Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Mais filtros

Bases de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Nat Prod ; 87(4): 1023-1035, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38536967

RESUMO

The plant Goniothalamus leiocarpus of the Annonaceae family is used as an alternative medicine in tropical regions. Applying high-speed counter current chromatography (HSCCC), eight new bioactive styrylpyrone isomers, including 6R,7S,8R,2'S-goniolactone B (1), 6S,7S,8S,2'S-goniolactone B (2), 6R,7R,8R,2'S-goniolactone B (3), 6R,7S,8S,2'S-goniolactone C (4), 6R,7S,8R,2'S-goniolactone C (5), 6S,7R,8S,2'S-goniolactone C (6), and two positional isomers, 6R,7R,8R,2'S-goniolactone G (7) and 6S,7R,8R,2'S-goniolactone G (8), were isolated from a chloroform fraction (2.1 g) of G. leiocarpus, which had a prominent spot by TLC analysis. The structures of the new compounds were elucidated by MS, NMR, IR, and UV spectra, and their absolute configurations were determined by Mosher's method, ECD, and X-ray diffraction analysis. The isolates are characteristic components found in plants of the genus Goniothalamus and consist of two structural moieties: a styrylpyrone and a dihydroflavone unit. The isolation of the eight new compounds demonstrates the effectiveness of HSCCC in separating the isomers of natural styrylpyrone. In a bioactivity assessment, compounds 1 and 6 exhibited cytotoxic effects against the human colon carcinoma cell lines LS513 and SW620 with IC50 values ranging from 1.6 to 3.9 µM. Compounds 1, 2, 7, and 8 showed significant synergistic activity against antibiotic-resistant Staphylococcus aureus strains.


Assuntos
Goniothalamus , Casca de Planta , Pironas , Goniothalamus/química , Pironas/química , Pironas/farmacologia , Pironas/isolamento & purificação , Estrutura Molecular , Estereoisomerismo , Casca de Planta/química , Humanos , Distribuição Contracorrente/métodos , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação
2.
J Nat Prod ; 87(1): 14-27, 2024 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-38233978

RESUMO

Sorafenib was first approved as the standard treatment for advanced hepatocellular carcinoma (HCC). Despite providing an advantage in terms of patient survival, sorafenib has shown poor clinical efficacy and severe side effects after long-term treatment. Thus, combination treatment is a potential way to increase the effectiveness and reduce the dose-limiting toxicity of sorafenib. Extracts of the seeds of Annona montana have shown synergistic antitumor activity with sorafenib, and seven annonaceous acetogenins, including three new acetogenins, muricin P (2), muricin Q (3), and muricin R (4), were isolated from the extracts by bioguided fractionation and showed synergy with sorafenib. The structures of these compounds were determined using spectroscopic and chemical methods. Annonacin (1) and muricin P (2), which reduced intracellular ATP levels and promoted apoptosis, exhibited synergistic cytotoxicity with sorafenib in vitro. In vivo, annonacin (1) displayed synergistic antitumor activity by promoting tumor cell apoptosis. Moreover, the potential mechanism of annonacin (1) was predicted by transcriptomic analysis, which suggested that SLC33A1 is a potential target in HCC. Annonacin (1) might be a novel candidate for combination therapy with sorafenib against advanced HCC.


Assuntos
Antineoplásicos Fitogênicos , Carcinoma Hepatocelular , Furanos , Lactonas , Neoplasias Hepáticas , Humanos , Acetogeninas/farmacologia , Acetogeninas/química , Sorafenibe/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Estrutura Molecular , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Neoplasias Hepáticas/tratamento farmacológico , Linhagem Celular Tumoral , Apoptose
3.
Biomed Chromatogr ; 38(2): e5782, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38016814

RESUMO

Natural medicines play a crucial role in clinical drug applications, serving as a primary traditional Chinese medicine for the clinical treatment of liver fibrosis. Understanding the in vivo metabolic process of the Fuzheng Huayu (FZHY) formula is essential for delving into its material basis and mechanism. In recent years, there has been a growing body of research focused on the mechanisms and component analysis of FZHY. This study aimed to examine the pharmacokinetics of FZHY in healthy volunteers following oral administration. Blood samples were collected at designated time intervals after the oral intake of 9.6-g FZHY tablets. A UHPLC-Q/Exactive method was developed to assess the plasma concentrations of five components post-FZHY ingestion. The peak time for all components occurred within 10 min. The peak concentration (Cmax ) values for amygdalin, schisandrin, and schisandrin A ranged from 3.47 to 28.80 ng/mL, with corresponding AUC(0-t) values ranging from 10.63 to 103.20 ng h/mL. For schisandrin B and prunasin, Cmax values were in the range of 86.52 to 229.10 ng/mL, and their AUC(0-t) values ranged from 375.26 to 1875.54 ng h/mL, indicating significant exposure within the body. These findings demonstrate that the developed method enables rapid and accurate detection and quantification of the five components in FZHY, offering a valuable reference for its clinical study.


Assuntos
Medicamentos de Ervas Chinesas , Humanos , Medicamentos de Ervas Chinesas/farmacocinética , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Medicina Tradicional Chinesa/métodos , Administração Oral , Comprimidos
4.
Int J Mol Sci ; 25(6)2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38542523

RESUMO

The transcription factor is an essential factor for regulating the responses of plants to external stimuli. The WRKY protein is a superfamily of plant transcription factors involved in response to various stresses (e.g., cold, heat, salt, drought, ions, pathogens, and insects). During angiosperm evolution, the number and function of WRKY transcription factors constantly change. After suffering from long-term environmental battering, plants of different evolutionary statuses ultimately retained different numbers of WRKY family members. The WRKY family of proteins is generally divided into three large categories of angiosperms, owing to their conserved domain and three-dimensional structures. The WRKY transcription factors mediate plant adaptation to various environments via participating in various biological pathways, such as ROS (reactive oxygen species) and hormone signaling pathways, further regulating plant enzyme systems, stomatal closure, and leaf shrinkage physiological responses. This article analyzed the evolution of the WRKY family in angiosperms and its functions in responding to various external environments, especially the function and evolution in Magnoliaceae plants. It helps to gain a deeper understanding of the evolution and functional diversity of the WRKY family and provides theoretical and experimental references for studying the molecular mechanisms of environmental stress.


Assuntos
Magnoliopsida , Magnoliopsida/genética , Magnoliopsida/metabolismo , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo , Filogenia , Regulação da Expressão Gênica de Plantas , Família Multigênica
5.
Zhongguo Zhong Yao Za Zhi ; 48(9): 2316-2324, 2023 May.
Artigo em Zh | MEDLINE | ID: mdl-37282860

RESUMO

Patchoulol is an important sesquiterpenoid in the volatile oil of Pogostemon cablin, and is also considered to be the main contributing component to the pharmacological efficacy and fragrance of P. cablin oil, which has antibacterial, antitumor, antioxidant, and other biological activities. Currently, patchoulol and its essential oil blends are in high demand worldwide, but the traditional plant extraction method has many problems such as wasting land and polluting the environment. Therefore, there is an urgent need for a new method to produce patchoulol efficiently and at low cost. To broaden the production method of patchouli and achieve the heterologous production of patchoulol in Saccharomyces cerevisiae, the patchoulol synthase(PS) gene from P. cablin was codon optimized and placed under the inducible strong promoter GAL1 to transfer into the yeast platform strain YTT-T5, thereby obtaining strain PS00 with the production of(4.0±0.3) mg·L~(-1) patchoulol. To improve the conversion rate, this study used protein fusion method to fuse SmFPS gene from Salvia miltiorrhiza with PS gene, leading to increase the yield of patchoulol to(100.9±7.4) mg·L~(-1) by 25-folds. By further optimizing the copy number of the fusion gene, the yield of patchoulol was increased by 90% to(191.1±32.7) mg·L~(-1). By optimizing the fermentation process, the strain was able to achieve a patchouli yield of 2.1 g·L~(-1) in a high-density fermentation system, which was the highest yield so far. This study provides an important basis for the green production of patchoulol.


Assuntos
Óleos Voláteis , Pogostemon , Sesquiterpenos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sesquiterpenos/metabolismo , Óleos Voláteis/metabolismo
6.
Nanotechnology ; 34(7)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36384029

RESUMO

The tuning of band gap is very important for the application of two-dimensional (2D) materials in optoelectronic devices. Alloying of 2D transition metal dichalcogenides (TMDCs) is an important way to tune the wide band gap. In this study, we report a multi-step vapor deposition method to grow monolayer TMDC ternary alloy films with wafer scale, including Mo1-xWxS2, Mo1-xWxSe2and MoS2xSe2(1-x), which are accurately controllable in the elemental proportion (xis from 0 to 1). The band gap of the three 2D ternary alloy materials are continuously tuned for the whole range of metal and chalcogen compositions. The metal compositions are controlled by the as-deposited thickness. Raman, photoluminescence, elemental maps and TEM show the high spatial homogeneity in the compositions and optical properties across the whole wafer. The band gap can be continuously tuned from 1.86 to 1.99 eV for Mo1-xWxS2, 1.56 to 1.65 eV for Mo1-xWxSe2, 1.56 to 1.86 eV for MoS2xSe2(1-x). Electrical transport measurements indicate that Mo1-xWxS2and MoS2xSe2(1-x)monolayers shown-type semiconductor behaviors, and the carrier types of Mo1-xWxSe2can be tuned asn-type, bipolar andp-type. Moreover, this control process can be easily generalized to other 2D alloy films, even to quaternary or multi-element alloy materials. Our study presents a promising route for the preparation of large-scale homogeneous monolayer TMDC alloys and the application for future functional devices.

7.
Biomed Chromatogr ; 36(4): e5329, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34997600

RESUMO

Fuzheng Huayu recipe (FZHY) is a Chinese patent medicine for the treatment of liver fibrosis. This study aimed to investigate the toxicokinetics of FZHY in beagle dogs after oral administration. Blood samples were collected on days 1, 15 and 28 after oral gavage of FZHY dosages of 400 or 1,200 mg/kg body weight once a day. A UHPLC-Q-Orbitrap method was developed and validated to simultaneously determine and quantify eight components of FZHY in beagle dog plasma. The times to peak concentration for eight components were18-120 min. The peak concentrations (Cmax ) of amygdalin, genistein, daidzein and 3,4-dihydroxybenzaldehyde were 1.43-43.50 ng/ml, the areas under the concentration-time curve (AUC(0-t) ) were 2.45-6,098.25 ng min/ml, and the apparent volumes of distribution (Vd ) were 0.05-131.23 × 104 ml/kg. The values of Cmax of prunasin, schisantherin A, schisandrin A and schisandrin were 7.35-1,450.73 ng/ml, the values of AUC(0-t) were 3,642.30-330,388.65 ng min/ml, and the values of Vd were 11.15-1,087.18 × 104 ml/kg. No obvious accumulation of the eight compounds was observed in beagle dogs. The results showed that the method is rapid, accurate and sensitive, and is suitable for detecting the eight analytes of FZHY. This study provides an important basis for the assessment of FZHY safety.


Assuntos
Medicamentos de Ervas Chinesas , Animais , Cromatografia Líquida de Alta Pressão/métodos , Cães , Medicamentos de Ervas Chinesas/farmacocinética , Ratos , Ratos Wistar , Toxicocinética
8.
Zhongguo Zhong Yao Za Zhi ; 47(3): 651-658, 2022 Feb.
Artigo em Zh | MEDLINE | ID: mdl-35178947

RESUMO

Ginsenoside Rh_2 is a rare active ingredient in precious Chinese medicinal materials such as Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma, and Panacis Quinquefolii Radix. It has important pharmacological activities such as anti-cancer and improving human immunity. However, due to the extremely low content of ginsenoside Rh_2 in the source plants, the traditional way of obtaining it has limitations. This study intended to apply synthetic biological technology to develop a cell factory of Saccharomyces cerevisiae to produce Rh_2 by low-cost fermentation. First, we used the high protopanaxadiol(PPD)-yielding strain LPTA as the chassis strain, and inserted the Panax notoginseng enzyme gene Pn1-31, together with yeast UDP-glucose supply module genes[phosphoglucose mutase 1(PGM1), α-phosphoglucose mutase(PGM2), and uridine diphosphate glucose pyrophosphorylase(UGP1)], into the EGH1 locus of yeast chromosome. The engineered strain LPTA-RH2 produced 17.10 mg·g~(-1) ginsenoside Rh_2. This strain had low yield of Rh_2 while accumulated much precursor PPD, which severely restricted the application of this strain. In order to further improve the production of ginsenoside Rh_2, we strengthened the UDP glucose supply module and ginsenoside Rh_2 synthesis module by engineered strain LPTA-RH2-T. The shaking flask yield of ginsenoside Rh_2 was increased to 36.26 mg·g~(-1), which accounted for 3.63% of the dry weight of yeast cells. Compared with those of the original strain LPTA-RH2, the final production and the conversion efficiency of Rh_2 increased by 112.11% and 65.14%, respectively. This study provides an important basis for further obtaining the industrial-grade cell factory for the production of ginsenoside Rh_2.


Assuntos
Ginsenosídeos , Panax notoginseng , Panax , Fermentação , Humanos , Panax/genética , Saccharomyces cerevisiae/genética , Uridina Difosfato Glucose
9.
Zhongguo Zhong Yao Za Zhi ; 47(4): 897-905, 2022 Feb.
Artigo em Zh | MEDLINE | ID: mdl-35285188

RESUMO

Monoterpenes are widely used in cosmetics, food, medicine, agriculture and other fields. With the development of synthetic biology, it is considered as a potential way to create microbial cell factories to produce monoterpenes. Engineering Saccharomyces cerevisiae to produce monoterpenes has been a research hotspot in synthetic biology. In S. cerevisiae, the production of geranyl pyrophosphate(GPP) and farnesyl pyrophosphate(FPP) is catalyzed by a bifunctional enzyme farnesyl pyrophosphate synthetase(encoded by ERG20 gene) which is inclined to synthesize FPP essential for yeast growth. Therefore, reasonable control of FPP synthesis is the basis for efficient monoterpene synthesis in yeast cell factories. In order to achieve dynamic control from GPP to FPP biosynthesis in S. cerevisiae, we obtained a novel chassis strain HP001-pERG1-ERG20 by replacing the ERG20 promoter of the chassis strain HP001 with the promoter of cyclosqualene cyclase(ERG1) gene. Further, we reconstructed the metabolic pathway by using GPP and neryl diphosphate(NPP), cis-GPP as substrates in HP001-pERG1-ERG20. The yield of GPP-derived linalool increased by 42.5% to 7.6 mg·L~(-1), and that of NPP-derived nerol increased by 1 436.4% to 8.3 mg·L~(-1). This study provides a basis for the production of monoterpenes by microbial fermentation.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Fermentação , Geraniltranstransferase/genética , Monoterpenos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
10.
Anal Chem ; 93(50): 16873-16879, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34874148

RESUMO

The development of a simple and universal strategy for simultaneous quantification of proteins and nucleic acid biomarkers in one assay is valuable, particularly for disease diagnosis and pathogenesis studies. Herein, a universal and amplification-free quantum dot-doped nanoparticle counting platform was developed by integrating immunorecognition and nucleic acid hybridization in one assay. The assay can be performed at room temperature, which is friendly for routine analysis. Multiplexed biomarkers associated with Alzheimer's disease (AD) including proteins and nucleic acids were detected. For simultaneous detection of tetraplex biomarkers, the assay for amyloid ß 1-42 (Aß42), tau protein, miR-146a, and miR-138 presented limit of detection values of 250 pg/mL, 55.7 pg/mL, 52.5 pM, and 0.62 pM, respectively. By spiking all the above four biomarkers in one artificial cerebrospinal fluid sample, the recoveries were found to be 94.7-117.2%. Using tau protein as the model, four measurements in 88 days presented a coefficient of variance of 7.5%. The proposed platform for the multiplexed assay of proteins and nucleic acids presents the universality, reasonable sensitivity, and repeatability, which may open a new door for early diagnosis and pathogenesis research for AD and other diseases.


Assuntos
Doença de Alzheimer , MicroRNAs , Nanopartículas , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/genética , Peptídeos beta-Amiloides , Biomarcadores , Humanos , MicroRNAs/genética , Hibridização de Ácido Nucleico
11.
Metab Eng ; 67: 104-111, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34153454

RESUMO

Eukaryotic yeasts have a variety of subcellular compartments and are ideal platform strains for the construction of complex heterologous natural product biosynthesis pathways. Improving the synthesis efficiency of microbial cell factories through the utilization and modification of subcellular compartments by synthetic biology has good application prospects. Here, we used the yeast PLN1 protein to target the normally endoplasmic reticulum (ER)-localized cytochrome P450 enzyme protopanaxadiol (PPD) synthase (PPDS) to lipid droplets (LDs), which are the storage organelles of the PPDS substrate dammarenediol-II (DD). The efficiency of converting DD to PPD was significantly increased by 394%, and the conversion rate of DD increased from 17.4% to 86.0%. Furthermore, increasing the volume of LDs can significantly enhance the production of DD and its derivatives, but the change in the ratio of the volume and surface area of LDs decreased the conversion efficiency of DD to PPD. Additionally, the biosynthetic pathways of the PPD-type saponin ginsenoside compound K (CK) was reconstituted in a PPD-producing chassis strain, and CK production reached 21.8 mg/L/OD, 4.4-fold higher compared to the native ER-expression strategy. Next, we enhanced the expression of the Pn3-29 gene module to further reduce the accumulation of PPD and increase the production of CK to 41.3 mg/L/OD. Finally, the CK titer of the resulting strain reached 5 g/L in 5 L fed-batch fermentations. This study provides a new strategy for engineering yeast to produce complex natural products.


Assuntos
Produtos Biológicos , Ginsenosídeos , Vias Biossintéticas , Fermentação , Saccharomyces cerevisiae
12.
J Org Chem ; 86(16): 11072-11085, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-33439020

RESUMO

A phytochemical investigation of an extract of the leaves of Piper betle, guided by a synergistic antibacterial screen, led to the isolation and structural elucidation of 10 new neolignans, Pibeneolignan A-J (1-10), together with 11 known compounds. The structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic data, single-crystal X-ray diffraction analysis, and experimental and calculated ECD investigations. Compounds 1 and 2 are new naturally occurring neolignan skeletons, based on the cyclohept-2-ene-1,4-dione framework. We propose that these natural products are biosynthetically formed from bicyclic [3.2.1] neolignans by oxidative cleavage and ring opening at C-1' and C-2'. Among these compounds, 9, 13, 15, and 16, in combination with norfloxacin against an effluxing S. aureus strain (SA1199B), exhibited significant synergistic activity with fractional inhibitory concentration indices (FICIs) of 0.078, 0.156, 0.125, and 0.25, respectively. Bacterial growth curves, ethidium bromide (EtBr) efflux, and qRt-PCR were further employed to verify their synergistic antibacterial mechanism. Furthermore, computational molecular modeling suggested the binding of compounds 14-17 and 19 to the active site of the modeled structure of the NorA efflux pump, which is the main efflux pump in SA1199B.


Assuntos
Lignanas , Staphylococcus aureus Resistente à Meticilina , Piper betle , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Lignanas/farmacologia , Testes de Sensibilidade Microbiana , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Piper betle/metabolismo , Staphylococcus aureus
13.
BMC Genomics ; 21(1): 368, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32434522

RESUMO

BACKGROUND: SPL (SQUAMOSA-promoter binding protein-like) proteins form a large family of plant-specific transcription factors that play essential roles in various aspects of plant growth and development. They are potentially important candidates for genetic improvement of agronomic traits. However, there were limited information about the SPL genes in Jatropha curcas, an important biofuel plant. RESULTS: In Jatropha, 15 JcSPL genes were identified. Phylogenetic analysis revealed that most of the JcSPLs were closely related to SPLs from woody plant rather than herbaceous plant and distantly related to monocotyledon SPLs. Gene structure, conserved motif and repetitive sequence analysis indicated diverse and specific functions of some JcSPL genes. By combination of target prediction and degradome sequencing analysis, 10 of the 15 JcSPLs were shown to be targets of JcmiR156. Quantitative PCR analysis showed diversified spatial-temporal expression patterns of JcSPLs. It is interesting that the expression levels of JcSPL3 were the highest in all tissues examined in 7- or 10-year-old plants and exhibited increasing trend with plant age, suggesting its important role in the regulation of age development in Jatropha. Overexpression of JcSPL3 in Arabidopsis resulted in earlier flowering time, shorter silique length and reduced biomass of roots. CONCLUSIONS: Through comprehensive and systematic analysis of phylogenetic relationships, conserved motifs, gene structures, chromosomal locations, repetitive sequence and expression patterns, 15 JcSPL genes were identified in Jatropha and characterized in great detail. These results provide deep insight into the evolutionary origin and biological significance of plant SPLs and lay the foundation for further functional characterization of JcSPLs with the purpose of genetic improvement in Jatropha.


Assuntos
Genes de Plantas/genética , Genoma de Planta/genética , Jatropha/genética , Desenvolvimento Vegetal/genética , Arabidopsis/genética , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas , Jatropha/classificação , Jatropha/crescimento & desenvolvimento , MicroRNAs/genética , MicroRNAs/metabolismo , Família Multigênica , Motivos de Nucleotídeos , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Sequências Repetitivas de Ácido Nucleico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Metab Eng ; 61: 131-140, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32454222

RESUMO

UDP-glycosyltransferase (UGT)-mediated glycosylation is a widespread modification of plant natural products (PNPs), which exhibit a wide range of bioactivities, and are of great pharmaceutical, ecological and agricultural significance. However, functional annotation is available for less than 2% of the family 1 UGTs, which currently has 20,000 members that are known to glycosylate several classes of PNPs. This low percentage illustrates the difficulty of experimental study and accurate prediction of their function. Here, a synthetic biology platform for elucidating the UGT-mediated glycosylation process of PNPs was established, including glycosyltransferases dependent on UDP-glucose and UDP-xylose. This platform is based on reconstructing the specific PNPs biosynthetic pathways in dedicated microbial yeast chassis by the simple method of plug-and-play. Five UGT enzymes were identified as responsible for the biosynthesis of the main glycosylation products of triterpenes in Panax notoginseng, including a novel UDP-xylose dependent glycosyltransferase enzyme for notoginsenoside R1 biosynthesis. Additionally, we constructed a yeast cell factory that yields >1 g/L of ginsenoside compound K. This platform for functional gene identification and strain engineering can serve as the basis for creating alternative sources of important natural products and thereby protecting natural plant resources.


Assuntos
Panax notoginseng , Biologia Sintética , Triterpenos/metabolismo , Glicosilação , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Panax notoginseng/genética , Panax notoginseng/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Açúcares de Uridina Difosfato/genética , Açúcares de Uridina Difosfato/metabolismo
15.
Analyst ; 145(12): 4111-4123, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32490466

RESUMO

The drive for a simultaneous analysis of multiple targets with excellent accuracy and efficiency, which is often required in both basic biomedical research and clinical applications, demands the development of multiplexed bioassays with desired throughput. With the development of nanotechnologies, innovative multiplex optical bioassays have been achieved. Nanomaterials exhibit unique physical and chemical properties such as easily tunable size, large surface-to-volume ratio, excellent catalysis and the desired signal transduction mechanism, which makes them excellent candidates for the fabrication of novel optical nanoprobes. This mini review summarizes nanomaterial-based optical multiplex sensors from the last 5 years. Specific optical techniques covered in this review are fluorescence, surface-enhanced Raman scattering (SERS), localized surface plasmon resonance (LSPR), chemiluminescence (CL), and the multimodality with fundamentals and examples.

16.
Biotechnol Appl Biochem ; 65(5): 748-755, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29633344

RESUMO

A novel esterase gene TLip was identified from the strain Thauera sp. and expressed at high levels in Escherichia coli. The TLip protein shared the highest identity (48%) to esterase TesA from Pseudomonas aeruginosa when compared to enzymes with reported properties. Phylogenetic analysis showed that TLip belongs to the GDSL family of bacterial lipolytic enzymes. TLip was an alkaline esterase with a broad optimal temperature range 37-50 °C and an optimal pH of 8.0. Substrate specificity assays showed that TLip preferred medium chain p-nitrophenyl esters (C6 -C12 ). Besides, the activity of TLip was strongly inhibited by Cu2+ but greatly enhanced by Triton X-100 and Tween 80. Thermostability assay revealed that TLip was stable without loss of activity at 37 °C and still retained 69% activity at 50 °C after 2 H of incubation. Together, these provided a good candidate for further exploration of TLip as a promising biocatalyst in industry.


Assuntos
Esterases/metabolismo , Thauera/enzimologia , Sequência de Aminoácidos , Meios de Cultura , Estabilidade Enzimática , Escherichia coli/genética , Esterases/antagonistas & inibidores , Esterases/química , Esterases/genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Tensoativos/química
17.
Sci Adv ; 10(6): eadg9211, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38335284

RESUMO

We report on nonlinear terahertz third-harmonic generation (THG) measurements on YBa2Cu3O6+x thin films. Different from conventional superconductors, the THG signal starts to appear in the normal state, which is consistent with the crossover temperature T* of pseudogap over broad doping levels. Upon lowering the temperature, the THG signal shows an anomaly just below Tc in the optimally doped sample. Notably, we observe a beat pattern directly in the measured real-time waveform of the THG signal. We elaborate that the Higgs mode, which develops below Tc, couples to the mode already developed below T*, resulting in an energy level splitting. However, this coupling effect is not evident in underdoped samples. We explore different potential explanations for the observed phenomena. Our research offers valuable insight into the interplay between superconductivity and pseudogap.

18.
Biosensors (Basel) ; 13(1)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36671963

RESUMO

Metal-organic frameworks (MOFs)-based optical nanoprobes for luminescence and surface-enhanced Raman spectroscopy (SERS) applications have been receiving tremendous attention. Every element in the MOF structure, including the metal nodes, the organic linkers, and the guest molecules, can be used as a source to build single/multi-emission signals for the intended analytical purposes. For SERS applications, the MOF can not only be used directly as a SERS substrate, but can also improve the stability and reproducibility of the metal-based substrates. Additionally, the porosity and large specific surface area give MOF a sieving effect and target molecule enrichment ability, both of which are helpful for improving detection selectivity and sensitivity. This mini-review summarizes the advances of MOF-based optical detection methods, including luminescence and SERS, and also provides perspectives on future efforts.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Reprodutibilidade dos Testes , Metais/química , Análise Espectral Raman/métodos
19.
ACS Infect Dis ; 9(8): 1523-1533, 2023 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-37417322

RESUMO

Multidrug-resistant Staphylococcus aureus, a Gram-positive bacterium that causes several difficult-to-treat human infections, is a considerable threat to global healthcare. We hypothesize that there exist inner responsive molecules (IRMs) which can function synergistically with antibiotics to restore the sensitivity of resistant bacteria to existing antibiotics without inducing new antibiotic resistance. An investigation of the extracts of the Chinese medicinal herb Piper betle L. led to the isolation of six benzoate esters, BO-1-BO-6. Among these, BO-1 as a distinct IRM displayed considerable synergism by potentiating antibacterial activity against five antibiotic-resistant S. aureus strains. Mechanistic studies demonstrated that BO-1 acted as a suppressing drug resistance IRM via inhibiting efflux activity. A combination of BO-1 with ciprofloxacin significantly inhibited resistance to this antibiotic and reversed its resistance in the S. aureus strain. Furthermore, BO-1 effectively enhanced the activity of ciprofloxacin against the efflux fluoroquinolone-resistant S. aureus strain SA1199B that caused infection in two animal models and significantly decreased the inflammatory factors IL-6 and C-reactive protein of the infected mice, thereby showing the practice utility of this approach.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Animais , Camundongos , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ciprofloxacina/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
20.
Biomater Sci ; 11(21): 6977-7002, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37695360

RESUMO

The use of biomaterials in biomedicine and healthcare has increased in recent years. Macrophages are the primary immune cells that induce inflammation and tissue repair after implantation of biomaterials. Given that macrophages exhibit high heterogeneity and plasticity, the influence of biomaterials on macrophage phenotype should be considered a crucial evaluation criterion during the development of novel biomaterials. This review provides a comprehensive summary of the physicochemical, biological, and dynamic characteristics of biomaterials that drive the regulation of immune responses in macrophages. The mechanisms involved in the interaction between macrophages and biomaterials, including endocytosis, receptors, signalling pathways, integrins, inflammasomes and long non-coding RNAs, are summarised in this review. In addition, research prospects of the interaction between macrophages and biomaterials are discussed. An in-depth understanding of mechanisms underlying the spatiotemporal changes in macrophage phenotype induced by biomaterials and their impact on macrophage polarization can facilitate the identification and development of novel biomaterials with superior performance. These biomaterials may be used for tissue repair and regeneration, vaccine or drug delivery and immunotherapy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA