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1.
Crit Rev Food Sci Nutr ; : 1-22, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38889067

RESUMEN

Innovating food additives stands as a cornerstone for the sustainable evolution of future food systems. Peptides derived from food proteins exhibit a rich array of physicochemical and biological attributes crucial for preserving the appearance, flavor, texture, and nutritional integrity of foods. Leveraging these peptides as raw materials holds great promise for the development of novel food additives. While numerous studies underscore the potential of peptides as food additives, existing reviews predominantly focus on their biotic applications, leaving a notable gap in the discourse around their abiotic functionalities, such as their physicochemical properties. Addressing this gap, this review offers a comprehensive survey of peptide-derived food additives in food systems, accentuating the application of peptides' abiotic properties. It furnishes a thorough exploration of the underlying mechanisms and diverse applications of peptide-derived food additives, while also delineating the challenges encountered and prospects for future applications. This well-time review will set the stage for a deeper understanding of peptide-derived food additives.

2.
J Sep Sci ; 47(14): e2400250, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39034833

RESUMEN

Reconstituted tobacco (RT) is a product made by reprocessing tobacco waste, experiencing a growing demand for heat-not-burn products. The purpose of this study is to analyze the main flavor ingredients in RT aerosol, as well as the transfer behavior of key flavor substances from substrates to aerosol and the concentrations of these compounds in the substrate after heating. First, we demonstrated that the odor of four RT aerosol samples could be distinguished using an electronic nose. Through non-targeted analysis, 93 volatile compounds were detected by gas chromatography-mass spectrometry, and 286 non/semi-volatile compounds were identified by ultra-high-performance liquid electrophoresis chromatography-mass spectrometry in aerosol. Furthermore, we found that the formation of RT aerosol involves primarily evaporation and distillation, however, the total content delivered from unheated RT samples to aerosol remains relatively low due to compound volatility and cigarette filtration. Thermal reactions during heating indicated the pyrolysis of chlorogenic acid to generate catechol and resorcinol, while Maillard reactions involving glucose and proline produced 2,3-dihydro-3,5-dihydroxy-6-methyl-4h-pyran-4-one. The study highlighted that heating RT at approximately 300°C could mitigate the production of harmful substances while still providing a familiar sensory experience with combusted tobacco.


Asunto(s)
Aromatizantes , Cromatografía de Gases y Espectrometría de Masas , Nicotiana , Aromatizantes/análisis , Aromatizantes/química , Nicotiana/química , Calor , Aerosoles/química , Aerosoles/análisis , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/química , Productos de Tabaco/análisis , Calefacción , Odorantes/análisis
3.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1249-1254, 2024 Mar.
Artículo en Zh | MEDLINE | ID: mdl-38621971

RESUMEN

The chemical constituents of Draconis Sanguis were preliminarily studied by macroporous resin, silica gel, dextran gel, and high-performance liquid chromatography. One retro-dihydrochalcone, four flavonoids, and one stilbene were isolated. Their chemical structures were identified as 4-hydroxy-2,6-dimethoxy-3-methyldihydrochalcone(1), 4'-hydroxy-5,7-dimethoxy-8-methylflavan(2), 7-hydroxy-4',5-dimethoxyflavan(3),(2S)-7-hydroxy-5-methoxy-6-methylflavan(4),(2S)-7-hydroxy-5-methoxyflavan(5), and pterostilbene(6) by modern spectroscopy, physicochemical properties, and literature comparison. Compound 1 was a new compound. Compounds 2 and 6 were first found in the Arecaceae family. Compound 5 had the potential to prevent and treat diabetic kidney disease.


Asunto(s)
Arecaceae , Diabetes Mellitus , Nefropatías Diabéticas , Medicamentos Herbarios Chinos , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/prevención & control , Flavonoides/análisis , Medicamentos Herbarios Chinos/química , Cromatografía Líquida de Alta Presión/métodos
4.
World J Microbiol Biotechnol ; 38(5): 75, 2022 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-35298707

RESUMEN

γ-aminobutyric acid (GABA) has various physiological functions and is widely used in medicine, food, and other fields. Glutamate decarboxylase (GAD) is a key enzyme that catalyzes the decarboxylation of L-glutamate to synthesize GABA. However, the industrial application of microorganism-derived GAD is limited by its rapid loss of enzymatic activity with pH approaching neutrality. In this study, a novel glutamate decarboxylase, GADMSM, from Mycobacterium smegmatis was overexpressed and purified. On the basis of homologous modeling and substrate molecular docking, several GADMSM mutants were constructed, and their enzymatic properties were analyzed. The results showed that the optimal pH of wild-type GADMSM is 5.4; at pH 6.2, 22.8% enzymatic activity was retained. The T211I replacement in GAD and C-terminal deletion mutant GADMSMΔC showed relatively high catalytic activity in a pH range of 5.0-7.0. The Vmax and Km values of GADMSMΔC were 14.69 and 5.70, respectively, at pH 5.5, and 9.87 and 6.17, respectively, at pH 7.0. Compared with the wild-type GAD, GADMSMΔC maintained higher affinity and enzymatic activity of the substrate, maintaining 78.5% of the highest enzymatic activity even at pH 7.0, which is the highest reported activity retention for GAD under neutral pH condition. Therefore, GADMSMΔC can be used for the transformation of high-yielding strains and industrial production of GABA.


Asunto(s)
Glutamato Descarboxilasa , Mycobacterium smegmatis , Glutamato Descarboxilasa/química , Glutamato Descarboxilasa/genética , Concentración de Iones de Hidrógeno , Simulación del Acoplamiento Molecular , Mutagénesis , Mycobacterium smegmatis/genética
5.
Zhongguo Zhong Yao Za Zhi ; 47(17): 4715-4722, 2022 Sep.
Artículo en Zh | MEDLINE | ID: mdl-36164879

RESUMEN

This study aims to investigate the therapeutic effects of alkaloids in Tibetan medicine Bangna(Aconiti Penduli et Aconiti Flavi Radix) on osteoarthritis(OA) rats in vitro and in vivo and the underlying mechanisms. Chondrocytes were isolated from 2-3 week-old male SD rats and lipopolysaccharide(LPS) was used to induce OA in chondrocytes in vitro. Methyl thiazolyl tetrazolium(MTT) assay was used to investigate the toxicity of seven alkaloids(12-epi-napelline, songorine, benzoylaconine, aconitine, 3-acetylaconitine, mesaconitine, and benzoylmesaconine) to chondrocytes. Chondrocytes were classified into the control group, model group(induced by LPS 5 µg·mL~(-1) for 12 h), and administration groups(induced by LPS 5 µg·mL~(-1) for 12 h and incubated for 24 h). The protein expression of inflammatory factors cyclooxygenase-2(COX-2), inducible nitric oxide synthetase(iNOS), tumor necrosis factor-α(TNF-α), and interleukin-1ß(IL-1ß) in each group were detected by Western blot, and the protein expression of matrix metalloprotease-13(MMP-13), aggrecan, collagen Ⅱ, fibroblast growth factor 2(FGF2) by immunofluorescence staining. For the in vivo experiment, sodium iodoacetate was used to induce OA in rats, and the expression of MMP-13, TNF-α, and FGF2 in cartilage tissues of rats in each group was detected by immunohistochemistry. The results showed that the viability of chondrocytes could reach more than 90% under the treatment of the seven alkaloids in a certain dose range. Aconitine, 12-epi-napelline, songorine, 3-acetylaconitine, and mesaconitine could decrease the protein expression of inflammatory factors COX-2, iNOS, TNF-α and IL-1ß compared with the model group. Moreover, 12-epi-napelline, aconitine, and mesaconitine could down-regulate the expression of MMP-13 and up-regulate the expression of aggrecan and collagen Ⅱ. In addition, compared with the model group and other Bangna alkaloids, 12-epi-napelline significantly up-regulated the expression of FGF2. Therefore, 12-epi-napelline was selected for the animal experiment in vivo. Immunohistochemistry results showed that 12-epi-napelline could significantly reduce the expression of MMP-13 and TNF-α in cartilage tissues, and up-regulate the expression of FGF2 compared with the model group. In conclusion, among the seven Bangna alkaloids, 12-epi-napelline can promote the repair of OA in rats by down-regulating the expression of MMP-13 and TNF-α and up-regulating the expression of FGF2.


Asunto(s)
Aconitina , Aconitum , Alcaloides , Medicina Tradicional Tibetana , Osteoartritis , Aconitina/análogos & derivados , Aconitina/uso terapéutico , Aconitum/química , Agrecanos/metabolismo , Alcaloides/uso terapéutico , Animales , Células Cultivadas , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Factor 2 de Crecimiento de Fibroblastos/genética , Factor 2 de Crecimiento de Fibroblastos/uso terapéutico , Interleucina-1beta/metabolismo , Ácido Yodoacético/uso terapéutico , Lipopolisacáridos , Masculino , Metaloproteinasa 13 de la Matriz/metabolismo , FN-kappa B/metabolismo , Osteoartritis/tratamiento farmacológico , Ratas , Ratas Sprague-Dawley , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
6.
Soft Matter ; 17(17): 4496-4503, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-33949603

RESUMEN

We report a mechanical metamaterial-like behavior as a function of the micro/nanostructure of otherwise chemically identical aliphatic polyurea aerogels. Transmissibility varies dramatically with frequency in these aerogels. Broadband vibration mitigation is provided at low frequencies (500-1000 Hz) through self-assembly of locally resonant metastructures wherein polyurea microspheres are embedded in a polyurea web-like network. A micromechanical constitutive model based on a discrete element method is established to explain the vibration mitigation mechanism. Simulations confirm the metamaterial-like behavior with a negative dynamic material stiffness for the micro-metastructured aerogels in a much wider frequency range than the majority of previously reported locally resonant metamaterials.

7.
Chem Biodivers ; 15(11): e1800289, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30194898

RESUMEN

A number of podophyllotoxin derivatives (3A-3J) had been designed and synthesized, and their biological activities were evaluated in this study. Moreover, the antiproliferation activities of these compounds against four human cancer cell lines (HepG2, HeLa, A549, and MCF-7) were also tested. The results indicated that the most promising compound 3D displayed potent inhibitory activity over the four human cancer cell lines and was further demonstrated to have potent tubulin polymerization inhibitory effects without damaging the non-cancer cells. Additionally, 3D was verified to effectively interfere with tubulin and could prevent the mitosis of cancer cells, leading to cell cycle arrest and eventually inducing apoptosis in a dose- and time-dependent manner. Moreover, the Western blotting and siRNA results showed that Bcl-2 was downregulated in HepG2 cells treated with 3D. Finally, the molecular docking simulation results revealed that 3D could fit well in the colchicine-binding pocket. Taken together, this study has provided certain novel antitubulin agents for possible cancer chemotherapy.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Podofilotoxina/farmacología , Tubulina (Proteína)/metabolismo , Antineoplásicos Fitogénicos/síntesis química , Antineoplásicos Fitogénicos/química , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Conformación Molecular , Simulación del Acoplamiento Molecular , Podofilotoxina/síntesis química , Podofilotoxina/química , Relación Estructura-Actividad , Células Tumorales Cultivadas
8.
Zhongguo Zhong Yao Za Zhi ; 42(7): 1395-1400, 2017 Apr.
Artículo en Zh | MEDLINE | ID: mdl-29052405

RESUMEN

Artemisia hedinii occupies an important position in the Tibetan medicine. Plants in Artemisia vary a lot and are widely distributed in the Qinghai-Tibet Plateau, many plants in Artemisia look similar, making traditional identification methods laborious. In this article, ITS2 sequences were used as DNA barcoding to identify four kinds of confusable Tibetan medicine plants in Artemisia, aiming to establish a rapid and accurate identification methods. Twenty-one samples in Artemisia were collected from the Qinghai-Tibet Plateau, ITS2 sequence PCR amplification and sequencing were conducted after the extraction of DNA. Another 11 sequence downloaded from Genbank were added to the analysis. Genetic distance calculation and analysis, building Neighbor Joining (NJ) phylogenetic tree were conducted by MEGA 6.0, also comparison of secondary structures of ITS2 sequences among samples. A. hedinii, A. annua, A. dubia and A. argyi shared close genetic distance, but the maximum distance between the four species was much greater than the minimum distance within each species, NJ tree showed that the four species went to four separate branches, differences among secondary structures of ITS2 sequences also made it clear to identify these medical plants. It could be an accurate and rapid method for identification and recognition, as well as the evolutionary relationships between the species by using ITS2 sequence as DNA barcode for plants of Tibetan Artemisia. The study provides theoretical basis for quality control, medication safety and rational exploitation.


Asunto(s)
Artemisia/genética , Código de Barras del ADN Taxonómico , ADN Espaciador Ribosómico/genética , Filogenia , ADN de Plantas/genética , Plantas Medicinales/genética , Tibet
9.
Amino Acids ; 48(11): 2657-2670, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27487778

RESUMEN

Natural and nutrient substances for cardiovascular disease are promising and capture researchers' minds. Two kinds of novel bioactive peptides (high Fischer's ratio oligopeptides and anticoagulant peptides) were obtained from Whitmania pigra protein via enzymatic hydrolysis. An oligopeptide (MW<874.0 Da) named as HF2 was obtained via chromatography purification procedures with a high Fischer's ratio of 31.92 ± 1.36 and low phenylalanine + tyrosine content of 0.98 ± 0.04 %. Another peptide (WA3-1), prepared by alcalase AF 2.4 L-catalyzed hydrolysis and then purified by DEAE Sepharose FF, gel Sephadex G-15 chromatography, exhibited high anticoagulant activity with prolonging significantly plasma clotting time on activated partial thromboplastin time, prothrombin time, thrombin time (p < 0.01) and powerful thrombolytic activity. Amino acid composition and MALDI-TOF/TOF MS analysis showed that WA3-1 contained 11 amino acids (MW: 1422.0 Da) with the sequence as NH2-His-Asp-Phe-Leu-Asn-Asn-Lys-Leu-Glu-Tyr-Glu-COOH. Abundant negatively charged amino acids in C-terminal, as well as the special residue Lys contribute to its anticoagulant capacity. This research provided a novel natural candidate for the manufacture of nutrient oligopeptides with high branched chain amino acid, and anticoagulant thrombolytic agent in pharmaceutical industry with helping prevent from thrombosis and related cardiovascular diseases.


Asunto(s)
Secuencia de Aminoácidos , Anticoagulantes , Coagulación Sanguínea/efectos de los fármacos , Sanguijuelas/química , Oligopéptidos , Terapia Trombolítica , Aminoácidos de Cadena Ramificada , Animales , Anticoagulantes/química , Anticoagulantes/aislamiento & purificación , Anticoagulantes/farmacología , Humanos , Oligopéptidos/química , Oligopéptidos/genética , Oligopéptidos/aislamiento & purificación , Oligopéptidos/farmacología
10.
Appl Opt ; 55(8): 2018-23, 2016 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-26974797

RESUMEN

A novel and simple technique based on the light diffraction effect for visualization of low-frequency underwater acoustic waves (LFUAWs) in real time has been developed in this paper. A cylindrical object has been put on the surface of the water. A low-frequency underwater longitudinal wave can be generated into a water surface transversal capillary wave around the cylinder by our technique. Modulating the phase of a laser beam reflected from a water surface by surface acoustic waves (SAWs) realizes the acousto-optic effect. Then, a steady and visible diffraction pattern is experimentally observed. A physical model of the SAW is established to verify the feasibility of our technique. An analytical expression of wavelength, wave amplitude, and excitation frequency has been derived to study the physical properties of LFUAWs, and it explains the experimental phenomenon very well. As a result, the technique is effective, easy, and practical for visualizing LFUAWs and has significance for applications.

11.
Zhongguo Zhong Yao Za Zhi ; 40(13): 2674-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26697698

RESUMEN

The study focused on the therapeutic efficacy of Tibetan medicines on cerebral ischemia. The combined medication methods and administration habits in clinic for more than 10 years were simulated. Three typical Tibetan medicines, i.e., 25-Herb Shanhu pill, Wishful-Treasure pill and 20-Herb Chenxiang pill, were administered to the animal model of permanent middle cerebral artery occlusion in the morning, noon and evening, respectively. On the second day after the final administration, the activity of serum oxidative stress marker SOD and the content of MDA were evaluated. Infarct volumes were quantified through TTC staining. Inflammatory reaction maker NF-kappaB p65 gene and apoptosis. makers Bax and Cyct were selected to study the molecular mechanism of combined herbs with the immunohistochemistry technique. According to the result, the respective combination of 25-Herb Shanhu pill, Wishful-Treasure pill and 20-Herb Chenxiang pill in the morning, noon and evening showed unique advantages in reducing the damage of oxidative stress, infarct volumes, encephaledema caused by ischemia, inflammatory factor aggregation and inhibiting apoptosis, with consistent therapeutic efficacies in clinic.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Medicina Tradicional Tibetana , Animales , Isquemia Encefálica/metabolismo , Peroxidación de Lípido , Masculino , Ratas , Superóxido Dismutasa/metabolismo , Factores de Tiempo , Factor de Transcripción ReIA/fisiología
12.
Zhongguo Zhong Yao Za Zhi ; 40(8): 1453-8, 2015 Apr.
Artículo en Zh | MEDLINE | ID: mdl-26281578

RESUMEN

The study is aimed to ensure the quality and safety of medicinal plants by using ITS2 DNA barcode technology to identify Corydalis boweri, Meconopsis horridula and their close related species. The DNA of 13 herb samples including C. boweri and M. horridula from Lhasa of Tibet was extracted, ITS PCR were amplified and sequenced. Both assembled and web downloaded 71 ITS2 sequences were removed of 5. 8S and 28S. Multiple sequence alignment was completed and the intraspecific and interspecific genetic distances were calculated by MEGA 5.0, while the neighbor-joining phylogenetic trees were constructed. We also predicted the ITS2 secondary structure of C. boweri, M. horridula and their close related species. The results showed that ITS2 as DNA barcode was able to identify C. boweri, M. horridula as well as well as their close related species effectively. The established based on ITS2 barcode method provides the regular and safe detection technology for identification of C. boweri, M. horridula and their close related species, adulterants and counterfeits, in order to ensure their quality control, safe medication, reasonable development and utilization.


Asunto(s)
Corydalis/clasificación , Código de Barras del ADN Taxonómico/métodos , ADN de Plantas/genética , ADN Espaciador Ribosómico/genética , Papaveraceae/clasificación , Secuencia de Bases , China , Corydalis/química , Corydalis/genética , ADN de Plantas/química , ADN Espaciador Ribosómico/química , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Papaveraceae/química , Papaveraceae/genética , Filogenia , Plantas Medicinales/química , Plantas Medicinales/clasificación , Plantas Medicinales/genética
13.
Biochem Biophys Res Commun ; 452(4): 888-94, 2014 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-25181341

RESUMEN

The hydrolysate from duck egg white protein (DEWP) prepared by "SEEP-Alcalase" at degree of hydrolysis (DH) value of 21% (namely HSA21) exhibited high antioxidant capacity in different oxidation systems. A consecutive chromatographic method was then developed for separation and purification of HSA21, including ion-exchange chromatography, macroporous adsorption resin (MAR) and gel filter chromatography. The final peptides "P21-3-75-B" were obtained with significantly enhanced antioxidant activity (p<0.05). It was further confirmed that the product mainly consisted of five oligopeptides (Mr: 202.1, 294.1, 382.1, 426.3, and 514.4Da). Furthermore, the antioxidant activity of P21-3-75-B kept stable after in vitro digestive simulation. Antioxidant capacity of the purified peptides was closely related to the molecular mass, hydrophobic amino acid residues, acidic amino acid and some antioxidant amino acids. This research provided a valuable route for producing new natural-source peptides with strong antioxidant capacity and high nutritious value for our daily intake.


Asunto(s)
Antioxidantes/química , Antioxidantes/aislamiento & purificación , Patos/metabolismo , Proteínas del Huevo/química , Proteínas del Huevo/aislamiento & purificación , Oligopéptidos/química , Oligopéptidos/aislamiento & purificación , Animales , Estabilidad de Medicamentos , Radicales Libres/química , Contenido Digestivo/química , Hidrólisis , Oxígeno/química , Hidrolisados de Proteína/química , Hidrolisados de Proteína/aislamiento & purificación
14.
Biochem Biophys Res Commun ; 454(1): 157-61, 2014 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-25450373

RESUMEN

The Sterile Alpha Motif Domain-containing 9 (SAMD9) gene has been recently emphasized during the discovery that it is expressed at a lower level in aggressive fibromatosis and some cases of breast and colon cancer, however, the underlying mechanisms are poorly understood. Here, we found that SAMD9 is down-regulated in human non-small cell lung cancer (NSCLC). Furthermore, knockdown of SAMD9 expression is increased the invasion, migration and proliferation in H1299 cells in vitro and overexpression of SAMD9 suppressed proliferation and invasion in A549 cells. Finally, depletion of SAMD9 increases tumor formation in vivo. Our results may provide a strategy for blocking NSCLC tumorigenesis and progression.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/genética , Proteínas/genética , Biomarcadores de Tumor/genética , Carcinoma de Pulmón de Células no Pequeñas/etiología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Progresión de la Enfermedad , Regulación hacia Abajo , Técnicas de Silenciamiento del Gen , Humanos , Péptidos y Proteínas de Señalización Intracelular , Neoplasias Pulmonares/etiología , Neoplasias Pulmonares/patología , Invasividad Neoplásica , Proteínas/antagonistas & inhibidores , Proteínas/metabolismo , Regulación hacia Arriba
15.
Genome ; 57(6): 345-53, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25264805

RESUMEN

Gordonia neofelifaecis NRRL B-59395 was initially isolated from the fresh feces of a clouded leopard based on its ability to degrade cholesterol. The transcriptome profiles of G. neofelifaecis NRRL B-59395 grown with cholesterol, androstenedione (AD), and pyruvic acid were compared by RNA-Seq. The sterol catabolic genes are highly conserved in G. neofelifaecis, Rhodococcus jostii RHA1, and Mycobacterium tuberculosis. The RNA-Seq results indicated that the genes involved in the sterol side chain cleavage were exclusively induced by cholesterol, while the genes involved in the degradation of rings A/B and C/D were up-regulated by both cholesterol and AD. It appears that the induction mechanisms for the genes responsible for side chain cleavage and those for degradation of rings are different. There are approximately 21 genes encoding transporter proteins that are differentially expressed in cholesterol or AD compared with pyruvic acid. The genes camABCD and camM encode two systems that take up cholate, and they have been shown to be cholesterol- and AD-inducible. The potential biological functions of other differentially expressed genes are also discussed. These results will promote the functional characterization of the sterol catabolic genes and also provide important clues in understanding the mechanisms of their gene expression, and they may help us understand the mechanism underlying microbial cholesterol catabolism.


Asunto(s)
Bacteria Gordonia/genética , Bacteria Gordonia/metabolismo , Esteroides/metabolismo , Androstenodiona/metabolismo , Androstenodiona/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Colesterol/metabolismo , Colesterol/farmacología , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Bacteria Gordonia/crecimiento & desarrollo , Operón , Ácido Pirúvico/metabolismo , Ácido Pirúvico/farmacología , Esteroides/farmacología , Transcriptoma
16.
Microb Cell Fact ; 13: 143, 2014 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-25273324

RESUMEN

BACKGROUND: The use of biocatalysts has become an increasingly attractive alternative to traditional chemical methods, due to the high selectivity, mild reaction conditions and environmentally-friendly processes in nonaqueous catalysis of nucleosids. However, the extensive use of organic solvents may generally suffer from sever drawbacks such as volatileness and toxicity to the environment and lower activity of the biocatalyst. Recently, ionic liquids are considered promising solvents for nonaqueous biocatalysis of polyhydroxyl compounds as ILs are environmental-friendly. RESULTS: In this research, we developed new IL-containing reaction systems for synthesis of long chain nucleoside ester catalyzed by Pseudomonas fluorescens whole-cells. Various ILs exerted significant but different effects on the bio-reaction. And their effects were closely related with both the anions and cations of the ILs. Use of 10% [BMI][PF6]/THF gave high reaction efficiency of arabinocytosine laurate synthesis, in which the initial rate, product yield and 5'-regioselectivity reached 2.34 mmol/L·h, 81.1% and >99%, respectively. Furthermore, SEM analysis revealed that ILs can alter the cell surface morphology, improve the permeability of cell envelopes and thus facilitate the mass transfer of substrates to the active sites of cell-bound enzymes. CONCLUSION: Our research demonstrated the potential of ILs as promising reaction medium for achieving highly efficient and regioselective whole-cell catalysis.


Asunto(s)
Líquidos Iónicos/química , Nucleósidos/química , Pseudomonas fluorescens/química , Acilación , Catálisis , Nucleósidos/metabolismo , Pseudomonas fluorescens/metabolismo
17.
ACS Sens ; 9(7): 3549-3556, 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-38982583

RESUMEN

Mutation accumulation in RNAs results in closely located single-nucleotide mutations (SNMs), which is highly associated with the drug resistance of pathogens. Imaging of SNMs in single cells has significance for understanding the heterogeneity of RNAs that are related to drug resistance, but the direct "see" closely located SNMs remains challenging. Herein, we designed an encoded ligation-mediated in situ polymerase chain reaction method (termed enPCR), which enabled the visualization of multiple closely located SNMs in bacterial RNAs. Unlike conventional ligation-based probes that can only discriminate a single SNM, this method can simultaneously image different SNMs at closely located sites with single-cell resolution using modular anchoring probes and encoded PCR primers. We tested the capacity of the method to detect closely located SNMs related to quinolone resistance in the gyrA gene of Salmonella enterica (S. enterica), and found that the simultaneous detection of the closely located SNMs can more precisely indicate the resistance of the S. enterica to quinolone compared to the detection of one SNM. The multiplexing imaging assay for SNMs can serve to reveal the relationship between complex cellular genotypes and phenotypes.


Asunto(s)
Análisis de la Célula Individual , Análisis de la Célula Individual/métodos , Salmonella enterica/genética , Girasa de ADN/genética , Farmacorresistencia Bacteriana/genética , Reacción en Cadena de la Polimerasa/métodos , Mutación , Quinolonas/farmacología , ARN Bacteriano/genética
18.
Sci Rep ; 14(1): 17664, 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39085290

RESUMEN

The utilization of high-risk test cases constitutes an effective approach to enhance the safety testing of autonomous vehicles (AVs) and enhance their efficiency. This research paper presents a derivation of 2052 high-hazard pre-crash scenarios for testing autonomous driving, which were based on 23 high-hazard cut-in accident scenarios from the National Automobile Accident In-Depth Investigation System (NAIS) through combining importance sampling and combined testing methods. Compared to the direct combination of the original distribution after sampling, the proposed method has a 2.92 times higher crash rate of 69.32% for the test case set in this paper. It also has a 5.8 times higher rate of triggering Automatic Emergency Braking (AEB), improving hazardous scenario coverage. Using the proposed method, the generated parameters of the cut-in accident scenario test set were compared with those of the cut-in test scenarios included in existing Chinese autonomous driving test protocols and standards. The velocity of the ego-vehicle obtained using the proposed method matched those in the existing protocols, whereas the velocity, time gap, and time to collision of the target vehicle were significantly lower than those existing protocols indicating scenarios obtained from accident data can enrich the selection of testing scenarios for autonomous driving.

19.
Front Oncol ; 14: 1343170, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38357195

RESUMEN

Purpose: This study aims to develop an optimal machine learning model that uses lung equivalent uniform dose (lung EUD to predict radiation pneumonitis (RP) occurrence in lung cancer patients treated with volumetric modulated arc therapy (VMAT). Methods: We analyzed a cohort of 77 patients diagnosed with locally advanced squamous cell lung cancer (LASCLC) receiving concurrent chemoradiotherapy with VMAT. Patients were categorized based on the onset of grade II or higher radiation pneumonitis (RP 2+). Dose volume histogram data, extracted from the treatment planning system, were used to compute the lung EUD values for both groups using a specialized numerical analysis code. We identified the parameter α, representing the most significant relative difference in lung EUD between the two groups. The predictive potential of variables for RP2+, including physical dose metrics, lung EUD, normal tissue complication probability (NTCP) from the Lyman-Kutcher-Burman (LKB) model, and lung EUD-calibrated NTCP for affected and whole lung, underwent both univariate and multivariate analyses. Relevant variables were then employed as inputs for machine learning models: multiple logistic regression (MLR), support vector machine (SVM), decision tree (DT), and K-nearest neighbor (KNN). Each model's performance was gauged using the area under the curve (AUC), determining the best-performing model. Results: The optimal α-value for lung EUD was 0.3, maximizing the relative lung EUD difference between the RP 2+ and non-RP 2+ groups. A strong correlation coefficient of 0.929 (P< 0.01) was observed between lung EUD (α = 0.3) and physical dose metrics. When examining predictive capabilities, lung EUD-based NTCP for the affected lung (AUC: 0.862) and whole lung (AUC: 0.815) surpassed LKB-based NTCP for the respective lungs. The decision tree (DT) model using lung EUD-based predictors emerged as the superior model, achieving an AUC of 0.98 in both training and validation datasets. Discussions: The likelihood of developing RP 2+ has shown a significant correlation with the advancements in RT technology. From traditional 3-D conformal RT, lung cancer treatment methodologies have transitioned to sophisticated techniques like static IMRT. Accurately deriving such a dose-effect relationship through NTCP modeling of RP incidence is statistically challenging due to the increased number of degrees-of-freedom. To the best of our knowledge, many studies have not clarified the rationale behind setting the α-value to 0.99 or 1, despite the closely aligned calculated lung EUD and lung mean dose MLD. Perfect independence among variables is rarely achievable in real-world scenarios. Four prominent machine learning algorithms were used to devise our prediction models. The inclusion of lung EUD-based factors substantially enhanced their predictive performance for RP 2+. Our results advocate for the decision tree model with lung EUD-based predictors as the optimal prediction tool for VMAT-treated lung cancer patients. Which could replace conventional dosimetric parameters, potentially simplifying complex neural network structures in prediction models.

20.
Comput Biol Med ; 178: 108693, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38850960

RESUMEN

AIM: Kaempferitrin is an active component in Chenopodium ambrosioides, showing medicinal functions against liver cancer. This study aimed to identify the potential targets and pathways of kaempferitrin against liver cancer using network pharmacology and molecular docking, and verify the essential hub targets and pathway in mice model of SMMC-7721 cells xenografted tumors and SMMC-7721 cells. METHODS: Kaempferitrin therapeutical targets were obtained by searching SwissTargetPrediction, PharmMapper, STITCH, DrugBank, and TTD databases. Liver cancer specific genes were obtained by searching GeneCards, DrugBank, TTD, OMIM, and DisGeNET databases. PPI network of "kaempferitrin-targets-liver cancer" was constructed to screen the hub targets. GO, KEGG pathway and MCODE clustering analyses were performed to identify possible enrichment of genes with specific biological subjects. Molecular docking and molecular dynamics simulation were employed to determine the docking pose, potential and stability of kaempferitrin with hub targets. The potential anti-liver cancer mechanisms of kaempferitrin, as predicted by network pharmacology analyses, were verified by in vitro and in vivo experiments. RESULTS: 228 kaempferitrin targets and 2186 liver cancer specific targets were identified, of which 50 targets were overlapped. 8 hub targets were identified through network topology analysis, and only SIRT1 and TP53 had a potent binding activity with kaempferitrin as indicated by molecular docking and molecular dynamics simulation. MCODE clustering analysis revealed the most significant functional module of PPI network including SIRT1 and TP53 was mainly related to cell apoptosis. GO and KEGG enrichment analyses suggested that kaempferitrin exerted therapeutic effects on liver cancer possibly by promoting apoptosis via p21/Bcl-2/Caspase 3 signaling pathway, which were confirmed by in vivo and in vitro experiments, such as HE staining of tumor tissues, CCK-8, qRT-PCR and Western blot. CONCLUSION: This study provided not only insight into how kaempferitrin could act against liver cancer by identifying hub targets and their associated signaling pathways, but also experimental evidence for the clinical use of kaempferitrin in liver cancer treatment.


Asunto(s)
Quempferoles , Neoplasias Hepáticas , Simulación del Acoplamiento Molecular , Animales , Humanos , Quempferoles/farmacología , Quempferoles/química , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/metabolismo , Ratones , Línea Celular Tumoral , Farmacología en Red , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/química , Ratones Desnudos
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