Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 215
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Blood ; 140(16): 1790-1802, 2022 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-35981465

RESUMO

The bispecific T-cell engager (BiTE) blinatumomab against CD19 and CD3 has emerged as the most successful bispecific antibody (bsAb) to date; however, a significant proportion of patients do not respond to the treatments or eventually experience relapse after an initial response, and the recurrence rate increases significantly due to escape or downregulation of the CD19 antigen. To enhance antitumor efficacy and overcome potential immune escape, we developed a novel approach to design a CD19/CD22/CD3 trispecific antibody (tsAb) by site-specifically fusing anti-CD19 scFv (FMC63) and anti-CD22 nanobody (Nb25) to the defined sites of the CD3 antigen-binding fragment (Fab, SP34). This strategy allows for the optimal formation of immune synapses mediated by CD19/CD22/CD3 between target cells and T cells. Optimized tsAb can be superior for inducing T-cell-specific cytotoxicity and cytokine production against CD19+ and/or CD22+ tumor cells compared to other tsAb formats, and demonstrated significantly enhanced antitumor efficacy and the ability to overcome immune escape compared with the corresponding bsAbs alone or in combination, as well as with blinatumomab. In addition, tsAb treatment can lead to the long-term elimination of primary B-ALL patient samples in the PDX model and significantly prolong survival. This novel approach provides unique insight into the structural optimization of T-cell-redirected multispecific antibodies using site-specific recombination, and may be broadly applicable to heterogeneous and resistant tumor populations as well as solid tumors.


Assuntos
Anticorpos Biespecíficos , Linfoma de Burkitt , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Antígenos CD19 , Complexo CD3 , Recidiva Local de Neoplasia/tratamento farmacológico , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Linfoma de Células B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Linfoma de Burkitt/tratamento farmacológico , Citocinas , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico
2.
Org Biomol Chem ; 22(11): 2271-2278, 2024 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-38391281

RESUMO

Two previously unreported lignans (1-2) and four undescribed [11]-chaetoglobosins (3-6) were obtained from the culture extract of an endophytic fungus Pseudeurotium bakeri P1-1-1. Their structures with absolute configurations were determined by spectroscopic data analysis, single-crystal X-ray diffraction, electronic circular dichroism (ECD) calculations, the modified Mosher's method, and Mo2(OAc)4-induced electronic circular dichroism (ICD) experiments. Compounds 5 and 6 showed moderate cytotoxic effects against seven human cancer cell lines. Compounds 2-4 exhibited immunosuppressive activities on concanavalin A-induced T cell proliferation with IC50 values of 3.7, 3.4, and 14.5 µM, and on lipopolysaccharide-induced B cell proliferation with IC50 values of 4.1, 3.9, and 14.2 µM, respectively. Further investigation revealed that 2 and 3 induced apoptosis in activated T cells in a dose-dependent manner.


Assuntos
Ascomicetos , Lignanas , Humanos , Lignanas/química , Linhagem Celular , Alcaloides Indólicos , Imunossupressores , Estrutura Molecular
3.
Int J Mol Sci ; 25(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473980

RESUMO

Liver fibrosis poses a significant global health risk due to its association with hepatocellular carcinoma (HCC) and the lack of effective treatments. Thus, the need to discover additional novel therapeutic targets to attenuate liver diseases is urgent. Leucine-rich repeat containing 1 (LRRC1) reportedly promotes HCC development. Previously, we found that LRRC1 was significantly upregulated in rat fibrotic liver according to the transcriptome sequencing data. Herein, in the current work, we aimed to explore the role of LRRC1 in liver fibrosis and the underlying mechanisms involved. LRRC1 expression was positively correlated with liver fibrosis severity and significantly elevated in both human and murine fibrotic liver tissues. LRRC1 knockdown or overexpression inhibited or enhanced the proliferation, migration, and expression of fibrogenic genes in the human hepatic stellate cell line LX-2. More importantly, LRRC1 inhibition in vivo significantly alleviated CCl4-induced liver fibrosis by reducing collagen accumulation and hepatic stellate cells' (HSCs) activation in mice. Mechanistically, LRRC1 promoted HSC activation and liver fibrogenesis by preventing the ubiquitin-mediated degradation of phosphorylated mothers against decapentaplegic homolog (Smad) 2/3 (p-Smad2/3), thereby activating the TGF-ß1/Smad pathway. Collectively, these results clarify a novel role for LRRC1 as a regulator of liver fibrosis and indicate that LRRC1 is a promising target for antifibrotic therapies.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ratos , Humanos , Camundongos , Animais , Células Estreladas do Fígado/metabolismo , Leucina/metabolismo , Regulação para Cima , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Cirrose Hepática/metabolismo , Fígado/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Proteínas Smad/metabolismo
4.
Saudi Pharm J ; 32(1): 101889, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38090737

RESUMO

The present study utilized molecular docking and density functional theory (DFT) approaches, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties to investigate the binding interactions, reactivity, stability, and drug-likeness of curcumin (1), tetrahydrocurcumin (2), and tetrahydrocurcumin derivatives (3-6) as potential anti-cancer agents. MGL (Molecular Graphic Laboratory) and Discovery Studio Visualizer (DSV) software employed for docking studies. Pharmacokinetic and pharmacodynamic (ADME-Tox) analyses were conducted using SwissADME and pKCSM web servers. Total Electron Density (TED) measurements identified molecular adsorption sites, considering various factors, including quantum chemical characteristics, to assess compound effectiveness using DFT method implanted in the Gaussian software. The binding energy (Eb) from docking simulations was used to evaluate inhibitory potential. ADMET analysis suggested favorable oral bioavailability and pharmacokinetics for all studied substances, excluding compound 4. DFT and docking investigations highlighted compounds 1, 2, and 6 as optimal scaffolds for drug design based on in silico screening tests.

5.
J Nat Prod ; 86(11): 2571-2579, 2023 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-37947788

RESUMO

Eleven new phenyltetracenoid polyketides, streptovertimycins U (1) and V (2), 14-bromo-streptovertidione (3), streptovertimycins W-Y (4-6), and streptovertimycins Z1-Z5 (7-11), together with the known congeners fasamycins R (12) and S (13) and accramycins A (14) and B (15), were isolated from the NaBr-supplemented rice-grown cultures of Streptomyces morookaense SC1169. Their structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray diffraction analysis, and theoretical computations of ECD spectra. Compounds 1 and 2 are methylene-bridged dimers of accramycin A, and compounds 3 and 7-11 are brominated fasamycin congeners. Compounds 5 and 8-14 exhibited activity against the drug-resistant bacteria MRSA and VRE (MIC = 0.6-5.0 µg/mL), and the dimer 1 displayed activity against MRSA (MIC = 2.5 µg/mL). Compounds 6-15 showed cytotoxicity against the human carcinoma A549, HeLa, HepG2, and MCF-7 cells in the IC50 range between 1.7 and 9.2 µM.


Assuntos
Streptomyces , Humanos , Streptomyces/química , Células HeLa , Análise Espectral , Células MCF-7 , Antibacterianos/química , Estrutura Molecular
6.
Artigo em Inglês | MEDLINE | ID: mdl-36762500

RESUMO

Squamocin, an annonaceous acetogenin isolated from plants in the Annonaceae family, has antitumour activity. In this study, we report that Sq-2, a biotinylated squamocin monomer, has a favorable antitumour effect on MDA-MB-231 and SKBR3 breast cancer cells in vitro. MTT assays show that Sq-2 has a better antitumour effect on MDA-MB-231 cells than Sq-5 and Sq-6. Furthermore, RNA-Seq and KEGG enrichment analyses reveal that Sq-2 activates the MAPK signaling pathway, and results of western blot analysis demonstrate that Sq-2 activates the JNK and p38 pathways in MDA-MB-231 and SKBR3 cells. Flow cytometry and western blot analysis reveal that Sq-2 induces cell apoptosis by increasing the expressions of cleaved Caspase-3 and cleaved PARP as well as the ratio of Bax/Bcl-2. Inhibition of the Caspase family by Z-VAD-FMK attenuates the viability of MDA-MB-231 cells, indicating that Sq-2 induces apoptosis in a Caspase-dependent manner. Additionally, pretreatment with the p38 inhibitor SB203580 or JNK inhibitor SP600125 partially reverses the increase in the apoptosis rate and decrease in cell viability prompted by Sq-2. Furthermore, Sq-2 treatment decreases the expression level of CyclinD1 and increases the expression levels of p21, p27, CyclinA1, and CDK2, causing S-phase arrest in MDA-MB-231 and SKBR3 cells. Further study indicates that Sq-2 stimulates autophagy in MDA-MB-231 and SKBR3 cells, and inhibition of autophagy by bafilomycin A1 increases cell viability and promotes cell survival. Sq-2, a novel biotin-squamocin compound, shows a significant inhibitory effect on the propagation of SKBR3 and MDA-MB-231 breast cancer cells. Furthermore, Sq-2 treatment not only induces S-phase arrest and activates the JNK and p38 pathways to trigger apoptosis but also causes autophagy to promote apoptosis in MDA-MB-231 and SKBR3 cells.

.

7.
Int J Mol Sci ; 24(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36902274

RESUMO

Daylily (Hemerocallis citrina Baroni) is an edible plant widely distributed worldwide, especially in Asia. It has traditionally been considered a potential anti-constipation vegetable. This study aimed to investigate the anti-constipation effects of daylily from the perspective of gastro-intestinal transit, defecation parameters, short-chain organic acids, gut microbiome, transcriptomes and network pharmacology. The results show that dried daylily (DHC) intake accelerated the defecation frequency of mice, while it did not significantly alter the levels of short-chain organic acids in the cecum. The 16S rRNA sequencing showed that DHC elevated the abundance of Akkermansia, Bifidobacterium and Flavonifractor, while it reduced the level of pathogens (such as Helicobacter and Vibrio). Furthermore, a transcriptomics analysis revealed 736 differentially expressed genes (DEGs) after DHC treatment, which are mainly enriched in the olfactory transduction pathway. The integration of transcriptomes and network pharmacology revealed seven overlapping targets (Alb, Drd2, Igf2, Pon1, Tshr, Mc2r and Nalcn). A qPCR analysis further showed that DHC reduced the expression of Alb, Pon1 and Cnr1 in the colon of constipated mice. Our findings provide a novel insight into the anti-constipation effects of DHC.


Assuntos
Constipação Intestinal , Hemerocallis , Laxantes , Animais , Camundongos , Constipação Intestinal/terapia , Microbioma Gastrointestinal , Hemerocallis/química , Farmacologia em Rede , RNA Ribossômico 16S , Laxantes/química , Laxantes/farmacologia , Laxantes/uso terapêutico , Ceco/efeitos dos fármacos
8.
J Nat Prod ; 85(3): 625-633, 2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-34852194

RESUMO

Three new actinopyrone derivatives, actinopyrones E-G (1, 3, and 4), together with three known analogues, PM050463 (2), actinopyrone D (5), and PM050511 (6), were isolated from Streptomyces sp. SCSIO ZS0520 derived from a deep-sea hydrothermal vent. Their structures, complete with absolute configurations, were elucidated using extensive spectroscopic analyses combined with Mosher's method, ECD calculations, and bioinformatics analyses. These findings corrected the absolute configurations of previously reported actinopyrone analogues 2, 5, and 6 at C-3, C-9, and C-10. Notably, compound 6 displayed notable cytotoxicity against six human cell lines with IC50 values of 0.26-2.22 µM. A likely biosynthetic pathway and annotations of protein function are proposed on the basis of bioinformatics analyses. Genes coding for methyltransferase and glycosyltransferase tailoring chemistries needed to generate final structures were notably absent from the biosynthetic gene cluster. Taken together, these results enable further bioengineering of the actinopyrones and related congeners as potential antitumor agents.


Assuntos
Antineoplásicos , Policetídeos , Streptomyces , Antineoplásicos/química , Antineoplásicos/farmacologia , Humanos , Estrutura Molecular , Família Multigênica , Policetídeos/farmacologia , Streptomyces/química
9.
J Nat Prod ; 85(9): 2142-2148, 2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36040315

RESUMO

Four new cyclic diarylheptanoids, casuarinols A-C (1-3) and casuarinolide A (4), together with six known ones (5-10), were isolated from the roots of Casuarina equisetifolia. Structures were elucidated by extensive spectroscopic analysis, theoretical conformational, and electronic circular dichroism analyses. Casuarinol C (3) is a novel cyclic diarylheptanoid-aldehyde adduct. Casuarinolide A (4) represents the first structure of a seco-cyclic diarylheptanoid. Compounds 1-9 were evaluated for their anti-influenza A virus (IAV) activity against A/WSN/33 (H1N1). (-)-(M)-11-Oxo-3,12R,17-trihydroxy-9-ene-[7,0]-metacyclophane (5) displayed significant anti-IAV activity with an IC50 value of 8.64 ± 2.49 µM and a CC50 higher than 100 µM.


Assuntos
Diarileptanoides , Vírus da Influenza A Subtipo H1N1 , Raízes de Plantas , Aldeídos/química , Diarileptanoides/química , Diarileptanoides/isolamento & purificação , Diarileptanoides/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Estrutura Molecular , Raízes de Plantas/química
10.
Mar Drugs ; 20(2)2022 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-35200679

RESUMO

Three new metabolites, including a cyclic tetrapeptide asperhiratide (1), an ecdysteroid derivative asperhiratine (2), and a sesquiterpene lactone asperhiratone (3), were isolated and identified from the soft coral-derived fungus Aspergillus hiratsukae SCSIO 5Bn1003, together with 10 known compounds. Their structures were elucidated via spectroscopic analysis, X-ray diffraction analysis, and electronic circular dichroism calculations. In addition, the absolute configuration of 1 was determined by Marfey's technique and an analysis of the acid hydrolysates using a chiral phase HPLC column. Among all the compounds, 6 and 8 showed medium cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), with IC50 values ranging from 31.03 ± 3.04 to 50.25 ± 0.54 µM. Meanwhile, they strongly inhibited α-glucosidase activities, with IC50 values of 35.73 ± 3.94 and 22.00 ± 2.45 µM, which were close to and even stronger than the positive control acarbose (IC50 = 32.92 ± 1.03 µM). Compounds 6-8 showed significant antibacterial activities against Bacillus subtilis, with MIC values of 10.26 ± 0.76 µM, 17.00 ± 1.25 µM, and 5.30 ± 0.29 µM, respectively. Compounds 9 and 12 exhibited potent radical scavenging activities against DPPH, with IC50 values of 12.23 ± 0.78 µM and 7.38 ± 1.16 µM. In addition, asperhiratide (1) was evaluated for anti-angiogenic activities in the in vivo zebrafish model, which showed a weak inhibitory effect on intersegmental vessel (ISV) formation.


Assuntos
Antozoários/microbiologia , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Aspergillus/metabolismo , Células A549 , Animais , Antibacterianos/administração & dosagem , Antibacterianos/isolamento & purificação , Antineoplásicos/administração & dosagem , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Células Hep G2 , Humanos , Concentração Inibidora 50 , Células MCF-7 , Testes de Sensibilidade Microbiana , Metabolismo Secundário , Peixe-Zebra
11.
Molecules ; 27(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36014493

RESUMO

OBJECTIVE: A sensitive and selective fluorescence-detection platform based on carbon quantum dots (CQDs) was designed and developed for the determination of methotrexate (MTX), for the purpose of minimizing the possible toxic threat of MTX in clinics. METHODS: The approach was prepared for the first time by a simple, hydrothermal method, making the synthesis and modification processes realized in one step using polyethyleneimine (PEI), and the proposed PEI-CQDs were obtained with high fluorescence quantum yield (38%). RESULTS: MTX was found highly responsive and effective in quenching the fluorescence of the PEI-CQDs, due to a suggested fluorescence resonance energy transfer mechanism or inner-filter effect. The linear range of MTX was between 1 and 600 µmol/L under optimum conditions, with a detection limit (LOD) as low as 0.33 µmol/L. Furthermore, the fluorescent method was established for the MTX assay, and satisfactory results were acquired in real-sample determination. The average labeled quantity was 98.2%, and the average added standard recovery was 100.9%. CONCLUSIONS: The proposed PEI-CQDs showed a remarkable potential for broad applications in biological molecule determination and environmental analysis.


Assuntos
Pontos Quânticos , Carbono , Corantes Fluorescentes , Limite de Detecção , Metotrexato , Polietilenoimina , Polivinil , Espectrometria de Fluorescência/métodos
12.
Molecules ; 27(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35408528

RESUMO

(1) Background: Carbon quantum dots (CQDs) are a new class of carbon nanomaterials with favorable features, such as tunable luminescence, unique optical properties, water solubility, and lack of cytotoxicity; they are readily applied in biomedicine. (2) Methods: S, N co-doped CQDs were prepared to develop a highly selective and sensitive fluorescence technique for the detection of methotrexate (MTX). For this purpose, citric acid and thiourea were used as C, N, and S sources in a single-step hydrothermal process to prepare the S, N co-doped CQDs, which displayed remarkable fluorescence properties. (3) Results: Two optimal emissions were observed at the excitation/emission wavelengths of 320/425 nm, respectively. The two emissions were significantly quenched in the presence of MTX. Under optimal conditions, MTX was detected in the linear concentration range of 1-300 µmol/L, with the detection limit of 0.33 µmol/L. The sensing mechanism was due to the fact that the effect of the inner filter on MTX and S, N-CQDs causes fluorescence quenching. The contents of MTX in real medicine samples were evaluated with acceptable recoveries of 98-101%. (4) Conclusions: This approach has great potential for detecting MTX in pharmaceutical analysis.


Assuntos
Pontos Quânticos , Carbono , Metotrexato , Nitrogênio , Espectrometria de Fluorescência/métodos
13.
Compr Rev Food Sci Food Saf ; 21(3): 2455-2488, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35347871

RESUMO

Food fraud is currently a growing global concern with far-reaching consequences. Food authenticity attributes, including biological identity, geographical origin, agricultural production, and processing technology, are susceptible to food fraud. Metabolic markers and their corresponding authentication methods are considered as a promising choice for food authentication. However, few metabolic markers were available to develop robust analytical methods for food authentication in routine control. Untargeted metabolomics by liquid chromatography-mass spectrometry (LC-MS) is increasingly used to discover metabolic markers. This review summarizes the general workflow, recent applications, advantages, advances, limitations, and future needs of untargeted metabolomics by LC-MS for identifying metabolic markers in food authentication. In conclusion, untargeted metabolomics by LC-MS shows great efficiency to discover the metabolic markers for the authenticity assessment of biological identity, geographical origin, agricultural production, processing technology, freshness, cause of animals' death, and so on, through three main steps, namely, data acquisition, biomarker discovery, and biomarker validation. The application prospects of the selected markers by untargeted metabolomics require to be valued, and the selected markers need to be eventually applicable at targeted analysis assessing the authenticity of unknown food samples.


Assuntos
Metabolômica , Espectrometria de Massas em Tandem , Animais , Biomarcadores/análise , Cromatografia Líquida , Alimentos , Metabolômica/métodos , Espectrometria de Massas em Tandem/métodos
14.
Artigo em Inglês | MEDLINE | ID: mdl-33361311

RESUMO

Schistosomiasis poses a serious threat to human health and remains a major tropical and parasitic disease in more than 70 countries. Praziquantel (PZQ) has been the primary treatment for schistosomiasis for nearly 4 decades. However, its efficacy against migratory-stage schistosomula is limited. Radicicol (RAD), a ß-resorcylic acid lactone derived from Paecilomyces sp. strain SC0924, was investigated as an alternative treatment for Schistosoma japonicumIn vitro tests showed that within 72 h, RAD (10 µmol/liter) completely killed schistosomula of both skin and liver stages with an efficacy significantly higher than that of PZQ, although it was less potent against adult worms than PZQ. In vivo, RAD reduced worm burdens and liver eggs by 91.18% and 86.01%, respectively, by killing migratory-stage schistosomula. Optical microscopy and scanning electron microscopy revealed that RAD damaged the epiderm and tegument morphology of S. japonicum worms at various stages and altered their motility to different degrees. RAD exhibited schistosomicidal effects at different stages in vitro and in vivo, especially at the migratory stage, implying that its mechanism could be different from that of PZQ. Collectively, these results showed that RAD is promising as a lead for the development of drugs to control the migratory-stage schistosomula of S. japonicum.


Assuntos
Schistosoma japonicum , Esquistossomicidas , Animais , Humanos , Chumbo , Macrolídeos , Praziquantel/farmacologia , Schistosoma mansoni , Esquistossomicidas/farmacologia
15.
J Nat Prod ; 84(6): 1806-1815, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34081476

RESUMO

Formicapyridine-type racemates, streptovertidines A (1) and B (2), a 7,24-seco-fasamycin, streptovertidione (3), and the fasamycin-type streptovertimycins I-T (4-15), together with 13 known fasamycin congeners (16-28), were isolated from soil-derived Streptomyces morookaense SC1169. Their structures were elucidated by extensive spectroscopic analysis and theoretical computations of ECD spectra. The fasamycin-type compounds 5, 8-12, 14, and 15 exhibited activity against the drug-resistant bacteria MRSA and VRE (MIC: 1.25-10.0 µg/mL). All isolates, except 3, 4, 10, and 24, displayed cytotoxicity against at least one of the human carcinoma A549, HeLa, HepG2, and MCF-7 cells (IC50 < 10.0 µM), of which some were also cytotoxic to the noncancerous Vero cells. Taken together, the activity data demonstrated that the fasamycin-type compounds were more selective to the tested bacteria over the mammalian cells. Structure-activity relationship analysis suggested that chlorination at C-2 in antibacterial fasamycin-type compounds improves the activity and selectivity to the bacteria. Theoretical simulations of reaction paths and chemical reactions for conversion of 3 to 1 were carried out and supported that the pyridine ring formation in formicapyridines proceeds nonenzymatically via 1,5-dicarbonyl condensation with ammonia.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Policetídeos/farmacologia , Streptomyces/química , Animais , Antibacterianos/isolamento & purificação , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , China , Chlorocebus aethiops , Humanos , Estrutura Molecular , Policetídeos/química , Policetídeos/isolamento & purificação , Microbiologia do Solo , Relação Estrutura-Atividade , Células Vero
16.
Mar Drugs ; 19(8)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34436279

RESUMO

We have previously shown deep-sea-derived Streptomyces koyangensis SCSIO 5802 to produce two types of active secondary metabolites, abyssomicins and candicidins. Here, we report the complete genome sequence of S. koyangensis SCSIO 5802 employing bioinformatics to highlight its potential to produce at least 21 categories of natural products. In order to mine novel natural products, the production of two polycyclic tetramate macrolactams (PTMs), the known 10-epi-HSAF (1) and a new compound, koyanamide A (2), was stimulated via inactivation of the abyssomicin and candicidin biosynthetic machineries. Detailed bioinformatics analyses revealed a PKS/NRPS gene cluster, containing 6 open reading frames (ORFs) and spanning ~16 kb of contiguous genomic DNA, as the putative PTM biosynthetic gene cluster (BGC) (termed herein sko). We furthermore demonstrate, via gene disruption experiments, that the sko cluster encodes the biosynthesis of 10-epi-HSAF and koyanamide A. Finally, we propose a plausible biosynthetic pathway to 10-epi-HSAF and koyanamide A. In total, this study demonstrates an effective approach to cryptic BGC activation enabling the discovery of new bioactive metabolites; genome mining and metabolic profiling methods play key roles in this strategy.


Assuntos
Lactamas Macrocíclicas/metabolismo , Streptomyces , Organismos Aquáticos , Genoma , Humanos , Família Multigênica , Fitoterapia , Sequenciamento Completo do Genoma
17.
Mar Drugs ; 19(10)2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34677441

RESUMO

To enlarge the chemical diversity of Eurotium sp. SCSIO F452, a talented marine-derived fungus, we further investigated its chemical constituents from a large-scale fermentation with modified culture. Four pairs of new salicylaldehyde derivative enantiomers, euroticins F-I (1-4), as well as a known one eurotirumin (5) were isolated and characterized. Compound 1 features an unprecedented constructed 6/6/6/5 tetracyclic structures, while 2 and 3 represent two new types of 6/6/5 scaffolds. Their structures were established by comprehensive spectroscopic analyses, X-ray diffraction, 13C NMR, and electronic circular dichroism calculations. Selected compounds showed significant inhibitory activity against α-glucosidase and moderate cytotoxic activities against SF-268, MCF-7, HepG2, and A549 cell lines.


Assuntos
Aldeídos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Eurotium , Aldeídos/química , Animais , Antineoplásicos/química , Antioxidantes/química , Organismos Aquáticos , Linhagem Celular Tumoral/efeitos dos fármacos , Humanos , Estrutura Molecular , Estereoisomerismo
18.
Proc Natl Acad Sci U S A ; 115(22): E4980-E4989, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29760061

RESUMO

Glycosylation is a prominent strategy to optimize the pharmacokinetic and pharmacodynamic properties of drug-like small-molecule scaffolds by modulating their solubility, stability, bioavailability, and bioactivity. Glycosyltransferases applicable for "sugarcoating" various small-molecule acceptors have been isolated and characterized from plants and bacteria, but remained cryptic from filamentous fungi until recently, despite the frequent use of some fungi for whole-cell biocatalytic glycosylations. Here, we use bioinformatic and genomic tools combined with heterologous expression to identify a glycosyltransferase-methyltransferase (GT-MT) gene pair that encodes a methylglucosylation functional module in the ascomycetous fungus Beauveria bassiana The GT is the founding member of a family nonorthologous to characterized fungal enzymes. Using combinatorial biosynthetic and biocatalytic platforms, we reveal that this GT is a promiscuous enzyme that efficiently modifies a broad range of drug-like substrates, including polyketides, anthraquinones, flavonoids, and naphthalenes. It yields both O- and N-glucosides with remarkable regio- and stereospecificity, a spectrum not demonstrated for other characterized fungal enzymes. These glucosides are faithfully processed by the dedicated MT to afford 4-O-methylglucosides. The resulting "unnatural products" show increased solubility, while representative polyketide methylglucosides also display increased stability against glycoside hydrolysis. Upon methylglucosidation, specific polyketides were found to attain cancer cell line-specific antiproliferative or matrix attachment inhibitory activities. These findings will guide genome mining for fungal GTs with novel substrate and product specificities, and empower the efficient combinatorial biosynthesis of a broad range of natural and unnatural glycosides in total biosynthetic or biocatalytic formats.


Assuntos
Antineoplásicos , Descoberta de Drogas , Fungos , Glicosiltransferases , Metiltransferases , Animais , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungos/enzimologia , Fungos/genética , Fungos/metabolismo , Glicosilação , Glicosiltransferases/química , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Humanos , Metiltransferases/química , Metiltransferases/genética , Metiltransferases/metabolismo , Policetídeo Sintases/química , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Policetídeos/metabolismo , Células Vero
19.
Chem Biodivers ; 18(3): e2000930, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33471368

RESUMO

Enzymatic hydrolysate of the crude polysaccharide (SFP) extracted from Sargassum fusiforme was purified by column DEAE-52 and Sephadex G-100 to yield four components, namely, ESFP1, ESFP2, ESFP3 and ESFP4. These components were characterized by chemical composition assay, GC/MS, HPGPC, UV and FT-IR techniques. The in vitro antioxidant activities of the four purified fractions were investigated by measuring their radical scavenging activity and reducing power. The results suggested that all the four components possess good antioxidant activities. Among them, ESFP1 was found to possess the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical-scavenging activity, and the greatest ferric reducing power. The immunomodulatory effect of these four polysaccharides was demonstrated by their ability to promote proliferation, and to enhance both phagocytic activity and NO release in a macrophage RAW264.7 model. The results revealed that the bioactivities of the polysaccharides are related to their molecular weight, and the uronic acid and sulfate contents.


Assuntos
Antioxidantes/farmacologia , Polissacarídeos/farmacologia , Sargassum/química , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , Peso Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Picratos/antagonistas & inibidores , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Células RAW 264.7 , Sargassum/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade
20.
J Asian Nat Prod Res ; 23(9): 819-824, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32646247

RESUMO

Three new phlorizin derivatives, 6"-O-vanilloylphlorizin (1), 6"-O-(4-hydroxybenzoyl)phlorizin (2), 6"-O-feruloylphlorizin (3), along with four known dihydrochalcones, phlorizin (4), 3-hydroxyphlorizin, trilobatin, and 6"-O-acetylphlorizin were isolated from the leaves of Lithocarpus litseifolius. Their structures were established by analysis of extensive spectroscopic data. The new compounds were shown to be non-cytotoxic when tested against A549, HeLa, HepG2, and MCF-7 cell lines.


Assuntos
Chalconas , Fagaceae , Chalconas/farmacologia , Estrutura Molecular , Folhas de Planta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA