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1.
Food Chem ; 300: 125192, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31362158

RESUMO

Dietary fiber has several benefits for humans, and the development of healthier rice with an improved dietary fiber composition has attracted increasing amounts of attention. Based on the method of AOAC 2002.02, we developed a simplified method to screen polished rice containing high total dietary fiber (TDF). Mutant cw with a high TDF content could be distinguished easily from R7954 (indica) and Nipponbare (japonica) by the digestion-resistant phenotype, which is characterized as an almost intact grain after hydrolysis by pepsin, pancreatic α-amylase and amyloglucosidase. The individuals identified from the F2 population showed digestion resistance all had TDF content higher than 5%, while those without a digestion-resistant phenotype had TDF content lower than 5%. The phenotype of digestion resistance could be a valuable index for identifying rice with higher TDF content, and the identification of this phenotype provides a simplified, economical and high throughput method for high TDF rice breeding.


Assuntos
Fibras na Dieta/análise , Análise de Alimentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Oryza/química , Culinária , Fibras na Dieta/metabolismo , Digestão , Glucana 1,4-alfa-Glucosidase/química , Glucana 1,4-alfa-Glucosidase/metabolismo , Humanos , Hidrólise , Pepsina A/química , Pepsina A/metabolismo , Sementes/química , Amido/análise , Amido/química , alfa-Amilases/química , alfa-Amilases/metabolismo
2.
J Photochem Photobiol B ; 197: 111541, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31272033

RESUMO

Here, we report the novel fabrication of ZnO nanoparticles using the Costus igneus leaf extract. Gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy to determine the bioactive components present in the plant extract. The synthesis of Ci-ZnO NPs (C. igneus- coated zinc oxide nanoparticles) was accomplished using a cost-effective and simple technique. Ci-ZnO NPs were specified using UV-visible spectroscopy, FTIR, XRD, and TEM. Ci-ZnO NPs was authenticated by UV-Vis and exhibited a peak at 365 nm. The XRD spectra proved the crystalline character of the Ci-ZnO NPs synthesized as hexagonal wurtzite. The FTIR spectrum illustrated the presence of possible functional groups present in Ci-ZnO NPs. The TEM micrograph showed evidence of the presence of a hexagonal organization with a size of 26.55 nm typical of Ci-ZnO NPs. The α-amylase and α-glucosidase inhibition assays demonstrated antidiabetic activity of Ci-ZnO NPs (74 % and 82 %, respectively), and the DPPH [2,2-diphenyl-1-picrylhydrazyl hydrate] assay demonstrated the antioxidant activity of the nanoparticles (75%) at a concentration of 100 µg/ml. The Ci-ZnO NPs exhibited promising antibacterial and biofilm inhibition activity against the pathogenic bacteria Streptococcus mutans, Lysinibacillus fusiformis, Proteus vulgaris, and Vibrio parahaemolyticus. Additionally, the Ci-ZnO NPs showed biocompatibility with mammalian RBCs with minimum hemolytic activity (0.633 % ±â€¯0.005 %) at a concentration of 200 µg/ml.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/química , Biofilmes/efeitos dos fármacos , Nanopartículas Metálicas/química , Extratos Vegetais/química , Óxido de Zinco/química , Antibacterianos/síntese química , Antibacterianos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Costus/química , Costus/metabolismo , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/fisiologia , Química Verde , Hemólise/efeitos dos fármacos , Humanos , Insulina/química , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
3.
J Agric Food Chem ; 67(31): 8617-8625, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31293160

RESUMO

Inhibiting starch digestion can effectively control postprandial blood sugar level. In this study, the in vitro digestion differences among the mixtures of five polyphenols (i.e., procyanidins [PAs], catechin [CA], tannic acid [TA], rutin [RU], and quercetin [QU]) and starch were analyzed through an in vitro simulation test of starch digestion. The interaction characteristics of these five polyphenols with α-amylase and α-glucosidase were investigated in terms of the inhibition effect, dynamics, fluorescence quenching, and circular dichroism (CD). The results revealed that the rapidly digestible starch (RDS) contents decreased, while the resistant starch (RS) contents increased. All five polyphenols inhibited the α-amylase activity through the noncompetitive approach but inhibited the α-glucosidase activity through the competitive approach. Five polyphenols combined with α-amylase spontaneously by using the hydrophobic effect. The interaction of PAs and QU with α-glucosidase were recognized as van der Waals forces and H bonding, whereas CA and TA interacted with α-glucosidase through the hydrophobic effect. All five polyphenols can cause conformational changes in enzymes.


Assuntos
Extratos Vegetais/química , Polifenóis/química , Amido/química , Animais , Digestão , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Cinética , Modelos Biológicos , Extratos Vegetais/metabolismo , Polifenóis/metabolismo , Amido/metabolismo , Suínos , Leveduras/enzimologia , alfa-Amilases/química , alfa-Amilases/metabolismo , alfa-Glucosidases/química , alfa-Glucosidases/metabolismo
4.
J Sci Food Agric ; 99(14): 6380-6391, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31283026

RESUMO

BACKGROUND: Prickly pears are potential candidates for the development of low-cost functional foods because they grow with low water requirements in arid regions of the world. They are sources of betalains and phenolic compounds, which have been reported to contribute to human health. The study of the biological activity of different varieties and of their isolated bioactive constitutes is fundamental in the design of functional foods. In this context, our objective is the assessment of the ability of Spanish and Mexican prickly-pear cultivars to inhibit enzymes related to type 2 diabetes and the inflammatory response, and the contribution of their bioactive compounds to their nutra-pharmaceutical potential. RESULTS: Prickly pear peels presented the highest antioxidant activity due to their high isorhamnetin glycoside content. Isorhamnetin glycosides showed significantly higher antioxidant and anti-inflammatory activity than aglycone, particularly isorhamnetin glucosyl-rhamnosyl-pentoside (IG2), which also reported antihyperglycemic activity. Morada, Vigor, and Sanguinos whole fruits exhibited moderate α-amylase inhibition and higher α-glucosidase inhibition, which is ideal for lowering glucose absorption in hyperglycemia management. Sanguinos peels presented the highest anti-inflammatory activity because of their high indicaxanthin content and isorhamnetin glycoside profile. CONCLUSIONS: In the design of prickly pear functional foods, technological processing should prioritize the retention or concentration of these bioactive compounds to preserve (or increase) their natural antioxidant, antihyperglycemic and anti-inflammatory activity. Peels of red and orange varieties should be further evaluated for antioxidant and anti-inflammatory purposes while whole fruits of red and purple varieties could be considered possible candidates for hyperglycemia management. © 2019 Society of Chemical Industry.


Assuntos
Anti-Inflamatórios/química , Diabetes Mellitus Tipo 2/enzimologia , Inibidores Enzimáticos/química , Hipoglicemiantes/química , Extratos Vegetais/química , Pyrus/química , Antioxidantes/química , Betalaínas/química , Diabetes Mellitus Tipo 2/metabolismo , Frutas/química , Inibidores de Glicosídeo Hidrolases/química , Humanos , Cinética , Fenóis/química , Pyrus/classificação , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Amilases/metabolismo , alfa-Glucosidases/química , alfa-Glucosidases/metabolismo
5.
Food Chem ; 295: 101-109, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174738

RESUMO

Edible seaweeds are highly consumed food with a rich chlorophyll profile. Although seaweeds are mainly cooked ingested, the influence of cooking on the chlorophyll bioaccessibility remains unknown. In this research, cooked Nori, Sea Lettuce and Kombu were subjected to an in vitro digestion and following micellarization investigations. The processing of red seaweed does not affect the chlorophyll recovery, while cooking green and brown seaweeds implies an important increase in chlorophyll recovery after in vitro digestion. In this line, while cooking affects negatively the micellarization rate of chlorophyll derivatives in Nori and Kombu, it does not modify the micellarization in Sea Lettuce. Generally, the chlorophyll bioaccessibility of microwaved seaweeds is always higher than that of boiled ones. However, cooking improves the chlorophyll bioaccessibility in brown seaweeds, while decreases in red seaweeds. In conclusion, the characteristics of food matrix are the determinant factor on the chlorophyll bioaccessibility of cooked seaweeds.


Assuntos
Clorofila/análise , Culinária , Laminaria/química , Porphyra/química , Ulva/química , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Laminaria/metabolismo , Micro-Ondas , Porphyra/metabolismo , Espectrofotometria , Ulva/metabolismo , alfa-Amilases/metabolismo
6.
Food Chem ; 297: 125018, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253265

RESUMO

Different Ohmic heating conditions (OH, 10, 100, and 1000 Hz at 25 V; 45, 60, and 80 V at 60 Hz) were assessed to manufacture whey-raspberry flavored beverages. The inhibition of α-glucosidase, α-amylase, and angiotensin-converting I enzymes, antioxidant capacity, fatty acid profile, and volatile organic compounds (VOCs) were determined. OH treated samples presented lower anthocyanins content than the conventional treatment (2.91 ±â€¯0.23 mg/g), while the mild-intermediate conditions (10,100-Hz at 25 V and 45,60-V at 60 Hz) presented the highest chemical antioxidant activity when compared to the extreme processing conditions (1000 Hz-25 V and 80 V-60 Hz). OH led to an increase of 10% in both α-glucosidase (>99%) and α-amylase (≥70%). Among the VOCs, furfural and 5-hydroxymethylfurfural, a major intermediate Maillard reaction product was found in all treatments. Overall, OH can be used in the processing of whey-flavored raspberry beverages.


Assuntos
Bebidas/análise , Aromatizantes/química , Rubus/química , Soro do Leite/química , Antocianinas/análise , Antioxidantes/química , Culinária , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Glucosidases/antagonistas & inibidores , Glucosidases/metabolismo , Ondas de Rádio , Temperatura Ambiente , Compostos Orgânicos Voláteis/análise , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
7.
Chem Commun (Camb) ; 55(45): 6417-6420, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31094364

RESUMO

An AIE dual-reactive supramolecular probe has been devised for the first time to simultaneously measure endogenous lipase and α-amylase activity in a homogeneous system. Fluorescence quantitative analysis of lipase and α-amylase in real biological samples enables rapid and accurate diagnosis of diseases.


Assuntos
Lipase/análise , Sondas Moleculares/química , alfa-Amilases/análise , Fluorescência , Humanos , Lipase/metabolismo , Substâncias Macromoleculares/química , alfa-Amilases/metabolismo
8.
Food Chem ; 294: 203-208, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126454

RESUMO

To investigate the potential of terahertz spectroscopy to monitor and quantify starch in plants, terahertz spectra (3.0-13.5 THz) of mung bean plants 1-7 days after germination were examined and compared to those of starch and its constituent saccharides (standard reagents). Day 1 seedlings showed similar spectral features with standard starch, and absorption peaks gradually disappeared in the subsequent 6 day growth period. To interpret this result and identify useful peaks for starch quantification, standard starch and day 1 seedlings were hydrolyzed by α-amylase in vitro. Since both standard starch and seedlings showed that absorption peak at 9.0 THz disappeared after amylase hydrolysis, this peak is sensitive to changes in starch. Additionally, intensity of this peak was correlated with starch content as quantified by chemical analysis (r = 0.98). Our results indicate terahertz spectra of seedlings can provide an identifiable peak that is attributed to starch and not affected by the constituent saccharides.


Assuntos
Amido/química , Espectroscopia Terahertz , Vigna/química , Germinação , Glucose/química , Hidrólise , Plântula/química , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Vigna/crescimento & desenvolvimento , Vigna/metabolismo , alfa-Amilases/metabolismo
9.
Food Chem ; 294: 248-259, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126460

RESUMO

In this study, ultrasound was used to modulate the molecular structure of retrograded starch (RS3) responsible for the digestion properties, and the relationships among the ultrasonic power, molecular structure, and RS3 digestibility were revealed. Results revealed that the morphological characteristics of RS3 changed after ultrasonic treatment, and high power resulted in more compact block-shape structure. The results of particle size analysis, Fourier transform infrared spectroscopy, and X-ray diffraction showed that ultrasound decreased the long-range orders but increased the median particle size, short-range orders, and V-type polymorph of ultrasound-treated RS3. A decreased (double helix of amylopectin) and an increased (single helix of V-amylose) enthalpy change were observed by differential scanning calorimeter. Digestion profiles showed that some fractions of rapidly-digestible starch were converted into slowly-digestible starch and/or resistant starch. This study provides a potential approach to regulate the digestion of starch-rich foods with desired digestibility through ultrasonic treatment.


Assuntos
Amido/química , Amilopectina/química , Amilopectina/metabolismo , Amilose/química , Varredura Diferencial de Calorimetria , Conformação Molecular , Tamanho da Partícula , Solubilidade , Sonicação , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/metabolismo , Difração de Raios X , alfa-Amilases/metabolismo
10.
Phytochemistry ; 164: 94-101, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31103779

RESUMO

Diabetes mellitus is a widespread metabolic disorder that affects millions of people around the world. The disease is a major burden on both economic and social levels, and there is a need for improved drugs with fewer side effects in the management of the disease. Current methods for isolation of anti-diabetic lead compounds from complex mixtures suffer from low resolution and sensitivity, and there is a need for improved alternatives. In this work, magnetic ligand fishing combined with high-performance liquid chromatography - photodiode-array detection - high-resolution mass spectrometry - solid-phase extraction - nuclear magnetic resonance spectroscopy (HPLC-PDA-HRMS-SPE-NMR) was developed and validated, with the aim of accelerating discovery of natural products targeting α-amylase. The enzyme was successfully immobilized onto magnetic beads and retained its catalytic activity for a period of 75 days, and the specificity of this method was successfully validated by testing the N-terminus coupled α-amylase immobilized magnetic beads on an artificial mixture. A proof of concept experiment, using a crude ethyl acetate extract of Ginkgo biloba leaves, proved that it was possible to fish out four α-amylase ligands. HPLC-PDA-HRMS-SPE-NMR analysis confirmed the presence of bilobetin, isoginkgetin, ginkgetin and sciadopitysin in the solutions resulting from α-amylase ligand fishing with Ginkgo biloba. IC50 curves revealed a reversed relationship between concentration of sciadopitysin and inhibition of α-amylase activity, suggesting that this compound activated the enzyme instead of inhibiting it.


Assuntos
Ginkgo biloba/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Extratos Vegetais/farmacologia , alfa-Amilases/antagonistas & inibidores , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Humanos , Ligantes , Magnetismo , Microesferas , Conformação Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Relação Estrutura-Atividade , alfa-Amilases/metabolismo
11.
Plant Physiol Biochem ; 139: 411-418, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30981157

RESUMO

Potato tuber dormancy is critical for the postharvest quality. The supply of carbohydrates is considered as one of the important factors controlling the rate of potato tuber sprouting. Starch is the major carbohydrate reserve in potato tuber, but very little is known about the specific starch degrading enzymes responsible for controlling tuber dormancy and sprouting. In this study, we demonstrate that an α-amylase gene StAmy23 is involved in starch breakdown and regulation of tuber dormancy. Silencing of StAmy23 delayed tuber sprouting by one to two weeks compared with the control. This phenotype is accompanied by reduced levels of reducing sugars and elevated levels of malto-oligosaccharides in tuber cortex and pith tissue below the bud eye of StAmy23-deficient potato tubers. Changes in soluble sugars is accompanied by a slight variation of phytoglycogen structure and starch granule size. Our results suggest that StAmy23 may stimulate sprouting by hydrolyzing soluble phytoglycogen to ensure supply of sugars during tuber dormancy.


Assuntos
Germinação/fisiologia , Proteínas de Plantas/metabolismo , Tubérculos/metabolismo , Tubérculos/fisiologia , Solanum tuberosum/metabolismo , Solanum tuberosum/fisiologia , alfa-Amilases/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Germinação/genética , Proteínas de Plantas/genética , Tubérculos/genética , Solanum tuberosum/genética , Amido/metabolismo , Sacarose/metabolismo , Açúcares/metabolismo , alfa-Amilases/genética
12.
J Microbiol Biotechnol ; 29(5): 765-775, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-30982319

RESUMO

A new α-amylase-encoding gene (amySL3) of glycoside hydrolase (GH) family 13 was identified in soda lake isolate Alkalibacterium sp. SL3. The deduced AmySL3 shares high identities (82-98%) with putative α-amylases from the genus Alkalibacterium, but has low identities (<53%) with functionally characterized counterparts. amySL3 was successfully expressed in Escherichia coli, and the recombinant enzyme (rAmySL3) was purified to electrophoretic homogeneity. The optimal temperature and pH of the activity of the purified rAmySL3 were determined to be 45°C and pH 7.5, respectively. rAmySL3 was found to be extremely halophilic, showing maximal enzyme activity at a nearly saturated concentration of NaCl. Its thermostability was greatly enhanced in the presence of 4 M NaCl, and it was highly stable in 5 M NaCl. Moreover, the enzyme did not require calcium ions for activity, and was strongly resistant to a range of surfactants and hydrophobic organic solvents. The major hydrolysis products of rAmySL3 from soluble starch were maltobiose and maltotriose. The high ratio of acidic amino acids and highly negative electrostatic potential surface might account for the halophilic nature of AmySL3. The extremely halophilic, calcium-independent, and surfactant-resistant properties make AmySL3 a promising candidate enzyme for both basic research and industrial applications.


Assuntos
Cálcio/efeitos adversos , Carnobacteriaceae/enzimologia , Halobacteriales , Tensoativos/efeitos adversos , alfa-Amilases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carnobacteriaceae/genética , Clonagem Molecular , DNA Bacteriano , Ensaios Enzimáticos , Estabilidade Enzimática , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Concentração de Íons de Hidrogênio , Lagos/microbiologia , Estrutura Terciária de Proteína , Proteínas Recombinantes/genética , Alinhamento de Sequência , Análise de Sequência de Proteína , Cloreto de Sódio , Solventes/efeitos adversos , Amido/metabolismo , Especificidade por Substrato , Temperatura Ambiente , alfa-Amilases/efeitos dos fármacos , alfa-Amilases/genética
13.
Microb Cell Fact ; 18(1): 69, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30971250

RESUMO

BACKGROUND: Our laboratory has constructed a Bacillus stearothermophilus α-amylase (AmyS) derivative with excellent enzymatic properties. Bacillus subtilis is generally regarded as safe and has excellent protein secretory capability, but heterologous extracellular production level of B. stearothermophilus α-amylase in B. subtilis is very low. RESULTS: In this study, the extracellular production level of B. stearothermophilus α-amylase in B. subtilis was enhanced by signal peptide optimization, chaperone overexpression and α-amylase mutant selection. The α-amylase optimal signal peptide (SPYojL) was obtained by screening 173 B. subtilis signal peptides. Although the extracellular α-amylase activity that was produced by the resulting recombinant strain was 3.5-fold greater than that of the control, significant quantities of inclusion bodies were detected. Overexpressing intracellular molecular chaperones significantly reduced inclusion body formation and further increased α-amylase activity. Error-prone PCR produced an amylase mutant K82E/S405R (AmySA) with enzymatic activity superior to that of AmyS. Expression of the amySA gene with the SPYojL while overexpressing molecular chaperones resulted in a 7.1-fold improvement in α-amylase activity. When the final expression strain (WHS11YSA) was cultivated in a 3-L fermenter for 92 h, the α-amylase activity of the culture supernatant was 9201.1 U mL-1, which is the highest level that has been reported to date. CONCLUSIONS: This is the first report that describes an improvement of B. stearothermophilus α-amylase extracellular production levels in B. subtilis using these strategies, and this represents the highest extracellular production level ever reported for α-amylase from B. stearothermophilus in B. subtilis. This high-level production provides a basis for enhanced industrial production of α-amylase. These extracellular production level improvement approaches are also expected to be valuable in the expression of other enzymes in B. subtilis.


Assuntos
Bacillus subtilis/genética , Geobacillus stearothermophilus/enzimologia , Chaperonas Moleculares/genética , Sinais Direcionadores de Proteínas , alfa-Amilases/genética , Bacillus subtilis/metabolismo , Proteínas de Bactérias/metabolismo , Fermentação , Expressão Gênica , Geobacillus stearothermophilus/genética , Microbiologia Industrial , Chaperonas Moleculares/metabolismo , Mutação , Regiões Promotoras Genéticas , alfa-Amilases/metabolismo
14.
J Food Sci ; 84(5): 946-953, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30947368

RESUMO

Germination of wheat maximizes phytochemical content and antioxidant activity while altering chemical composition, gluten content, and pasting properties. This study investigated the effect of short-term imbibition on gene expression profiles and the physical and functional characteristics of wheat. Changes in gene expression profiles of wheat during short-term imbibition (0, 16, and 24 hr) were evaluated by DNA microarray analysis. Gene Ontology (GO) analysis was carried out to categorize the function of genes with altered expression. Genes related to cellulose and cell wall synthesis were upregulated by imbibition for 16 hr, whereas those associated with polysaccharide catabolism and nucleosome assembly were upregulated in the subsequent 8 hr. The genes related to proteases and gluten were expressed in dry seeds but disappeared after 16 hr of imbibition. Genes encoding α-amylase were not expressed in dry seeds whereas those encoding ß-amylase were expressed in dry seeds and downregulated by imbibition. According to quantitative real-time PCR and enzymatic activity assay, α-Amylase expression increased by imbibition and reached a maximum 24 hr after imbibition, with a corresponding increase in enzymatic activity. Pasting properties of flour made from wheat seeds imbibed for different times were decreased when seeds were imbibed for over 16 hr, by examination with Rapid Visco Analyzer. Gluten content did not significantly change until 24-hr imbibition, although expression of genes encoding gliadin and glutenin disappeared by 16-hr imbibition. The data indicated that it was possible to use 16-hr imbibed wheat, with up to the 50% w/w replacement of nonimbibed wheat.


Assuntos
Farinha/análise , Regulação da Expressão Gênica de Plantas , Germinação/genética , Sementes , Triticum/genética , Água , alfa-Amilases/metabolismo , Antioxidantes , Grão Comestível , Qualidade dos Alimentos , Perfilação da Expressão Gênica , Genes de Plantas , Gliadina/metabolismo , Glutens/análise , Glutens/metabolismo , Humanos , Análise em Microsséries , Plântula/metabolismo , Sementes/enzimologia , Triticum/enzimologia , Triticum/metabolismo
15.
Appl Microbiol Biotechnol ; 103(12): 4789-4799, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31025072

RESUMO

Soybean meal is commonly applied as the raw material in the bio-fermentation industry, and bacitracin is a widely used feed additive in the feed industry. In this study, we investigated the influence of subtilisin enhancement on soybean meal utilization and bacitracin production in Bacillus licheniformis DW2, an industrial strain for bacitracin production. Firstly, blocking sRNA aprA expression benefited bacitracin synthesis, and the bacitracin yield produced by aprA-deficient strain DW2△PaprA reached 931.43 U/mL, 18.92% higher than that of DW2 (783.25 U/mL). The bacitracin yield was reduced by 14.27% in the aprA overexpression strain. Furthermore, our results showed that deficiency of aprA led to a 6.54-fold increase of the aprE transcriptional level and a 1.84-fold increase of subtilisin activity, respectively, which led to the increases of soybean meal utilization rate (28.86%) and precursor amino acid supplies for bacitracin synthesis. Additionally, strengthening the utilization rate of soybean meal also benefited heterologous protein production, and the α-amylase and nattokinase activities were respectively enhanced by 59.81% and 50.53% in aprA-deficient strains. Collectively, this research demonstrated that strengthening subtilisin production could improve the utilization rate of soybean meal and thereby enhance bacitracin and target protein production; also, this strategy would be useful for the improvement of protein/peptide production using soybean meal as the main nitrogen source in the fermentation process.


Assuntos
Bacillus licheniformis/metabolismo , Bacitracina/biossíntese , Fermentação , Soja , Subtilisina/genética , Bacillus licheniformis/genética , Proteínas de Bactérias/genética , Microbiologia Industrial , Interferência de RNA , Subtilisinas/metabolismo , alfa-Amilases/metabolismo
16.
Molecules ; 24(7)2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30986961

RESUMO

Ligustrum lucidum Aiton and its berries have been used in Chinese traditional medicine for around two thousand years. In the present study, L. lucidium berries harvested in two regions of Portugal were studied. Haemolytic activity and inhibition of oxidative haemolysis as well as the enzyme inhibitory activities (α-amylase enzyme and acetylcholinesterase) were assessed. Results suggest that the different biological activities varied according to the region where samples were collected. Results demonstrated that the sample obtained from region R1 was the most efficient extract for all parameters evaluated, presenting the lowest values of IC50, 10.67 ± 0.46 µg/mL for the inhibition of erythrocyte oxidative haemolysis, 58.28 ± 3.77 µg/mL for the α-amylase enzyme and 67.67 ± 2.10 µg/mL for the acetylcholinesterase inhibition. L. Lucidum berries may be an interesting source of compounds for use in the development of the therapeutic armamentarium for diseases where enzymatic disruption is believed to play a role.


Assuntos
Frutas/química , Ligustrum/química , Extratos Vegetais/farmacologia , Acetilcolinesterase/metabolismo , Ativação Enzimática/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Extratos Vegetais/química , alfa-Amilases/metabolismo
17.
Planta ; 250(1): 281-298, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31025197

RESUMO

MAIN CONCLUSION: The alpha-amylase and beta-amylase genes have been identified from tea plants, and their bioinformatic characteristics and expression patterns provide a foundation for further studies to elucidate their biological functions. Alpha-amylase (AMY)- and beta-amylase (BAM)-mediated starch degradation plays central roles in carbohydrate metabolism and participates extensively in the regulation of a wide range of biological processes, including growth, development and stress response. However, the AMY and BAM genes in tea plants (Camellia sinensis) are poorly understood, and the biological functions of these genes remain to be elucidated. In this study, three CsAMY and nine CsBAM genes from tea plants were identified based on genomic and transcriptomic database analyses, and the genes were subjected to comprehensive bioinformatic characterization. Phylogenetic analysis showed that the CsAMY proteins could be clustered into three different subfamilies, and nine CsBAM proteins could be classified into four groups. Putative catalytically active proteins were identified based on multiple sequence alignments, and the tertiary structures of these proteins were analyzed. Cis-element analysis indicated that CsAMY and CsBAM were extensively involved in tea plant growth, development and stress response. In addition, the CsAMY and CsBAM genes were differentially expressed in various tissues and were regulated by stress treatments (e.g., ABA, cold, drought and salt stress), and the expression patterns of these genes were associated with the postharvest withering and rotation processes. Taken together, our results will enhance the understanding of the roles of the CsAMY and CsBAM gene families in the growth, development and stress response of tea plants and of the potential functions of these genes in determining tea quality during the postharvest processing of tea leaves.


Assuntos
Camellia sinensis/enzimologia , Regulação da Expressão Gênica de Plantas , alfa-Amilases/metabolismo , beta-Amilase/metabolismo , Camellia sinensis/genética , Camellia sinensis/fisiologia , Secas , Perfilação da Expressão Gênica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Alinhamento de Sequência , Estresse Fisiológico , alfa-Amilases/genética , beta-Amilase/genética
18.
Chem Biodivers ; 16(6): e1900032, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30957403

RESUMO

The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC50 =114.80 µm) and α-glucosidase (IC50 =153.87 µm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.


Assuntos
Alpinia/química , Diterpenos/química , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Alpinia/metabolismo , Sítios de Ligação , Domínio Catalítico , Diterpenos/isolamento & purificação , Diterpenos/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Cinética , Simulação de Acoplamento Molecular , Extratos Vegetais/química , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/química
19.
Microb Pathog ; 132: 117-123, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31009656

RESUMO

In this study, we isolated four Weissella confusa strains from the healthy horse feces to test their potential as equine probiotics. The identification and characteristics of these isolates were determined as per standard methods. Resistance and susceptibility of the isolated strains were tested to low pHs, different heat treatments, commonly used antibiotics and against the pathogenic strains of Salmonella, Pasteurella, Staphylococcus aureus, and Escherichia coli. After 3 h cultural in different pH medium, the 4 strains still had a certain amount of survival above pH 3.0. WH2 and WH4 were still viable at pH2.5. All the isolated strains showed proper growth at 60 °C while no strain survived at 80 °C. The inhibition of α-amylase, the scavenging ability of free radical DPPH· and hydroxyl free radical HO·were also investigated. The results showed that WH4 had highest inhibition rate of α-amylase activity and DPPH· free radical scavenging rate, and the inhibition rate of α-amylase activity was 24.09% and the DPPH· free radical scavenging rate was 35.78%. The inhibition rate ofα-amylase activity and DPPH· scavenging rate of free radicals in the other three strains were about 10%. The clearance rate of hydroxyl radical (HO·) in 4 strains was between 12% and 15%. The antibiotic susceptibilities varied for these four Weisella strains but all of them showed resistance against the frequently used equine antibiotics. All the four strains successfully suppressed the growth of standard strains in in vitro bacteriostasis experiment, which included Salmonella enteritidis (NTNC13349), Escherichia coli (C83902) and Staphylococcus aureus (BNCC186335). they also successfully suppressed the growth of state key laboratory isolating pathogens, which are Pasterurella multocida and Salmonella. Our findings suggest that the isolated strains of Weissella confusa can act as potential equine probiotics and should be explored further.


Assuntos
Fezes/microbiologia , Probióticos/isolamento & purificação , Weissella/isolamento & purificação , Weissella/fisiologia , Animais , Antibacterianos/farmacologia , Compostos de Bifenilo , Escherichia coli/crescimento & desenvolvimento , Cavalos , Concentração de Íons de Hidrogênio , Radical Hidroxila , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Pasteurella/crescimento & desenvolvimento , Filogenia , Picratos , Salmonella/crescimento & desenvolvimento , Análise de Sequência de DNA , Staphylococcus aureus/crescimento & desenvolvimento , Estresse Fisiológico , Weissella/efeitos dos fármacos , Weissella/crescimento & desenvolvimento , alfa-Amilases/metabolismo
20.
Food Chem ; 288: 413-421, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902312

RESUMO

An accurate high-performance anion-exchange chromatography (HPAEC) method is presented to measure the inhibition property of flavonoids against mammalian starch digestive enzymes, because flavonoids interfere with commonly used 3,5-dinitrosalicylic acid (DNS) and glucose oxidase/peroxidase (GOPOD) methods. Eriodictyol, luteolin, and quercetin increased absorbance values (without substrate) in the DNS assay and, with substrate, either overestimated or underestimated values in the DNS and GOPOD assays. Using a direct HPAEC measurement method, flavonoids showed different inhibition properties against α-amylase and α-glucosidases, showing different inhibition constants (Ki) and mechanisms. The double bond between C2 and C3 on the C-ring of flavonoids appeared particularly important to inhibit α-amylase, while the hydroxyl group (OH) at C3 of the C-ring was related to inhibition of α-glucosidases. This study shows that direct measurement of starch digestion products by HPAEC should be used in inhibition studies, and provides insights into structure-function aspects of polyphenols in controlling starch digestion rate.


Assuntos
Inibidores Enzimáticos/química , Flavonoides/química , Amido/metabolismo , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Colorimetria , Ensaios Enzimáticos , Inibidores Enzimáticos/metabolismo , Flavonoides/metabolismo , Cinética , Amido/análise , Especificidade por Substrato , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/química
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