of Cyclin Y. Collectively, we define Cyclin Y/CDK16 as downstream effector of AMPK for inducing autophagy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/fisiologia , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Animais , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/metabolismo , Quinases Ciclina-Dependentes/genética , Ciclinas/genética , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Células NIH 3T3 , Fosforilação/efeitos dos fármacos , Análise Serial de Proteínas , Pironas/farmacologia , Serina/metabolismo , Tiofenos/farmacologia
20.
Chemistry ; 26(22): 4997-5009, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32065454

RESUMO

Cancer is one of the main causes of death worldwide. Chemotherapy, despite its severe side effects, is to date one of the leading strategies against cancer. Metal-based drugs present several potential advantages when compared to organic compounds and they have gained trust from the scientific community after the approval on the market of the drug cisplatin. Recently, we reported the ruthenium complex ([Ru(DIP)2 (sq)](PF6 ) (where DIP is 4,7-diphenyl-1,10-phenantroline and sq is semiquinonate) with a remarkable potential as chemotherapeutic agent against cancer, both in vitro and in vivo. In this work, we analyse a structurally similar compound, namely [Ru(DIP)2 (mal)](PF6 ), carrying the flavour-enhancing agent approved by the FDA, maltol (mal). To possess an FDA approved ligand is crucial for a complex, whose mechanism of action might include ligand exchange. Herein, we describe the synthesis and characterisation of [Ru(DIP)2 (mal)](PF6 ), its stability in solutions and under conditions that resemble the physiological ones, and its in-depth biological investigation. Cytotoxicity tests on different cell lines in 2D model and on HeLa MultiCellular Tumour Spheroids (MCTS) demonstrated that our compound has higher activity than cisplatin, inspiring further tests. [Ru(DIP)2 (mal)](PF6 ) was efficiently internalised by HeLa cells through a passive transport mechanism and severely affected the mitochondrial metabolism.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Complexos de Coordenação/farmacologia , Pironas/farmacologia , Rutênio/química , Antineoplásicos/química , Cisplatino/química , Complexos de Coordenação/química , Células HeLa , Humanos , Ligantes , Estrutura Molecular , Pironas/química , Rutênio/farmacologia
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