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1.
Cryobiology ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32057735

RESUMO

Cryopreservation of human spermatozoa with low concentration while maintaining adequate post-thawing motility remains a major challenge for male fertility preservation. A convenient and efficient ultra-rapid freezing method for small amounts of human spermatozoa in a closed Hemi-Straw carrier system (CHS) was developed. Spermatozoa from 60 healthy men were involved in a parameter refining test and another 15 extreme oligozoospermic specimens were assigned to a verification test. A commercialized sperm freezing medium, Quinn's Advantage® Sperm Freeze medium (glycerol and sucrose as the cryoprotective agent) was used in the study. The results showed that the highest recovery rates would be obtained via the method of 2 µl single droplet sequential interval loading, by placing the straw at 1 cm above the liquid nitrogen (LN2) surface for 60 s during freezing and 2 cm above the LN2 for 2 min during thawing. This method was applied in cryopreservation for the normozoospermic specimens and compared with a conventional slow freezing method. The results were better than those in the control group in the total motility recovery rate (77.8 ±â€¯11.2% vs 56.6 ±â€¯11.9%, P < 0.01), progressive motility recovery rate (77.6 ±â€¯13.2% vs 47.7 ±â€¯14.6%, P < 0.01), 24 h survival index (60.9 ±â€¯13.4% vs 42.1 ±â€¯14.1%, P < 0.01) and the sperm DNA fragment index (4.2 ±â€¯3.7% vs 5.8 ±â€¯3.7%, P = 0.126). This method was applied to the oligozoospermic specimens. Motile spermatozoa could be found in 12 of 15 cases in the ultra-rapid freezing group, while only in 7 cases in control group. The results indicated that this freezing method was simple, convenient and bio-safe for cryopreservation of severe oligozoospermic specimens.

2.
Int J Biol Macromol ; 147: 363-368, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31923510

RESUMO

This study investigated the effect of Lactobacillus fermentum fermentation treatment on the gastrointestinal digestion and fermentation in vitro of polysaccharides from longan pulp. Polysaccharide isolated from unfermented and fermented longan pulp named LP and LP-F, respectively. The molecular weight of LP-F declined from 109.62 ± 10.66 kDa to 51.46 ± 6.26 kDa while that of LP declined from 221.63 ± 2.41 kDa to 69.68 ± 2.36 kDa with gastrointestinal digestion. At same time, the reducing sugars content of LP and LP-F were both increased significantly. In addition, after 48 h gut microbiota fermentation, there were more total short chain fatty acids and acetic acid, as well as more Enterococcus, Bifidobacterium, and Clostridium in LP-F fermentation culture than those in LP fermentation culture. Moreover, LP-F fermentation culture showed lower pH value and less residual carbohydrate percentage than that of LP. These results indicated that LP-F is easier than LP to be fermented by human gut microbiota.

3.
Bioorg Med Chem Lett ; 30(1): 126770, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31735601

RESUMO

Seven novel 4-amino acid derivative substituted pyrimidine nucleoside analogues were designed, synthesized, and tested for their anti-CVB3 activity. Initial biological studies indicated that among these 4-amino acid derivative substituted pyrimidine nucleoside analogues, 4-N-(2'-amino-glutaric acid-1'-methylester)-1-(2'- deoxy-2'-ß-fluoro-4'-azido)-furanosyl-cytosine 2 exhibited the most potent anti-CVB activity (IC50 = 9.3 µM). The cytotoxicity of these compounds has also been assessed. The toxicity of compound 2 was similar to that of ribavirin.

4.
Carbohydr Polym ; 229: 115475, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826430

RESUMO

The integrity of the intestinal mucosal barrier is important for the health of the host. In this study, longan pulp polysaccharides (LP) prevented the intestinal mucosal injury by increasing the expression of mucin 2, tight junction proteins zonulae occludens-1 (ZO-1), claudin-1, claudin-4, and adherens junction E-cadherin in cyclophosphamide-treated mice. To further identify the principle bioactive component of LP, four acidic polysaccharides (LPIa, LPIIa, LPIIIa, and LPIVa) were purified, and their intestinal protection activity in vitro was compared. LPIa, LPIIa, and LPIIIa displayed an ability to increase mRNA expression of ZO-1, claudin-1, occludin, and E-cadherin in differentiated Caco-2 cells, especially LPIa. LPIa has specific structure characteristics: porous surface structure, a high molecular weight (1.47 × 105 Da), and two specific glycosidic linkages of α-Araf-(1→ and →5)-α-Araf-(1→. These structure characteristics might primarily contribute to greater intestinal barrier protective effect of LPIa.

5.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(10): 886-891, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31814564

RESUMO

Objective To establish and optimize the prokaryotic expression method for the recombinant mouse myelin proteolipid protein (PLP, 139-208 aa) which is a critical immunogenic polypeptide of PLP. Methods The sequence coding for PLP139-208 polypeptide was cloned into pET-32a(+) vector. Afterwards, the expression vector prepared in this research was transformed into E. coli BL21, and the recombinant PLP polypeptide was induced to express by isopropyl-ß-D-thiogalactoside (IPTG). Two key prokaryotic expression conditions, IPTG's induction length and temperature, were analyzed for further optimization. The recombinant PLP polypeptide was induced to express by the expression method under the optimal expression conditions, and then was purified by Ni-NTA agarose and amylose resin. Finally, the gain of PLP139-208 polypeptide was verified by Western blot analysis. Results The results in the combinatorial optimization revealed that the expression of PLP139-208 was obtained at a satisfactory level when it was incubated at 23DegreesCelsius for 20 hours with the IPTG concentration of 0.5 mmol/L. Conclusion The optimized prokaryotic expression method for the recombinant mouse PLP139-208 was successfully established and effectively performed. This will shed light on the further researches on the improved preparation for experimental autoimmune encephalitis (EAE, an animal model of multiple sclerosis) and the underlying mechanism underlying PLP-induced autoimmune demyelination.


Assuntos
Proteína Proteolipídica de Mielina/biossíntese , Animais , Escherichia coli , Isopropiltiogalactosídeo , Camundongos , Peptídeos , Proteínas Recombinantes/biossíntese
6.
J Agric Food Chem ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31722525

RESUMO

Alcoholic liver injury, known as the most general result of chronic alcohol intake, is induced by inflammatory responses, which is activated by intestine-derived endotoxins formed from intestinal dysbiosis. The hepatoprotective activity of rice bran phenolic extract (RBPE) on ethanol-fed mice was investigated for the first time in this study, and the underlying mechanism was explored from gut microbiota, barrier function, and hepatic inflammation. Mice were fed an alcohol-containing liquid diet alone or in mixture with RBPE for 8 weeks. RBPE treatment mitigated ethanol-induced liver damage, evidenced by the declined lipid profile levels and hepatic function markers. Moreover, ethanol intake induced intestinal microbiota dysbiosis, which was attenuated by RBPE supplementation. RBPE treatment improved the alcohol-induced decrease in the expression of ZO-1, Claudin-1, Claudin-4, and Reg3g, revealing the ameliorative effect of RBPE on intestinal barrier dysfunction. Furthermore, RBPE treatment repressed the alcohol-induced trigger of the hepatic endotoxin-TLR4-NF-κB pathway, followed by the mitigated liver inflammation. The findings indicate that RBPE supplementation ameliorates intestinal microbiota dysbiosis and barrier dysfunction, inactivates the endotoxin-TLR4-NF-κB pathway, and represses inflammatory responses in liver, and therefore, intake of RBPE or brown rice may be an effective way to mitigate alcoholic liver injury.

7.
J Agric Food Chem ; 67(46): 12796-12805, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31659898

RESUMO

Whole-grain dietary fiber is rich in bound-form phenolics, and the biological activity of this special structural feature has attracted increasing attention. In this study, rice bran dietary fiber (RBDF) was subjected to in vitro gastrointestinal digestion and colonic fermentation to investigate the liberation of bound phenolics and their potential activities. Bound phenolics were released at a higher ratio during colonic fermentation (27.57%) than gastrointestinal digestion (2.68%). Nine phenolic compounds were detected from the fermentation supernatants. The released phenolics showed radical scavenging activity (DPPH and ABTS assays) and α-glucosidase inhibitory activity (IC50 = 19.11 µg GAE/mL). Compared with phenolics-removed RBDF (PR-RBDF), RBDF had a significantly stronger prebiotic effect on the microbes associated with diabetes (Lactobacillus spp., Akkermansia muciniphila, and Faecalibacterium prausnitzii). These findings indicate that bound phenolics may act as important functional components that could contribute to the health benefits of whole-grain dietary fiber.


Assuntos
Colo/metabolismo , Fibras na Dieta/análise , Trato Gastrointestinal/metabolismo , Oryza/metabolismo , Fenóis/química , Compostos Fitoquímicos/química , Prebióticos/análise , Adulto , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Colo/microbiologia , Fibras na Dieta/metabolismo , Feminino , Fermentação , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Humanos , Masculino , Oryza/química , Fenóis/metabolismo , Compostos Fitoquímicos/metabolismo , Adulto Jovem
8.
mSphere ; 4(5)2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484736

RESUMO

Magnaporthe oryzae causes the rice blast disease, which is one of the most serious diseases of cultivated rice worldwide. Glycosylation is an important posttranslational modification of secretory and membrane proteins in all eukaryotes, catalyzed by glycosyltransferases (GTs). In this study, we identified and characterized a type 2 glycosyltransferase, MoGt2, in M. oryzae Targeted gene deletion mutants of MoGT2 (mogt2Δ strains) were nonpathogenic and were impaired in vegetative growth, conidiation, and appressorium formation at hyphal tips. Moreover, MoGT2 plays an important role in stress tolerance and hydrophobin function of M. oryzae Site-directed mutagenesis analysis showed that conserved glycosyltransferase domains (DxD and QxxRW) are critical for biological functions of MoGt2. MoGT2 deletion led to altered glycoproteins during M. oryzae conidiation. By liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified several candidate proteins as potential substrates of MoGt2, including several heat shock proteins, two coiled-coil domain-containing proteins, aminopeptidase 2, and nuclease domain-containing protein 1. On the other hand, we found that a conidiation-related gene, genes involved in various metabolism pathways, and genes involved in cell wall integrity and/or osmotic response were differentially regulated in the mogt2Δ mutant, which may potentially contribute to its condiation defects. Taken together, our results show that MoGt2 is important for infection-related morphogenesis and pathogenesis in M. oryzae IMPORTANCE The ascomycete fungus Magnapothe oryzae is the causal agent of rice blast disease, leading to severe loss in cultivated rice production worldwide. In this study, we identified a conserved type 2 glycosyltransferase named MoGt2 in M. oryzae The mogt2Δ targeted gene deletion mutants exhibited pleiotropic defects in vegetative growth, conidiation, stress response, hyphal appressorium-mediated penetration, and pathogenicity. Furthermore, conserved glycosyltransferase domains are critical for MoGt2 function. The comparative transcriptome analysis revealed potential target genes under MoGt2 regulation in M. oryzae conidiation. Identification of potential glycoproteins modified by MoGt2 provided information on its regulatory mechanism of gene expression and biological functions. Overall, our study represents the first report of type 2 glycosyltransferase function in M. oryzae infection-related morphogenesis and pathogenesis.

9.
BMC Chem ; 13(1): 27, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31384775

RESUMO

Background: Lychee pericarp is rich in phenolic and has good antioxidant activity. The effects of simulated gastric (SGF) and intestinal fluid (SIF) digestion on the contents, composition, and antioxidant activities of the phenolic substances in the pericarp of different lychee cultivars (cv Jizui, Lizhiwang, Guiwei, Yuhe, Nuomici and Guihong) were investigated. Results: Compared with distilled water (DW) treatment, the total phenolic content (TPC) and total flavonoid content (TFC) in the pericarp of different lychee cultivars decreased after SGF digestion; especially, the TFC in "Lizhiwang" decreased by 41.5%. The TPC and TFC of lychee pericarp also decreased after SIF digestion. However, the TPC in "Jizui", "Guiwei" and "Yuhe" increased. The SGF and SIF also had different effects on the FRAP and ABTS antioxidant activities of different lychee cultivars. The SGF digestion decreased the ABTS antioxidant capacity of lychee pericarp but enhanced the FRAP value of some lychee cultivars. However, the SIF digestion decreased the FRAP antioxidant activity of different lychee cultivar pericarps but enhanced the ABTS antioxidant capacity of lychee. The HPLC results showed that lychee pericarp had relatively high contents of procyanidin B2 and procyanidin A2. After SIF digestion, caffeic acid and isoquercitrin could not be detected in any of the lychee varieties. However, quercetin-3-rutinose-7-rhamnoside and isoquercitrin were increased after SGF digestion. Conclusions: Lychee pericarp could be used as an inexpensive functional food ingredient.

10.
Int J Biol Macromol ; 140: 965-972, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442503

RESUMO

This study investigated the structural characteristic and in vitro digestion and fermentation behaviours of polysaccharide from litchi pulp (LPII). The results showed that LPII was 161.24kDa, and consisted of arabinose, galactose, rhamnose and glucose. The glycosidic linkages were identified as α-L-Araf-(1→, →5)-α-Araf-(1→ and →3,6)-ß-D-Galp-(1→. After 4h gastric digestion, the molecular weight (Mw) of LPII was declined and the reducing sugars content (CR) was increased significantly. But, the intestinal digestion had no effect on the structure of LPII. In addition, after 24h gut microbiota fermentation, the neutral sugars content and pH value decreased while total bacteria amount, CR, the production of short-chain fatty acids, acetic acid and n-butyric acid increased. These results showed that LPII could be digested in gastric digestion and fermented in large intestine fermentation broth, but not changed in small intestinal fluid. The digestion and fermentation behaviours of LPII may be related with its structural features.

12.
Int J Biol Macromol ; 132: 915-921, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30959133

RESUMO

Lactic acid bacteria fermentation is an important processing technology for fruits and vegetables. Bioactive compounds such as polysaccharides are altered during the fermentation process. Polysaccharides from longan pulp (LPs) were extracted after different fermentation times and their physicochemical and prebiotic properties were investigated, such as longan polysaccharides named LP-0 and LP-12 means they were extracted from longan pulp fermented for 0 and 12 h, respectively. The yield, contents of neutral sugar and uronic acid, molecular weight (Mw), and monosaccharide composition of LPs were significantly changed with different fermentation times. Specially, the yield and uronic acid content of LPs were first increase and then decline. LP-12 contained the smallest Mw (108.71 ±â€¯5.55 kDa) of the tested LPs (p < 0.05). When compared with unfermented LP-0, the glucose molar percentages of fermented LPs declined, while those of rhamnose and galactose increased, except for LP-6. Fermented LPs also exhibited a stronger stimulatory effect on Lactobacillus strain proliferation, with the proliferative effect of LP-12 being the strongest (p < 0.05). These results suggest that lactic acid bacteria fermentation can change the physicochemical properties and enhance the prebiotic activities of polysaccharides from longan pulp.


Assuntos
Fermentação , Polissacarídeos/química , Polissacarídeos/farmacologia , Prebióticos , Sapindaceae/metabolismo , Fenômenos Químicos , Lactobacillus acidophilus/efeitos dos fármacos , Polissacarídeos/biossíntese
13.
Biosci Biotechnol Biochem ; 83(9): 1747-1755, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31017523

RESUMO

Citrus plants are rich in flavonoids and beneficial for lipid metabolism. However, the mechanism has not been fully elucidated. Both citrus peel flavonoid extracts (CPFE) and a mixture of their primary flavonoid compounds, namely, nobiletin, tangeretin and hesperidin, citrus flavonoid purity mixture (CFPM), were found to have lipid-lowering effects on oleic acid-induced lipid accumulation in HepG2 cells. The carnitine palmitoyltransferase 1α (CPT1α) gene was markedly increased, while the fatty acid synthase (FAS) gene was significantly decreased by both CPFE and CFPM in oleic acid-treated HepG2 cells. Flavonoid compounds from citrus peel suppressed miR-122 and miR-33 expression, which were induced by oleic acid. Changes in miR-122 and miR-33 expression, which subsequently affect the expression of their target mRNAs FAS and CPT1α, are most likely the principal mechanisms leading to decreased lipid accumulation in HepG2 cells. Citrus flavonoids likely regulate lipid metabolism by modulating the expression levels of miR-122 and miR-33.


Assuntos
Citrus/química , Flavonoides/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , MicroRNAs/genética , Extratos Vegetais/farmacologia , Regulação para Baixo/efeitos dos fármacos , Ácido Graxo Sintase Tipo I/genética , Células Hep G2 , Humanos , Lipogênese/genética , Ácido Oleico/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima/efeitos dos fármacos
14.
Environ Entomol ; 48(1): 147-155, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30508198

RESUMO

Entomopathogenic fungi (EPF), such as Metarhizium spp. and Beauveria bassiana, are widely used in the biocontrol of many species of insect pests. Tobacco is an economically important crop in Guangdong Province of China, but insect pests, such as Spodoptera litura Fabricius, are a major threat to production. Here, we tested the persistence of five Metarhizium species and B. bassiana in glasshouse pot and field experiments and assessed their long-term efficacy against S. litura. We found that the colony forming units of these EPF decreased by c. 93% by 180 d in the pot soils declines tended to be exponential. In contrast, declines of c. 99% in field soils were more gradual (linear), occurring throughout the 360 d experiment. Metarhizium anisopliae Ma09 had the longest estimated half-life of 41 d, while that of B. bassiana was the shortest (9 d). Fungal density in the upper soil layer (0-5 cm) decreased rapidly and was undetectable after 150 d, whereas density was consistently greatest in the mid-layer (10-15 cm). At 180 d after inoculation, strain Ma09 elicited highest rates of mortality in S. litura. We conclude that soils in Guangdong Province are all suitable for the use of Metarhizium as a biocontrol agent, where M. anisopliae Ma09 offers greatest residual activity.


Assuntos
Beauveria/fisiologia , Metarhizium/fisiologia , Controle Biológico de Vetores , Microbiologia do Solo , Spodoptera , Animais , China , Pupa , Esporos Fúngicos/fisiologia , Tabaco
15.
Int J Biol Macromol ; 125: 232-237, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30528994

RESUMO

Longan polysaccharides are valuable compounds with many biological activities. Lactobacillus fermentum was selected to ferment longan pulp and the polysaccharides from unfermented and fermented longan pulp (denoted as LP and LP-F, respectively) were isolated. Their physicochemical, immunomodulatory and prebiotic activities were investigated. The results revealed that LP-F, the molecular weight of which was lower than that of LP, contained less neutral sugar, uronic acid and glucose but more arabinose, galactose, rhamnose and mannose. Compared with LP, LP-F had better solubility, lower apparent viscosity and particle size. LP-F exhibited stronger stimulation on macrophages secretion of NO and IL-6, as well as better proliferation of Leuconostoc mesenteroides and Lactobacillus casei. In summary, fermentation treatment could change the physicochemical properties and enhance the bioactivity of polysaccharides from longan pulp.


Assuntos
Fenômenos Químicos , Curcuma/química , Fermentação , Lactobacillus fermentum/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Animais , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Imunomodulação/efeitos dos fármacos , Camundongos , Peso Molecular , Polissacarídeos/farmacologia , Células RAW 264.7 , Solubilidade , Análise Espectral , Viscosidade
16.
Carbohydr Polym ; 206: 344-351, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30553331

RESUMO

Longan pulp polysaccharides were extracted with hot water (LP-H), superfine grinding (LP-S) and superfine grinding-assisted enzymatic treatments (LP-SE). The yields, physicochemical properties and prebiotic activities of polysaccharides were investigated. Compared with LP-H and LP-S, the yield, sugar content, solubility, arabinose and mannose percentage of LP-SE increased while its apparent viscosity, particle size, Mw and glucose percentage declined. Three LPs contained similar glycosidic linkage of →3)-α-l-Araf-(1→, →3,6)-ß-d-Galp-(1→ and α-l-Rhap(l→, while they each contained specific glycosidic linkage of →4)-ß-d-Glcp(l→, →4)-ß-d-Galp-(1→ and →5)-α-l-Araf-(1→ in LP-H, LP-S and LP-SE, respectively. Moreover, LP-SE exhibited stronger stimulation than LP-H and LP-S on the proliferation of Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus fermentum and Leuconostoc mesenteroides. The results indicated three extraction methods had some effect on chemical composition and structure of polysaccharide. LP-SE extracted by superfine grinding-assisted enzymatic treatment exhibited the highest prebiotic activities, which have a great potential in applying in functional food and medical industry.


Assuntos
Polissacarídeos/química , Polissacarídeos/farmacologia , Prebióticos , Sapindaceae/química , Sequência de Carboidratos , Lactobacillus/efeitos dos fármacos , Leuconostoc mesenteroides/efeitos dos fármacos , Peso Molecular , Polissacarídeos/isolamento & purificação , Extração em Fase Sólida/métodos , Solubilidade , Viscosidade
17.
mSystems ; 3(6)2018.
Artigo em Inglês | MEDLINE | ID: mdl-30505942

RESUMO

The rice blast fungus Magnaporthe oryzae poses a great threat to global food security. During its conidiation (asexual spore formation) and appressorium (infecting structure) formation, autophagy is induced, serving glycogen breakdown or programmed cell death function, both essential for M. oryzae pathogenicity. Recently, we identified an M. oryzae histone acetyltransferase (HAT) Gcn5 as a key regulator in phototropic induction of autophagy and asexual spore formation while serving a cellular function other than autophagy induction during M. oryzae infection. To further understand the regulatory mechanism of Gcn5 on M. oryzae pathogenicity, we set out to identify more Gcn5 substrates by comparative acetylome between the wild-type (WT) and GCN5 overexpression (OX) mutant and between OX mutant and GCN5 deletion (knockout [KO]) mutant. Our results showed that Gcn5 regulates autophagy induction and other important aspects of fungal pathogenicity, including energy metabolism, stress response, cell toxicity and death, likely via both epigenetic regulation (histone acetylation) and posttranslational modification (nonhistone protein acetylation). IMPORTANCE Gcn5 is a histone acetyltransferase that was previously shown to regulate phototropic and starvation-induced autophagy in the rice blast fungus Magnaporthe oryzae, likely via modification on autophagy protein Atg7. In this study, we identified more potential substrates of Gcn5-mediated acetylation by quantitative and comparative acetylome analyses. By epifluorescence microscopy and biochemistry experiments, we verified that Gcn5 may regulate autophagy induction at both the epigenetic and posttranslational levels and regulate autophagic degradation of a critical metabolic enzyme pyruvate kinase (Pk) likely via acetylation. Overall, our findings reveal comprehensive posttranslational modification executed by Gcn5, in response to various external stimuli, to synergistically promote cellular differentiation in a fungal pathogen.

18.
Molecules ; 23(9)2018 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-30200581

RESUMO

Changes of phenolic profiles and antioxidant activity of litchi pericarp during storage at 4 °C for seven days and at room temperature (RT) for 72 h were evaluated in this study. The contents of total phenolic and procyanidin decreased by 20.2% and 24.2% at 4 °C and by 37.8% and 47.8% at RT, respectively. Interestingly, the corresponding reductions of anthocyanins were 41.3% and 73%, respectively. Four phenolic compounds, including epicatechin, procyanidin A2, procyanidin B2, and quercetin-3-O-rutinoside-7-O-α-l-rhamnosidase were detected in litchi pericarp. Their contents after storage at 4 °C and at RT were decreased by 22.1⁻49.7% and 27.6⁻48.7%, respectively. The oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) of litchi pericarp decreased by 17.6% and 58.7% at 4 °C, and by 23.4% and 66.0% at RT, respectively. The results indicated that storage at 4 °C preserved more phenolics and retained higher antioxidant activity in litchi pericarp compared to storage at RT, suggesting that storage at 4 °C should be considered as a more effective method for slowing down the degradation of litchi pericarp phenolics.


Assuntos
Antioxidantes/química , Litchi/química , Fenóis/química , Extratos Vegetais/química , Biflavonoides/química , Catequina/química , Cromatografia Líquida de Alta Pressão , Frutas/química , Glucosídeos/química , Glicosídeo Hidrolases/química , Proantocianidinas/química , Quercetina/análogos & derivados , Quercetina/química
19.
Int J Biol Macromol ; 112: 968-975, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29438750

RESUMO

Litchi polysaccharide (LP) was extracted from litchi pulp. Its chemical composition, microstructure, zeta potential, flow and viscoelastic behavior were investigated. LP contained uronic acid (41.18%), neutral sugar (42.23%), and protein (2.72%). The monosaccharide composition was mostly arabinose, galactose, and a small amount of mannose, rhamnose and glucose. Scanning electron microscopy (SEM) showed LP was porous network structure. LP concentration had no effect on its zeta potential value while salts reduced them. LP showed shear-thinning behavior during the tested shear rate range. The power-law model was used to evaluate the flow behavior of LP; both its flow behavior index and consistency index changed with different concentrations. The viscosity of LP increased under acidic conditions (pH2-4), but was stable with heat treatment. The LP dispersion displayed as a liquid viscoelastic behavior in 1% and 2% concentrations and behaved as an elastic gel at 3% concentration as well as the addition of NaCl and CaCl2.


Assuntos
Frutas/química , Litchi/química , Polissacarídeos/química , Reologia , Elasticidade , Frutas/ultraestrutura , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Litchi/ultraestrutura , Monossacarídeos/análise , Padrões de Referência , Sais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Temperatura Ambiente , Viscosidade
20.
Molecules ; 23(1)2018 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-29346313

RESUMO

The composition, in vitro bioaccessibility and antioxidant activities of the phenolic compounds in defatted rice bran (DRB) and its soluble and insoluble dietary fibres were systematically evaluated in this study. The total phenolic content of insoluble dietary fibre from DRB (IDFDRB) was much higher than that of the soluble dietary fibre from DRB (SDFDRB) but was 10% lower than that of DRB. Bound phenolics accounted for more than 90% of the total phenolics in IDFDRB, whereas they accounted for 34.2% and 40.5% of the total phenolics in DRB and SDFDRB, respectively. Additionally, the phenolic profiles and antioxidant activities were significantly different in DRB, SDFDRB and IDFDRB. The phenolic compounds in IDFDRB were much less bioaccessibility than those in DRB and SDFDRB due to the higher proportion of bound phenolics in IDFDRB. Considering that bound phenolics could be released from food matrices by bacterial enzymes in the large intestine and go on to exert significant beneficial health effects in vivo, further studies on IDFDRB are needed to investigate the release of the phenolics from IDFDRB via gut microbiota and the related health benefits.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Fibras na Dieta/análise , Oryza/química , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Flavonoides/química , Flavonoides/farmacologia , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia
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