Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.613
Filtrar
1.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1822-1828, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342708

RESUMO

The flower of Hibiscus syriacus has good ornamental and edible-medicinal values.In this study,four samples of two varieties,namely white multiple petals flower and pink multiple petals flower,were selected as test materials.And the optimum extraction conditions,relative molecular weight,monosaccharide composition and antioxidant activity of polysaccharides in flower were investigated.Through single factor experiment and response surface,the optimal extract conditions of polysaccharide were designed as follows:extraction temperature at 96.8℃,ratio of material to liquid of 43.5∶1 m L·g~(-1),extraction time of 3.1 h.Polysaccharides of H.syriacus flowers were analyzed by high performance gel chromatography.The average molecular masses of the 4 polysaccharide samples were1.49×10~5,1.25×10~5,1.01×10~5,1.37×10~5,respectively.Polysaccharides of H.syriacus flowers were mainly composed of glucose,mannose,galactose,rhamnose and arabinose by pre-column derivatization HPLC.The ratio of galactose was the highest in five monosaccharide,and the ratio of galactose to glucose was 1.656-4.496.In addition,crude polysaccharides of H.syriacus flowers showed potential antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)assay,total reducing capacity assay and ABTS assay in vitro,and its antioxidant effect showed a good dose-effect relationship with the concentration of crude polysaccharides.Among the tested varieties,polysaccharides of pink multiple petals flower and white multiple petals flower had the same molecular masses and monosaccharides composition,but the antioxidant activity of the polysaccharides of pink multiple petals flower was higher than that of the white flowers.The results of this study can provide a theoretical basis for the application of H.syriacus flower in the field of functional foods.


Assuntos
Antioxidantes/farmacologia , Hibiscus/química , Polissacarídeos/farmacologia , Antioxidantes/química , Flores/química , Monossacarídeos/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Pigmentação , Polissacarídeos/química
2.
J Chem Phys ; 151(3): 034504, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31325935

RESUMO

Although by now the glass transition temperature of uncrystallized bulk water is generally accepted to manifest at temperature Tg near 136 K, not much known are the spectral dispersion of the structural α-relaxation and the temperature dependence of its relaxation time τα,bulk(T). Whether bulk water has the supposedly ubiquitous Johari-Goldstein (JG) ß-relaxation is a question that has not been answered. By studying the structural α-relaxation over a wide range of temperatures in several aqueous mixtures without crystallization and with glass transition temperatures Tg close to 136 K, we deduce the properties of the α-relaxation and the temperature dependence of τα,bulk(T) of bulk water. The frequency dispersion of the α-relaxation is narrow, indicating that it is weakly cooperative. A single Vogel-Fulcher-Tammann (VFT) temperature dependence can describe the data of τα,bulk(T) at low temperatures as well as at high temperatures from neutron scattering and GHz-THz dielectric relaxation, and hence, there is no fragile to strong transition. The Tg-scaled VFT temperature dependence of τα,bulk(T) has a small fragility index m less than 44, indicating that water is a "strong" glass-former. The existence of the JG ß-relaxation in bulk water is supported by its equivalent relaxation observed in water confined in spaces with lengths of nanometer scale and having Arrhenius T-dependence of its relaxation times τconf(T). The equivalence is justified by the drastic reduction of cooperativity of the α-relaxation in nanoconfinement and rendering it to become the JG ß-relaxation. Thus, the τconf(T) from experiments can be taken as τß,bulk(T), the JG ß-relaxation time of bulk water. The ratio τα,bulk(Tg)/τß,bulk(Tg) is smaller than most glass-formers, and it corresponds to the Kohlrausch α-correlation function, exp[-(t/τα,bulk)1-n], having (1-n) = 0.90. The dielectric data of many aqueous mixtures and hydrated biomolecules with Tg higher than that of water show the presence of a secondary ν-relaxation from the water component. The ν-relaxation is strongly connected to the α-relaxation in properties, and hence, it belongs to the special class of secondary relaxations in glass-forming systems. Typically, its relaxation time τν(T) is longer than τß,bulk(T), but τν(T) becomes about the same as τß,bulk(T) at sufficiently high water content. However, τν(T) does not become shorter than τß,bulk(T). Thus, τß,bulk(T) is the lower bound of τν(T) for all aqueous mixtures and hydrated biomolecules. Moreover, it is τß,bulk(T) but not τα(T) that is responsible for the dynamic transition of hydrated globular proteins.


Assuntos
Biopolímeros/química , Modelos Químicos , Água/química , Animais , Dissacarídeos/química , Glicogênio/química , Monossacarídeos/química , Mytilus/química , Polissacarídeos/química , Ribonuclease Pancreático/química , Termodinâmica
3.
J Agric Food Chem ; 67(29): 8138-8148, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31294563

RESUMO

The aim of the present study was to compare various glycated ovalbumin (OVA)-monosaccharides, including OVA-mannose (Man), -glucose, -ribose, and -fructose, in the attenuation of OVA-induced allergic response in a BALB/C mouse model and the potential mechanisms of immunological modulation. The glycated OVA forms were prepared by Maillard reactions. OVA-Man significantly reduced the frequency of allergic signs. Mouse mast cell protease enzyme concentration was significantly reduced in the OVA-Man group (549.80 ± 84.67 ng/mL, p < 0.05). The OVA-Man group also had a lower histamine concentration (30.96 ± 1.12 ng/mL) as compared with the positive control OVA group (44.43 ± 0.71 ng/mL, p < 0.05). Both specific IgG and IgE were significantly reduced in the OVA-Man-treated group (p < 0.05). The OVA-Man group exhibited decreased concentrations of IL-4 (67.98 ± 3.11 pg/mL) and IL-17 (67.98 ± 3.11 pg/mL) and an increased concentration of IL-12 (336.70 ± 18.69 pg/mL, p < 0.05) compared with the positive control. Mannosylation played a vital role in allergen recognition, implicating deleterious downstream Th2 cell activation, cytokine secretion, and IgE production. This result indicates that different glycans target specific DC receptors, and differential DC processing, antigen presentation, and T cell response leads to altered variation in allergic response. OVA-Man exhibited minimal DC internalization, DC processing, MHC antigen presentation, and antigen-specific T cell activation, resulting in an attenuated allergic response and validating its efficacy as a potential immunotherapeutic candidate to treat egg allergy.


Assuntos
Hipersensibilidade a Ovo/imunologia , Monossacarídeos/química , Ovalbumina/química , Ovalbumina/imunologia , Animais , Citocinas/imunologia , Células Dendríticas/imunologia , Modelos Animais de Doenças , Hipersensibilidade a Ovo/etiologia , Feminino , Glicosilação , Humanos , Imunoglobulina E/imunologia , Reação de Maillard , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/efeitos adversos , Linfócitos T/imunologia
4.
Carbohydr Polym ; 216: 167-179, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047053

RESUMO

In this paper, acid-catalyzed conversion of nine sugars (xylose, glucose, fructose, galactose, sucrose, maltose, lactose, raffinose, and ß-cyclodextrin) with different sizes, steric structures and functionalities were investigated and impacts of the varied sugars on structures of resulting polymers were focused. Under similar reaction conditions, the yields of the carbon materials (insoluble polymers) formed followed the order: xylose ¼ lactose > galactose > ß-cyclodextrin > maltose > sucrose > fructose > glucose > raffinose. Increasing temperature enhanced transformation of soluble oligomers into insoluble ones. Morphologies of the carbon materials were closely related to sugar structures. Diameters of carbon materials (microsphere form) obtained from the disaccharides and oligosaccharides were larger than that of monosaccharides. Furthermore, the microspheres from oligosaccharides had a higher affinity to each other, resulting from continued polymerization as some reactive functionalities were retained in carbon materials. In addition, graphite structure was formed in the carbon materials, even at 160 °C.


Assuntos
Monossacarídeos/química , Oligossacarídeos/química , Polímeros/química , beta-Ciclodextrinas/química , Catálise , Hidrólise , Microesferas , Estrutura Molecular , Polímeros/síntese química , Solubilidade , Ácidos Sulfúricos/química , Temperatura Ambiente
5.
Molecules ; 24(9)2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31086063

RESUMO

Lentinus edodes, whose polysaccharides possess diverse bioactivities, commonly grows on hardwood sawdust composed of hemicellulose, lignin and cellulose. In this study the effect of hemicellulose and lignin on the growth of mycelia, as well as the physicochemical properties of polysaccharides from L. edodes mycelia (LEPs) were investigated. The antioxidant properties of LEPs were evaluated through radical scavenging assays in vitro and through the Caenorhabditis elegans model in vivo. The results showed that hemicellulose at a concentration of 4% increased the yield of the mycelia biomass to twice that of the control group. Meanwhile, when cultured with 4.0% hemicellulose, the polysaccharide content of the mycelia was raised by 112.2%. In addition, the appropriate concentration of lignin could stimulate mycelia growth and polysaccharide biosynthesis in L. edodes. Monosaccharide composition analysis showed that a higher content of xylose was found when mycelia were cultured with higher concentrations of hemicellulose. The molecular structure, including the molecular weight distribution and configuration type, was affected by hemicellulose and lignin. Antioxidant assays indicated that LEPs supplemented with hemicellulose and/or lignin possessed higher radical scavenging abilities in vitro and exhibited a thermal resistance effect on C. elegans, implying that the antioxidant effect is potent in vivo. In summary, the addition of hemicellulose and lignin improved the biosynthesis and bioactivity of LEPs.


Assuntos
Antioxidantes/química , Lignina/química , Polissacarídeos/química , Cogumelos Shiitake/química , Animais , Caenorhabditis elegans/efeitos dos fármacos , Monossacarídeos/química , Polissacarídeos/farmacologia
6.
Food Chem ; 294: 547-556, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126498

RESUMO

This study analyzed six uvaia (Eugenia pyriformis Cambess) accessions ('Comum', 'Rugosa', 'Doce de Patos de Minas', 'Pêra', 'Rugosa Doce' and 'Dura') with respect to chemical composition, nutritional value, bioactive compounds and antioxidant capacity. The 'Rugosa Doce' and 'Doce de Patos de Minas' accessions were sweeter (20.18 g 100 g-1 and 18.88 g 100 g-1, respectively), while the 'Rugosa' and 'Pêra' accessions were less acid (0.28 g 100 g-1 and 0.33 g 100 g-1, respectively). Terpenes were the major volatile compounds (46.75%) identified by SPME-GC/MS. The 'Rugosa' accession contained high levels of fibers (43.81 g 100 g-1) and minerals (2235.10  mg 100 g-1). The 'Rugosa Doce' and 'Rugosa' accessions were distinguished by total flavonoids and phenolic compounds. 'Rugosa Doce' and 'Rugosa' may potentially serve as a raw material for food, while 'Doce de Patos de Minas' and 'Pêra' can be used for cosmetic and pharmaceutical industries purposes.


Assuntos
Antioxidantes/química , Eugenia/química , Valor Nutritivo , Eugenia/metabolismo , Flavonoides/análise , Flavonoides/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Monossacarídeos/química , Monossacarídeos/isolamento & purificação , Fenóis/análise , Fenóis/isolamento & purificação , Microextração em Fase Sólida , Terpenos/química , Terpenos/isolamento & purificação
7.
Molecules ; 24(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018583

RESUMO

Polysaccharides are a main active substance in Panax ginseng; however, microwave-assisted extraction used to prepare P. ginseng polysaccharides (MPPG) has rarely been reported, and knowledge of the bactericidal activity of P. ginseng polysaccharides remains low. Thus, this study was designed to investigate the extraction of P. ginseng polysaccharides by using two methods-hot water extraction and microwave-assisted extraction-and compare their chemical composition and structure. In addition, their antibacterial and antioxidant activities were also determined. The data implied that P. ginseng polysaccharides extracted by microwave-assisted extraction possessed a higher extraction yield than hot water extraction (WPPG) under optimized conditions, and the actual yields were 41.6% ± 0.09% and 28.5% ± 1.62%, respectively. Moreover, the preliminary characterization of polysaccharides was identified after purification. The WPPG with the molecular weight (Mw) of 2.07 × 105 Da was composed of Man, Rib, Rha, GalA, Glu, Gal, and Arab, and the typical characteristics of polysaccharides were determined by IR spectra. Compared with WPPG, MPPG had a higher Mw, uronic acid content, and Glu content. More importantly, the antioxidant activity of MPPG was higher than WPPG, which was probably ascribed to its highly Mw and abundant uronic acid content. Besides, both of them exhibited high bactericidal activity. These results demonstrate that microwave-assisted extraction is an effective method for obtaining P. ginseng polysaccharides, and MPPG could be applied as an antioxidant and antibacterial agent.


Assuntos
Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Extração Líquido-Líquido/métodos , Panax/química , Polissacarídeos/isolamento & purificação , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Análise Fatorial , Ginsenosídeos/química , Ginsenosídeos/isolamento & purificação , Ginsenosídeos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/crescimento & desenvolvimento , Temperatura Alta , Extração Líquido-Líquido/instrumentação , Testes de Sensibilidade Microbiana , Micro-Ondas , Peso Molecular , Monossacarídeos/química , Monossacarídeos/isolamento & purificação , Monossacarídeos/farmacologia , Extratos Vegetais/química , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Raízes de Plantas/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Ácidos Urônicos/química , Ácidos Urônicos/isolamento & purificação , Ácidos Urônicos/farmacologia , Água/química
8.
Yakugaku Zasshi ; 139(4): 591-598, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-30930394

RESUMO

New meta-arylene ethynylene foldamers were developed by employing pyridine and phenol units. These demonstrated interesting properties related to the hydrogen-bonding behavior of the arylene units. Pyridine-acetylene-phenol foldamers showed improved saccharide recognition abilities compared with pyridine-acetylene foldamers with no phenol units. Solid-liquid extraction could be achieved due to the strong binding. Hydrocarbon stapling by alkene metathesis under templation was attempted, and the helical structure was efficiently stabilized. Phenol-acetylene oligomers spontaneously formed helical structures via intramolecular hydrogen bonding. The helical sense could be biased by adding chiral amines.


Assuntos
Substâncias Macromoleculares/química , Monossacarídeos/química , Acetileno/química , Alcenos/química , Glucose , Hidrocarbonetos/química , Ligações de Hidrogênio , Conformação Molecular , Fenômenos de Química Orgânica , Fenol/química , Piridinas/química , Extração em Fase Sólida
9.
Int J Biol Macromol ; 131: 933-940, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30905754

RESUMO

The photosynthetic bacterium, Rhodopseudomonas palustris has been widely used as probiotics in aquaculture, while the molecular basis underlying the probiotic properties of this organism remains largely unknown. In this study, a novel extracellular polysaccharides (RPEPS-30) extracted from the fermentation of Rhodopseudomonas palustris was characterized. Results illustrated that RPEPS-30 was an α-mannan with a molecular weight of 46.82 kDa, which possessed a backbone consisted of 1, 2-linked and 1, 4-linked mannose residues, with side chains composed of 1 → 6 linked and 1 → 2,6 linked mannose residues and substitution at O-6. The in vitro immunomodulatory tests revealed that RPEPS-30 could enhance phagocytic capacity, NO release and mRNA expression of cytokines in macrophages. In addition, RPEPS-30 was shown to promote the growth of resident beneficial gut microbiotasuch as Lactobacillus reuteri, Bacteroides thetaiotaomicron and Akkermansia muciniphila. These findings might help us to partially understand the molecular mechanism concerning the probiotic properties of Rhodopseudomonas palustris, in which the extracellular polysaccharide RPEPS-30 stimulated host immune response and favored the growth of specific benificial micriobiota in the gut.


Assuntos
Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação , Rodopseudomonas/química , Animais , Fracionamento Químico/métodos , Imunomodulação , Macrófagos/imunologia , Metilação , Camundongos , Peso Molecular , Monossacarídeos/química , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Polissacarídeos Bacterianos/imunologia , Polissacarídeos Bacterianos/ultraestrutura , Rodopseudomonas/imunologia , Análise Espectral
10.
Int J Biol Macromol ; 131: 97-106, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30844453

RESUMO

In this paper, Fritillaria pallidiflora schrenk polysaccharides were extracted with different methods and isolated by anion-exchange and gel-permeation chromatography. Physicochemical properties, structural characteristics and antioxidant activities were investigated for the first time. The polysaccharides composed of glucose, galactose, arabinose, xylose, mannose and rhamnose with different molar ratio and molecular weight. Fourier transform infrared spectroscopy and nuclear magnetic resonance analysis exhibited the presence of key functional groups of polysaccharides whereas scanning electron microscopy analysis revealed the characteristic morphology of different fractions. The thermogravimetric analysis manifested the thermal stability of polysaccharides. The reducing power and antioxidant activities of polysaccharides were evaluated in vitro. Among them, the acidic fraction FPSP-H2-1 has a strong antioxidant effect against DPPH, hydroxyl and ABTS free radicals. The results revealed the polysaccharide's important role as potential natural antioxidant agents during the investigation and application of bioactive polysaccharide.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Fritillaria/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Antioxidantes/isolamento & purificação , Fracionamento Químico , Relação Dose-Resposta a Droga , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/isolamento & purificação , Depuradores de Radicais Livres/farmacologia , Peso Molecular , Monossacarídeos/química , Polissacarídeos/isolamento & purificação , Análise Espectral , Termogravimetria
11.
Int J Biol Macromol ; 131: 323-328, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30857960

RESUMO

In this work, response surface methodology (RSM) and microwave pretreatment were used to extract pectin from Premna microphylla Turcz leaves (PMTL). The process variables were optimized by the isovariant central composite design to improve the pectin extraction yield. The optimum conditions obtained were as follows, extraction time 2 h, temperature 90 °C, pH 2 and liquid-solid (LS) ratio 50 mL/g. The extraction yield was 18.25% under these conditions, which was close to the predicted value (17.60%). Then the pectin was characterized by gas chromatographic (GC), spectrophotometric (UV-visible Spectroscopy) and spectroscopic (Fourier transform infrared) methods. The galacturonic acid content was 82.75%, and on this basis, the other monosaccharide composition analysis illustrated that pectin from PMTL was also composed of rhamnose, arabinose, mannose, glucose and galactose in a ratio of 2.96:1.17:1.04:8.07:2.05. The pectin of PMTL had an esterification degree of 62.50% and it showed good antioxidant activity. Taken together, the pectin of PMTL could be used as potential additive in food industry.


Assuntos
Lamiaceae/química , Pectinas/química , Pectinas/isolamento & purificação , Folhas de Planta/química , Algoritmos , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Fracionamento Químico , Modelos Teóricos , Peso Molecular , Monossacarídeos/química , Análise Espectral
12.
Int J Biol Macromol ; 131: 886-895, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30857966

RESUMO

In this study, we purified a water-soluble polysaccharide, SBPW3, from the whole plant of Scutellaria barbata D. Don through ethanol precipitation, deproteinization, lyophilization, dialysis and separation using a DEAE cellulose column and a Superdex 200 gel filtration chromatography column. SBPW3 is a homogeneous polysaccharide with a molecular weight of 10.2 kDa and is composed of rhamnose (2.51%), arabinose (25.68%), xylose (10.94%), mannose (12.56%), glucose (20.59%) and galactose (27.72%). FT-IR spectrum analysis of the polysaccharide showed that SBPW3 contained a pyranose ring. The effects of SBPW3 on TGF-ß1-induced epithelial-mesenchymal transition (EMT) were tested in colon cancer cells. These results suggested that SBPW3 significantly suppressed TGF-ß1-induced migration and invasion. Additionally, SBPW3 reduced EMT by increasing the expression of epithelial markers and by decreasing the expression of mesenchymal markers by blocking the Smad2/3 signalling pathway in colon cancer cells. Furthermore, to explore the anti-metastatic effect of SBPW3, we established a mouse model of colon cancer metastasis and found that SBPW3 significantly inhibited the metastatic dissemination of the primary tumour to the liver. These findings provide us with a potential chemotherapeutic strategy for the treatment of human colorectal cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Movimento Celular/efeitos dos fármacos , Polissacarídeos/farmacologia , Scutellaria/química , Fator de Crescimento Transformador beta1/farmacologia , Animais , Antineoplásicos Fitogênicos/química , Linhagem Celular Tumoral , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Células HT29 , Humanos , Camundongos , Peso Molecular , Monossacarídeos/química , Polissacarídeos/química , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Int J Biol Macromol ; 131: 484-494, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30904524

RESUMO

In this study, the structural characterization and anti-inflammation effect of dilute alkali-soluble polysaccharides from purple sweet potato were investigated. Three fractions (F-1, F-2 and F-3) were obtained by purifying crude polysaccharides on DEAE-52 cellulose column. The main fraction (F-1) was further purified on Sephadex G-200 column to afford purified alkali-soluble sweet potato polysaccharide (ASPP). The chemical structure of ASPP was analyzed by gas chromatography, Fourier transform infrared spectroscopy, methylation analysis and nuclear magnetic resonance spectroscopy. Monosaccharide compositional analysis showed ASPP was composed of rhamnose, arabinose, xylose, mannose and glucose in the molar ratio of 2.8:1.9:1.0:7.6:53.3. Moreover, the backbone of ASPP was composed of 1,4-linked Glcp with side chains attached to the O-6 position. The anti-inflammation effect of ASPP was further investigated by in vitro and in vivo experiments. Results showed ASPP could inhibit the levels of nitric oxide, interleukin (IL)-6, IL-1ß and TNF-α but increase the production of IL-10 in lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. In addition ASPP could reduce the secretion of IL-6, IL-1ß and TNF-α in LPS-treated mice. Our results suggest ASPP can be developed as a novel anti-inflammation agent.


Assuntos
Álcalis/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Ipomoea batatas/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Animais , Biomarcadores , Citocinas/metabolismo , Feminino , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Metilação , Camundongos , Monossacarídeos/química , Óxido Nítrico/metabolismo , Células RAW 264.7 , Solubilidade , Análise Espectral , Relação Estrutura-Atividade
14.
Int J Biol Macromol ; 131: 309-314, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30872058

RESUMO

The present paper aimed to obtain the polysaccharides with potent tyrosinase inhibitory activity from chestnut kernel. The ultrasound extracted polysaccharide fractions 1-1 (UEP1-1) and UEP2-1 were obtained by successive ultrasound-assisted-extraction, DEAE-52 and Sephadex G-100 chromatography. The Fourier transform infrared spectrum revealed that both UEP1-1 and UEP2-1 had the characteristic absorption peaks of polysaccharides. The degree of esterification of UEP1-1 (52.4%) and UEP2-1 (49.0%) was higher than that of the crude UEP (33.0%), indicating that the gel properties of the polysaccharides changed after purification. The x-ray diffraction patterns of UEP1-1 and UEP2-1 suggested that they were semi-crystalline polymers with a degree of crystallinity of 23.9 and 35.8%, respectively. The weight-average molecular weight (Mw) of UEP1-1 and UEP2-1 was 75.4 and 59.9 kDA, respectively. The monosaccharide composition of UEP1-1 and UEP2-1 was glucose, galactose, arabinose, mannose, xylose, rhamnose and fructose with different proportions. UEP1-1 displayed a dose-dependent inhibitory effect on tyrosinase activity, and the inhibition mode was found to be competitive.


Assuntos
Fagaceae/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Peso Molecular , Monossacarídeos/química , Polissacarídeos/isolamento & purificação , Análise Espectral
15.
Int J Biol Macromol ; 131: 453-460, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30880054

RESUMO

Amana edulis polysaccharides (AEPs) specifically HBSS, CHSS, DASS, and CASS were sequentially extracted with four different solvents. The present study characterized the AEPs with particular focus on their physicochemical and anti-oxidant based functional properties. Initially, monosaccharide analysis revealed arabinose (31.7%, 32.5%, 36.5%) as the main sugar in HBSS, CHSS, and DASS whereas, galactose (31.4%) in CASS besides their respective molecular weights of 6.29 × 102, 1.5 × 102, 8.1 × 102, and 2.6 × 103 kD. HBSS showed the maximum solubility, while, CASS was observed for higher foam capacity and foam stability. Among all the fractions, DASS was observed with higher thermal stability. HBSS showed the highest ABTS+ scavenging activity. HBSS and CASS had higher DPPH and OH- scavenging activities. DASS depicted the highest chelation and reducing ability. To summarize, these polysaccharides fractions may be further utilized for their enormous prospective in functional foods preparation.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Liliaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Antioxidantes/isolamento & purificação , Fracionamento Químico , Fenômenos Químicos , Peso Molecular , Monossacarídeos/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/isolamento & purificação , Polissacarídeos/isolamento & purificação , Solubilidade , Análise Espectral , Termodinâmica
16.
J Agric Food Chem ; 67(12): 3412-3422, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30827106

RESUMO

The formation conditions of the Amadori compound (ARP) N-(1-deoxy-d-xylulos-1-yl)-alanine were determined in an aqueous Maillard reaction between l-alanine and d-xylose under a two-step temperature rising process with (-)-epigallocatechin gallate (EGCG) as an indicator followed by browning intensity detection of the final Maillard reaction products (MRPs). To clarify the mechanism of EGCG indication on the ARP formation, the change in the concentration of some key products generated during the Maillard reaction with EGCG addition was investigated. Results showed an inhibition effect of EGCG on the browning precursor formation through the generation of ARP-EGCG adducts and deoxyosone-EGCG adducts, which was proposed as an important pathway to inhibit browning during the Maillard reaction and to indicate ARP formation.


Assuntos
Arginina/análogos & derivados , Catequina/análogos & derivados , Monossacarídeos/química , Alanina/química , Arginina/química , Catequina/química , Produtos Finais de Glicação Avançada/química , Reação de Maillard , Temperatura Ambiente , Xilose/química
17.
Chem Asian J ; 14(9): 1409-1412, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-30859722

RESUMO

Purpose-designed 2-phenylquinoline (PQ)-sugar hybrids 1 and 2 were synthesized and evaluated for their photodegradation activities against an α-glucosidase target. The results indicated that PQ-mannose hybrid 2 selectively and effectively photodegraded α-glucosidase and significantly inhibited its enzymatic activity upon irradiation with long-wavelength UV light in the absence of any additives under neutral and aqueous conditions. Furthermore, 2 selectively and effectively inhibited α-glucosidase activity only with photo-irradiation even in complex cell lysate.


Assuntos
Inibidores de Glicosídeo Hidrolases/química , Monossacarídeos/química , Quinolinas/química , alfa-Glucosidases/metabolismo , 1-Desoxinojirimicina/química , Glucosamina/análogos & derivados , Glucosamina/química , Inibidores de Glicosídeo Hidrolases/síntese química , Inibidores de Glicosídeo Hidrolases/metabolismo , Fotólise/efeitos da radiação , Raios Ultravioleta , alfa-Glucosidases/química
18.
Int J Biol Macromol ; 129: 377-385, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30742920

RESUMO

In the present study, crude polysaccharides were extracted from Gelidium pacificum Okamura, and further purified to obtain the sulfated polysaccharide with molecular weight of 28,807 Da. Its monosaccharide composition mainly consisted of xylose (7.1%), galactose (59.7%) and galacturonic acid (19.76%). And the sulfate ester content of the sulfated polysaccharide was estimated as 8.8%. Structure analysis showed that the sulfated polysaccharide comprised of 1,4-linked-α-D-Galp3S, 1,2-linked-α-D-Xylp and 1,3-linked-ß-D-GalpA residues, respectively. Its anti-inflammatory effects were investigated in LPS-stimulated human monocytic (THP-1) cells. The sulfated polysaccharide at a concentration of 5 µg/mL fully protected the THP-1 cells against LPS-stimulated cytotoxicity. Furthermore, the addition of sulfated polysaccharide resulted in a significant reduction of NO production in LPS-treated cells, and this effect appeared to be dose-related. The sulfated polysaccharide (5 µg/mL) significantly suppressed the mRNA and protein expression of toll-like receptor-4 (TLR-4), myeloid differentiation factor (MyD88) and tumor necrosis factor receptor-associated factor-6 (TRAF-6) in LPS-stimulated THP-1 cells. These results showed the sulfated polysaccharide not only provided a good protection against LPS-induced cell toxicity, but also exerted an anti-inflammatory effect via the TLR4 signaling pathway.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Polissacarídeos , Alga Marinha/química , Sulfatos , Anti-Inflamatórios/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peso Molecular , Monossacarídeos/química , Óxido Nítrico/metabolismo , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Análise Espectral , Relação Estrutura-Atividade , Sulfatos/química , Células THP-1
19.
Int J Biol Macromol ; 129: 744-749, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771389

RESUMO

Chitin oligosaccharides, composed of homogeneous ß(1 → 4)-linked N-acetyl-D-glucosamine (GlcNAc) sequences, is a well-known elicitor of plant immune defense, and also occur as structural elements of chitosan and nodulation (Nod) factor. Detailed microstructure characterization is required for understanding the function mode of these bioactive molecules. Herein, experimental conditions for detection and elucidation of the 1H NMR resonances of amide groups in chitin oligosaccharides are presented. The binary mixture of 70% H2O: 30% DMSO­d6 was found to be the optimal solvent for amide proton measurements in homogeneous GlcNAc sequences, facilitating differentiation of the local chemical microenvironments of all four amide groups of the chitin tetrasaccharide. Experimental evidence that anomeric end-effect triggers amide proton resonance differentiation at the adjacent residue has potential to provide important insights into the solution structure of chitin and other amino sugars containing GlcNAc sequences.


Assuntos
Quitina/química , Dimetil Sulfóxido/química , Água/química , Acetilglucosamina/química , Espectroscopia de Ressonância Magnética , Monossacarídeos/química , Oxirredução , Soluções , Estereoisomerismo
20.
Biomed Pharmacother ; 112: 108624, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30784921

RESUMO

Rheumatoid arthritis (RA) is a chronic autoimmune disease of synovial inflammation and joint destruction. This study reports anti-arthritic potential of opuntioside-I opuntiol, and its gold and silver nanoparticles (NPs) against Complete Freund's Adjuvant (CFA)-induced arthritic rats. The mechanistic studies were performed targeting TLRs (TLR-2 and TLR-4) and cytokines (IL-1ß and TNF-α) expressions to validate their anti-inflammatory and immuno-modulatory response. The nano-formulations were successfully characterized employing Atomic Force Microscopy (AFM) and Dynamic Light Scattering (DLS) analysis. Opuntiol and opuntioside (OP and OPG: 10, 50 and 100 mg/kg) and opuntiol-coated silver and gold NPs (OP-AgNPs and OP-AuNPs: 0.5, 1 and 3 mg/kg) treatments in arthritic rat have shown minimal arthritic score exhibiting mild to moderate articular changes and tissue swelling in ankle joints. Radiographic examination reveals significant reduction in synovitis with improvement in joints degenarative changes in the presence of aforementioned treatments. Likewise, histology of rat ankle joints depicted comparatively lesser influx of inflammatory cells and diminished granulamatous inflammation. Moreover, treatment groups suppressed protein and mRNA expressions of TLRs (TLR-2 and TLR-4) and cytokines (IL-1ß and TNF-α) levels were also significantly declined in the presence of OPG, OP and its NPs comparing to arthritic control. This investigation concludes, the tested compounds and nano-formulations successfully restored the disease progression in CFA-induced arthritic rat owing to their immunomodulatory and anti-inflammatory potentials and can be considered for RA targeted therapy to address the utmost challenges of the disease.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Experimental/tratamento farmacológico , Ácidos Cumáricos/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Monossacarídeos/uso terapêutico , Receptor 2 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/antagonistas & inibidores , Animais , Antirreumáticos/administração & dosagem , Antirreumáticos/química , Artrite Experimental/imunologia , Artrite Experimental/metabolismo , Ácidos Cumáricos/administração & dosagem , Ácidos Cumáricos/química , Feminino , Adjuvante de Freund , Ouro/química , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Monossacarídeos/administração & dosagem , Monossacarídeos/química , Ratos Wistar , Prata/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA