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1.
Fitoterapia ; 143: 104532, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32151636

RESUMO

Six new compounds, including two new isochromane lactones, versicoisochromanes A and B (1 and 2), two new benzolactones, versicobenzos A and B (3 and 4), one furancarboxylic derivate, asperfuran A (6) and one ergosterol-type steroid, asperergoster A (7), along with five known steroids (8-12), were isolated from the Anoectochilus roxburghii endophytic fungus Aspergillus versicolor. The structures of these new compounds were determined by extensive spectroscopic techniques and electronic circular dichroism (ECD) calculations. It is notable that the new compound 7 exhibited obvious IL-1ß, NO and TNF-α inhibitory activity in LPS-stimulated RAW264.7 macrophages, with IC50 values of 35.5, 33.9 and 31.3 µM, respectively. Furthermore, compounds 7 and 8 displayed potential inhibitory effects on murine splenocytes proliferation stimulated by anti-CD3/anti-CD28 monoclonal antibodies (mAbs), meanwhile suppress the lipopolysaccharide (LPS) irritated murine splenocytes proliferation.

2.
J Nat Prod ; 82(10): 2925-2930, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31490677

RESUMO

A pyridone alkaloid, asperpyridone A (1), which possesses an unusual pyrano[3,2-c]pyridine scaffold, was isolated from solid cultures of the endophytic fungus Aspergillus sp. TJ23. Its structure, including its absolute configuration, was determined using a combination of nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, quantum chemical calculations (electronic circular dichroism), and X-ray crystallography. In vitro bioassays demonstrated that asperpyridone A (1) could function as a potential hypoglycemic agent, which exhibited pronounced glucose uptake effect in liver HepG2 cells, under both normal and insulin-resistant conditions, with higher efficacy than metformin. The underlying mechanism of asperpyridone A was elucidated by analyzing the genes expressed, the Gene Ontology (GO) function enrichment, the protein interaction network, and real-time quantitative reverse transcription polymerase chain reaction, which suggested that asperpyridone A exhibits hypoglycemic activity by activating the insulin signaling pathway. Moreover, on the basis of the hypoglycemic potency, fibroblast growth factor 21 (FGF21) was determined to be a potential target for asperpyridone A.

3.
Org Biomol Chem ; 17(35): 8234-8242, 2019 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-31441489

RESUMO

Chemical investigation of the extracts of the aerial parts of Hypericum przewalskii Maxim. resulted in the isolation and identification of six new epoxychromene-containing polycyclic polyprenylated acylphloroglucinols (PPAPs), named przewalcyrones A-F (1-6), and one known analogue (7). All of the structures were determined based on extensive spectroscopic analyses, X-ray crystallographic analysis, modified Mosher's method, [Rh2(OCOCF3)4]-induced ECD, and electronic circular dichroism (ECD) comparison. Structurally, przewalcyrones A-F represent the first examples of PPAPs containing an unexpected 8,8-dimethyl-3,9-epoxychromene moiety. All these compounds were evaluated for the immunosuppressive activity in anti-CD3/anti-CD28 monoclonal antibody (mAb)-stimulated human T cells. Among them, przewalcyrones C and D exhibited potential in vitro immunosuppressive activity, with IC50 values of (5.01 ± 0.52) µM and (5.26 ± 0.56) µM, respectively, highlighting those compounds as a promising starting point for the development of new immunosuppressive agents.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Hypericum/química , Imunossupressores/farmacologia , Floroglucinol/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Voluntários Saudáveis , Humanos , Imunossupressores/química , Imunossupressores/isolamento & purificação , Leucócitos Mononucleares/efeitos dos fármacos , Conformação Molecular , Floroglucinol/análogos & derivados , Floroglucinol/química , Estereoisomerismo , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
4.
Org Biomol Chem ; 16(46): 9046-9052, 2018 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30430177

RESUMO

Chemical investigation of the extracts of Aspergillus terreus resulted in the identification of terreusterpenes A-D (1-4), four new 3,5-dimethylorsellinic acid-based meroterpenoids. The structures and absolute configurations of 1-4 were elucidated by spectroscopic analyses including HRESIMS and 1D- and 2D-NMR, chemical conversion, and single crystal X-ray diffraction. Terreusterpenes A (1) and B (2) featured 2,3,5-trimethyl-4-oxo-5-carboxy tetrahydrofuran moieties. Terreusterpene D (4) was characterized by a 4-hydroxy-3-methyl gamma lactone fragment that was generated by accident from the rearrangement of 3 in a mixed tetrahydrofuran-H2O-MeOH solvent. All these compounds were evaluated for the ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1) and acetylcholinesterase (AchE) inhibitory activities. Among them, compounds 1 and 2 showed potentially significant BACE1 inhibitory activity, with IC50 values of 5.98 and 11.42 µM, respectively. Interestingly, compound 4 exhibited promising BACE1 and AchE inhibitory activities, with IC50 values of 1.91 and 8.86 µM, respectively, while 3 showed no such activity. Taken together, terreusterpenes A and B could be of great importance for the development of new BACE1 inhibitors, while terreusterpene D could serve as the first dual-targeted 3,5-dimethylorsellinic acid-based meroterpenoid for the treatment of Alzheimer's disease.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Aspergillus/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Resorcinóis/química , Resorcinóis/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Inibidores da Colinesterase/síntese química , Cristalografia por Raios X , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/metabolismo , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Resorcinóis/síntese química
5.
Chem Biodivers ; 15(12): e1800395, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30294975

RESUMO

Eight secondary metabolites, including a new polyketide, named asperetide (1) and a new prenylxanthone derivative, called asperanthone (4), and six known compounds, (S)-3-butyl-7-methoxyphthalide (2), ruguloxanthone C (3), tajixanthone hydrate (5), tajixanthone methanoate (6), salimyxin B (7), and ergosterol (8), were isolated and identified from the medicinal plant-derived fungus, Aspergillus sp. TJ23. The new structures and their absolute configurations were elucidated via multiple methods, including 1D- and 2D-NMR, HR-ESI-MS, UV, IR, and the electronic circular dichroism (ECD) calculations. All of the isolates were characterized from the strain for the first time. The in vitro bioassay showed that compounds 3-5 and 8 exerted inhibitory activities against five cancer cell lines (B16, MDA-MB-231, 4T1, HepG2, and LLC) with IC50 values ranging from 5.13 to 36.8 µm.


Assuntos
Aspergillus/química , Policetídeos/química , Xantonas/química , Aspergillus/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Humanos , Espectroscopia de Ressonância Magnética , Conformação Molecular , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Xantonas/isolamento & purificação , Xantonas/farmacologia
6.
J Nat Prod ; 81(6): 1311-1320, 2018 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-29771527

RESUMO

To explore the chemical diversity of metabolites from endophytic fungi, the strain Phomopsis sp. TJ507A, isolated from the medicinal plant Phyllanthus glaucus, was investigated. A 2,3- seco-protoilludane-type sesquiterpenoid (1), eight protoilludane-type sesquiterpenoids (2-9), four illudalane-type sesquiterpenoids (10a/10b, 11, and 12), and a botryane-type sesquiterpenoid (13) in addition to seven known sesquiterpenoids (14-20) were identified from the liquid culture of the fungus. Structures of the isolated compounds, including their absolute configurations, were elucidated based on extensive spectroscopic analyses, a modified Mosher analysis, electronic circular dichroism (ECD) calculations, and [Rh2(OCOCF3)4]-induced ECD spectra as well as X-ray crystallographic analyses. Compound 1 represents the first example of a naturally occurring sesquiterpenoid containing the unusual 2,3- seco-protoilludane scaffold. Compounds 1 ( p < 0.001); 2-6, 15, and 18 ( p < 0.01); and 7, 9, and 20 ( p < 0.05) displayed ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitory activities ranging from 19.4% to 43.8% at the concentration of 40 µM. LY2811376 was used as the positive control with an inhibitory activity of 38.6% ( p < 0.01). Furthermore, none of these compounds showed obvious hepatotoxicity at concentration of 40 µM.


Assuntos
Ascomicetos/química , Endófitos/química , Sesquiterpenos/química , Terpenos/química , Linhagem Celular , Cristalografia por Raios X , Humanos , Fungos Mitospóricos/química , Sesquiterpenos Policíclicos , Sesquiterpenos/farmacologia , Terpenos/farmacologia
7.
Sci Rep ; 8(1): 5454, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29615766

RESUMO

Rising drug resistance limits the treatment options infected by methicillin-resistant Staphylococcus aureus (MRSA). A promising solution for overcoming the resistance of MRSA is to inhibit the penicillin-binding protein 2a (PBP2a). A novel terpene-polyketide hybrid meroterpenoid, aspermerodione (1), characterized by an unusual 2,6-dioxabicyclo[2.2.1]heptane core skeleton, and a new heptacyclic analogue, andiconin C (2), were isolated and identified from the liquid cultures of endophytic fungus Aspergillus sp. TJ23. The structures and their absolute configurations of all chiral centers were elucidated via extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations and determined via single-crystal X-ray diffraction analysis. Aspemerodione (1) was found to be a potential inhibitor of PBP2a, and work synergistically with the ß-lactam antibiotics oxacillin and piperacillin against MRSA.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Aspergillus/metabolismo , Proteínas de Ligação às Penicilinas/antagonistas & inibidores , Policetídeos/química , Policetídeos/farmacologia , Terpenos/química , Terpenos/farmacologia , Antibacterianos/metabolismo , Testes de Sensibilidade Microbiana , Modelos Moleculares , Conformação Molecular , Policetídeos/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Terpenos/metabolismo
8.
J Nat Prod ; 79(12): 3134-3142, 2016 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-27966950

RESUMO

Eighteen compounds, including eight new cassane-type furanoditerpenoids, 3ß-hydroxyphanginin H (1), 3ß-acetoxyphanginin H (2), 7ß-acetoxyphanginin H (3), 7ß-hydroxyphanginin H (4), 4-epi-3ß-hydroxycaesalpinilinn (5), 4-epi-3ß-acetoxycaesalpinilinn (6), 20-acetoxytaepeenin D (7), and tomocin E (8), along with 10 known compounds (9-18) were isolated from the roots of Caesalpinia decapetala. Compounds 1-13 were isolated from C. decapetala for the first time. The new compounds with their absolute configurations were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compounds 1, 4, 5, 7, and 11 exhibited inhibitory activities against the SW1990 human pancreatic cancer cell line with IC50 values ranging from 2.9 to 8.9 µM.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Caesalpinia/química , Diterpenos/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Cristalografia por Raios X , Ciclosporina/farmacologia , Diterpenos/química , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Masculino , Camundongos Endogâmicos BALB C , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/classificação , Sementes/química
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