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1.
Molecules ; 29(9)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38731652

RESUMO

Bovine milk is an essential supplement due to its rich energy- and nutrient-rich qualities. Caseins constitute the vast majority of the proteins in milk. Among these, ß-casein comprises around 37% of all caseins, and it is an important type of casein with several different variants. The A1 and A2 variants of ß-casein are the most researched genotypes due to the changes in their composition. It is accepted that the A2 variant is ancestral, while a point mutation in the 67th amino acid created the A1 variant. The digestion derived of both A1 and A2 milk is BCM-7. Digestion of A2 milk in the human intestine also forms BCM-9 peptide molecule. The opioid-like characteristics of BCM-7 are highlighted for their potential triggering effect on several diseases. Most research has been focused on gastrointestinal-related diseases; however other metabolic and nervous system-based diseases are also potentially triggered. By manipulating the mechanisms of these diseases, BCM-7 can induce certain situations, such as conformational changes, reduction in protein activity, and the creation of undesired activity in the biological system. Furthermore, the genotype of casein can also play a role in bone health, such as altering fracture rates, and calcium contents can change the characteristics of dietary products. The context between opioid molecules and BCM-7 points to a potential triggering mechanism for the central nervous system and other metabolic diseases discussed.


Assuntos
Caseínas , Endorfinas , Humanos , Animais , Caseínas/química , Caseínas/metabolismo , Caseínas/genética , Endorfinas/química , Endorfinas/metabolismo , Leite/química , Leite/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/genética , Peptídeos Opioides/química , Peptídeos Opioides/metabolismo , Bovinos
2.
J Sci Food Agric ; 104(5): 2597-2609, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37991930

RESUMO

BACKGROUND: Lotus (Nelumbo nucifera) leaf has been described to have anti-obesity activity, but the role of white fat 'browning' or 'beiging' in its beneficial metabolic actions remains unclear. Here, 3T3-L1 cells and high-fat-diet (HFD)-fed mice were used to evaluate the effects of miquelianin-rich lotus leaf extract (LLE) on white-to-beige fat conversion and its regulatory mechanisms. RESULTS: Treatment with LLE increased mitochondrial abundance, mitochondrial membrane potential and NAD+ /NADH ratio in 3T3-L1 cells, suggesting its potential in promoting mitochondrial activity. qPCR and/or western blotting analysis confirmed that LLE induced the expression of beige fat-enriched gene signatures (e.g. Sirt1, Cidea, Dio2, Prdm16, Ucp1, Cd40, Cd137, Cited1) and mitochondrial biogenesis-related markers (e.g. Nrf1, Cox2, Cox7a, Tfam) in 3T3-L1 cells and inguinal white adipose tissue of HFD-fed mice. Furthermore, we found that LLE treatment inhibited mitochondrial fission protein DRP1 and blocked mitophagy markers such as PINK1, PARKIN, BECLIN1 and LC-3B. Chemical inhibition experiments revealed that AMPK/DRP1 signaling was required for LLE-induced beige fat formation via suppressing PINK1/PARKIN/mitophagy. CONCLUSION: Our data reveal a novel mechanism underlying the anti-obesity effect of LLE, namely the induction of white fat beiging via AMPK/DRP1/mitophagy signaling. © 2023 Society of Chemical Industry.


Assuntos
Proteínas Quinases Ativadas por AMP , Glucosídeos , Mitofagia , Quercetina/análogos & derivados , Animais , Camundongos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo Branco/metabolismo , Obesidade/tratamento farmacológico , Obesidade/genética , Obesidade/metabolismo , Ubiquitina-Proteína Ligases/genética , Extratos Vegetais/farmacologia
3.
Crit Rev Food Sci Nutr ; 63(20): 4288-4324, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34792409

RESUMO

Diabetes mellitus is a metabolic syndrome which cannot be cured. Recently, considerable interest has been focused on food ingredients to prevent and intervene in complications of diabetes. Polyphenolic compounds are one of the bioactive phytochemical constituents with various biological activities, which have drawn increasing interest in human health. Fruits are part of the polyphenol sources in daily food consumption. Fruit-derived polyphenols possess the anti-diabetic activity that has already been proved either from in vitro studies or in vivo studies. The mechanisms of fruit polyphenols in treating diabetes and related complications are under discussion. This is a comprehensive review on polyphenols from the edible parts of fruits, including those from citrus, berries, apples, cherries, mangoes, mangosteens, pomegranates, and other fruits regarding their potential benefits in preventing and treating diabetes mellitus. The signal pathways of characteristic polyphenols derived from fruits in reducing high blood glucose and intervening hyperglycemia-induced diabetic complications were summarized.


Assuntos
Diabetes Mellitus , Hiperglicemia , Síndrome Metabólica , Humanos , Frutas/química , Polifenóis/química , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/prevenção & controle , Síndrome Metabólica/metabolismo , Antioxidantes/farmacologia , Hiperglicemia/tratamento farmacológico , Hiperglicemia/prevenção & controle
4.
Crit Rev Food Sci Nutr ; 63(19): 4026-4052, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34738509

RESUMO

Fat browning has piqued the interest of researchers as a potential target for treating obesity and related metabolic disorders. Recruitment of brown adipocytes leads to enhanced energy dissipation and reduced adiposity, thus facilitating the maintenance of metabolic homeostasis. Evidence is increasing to support the crucial roles of polyphenols and gut microecology in turning fat "brown". However, it is not clear whether the intestinal microecology is involved in polyphenol-mediated regulation of adipose browning, so this concept is worthy of exploration. In this review, we summarize the current knowledge, mostly from studies with murine models, supporting the concept that the effects of food phenolics on brown fat activation and white fat browning can be attributed to their regulatory actions on gut microecology, including microbial community profile, gut metabolites, and gut-derived hormones. Furthermore, the potential underlying pathways involved are also discussed. Basically, understanding gut microecology paves the way to determine the underlying roles and mechanisms of food phenolics in adipose browning.


Assuntos
Adipócitos , Obesidade , Camundongos , Humanos , Animais , Obesidade/metabolismo , Tecido Adiposo Marrom/metabolismo , Adiposidade , Tecido Adiposo Branco/metabolismo , Polifenóis/farmacologia , Polifenóis/metabolismo
5.
Crit Rev Food Sci Nutr ; 63(21): 4867-4900, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34845950

RESUMO

Different parts of lotus (Nelumbo nucifera Gaertn.) including the seeds, rhizomes, leaves, and flowers, are used for medicinal purposes with health promoting and illness preventing benefits. The presence of active chemicals such as alkaloids, phenolic acids, flavonoids, and terpenoids (particularly alkaloids) may account for this plant's pharmacological effects. In this review, we provide a comprehensive overview and summarize up-to-date research on the biosynthesis, pharmacokinetics, and bioactivity of lotus alkaloids as well as their safety. Moreover, the potential uses of lotus alkaloids in the food, pharmaceutical, and cosmetic sectors are explored. Current evidence shows that alkaloids, mainly consisting of aporphines, 1-benzylisoquinolines, and bisbenzylisoquinolines, are present in different parts of lotus. The bioavailability of these alkaloids is relatively low in vivo but can be enhanced by technological modification using nanoliposomes, liposomes, microcapsules, and emulsions. Available data highlights their therapeutic and preventive effects on obesity, diabetes, neurodegeneration, cancer, cardiovascular disease, etc. Additionally, industrial applications of lotus alkaloids include their use as food, medical, and cosmetic ingredients in tea, other beverages, and healthcare products; as lipid-lowering, anticancer, and antipsychotic drugs; and in facial masks, toothpastes, and shower gels. However, their clinical efficacy and safety remains unclear; hence, larger and longer human trials are needed to achieve their safe and effective use with minimal side effects.


Assuntos
Alcaloides , Lotus , Nelumbo , Humanos , Extratos Vegetais/farmacologia , Folhas de Planta
6.
Molecules ; 28(4)2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36838740

RESUMO

The effects of protein-glutaminase (PG) on calcium sulphate (CaSO4)-induced gels of soy protein isolate (SPI) with different heat treatment levels were investigated. The time-dependent degree of deamidation showed that the mild denaturation of the protein favored the deamidation. The particle size distribution showed that the heat treatment increased the SPI particle size, and the particle size distribution of the SPI shifted to the right or increased the proportion of the large particle size component as the degree of deamidation increased for each sample. Rheological analysis showed that the deamidation substantially pushed up the gel temperature and decreased the value of G'. The gel strength and water-holding capacity showed that the higher the amount of enzyme added, the more significant the decrease in gel strength, while the gel water-holding capacity increased. In summary, the deamidation of PG and heat treatment can affect the gel properties of SPI synergistically.


Assuntos
Sulfato de Cálcio , Glutaminase , Glutaminase/metabolismo , Proteínas de Soja , Géis , Água , Reologia
7.
Molecules ; 28(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36677944

RESUMO

Recent scientific studies have established a relationship between the consumption of phytochemicals such as carotenoids, polyphenols, isoprenoids, phytosterols, saponins, dietary fibers, polysaccharides, etc., with health benefits such as prevention of diabetes, obesity, cancer, cardiovascular diseases, etc. This has led to the popularization of phytochemicals. Nowadays, foods containing phytochemicals as a constituent (functional foods) and the concentrated form of phytochemicals (nutraceuticals) are used as a preventive measure or cure for many diseases. The health benefits of these phytochemicals depend on their purity and structural stability. The yield, purity, and structural stability of extracted phytochemicals depend on the matrix in which the phytochemical is present, the method of extraction, the solvent used, the temperature, and the time of extraction.


Assuntos
Compostos Fitoquímicos , Fitosteróis , Compostos Fitoquímicos/uso terapêutico , Compostos Fitoquímicos/química , Polifenóis/uso terapêutico , Polifenóis/química , Suplementos Nutricionais , Antioxidantes/uso terapêutico
8.
J Sci Food Agric ; 103(9): 4441-4449, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36869599

RESUMO

BACKGROUND: Wheat and wheat flour are important raw materials of staple foods. Medium-gluten wheat is now the dominant wheat in China. In order to expand the application of medium-gluten wheat, radio-frequency (RF) technology was used to improve its quality. Effects of tempering moisture content (TMC) of wheat and RF treatment time on wheat quality were investigated. RESULTS: No evident change in protein content after RF treatment, but a reduction in wet gluten content of the sample with 10-18% TMC and RF treatment for 5 min, was observed. By contrast, protein content increased to 31.0% after RF treatment for 9 min in 14% TMC wheat, achieving the requirement of high-gluten wheat (≥30.0%). Thermodynamic and pasting properties indicated that RF treatment (14% TMC, 5 min) can alter the double-helical structure and pasting viscosities of flour. In addition, the results of textural analysis and sensory evaluation for Chinese steamed bread showed that RF treatment for 5 min with different TMC (10-18%) wheat could deteriorate wheat quality, while the wheat (14% TMC) treated with RF for 9 min had the best quality. CONCLUSION: RF treatment for 9 min can improve wheat quality when the TMC was 14%. The results are beneficial to the application of RF technology in wheat processing and improvement of wheat flour quality. © 2023 Society of Chemical Industry.


Assuntos
Triticum , Glutens/química , Triticum/química , Água/química , Viscosidade , Farinha/análise , Fenômenos Químicos
9.
J Sci Food Agric ; 103(13): 6483-6490, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37219070

RESUMO

BACKGROUND: Complex interactions that occur among starch, protein, and fat during food processing affect the taste, texture, and digestibility of starch-based food. The physicochemical properties of starch, in particular its slow digestibility, are greatly influenced by processing techniques such as extrusion and roller-drying. This study investigated the effects of various food ingredients and additives on the digestion properties of maize starch treated with extrusion and roller drying. It designed a nutritional formula to develop low glycemic index products. RESULTS: The extruded group containing raw maize starch, soybean protein isolate, soybean oil, lecithin and microcrystalline cellulose in the ratio of 580:250:58:20:3 had the best slow digestion properties. Nutritional formulas were designed at the above ratio, with supplements including calcium casein peptide, multi-vitamins, sodium ascorbate, fructooligosaccharides, xylitol, and peanut meal. The sample containing 10% peanut meal and a 1:3 ratio of fructooligosaccharides and xylitol additions obtained the highest sensory evaluation scores. An obvious slow digestion effect was observed in samples produced from the optimal formula. CONCLUSION: The results of the present study could contribute to the development and production of a low glycemic index, nutritional powder. © 2023 Society of Chemical Industry.


Assuntos
Ingredientes de Alimentos , Zea mays , Zea mays/química , Pós/metabolismo , Digestão , Índice Glicêmico , Xilitol/metabolismo , Amido/química
10.
Crit Rev Food Sci Nutr ; 62(5): 1417-1425, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33153277

RESUMO

The current cohort study shows the inconsistent association between potato consumption and the risk of type 2 diabetes mellitus (T2DM). Therefore, we conducted a systematic review and dose-response meta-analysis of published prospective cohort studies to quantitatively estimate this association. We searched PubMed, Embase, MEDLINE, Web of Knowledge, and the Cochrane Library up to September 2019 for all published articles. Seven of the articles reported nine cohort studies with 383,211 participants, with 23,189 T2DM cases that met the inclusion criteria and were included for our analysis. The results of random effects model pooled relative risk (RR) showed an association between potato intake and the risk of T2DM (pooled RR = 1.13, 95% CI: 1.02-1.26, p > 0.01). In the subgroup analysis, French fries, long-term follow-up, large sample size, and high-quality studies were associated with an increased T2DM risk. Further, a linear dose-response analysis indicated that 100 g/day increment of total potato (RR = 1.05, 95% CI: 1.02-1.08) and French fries (RR = 1.10, 95% CI: 1.07-1.14) consumption may increase the risk of T2DM by 5% and 10%, respectively. Our meta-analysis showed that potato consumption, especially French fries consumption, was associated with increased T2DM risk.


Assuntos
Diabetes Mellitus Tipo 2 , Solanum tuberosum , Estudos de Coortes , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Humanos , Estudos Prospectivos , Fatores de Risco
11.
Can J Microbiol ; 68(12): 711-721, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36130402

RESUMO

Pichia pastoris is an expression platform widely used for foreign protein expression, while it is unknown how the global lipid profiles changed during the cultivation process, which is crucial for fermentation optimization and chassis design. Therefore, this study aimed to reveal the diverse lipid profiles of P. pastoris controlled by constitutive promoter of glyceraldehyde-3-phosphate dehydrogenase gene and to unravel their change in the lag, logarithmic, stationary, and death phases, using ultra-performance liquid chromatography/nano-electrospray ionization-tandem mass spectrometry. Two hundred forty lipid species across 11 lipid classes were detected, including various glycerolipids, glycerophospholipids, and sphingolipids. Pichia cells displayed high diversity and variability of lipids in lipid profile, relative intensity, phosphatidylinositol/phosphatidylserine ratio, fatty acid chain length, and unsaturation degree. Notably, increase of unsaturated triacylglycerol level was accompanied by rise of malondialdehyde level under oxidative stress. The increased ceramide with long fatty acid chain could be a key feature at death phase. This work deepened our understanding of the physiology of P. pastoris during cultivation and provided valuable information for further improvement of the P. pastoris expression system.


Assuntos
Lipidômica , Pichia , Pichia/genética , Pichia/metabolismo , Esfingolipídeos/análise , Esfingolipídeos/metabolismo , Ácidos Graxos/metabolismo
12.
Molecules ; 27(23)2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36500320

RESUMO

This study investigated the effect of ultrasound on gel properties of soy protein isolates (SPIs) at different salt concentrations. The results showed that ultrasound could significantly improve the gel hardness and the water holding capacity (WHC) of the salt-containing gel (p < 0.05). The gel presents a uniform and compact three-dimensional network structure. The combination of 200 mM NaCl with 20 min of ultrasound could significantly increase the gel hardness (four times) and the WHC (p < 0.05) compared with the SPI gel without treatment. With the increase in NaCl concentration, the ζ potential and surface hydrophobicity increased, and the solubility decreased. Ultrasound could improve the protein solubility, compensate for the loss of solubility caused by the addition of NaCl, and further increase the surface hydrophobicity. Ultrasound combined with NaCl allowed proteins to form aggregates of different sizes. In addition, the combined treatment increased the hydrophobic interactions and disulfide bond interactions in the gel. Overall, ultrasound could improve the thermal gel properties of SPI gels with salt addition.


Assuntos
Temperatura Alta , Proteínas de Soja , Proteínas de Soja/química , Géis/química , Concentração Osmolar , Interações Hidrofóbicas e Hidrofílicas , Água/química , Cloreto de Sódio
13.
Molecules ; 26(5)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652771

RESUMO

The aim of this research was to investigate the effect of the number of freeze-thaw cycles (0, 1, 3, 5, and 7) on porcine longissimus protein and lipid oxidation, as well as changes in heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs) and their precursors. We analyzed the relationship among HAAs, AGEs, oxidation, and precursors and found the following results after seven freeze-thaw cycles. The HAAs, Norharman and Harman, were 20.33% and 16.67% higher, respectively. The AGEs, Nε-carboxyethyllysine (CEL) and Nε-carboxymethyllysine (CML), were 11.81% and 14.02% higher, respectively. Glucose, creatine, and creatinine were reduced by 33.92%, 5.93%, and 1.12%, respectively after seven freeze-thaw cycles. Norharman was significantly correlated with thiobarbituric acid reactive substances (TBARS; r2 = 0.910) and glucose (r2 = -0.914). Harman was significantly correlated to TBARS (r2 = 0.951), carbonyl (r2 = 0.990), and glucose (r2 = -0.920). CEL was correlated to TBARS (r2 = 0.992) and carbonyl (r2 = 0.933). These changes suggest that oxidation and the Maillard reaction during freeze-thaw cycles promote HAA and AGE production in raw pork.


Assuntos
Tecido Adiposo/metabolismo , Aminas/metabolismo , Compostos Heterocíclicos/metabolismo , Proteínas/metabolismo , Aminas/química , Animais , Galinhas , Culinária , Congelamento/efeitos adversos , Compostos Heterocíclicos/química , Humanos , Reação de Maillard , Carne/análise , Oxirredução , Carne de Porco/análise , Suínos , Substâncias Reativas com Ácido Tiobarbitúrico/química , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
14.
Molecules ; 26(6)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808779

RESUMO

The interaction of soy protein isolate (SPI) and its hydrolysates (SPIHs) with cyanidin-3-O-glucoside (C3G) at pH 7.0 were investigated to clarify the changes in the antioxidant capacity of their complexes. The results of intrinsic fluorescence revealed that C3G binds to SPI/SPIHs mainly through hydrophobic interaction, and the binding affinity of SPI was stronger than that of SPIHs. Circular dichroism and Fourier-transform infrared spectroscopy analyses revealed that the interaction with C3G did not significantly change the secondary structures of SPI/SPIHs, while the surface hydrophobicity and average particle size of proteins decreased. Furthermore, the SPI/SPIHs-C3G interaction induced an antagonistic effect on the antioxidant capacity (ABTS and DPPH) of the complex system, with the masking effect on the ABTS scavenging capacity of the SPIHs-C3G complexes being lower than that of the SPI-C3G complexes. This study contributes to the design and development of functional beverages that are rich in hydrolysates and anthocyanins.


Assuntos
Antocianinas/química , Antioxidantes/química , Glycine max/química , Hidrolisados de Proteína/química , Proteínas de Soja/química
15.
J Sci Food Agric ; 100(6): 2732-2741, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32003461

RESUMO

BACKGROUND: Recombinant plant-based whipping cream (RSWC) has been widely studied in recent years. The present study investigated the effects of soybean protein and its hydrolysates on the stability and physical properties of the RSWC. The RSWC was made with 28% soybean oil bodies and 4% additional soy proteins or its hydrolysates. The proteins used were soy protein isolate, 7S, 11S, oil body protein, soybean proteins isolate hydrolyzed by pepsin (SPHPe) and soybean protein isolate hydrolyzed by papain (SPHPa). RESULTS: RSWC made with SPHPa containing a large amount of small-molecule polypeptide had the lowest apparent viscosity, shortest whipping time, best overrun and worst whipping stability, whereas RSWC made with SPHPe containing the α, ß subunit and small-molecule polypeptides exhibited the second highest overrun and best whipping stability. The partial coalescence of fat and confocal micrographs of cream emulsions suggested that oil body protein was displaced by the small peptides from the interface, which led to partial destabilization and sufficient coalescence of fat globules after aging and whipping. CONCLUSION: Selectively hydrolyzed soy protein, such as SPHPe, can be used for the production of RSWC with sufficient overrun and whipping stability. This research is of great significance and opens a route to production of the recombinant plant-based cream in the future. © 2020 Society of Chemical Industry.


Assuntos
Emulsões/química , Tecnologia de Alimentos/métodos , Proteínas de Soja/química , Fenômenos Físicos , Óleo de Soja/química , Viscosidade
16.
Anal Chem ; 91(4): 2634-2643, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30636403

RESUMO

Low-molecular-weight (low-MW) compounds have many essential functions in biological processes, and the molecular imaging of as many low-MW compounds as possible is critical for understanding complex biological processes. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is an emerging molecular-imaging technology that enables determination of the spatial distributions and the relative abundances of diverse endogenous compounds in tissues. New matrices suitable for the imaging of low-MW compounds by MALDI-MSI are important for the technological advancement of tissue imaging. In this study, 3,4-dimethoxycinnamic acid (DMCA) was evaluated as a new matrix for enhanced low-MW compound detection by MALDI-MSI because of its strong ultraviolet absorption, low matrix-ion related interferences below m/ z 500, and high ionization efficiency for the analysis of low-MW compounds. DMCA was successfully used for improved in situ detection of low-molecular-weight metabolites ( m/ z < 500) and lipids in rat liver, rat brain, and germinating Chinese-yew seed tissue sections. The use of DMCA led to the successful in situ detection of 303, 200, and 248 low-MW compound ion signals from these three tissues, respectively. Both MALDI-MS/MS and LC-MS/MS were used to identify these ion signals, leading to the identification of 115 low-MW compounds from rat liver (including 53 lipids, 29 oligopeptides, and 33 metabolites), 130 low-MW compounds from rat brain (including 104 lipids, 5 oligopeptides, and 21 metabolites), and 111 low-MW compounds from germinating Chinese-yew seeds (including 77 lipids, 22 oligopeptides, 8 flavonoids, and 4 alkaloids). A larger number of low-MW compounds could be detected and imaged when DMCA was used as the MALDI matrix than with other commonly used MALDI matrices such as 2,5-dihydroxybenzoic acid, α-cyano-4-hydroxycinnamic acid, 2-mercaptobenzothiazole, graphene oxide, and silver nanoparticles. Our work provides a new and powerful matrix for enhanced MALDI-MS profiling of low-MW compounds in both animal and plant tissues.


Assuntos
Cinamatos/química , Lipídeos/análise , Compostos Orgânicos/análise , Peptídeos/análise , Animais , Encéfalo/metabolismo , Química Encefálica , Cinamatos/efeitos da radiação , Limite de Detecção , Fígado/química , Fígado/metabolismo , Masculino , Ratos Sprague-Dawley , Sementes/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Taxus/química , Raios Ultravioleta
17.
Opt Lett ; 44(19): 4877-4880, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31568465

RESUMO

We present a way to estimate the aerosol complex refractive indices (ACRI) based on a real-time Stokes vector measurement technology. First, we introduce how to simultaneously get the multi-polarization signals of multi-scattering angles. Then we demonstrate the numerical inversion to retrieve an ACRI based on an iterative Mie algorithm. Meanwhile, we show the experimental results of several types of aerosol samples. Our optimal estimation of ACRI inversion shows a good agreement with the references, which confirms the feasibility and then implies a good prospect of multidimensional polarization characterization applied in the future aerosol recognition, especially suitable for near-spherical scatters.

18.
Int J Mol Sci ; 20(4)2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30823542

RESUMO

Due to their beneficial effects on human health, antioxidant peptides have attracted much attention from researchers. However, the structure-activity relationships of antioxidant peptides have not been fully understood. In this paper, quantitative structure-activity relationships (QSAR) models were built on two datasets, i.e., the ferric thiocyanate (FTC) dataset and ferric-reducing antioxidant power (FRAP) dataset, containing 214 and 172 unique antioxidant tripeptides, respectively. Sixteen amino acid descriptors were used and model population analysis (MPA) was then applied to improve the QSAR models for better prediction performance. The results showed that, by applying MPA, the cross-validated coefficient of determination (Q²) was increased from 0.6170 to 0.7471 for the FTC dataset and from 0.4878 to 0.6088 for the FRAP dataset, respectively. These findings indicate that the integration of different amino acid descriptors provide additional information for model building and MPA can efficiently extract the information for better prediction performance.


Assuntos
Antioxidantes/química , Oligopeptídeos/química , Relação Quantitativa Estrutura-Atividade , Aminoácidos/química , Antioxidantes/farmacologia , Conjuntos de Dados como Assunto , Humanos , Modelos Químicos , Oligopeptídeos/farmacologia
19.
Phytochem Anal ; 29(4): 351-364, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29667236

RESUMO

INTRODUCTION: Mass spectrometry imaging (MSI) as a label-free and powerful imaging technique enables in situ evaluation of a tissue metabolome and/or proteome, becoming increasingly popular in the detection of plant endogenous molecules. OBJECTIVE: The characterisation of structure and spatial information of endogenous molecules in plants are both very important aspects to better understand the physiological mechanism of plant organism. METHODS: Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a commonly-used tissue imaging technique, which requires matrix to assist in situ detection of a variety of molecules on the surface of a tissue section. In previous studies, MALDI-MSI was mostly used for the detection of molecules from animal tissue sections, compared to plant samples due to cell structural limitations, such as plant cuticles, epicuticular waxes, and cell walls. Despite the enormous progress that has been made in tissue imaging, there is still a challenge for MALDI-MSI suitable for the imaging of endogenous compounds in plants. RESULTS: This review summarises the recent advances in MALDI-MSI, focusing on the application of in situ detection of endogenous molecules in different plant organs, i.e. root, stem, leaf, flower, fruit, and seed. CONCLUSION: Further improvements on instrumentation sensitivity, matrix selection, image processing and sample preparation will expand the application of MALDI-MSI in plant research.


Assuntos
Estruturas Vegetais/metabolismo , Plantas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Metabolômica , Proteômica
20.
Appl Opt ; 56(14): 4123-4129, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-29047545

RESUMO

Soot is the main light-absorbing particle in the visible range. Light scattering and absorption by air particulates can change their optical polarization state, and the information upon polarization can reflect the nature of particles. In this paper, a polarization scattering method has been developed for the feasibility study concerning differentiating soot from other typical air particulates. Simulation results indicate that S2/S0 at the scattering angle of 115° can identify the soot particles specifically. Single component experiments and double composition experiments are carried out, which confirm the validity of differentiating soot by a polarization indicator. These preliminary simulations, experiments, and field tests also imply the potential of polarization characterization applied in air pollutants analysis.

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