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1.
Theor Appl Genet ; 134(4): 1063-1081, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33438060

RESUMO

KEY MESSAGE: Combining GWAS, QTL-seq and transcriptome sequencing detected basal defense-related genes showing gDNA sequence variation and expression difference in diverse cotton lines, which might be the molecular mechanisms of VW resistance in G. hirsutum. Verticillium wilt (VW), which is caused by the soil-borne fungus Verticillium dahliae, is a major disease in cotton (Gossypim hirsutum) worldwide. To facilitate the understanding of the genetic basis for VW resistance in cotton, a genome-wide association study (GWAS), QTL-seq and transcriptome sequencing were performed. The GWAS of VW resistance in a panel of 120 core elite cotton accessions using the Cotton 63K Illumina Infinium SNP array identified 5 QTL from 18 significant SNPs meeting the 5% false discovery rate threshold on 5 chromosomes. All QTL identified through GWAS were found to be overlapped with previously reported QTL. By combining GWAS, QTL-seq and transcriptome sequencing, we identified eight candidate genes showing both gDNA sequence variation and expression difference between resistant and susceptible lines, most related to transcription factors (TFs), flavonoid biosynthesis and those involving in the plant basal defense and broad-spectrum disease resistance. Ten KASP markers were successfully validated in diverse cotton lines and could be deployed in marker-assisted breeding to enhance VW resistance. These results supported our inference that the gDNA sequence variation or expression difference of those genes involving in the basal defense in diverse cotton lines might be the molecular mechanisms of VW resistance in G. hirsutum.


Assuntos
Resistência à Doença/genética , Genes de Plantas , Marcadores Genéticos , Gossypium/genética , Locos de Características Quantitativas , Transcriptoma , Verticillium/fisiologia , Mapeamento Cromossômico , Estudo de Associação Genômica Ampla , Gossypium/crescimento & desenvolvimento , Gossypium/microbiologia , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único
2.
Int J Mol Sci ; 22(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34502024

RESUMO

Verticillium wilt (VW) is a typical fungal disease affecting the yield and quality of cotton. The Trichome Birefringence-Like protein (TBL) is an acetyltransferase involved in the acetylation process of cell wall polysaccharides. Up to now, there are no reports on whether the TBL gene is related to disease resistance in cotton. In this study, we cloned a cotton TBL34 gene located in the confidence interval of a major VW resistance quantitative trait loci and demonstrated its relationship with VW resistance in cotton. Analyzing the sequence variations in resistant and susceptible accessions detected two elite alleles GhTBL34-2 and GhTBL34-3, mainly presented in resistant cotton lines whose disease index was significantly lower than that of susceptible lines carrying the allele GhTBL34-1. Comparing the TBL34 protein sequences showed that two amino acid differences in the TBL (PMR5N) domain changed the susceptible allele GhTBL34-1 into the resistant allele GhTBL34-2 (GhTBL34-3). Expression analysis showed that the TBL34 was obviously up-regulated by infection of Verticillium dahliae and exogenous treatment of ethylene (ET), and salicylic acid (SA) and jasmonate (JA) in cotton. VIGS experiments demonstrated that silencing of TBL34 reduced VW resistance in cotton. We deduced that the TBL34 gene mediating acetylation of cell wall polysaccharides might be involved in the regulation of resistance to VW in cotton.


Assuntos
Acetiltransferases/metabolismo , Resistência à Doença , Gossypium/enzimologia , Micoses , Doenças das Plantas , Acetiltransferases/química , Acetiltransferases/genética , Ascomicetos , Sequência de Bases , Regulação da Expressão Gênica de Plantas , Gossypium/genética , Gossypium/fisiologia , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas , Alinhamento de Sequência
3.
Appl Microbiol Biotechnol ; 104(10): 4321-4332, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32232531

RESUMO

Separation and enrichment of phenolics from peony flowers were performed to improve the anti-biofilm and antibacterial activities for the first time. Through several times of separation, the purity of phenolics components increased significantly, and the anti-biofilm and antibacterial activities of phenolics components against E. coli and S. aureus were also significantly improved. Finally, the phenolics of peony flowers in the eluent of silica gel column chromatography (PPF-ESGCC) were found to exhibit the highest anti-biofilm and antibacterial activities. The inhibition rates of PPF-ESGCC on biofilms of E. coli and S. aureus were 77.93%, and 87.03% respectively, at a very low concentration (1/2 MIC, 0.235 mg/mL). It was found that the biofilm inhibition was achieved by inhibiting their swimming, swarming, twitching motilities, exopolysaccharide (EPS) production, and quorum sensing (QS). Moreover, there was a positive dose-dependent relationship (r = 0.75 to 1) between the inhibition rates and concentrations of PPF-ESGCC during the critical biofilm-formation stage (1-3 days). Chemical composition analysis showed the PPF-ESGCC comprised of gallic acid, kaempferol-7-O-glucoside, and apigenin-7-O-glucoside. In conclusion, PPF-ESGCC exhibited strong inhibitory effect on biofilm formation and gallic acid, kaempferol-7-O-glucoside, and apigenin-7-O-glucoside might play a crucial role in inhibiting biofilm formation. Meanwhile, this study indicated that PPF-ESGCC, a new natural QS inhibitor and biofilm inhibitor, could be used as a novel intervention strategy to enhance the safety and quality of food.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Paeonia/química , Fenóis/farmacologia , Flores/química , Testes de Sensibilidade Microbiana , Fenóis/isolamento & purificação , Percepção de Quorum/efeitos dos fármacos
4.
BMC Plant Biol ; 14: 275, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25300306

RESUMO

BACKGROUND: Interspecific hybridization has long been recognized as a pivotal process in plant evolution and speciation. It occurs fairly common in the genera of the subtribe Pyrinae. In Eriobotrya, a small tree genus of Pyrinae, E. prinoides var. daduheensis has been recognized as either a variety of E. prinoides, a natural hybrid between E. prinoides and E. japonica, or a variety of E. japonica. However, to date, there has been no convincing evidence on its status. RESULTS: Four nuclear genes and two chloroplast regions were sequenced in 89 individuals of these three Eriobotrya taxa from two locations where they coexist. A few fixed nucleotide substitutions or gaps were found in each of the investigated nuclear and chloroplast loci between E. japonica and E. prinoides. Of the 35 individuals of E. prinoides var. daduheensis, 33 showed nucleotide additivity of E. japonica and E. prinoides in at least one nuclear gene, and 10 of them harboured nucleotide additivity at all the four nuclear genes. Most haplotypes of E. prinoides var. daduheensis were also shared with those of E. japonica and E. prinoides. In the two chloroplast regions, 28 and 7 individuals were identical with E. japonica and E. prinoides, respectively. CONCLUSIONS: Our study provides compelling evidence for a hybrid status for E. prinoides var. daduheensis. Most hybrid individuals are later-generation hybrids. Both E. japonica and E. prinoides can serve as female parent. Differential adaptation might maintain the species boundary of E. prinoides and E. japonica in the face of hybridization and potential introgression.


Assuntos
Eriobotrya/genética , Hibridização Genética , Eriobotrya/fisiologia
5.
Nat Commun ; 14(1): 112, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36611030

RESUMO

The removal of nitric oxide is an important environmental issue, as well as a necessary prerequisite for achieving high efficiency of CO2 electroreduction. To this end, the electrocatalytic denitrification is a sustainable route. Herein, we employ reaction phase diagram to analyze the evolution of reaction mechanisms over varying catalysts and study the potential/pH effects over Pd and Cu. We find the low N2 selectivity compared to N2O production, consistent with a set of experiments, is limited fundamentally by two factors. The N2OH* binding is relatively weak over transition metals, resulting in the low rate of as-produced N2O* protonation. The strong correlation of OH* and O* binding energies limits the route of N2O* dissociation. Although the experimental conditions of varying potential, pH and NO pressures can tune the selectivity slightly, which are insufficient to promote N2 selectivity beyond N2O and NH3. A possible solution is to design catalysts with exceptions to break the scaling characters of energies. Alternatively, we propose a reverse route with the target of decentralized ammonia synthesis.

6.
J Food Sci ; 88(8): 3577-3593, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37458288

RESUMO

This study explores potential hypoglycemic mechanisms by preparing and identifying novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from goat milk (GM) whey protein. Papain was used to hydrolyze the GM whey protein. After purification by ultrafiltration, the Sephadex column, and preparative RP-HPLC, the peptide inhibited DPP-IV, α-glucosidase, and α-amylase with IC50 of 0.34, 0.37, and 0.72 mg/mL, respectively. To further explore the inhibitory mechanism of peptides on DPP-IV, SPPEFLR, LDADGSY, YPVEPFT, and FNPTY were identified and synthesized for the first time, with IC50 values of 56.22, 52.16, 175.7, and 62.32 µM, respectively. Molecular docking and dynamics results show that SPPEFLR, LDADGSY, and FNPTY bind more tightly to the active pocket of DPP-IV, which was consistent with the in vitro activity. Furthermore, the first three N-terminals of SPPEFLR and FNPTY peptides exhibit proline characteristics and competitively inhibit DPP-IV. Notably, the first N-terminal leucine of LDADGSY may play a key role in inhibiting DPP-IV.


Assuntos
Inibidores da Dipeptidil Peptidase IV , Leite , Animais , Proteínas do Soro do Leite/metabolismo , Simulação de Acoplamento Molecular , Dipeptidil Peptidase 4/química , Inibidores da Dipeptidil Peptidase IV/farmacologia , Inibidores da Dipeptidil Peptidase IV/química , Peptídeos/química , Cabras
7.
Food Funct ; 14(14): 6526-6540, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37377000

RESUMO

Milk can improve sleep, and the effects of different animal milks vary. Accordingly, we evaluated the effectiveness of goat milk and cow milk in alleviating insomnia. The findings demonstrated that both goat milk and cow milk significantly increased the length of time that mice with insomnia slept compared to the model group and lowered the relative abundance of Colidextribacter, Escherichia-Shigella, and Proteus in these mice. A notable finding was that goat milk considerably increased the relative abundance of Dubosiella, Bifidobacterium, Lactobacillus, and Mucispirillum, whereas cow milk dramatically increased the relative abundance of Lactobacillus and Acinetobacter. Diazepam therapy could lengthen the slumber of mice; however, analysis of bacteria indicated that although the relative abundance of dangerous bacteria such as Mucispirillum, Parasutterella, Helicobacter, and Romboutsia increased, that of Blautia and Faecalibaculum decreased. Both Listeria and Clostridium experienced a large increase in relative abundance. Additionally, goat milk provided efficient restoration of neurotransmitters including 5-HT, GABA, DA, and NE. Besides that, the expression of genes and proteins for CREB, BDNF, and TrkB in the hypothalamus was up-regulated, and the pathophysiology of the hypothalamus was improved. Overall, the effects of goat and cow milk on insomnia in mouse models differed, and goat milk is preferred over cow milk.


Assuntos
Microbiota , Distúrbios do Início e da Manutenção do Sono , Bovinos , Feminino , Camundongos , Animais , Leite/microbiologia , Cabras , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Alérgenos , Bactérias/genética , Modelos Animais de Doenças
8.
J Oleo Sci ; 71(12): 1749-1760, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36464287

RESUMO

In this study, the recovery of pecan nut kernel oil (PNKO) obtained by mechanical pressing (MP) was compared with that obtained by ultrasonic-assisted aqueous enzymatic extraction (UAAEE). At the same time, contents of substances with proven bioactivity, fatty acid compositions, physicochemical properties and antioxidant activities of PNKO were also assessed. Obviously, the oil yield obtained by UAAEE (71.32%) was higher than that obtained by MP (56.81%). Therefore, Plackett-Burman design (PBD), as well as Box-Behnken design (BBD), further optimized the UAAEE process, and the highest oil yield of 78.83% was acquired under the following conditions: incubation time of 2 h, the mixed enzyme (cell ulase+hemicellulase+pectinase+neutrase, w/w/w/w=1/1/1/1) concentration of 2.9%, liquid-solid ratio of 4 mL/g, pH of 4, particle size of 300 µm, ultrasonic time of 20 min, ultrasonic power of 432 W and reaction temperature of 53°C. The PNKO obtained by the two methods possessed similar fatty acid composition, but that obtained by UAAEE had comparatively low acid value and peroxide value. Moreover, rich content of total phenolics, squalene and phytosterols, as well as strong scavenging activities against DPPH and ABTS+ free radicals, were also contained in the PNKO obtained by UAAEE. These results demonstrated that UAAEE was an efficient method to acquire pecan nut kernel oil with excellent quality and high recovery.


Assuntos
Carya , Nozes , Ultrassom , Tamanho da Partícula , Ácidos Graxos
9.
Food Res Int ; 161: 111729, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36192869

RESUMO

This study sought to develop a nanoscale delivery system to enhance the stability and bioaccessibility of goat milk whey protein peptides. Goat milk whey protein was hydrolyzed by papain, and the hydrolysate was ultrafiltered to obtain a low molecular weight peptide (GWP, <3 kDa) with strong hypoglycemic activity. The GWP-loaded liposomes and niosomes encapsulation systems were prepared using phytosterols (ergosterol, ß-sitosterol, mixed phytosterols, and stigmasterol) instead of cholesterol. Results showed that the GWP-loaded niosomes (GWP-NS) prepared from ß-sitosterol had the higher GWP encapsulation efficiency (90.46 ± 4.02 %) and the smaller particle size (92.07 ± 9.8 nm) than liposomes (GWP-LS). Additionally, the morphological results showed that two GWP-loaded systems were smooth and spherical, and the FT-IR spectroscopy confirmed the successful formation of the peptide-loaded system. Compared with GWP, GWP-LS and GWP-NS showed the higher stability under different pH, temperature, and NaCl concentration conditions, especially GWP-NS. Furthermore, GWP-NS could significantly improve the retention rate of GWP during simulated gastrointestinal digestion, in vitro bioaccessibility, and hypoglycemic activity. These findings suggest that ß-sitosterol could be a potential membrane stabilizer alternative to cholesterol, and GWP niosomes could be a potential new drug delivery system.


Assuntos
Lipossomos , Papaína , Animais , Colesterol/química , Ergosterol , Cabras , Hipoglicemiantes , Lipossomos/química , Leite , Nanoestruturas , Peptídeos , Cloreto de Sódio , Espectroscopia de Infravermelho com Transformada de Fourier , Estigmasterol , Proteínas do Soro do Leite
10.
Int J Biol Macromol ; 200: 1-11, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34968544

RESUMO

In the work, a novel filamentou sodium alginate (SA) /ε-polylysine (PL) fiber with excellent mechanical properties and controllable sizes is prepared in an efficient and environmentally friendly manner via continuous pulling of an electrostatically assembled SA/PL composites at the contact interface of aqueous solutions of cationic polyelectrolyte ε-PL and anionic natural polysaccharide SA. The SA/PL fiber exhibits good antibacterial activity, low cytotoxicity, anti-hemolysis, bioadhesion, and environmental friendliness due to its natural raw materials and green preparation process. In vivo experiments have shown that the SA/PL fiber can promote the healing and repair of skin wounds on the backs of mice via resistance to pathogen infection, reduction of inflammation, and anti-allogeneic allergy of the wound. In summary, these results demonstrate that the SA/PL fiber is a green and biosafe multifunctional natural polymer material, with potential applications in suturing wound.


Assuntos
Alginatos , Polilisina/análogos & derivados
11.
Carbohydr Polym ; 278: 118993, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34973796

RESUMO

In this work, a novel synthesis strategy of sodium alginate/carboxymethyl chitosan hydrogel beads promoted by hydrogen bond was described. The beads were prepared by dropping the blends of two polymers into the citric acid solution. Besides hydrogen bonding, electrostatic interactions were also involved in the formation of the hydrogel beads. The thermal stability experiments revealed that the more the content of carboxymethyl chitosan, the better the thermal stability of the beads. The beads exhibited excellent pH sensitivity, pH reversibility, and lactoferrin loading capacity. The swelling ratio of the bead and its protein releasing profile was pH-dependent, which could prevent premature protein release in the gastric environment. Also, the circular dichroism results demonstrated that lactoferrin could maintain its structure during the loading and releasing process. The obtained results revealed that the hydrogel beads prepared in this work could be used as a potential protein carrier for oral delivery.


Assuntos
Alginatos/química , Quitosana/análogos & derivados , Hidrogéis/química , Quitosana/química , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio
12.
Sci Adv ; 8(15): eabn4072, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35417241

RESUMO

Oxygen activation, including oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), is at the heart of many important energy conversion processes. However, the activation mechanism of Ba-containing perovskite materials is still ambiguous, because of the complex four-electron transfer process on the gas-solid interfaces. Here, we directly observe that BaO and BaO2 segregated on Ba-containing material surface participate in the oxygen activation process via the formation and decomposition of BaO2. Tens of times of increase in catalytic activities was achieved by introducing barium oxides in the traditional perovskite and inert Au electrodes, indicating that barium oxides are critical for oxygen activation. We find that BaO and BaO2 are more active than the B-site of perovskite for ORR and OER, respectively, and closely related to the high activity of Ba-containing perovskite.

13.
Int J Biol Macromol ; 192: 1169-1177, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34678379

RESUMO

Carboxymethyl chitosan (CMCS)-based complex coacervate has attracted much attention in drug oral delivery due to its pH-responsive property. As a unique ampholyte polymer, the self-coacervation of CMCS has great research potential. In this work, CMCS self-coacervates were prepared by adjusting the pH of the CMCS aqueous solution close to its isoelectric point. The Fourier-transformed infrared spectroscopy (FTIR) results revealed that electrostatic interactions, hydrogen bonding, and hydrophobic interactions were involved in the self-coacervation of CMCS. The obtained self-coacervates presented a dense surface structure, and were stable at a wide pH range of 3.0-6.0, and gradually dissolved under basic conditions. Although self-coacervation decreased the crystallinity and thermal stability of CMCS, the obtained coacervates showed excellent pH-responsive properties and ionic strength stability. We also investigated its potential in lactoferrin (LF) encapsulation and oral delivery. The CMCS self-coacervates exhibited a high encapsulation efficiency (EE) of 94.79 ± 0.49% and loading capacity (LC) of 26.29 ± 0.52% when the addition amount of LF was 2 mg. The simulated gastric digestion results demonstrated that CMCS self-coacervates could protect more than 80% of LF from hydrolysis and maintain the bioactivities of LF. Accordingly, the self-coacervation of CMCS could be used as a pH-responsive encapsulation and delivery strategy.


Assuntos
Quitosana/análogos & derivados , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Fenômenos Químicos , Quitosana/química , Composição de Medicamentos , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral , Termogravimetria
14.
Food Res Int ; 149: 110631, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600647

RESUMO

Epigallocatechin gallate (EGCG) has a variety of biological activities, but exhibits poor stability and low bioavailability. In this study, EGCG bilosome was prepared and characterized, and its stability during different storage conditions (pH, NaCl concentration, and temperature) and in gastrointestinal fluid was evaluated and compared with liposomes and niosomes. Among them, EGCG niosomes had the highest pH stability, and the existence of sodium cholate reduced the stability of bilosomes in acidic medium. EGCG stability was significantly increased in the presence of salt ions (0-100 mM NaCl) and under different temperatures (25 °C, 37 °C) when delivered as niosomes and bilosomes. Retention rate of EGCG in bilosomes was 71.64 ± 4.05% after incubation in simulated intestinal fluid for 2 h, which was significantly higher than retention rate of EGCG liposomes (24.02 ± 3.95%) and niosomes (55.74 ± 6.85%), thus indicating greater gastrointestinal stability of EGCG bilosomes. Furthermore, bioavailability of EGCG encapsulated in bilosomes was improved by 1.98 times. Overall, these findings indicate that EGCG bilosomes, as a new delivery system, had great potential application as a means to improve stability and bioavailability of EGCG.


Assuntos
Catequina , Disponibilidade Biológica , Catequina/análogos & derivados , Lipossomos
15.
J Phys Chem Lett ; 12(29): 6988-6995, 2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34283618

RESUMO

Recently, electrochemical NO reduction (eNORR) to ammonia has attracted enormous research interests due to the dual benefits in ammonia synthesis and denitrification fields. Herein, taking Ag as a model catalyst, we have developed a microkinetic model to rationalize the general selectivity trend of eNORR with varying potential, which has been observed widely in experiments, but not understood well. The model reproduces experiments well, quantitatively describing the selectivity turnover from N2O to NH3 and from NH3 to H2 with more negative potential. The first turnover of selectivity is due to the thermochemical coupling of two NO* limiting the N2O production. The second turnover is attributed to the larger transfer coefficient (ß) of HER than NH3 production. This work reveals how electrode potential regulate the selectivity of eNORR, which is also beneficial to understand the commonly increasing HER selectivity with the decrease of potential in some other electroreduction reactions such as CO2 reduction.

16.
Int J Biol Macromol ; 172: 503-514, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33454330

RESUMO

The study aimed to reveal the different mechanisms of delaying starch digestion by ECG, EGCG and Procyanidin based on the perspective of α-amylase-flavanol interaction and starch-flavanol interaction. The interaction characteristics of flavanols with α-amylase were studied from five aspects: enzyme inhibition, kinetics, fluorescence quenching, circular dichroism (CD) and computer simulation. The IC50 of flavanols (ECG, EGCG and Procyanidin) against α-amylase were 172.21 ± 0.22, 732.15 ± 0.13 and 504.45 ± 0.19 µg/mL according to the results of α-amylase inhibition experiment, respectively. ECG and Procyanidin showed mixed inhibition against α-amylase, while EGCG showed non-competition against α-amylase. However, thermodynamic parameters,computer-based docking and dynamic simulation proved that ECG and EGCG-α-amylase complexs were mainly driven by van der Waals and hydrogen bonds, while Procyanidin-α-amylase complexs was driven by hydrophobic interaction. In addition, it was indicated, by means of starch­iodine complex spectroscopy, that flavanols inhibited the digestion of starch not only through bind with α-amylase but also through bind with starch. Thus, flavanols as a starch-based food additive have the potential to be employed as adjuvant therapy for diabetes.


Assuntos
Biflavonoides/química , Catequina/análogos & derivados , Inibidores de Glicosídeo Hidrolases/química , Proantocianidinas/química , Amido/química , alfa-Amilases/química , Biflavonoides/metabolismo , Sítios de Ligação , Catequina/química , Catequina/metabolismo , Glucose/química , Inibidores de Glicosídeo Hidrolases/metabolismo , Hidrólise , Cinética , Maltose/química , Maltose/metabolismo , Simulação de Acoplamento Molecular , Proantocianidinas/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Amido/metabolismo , Especificidade por Substrato , Termodinâmica , Trissacarídeos/química , Trissacarídeos/metabolismo , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
17.
Anal Methods ; 13(6): 832-842, 2021 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-33507177

RESUMO

Epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) are the most abundant ester catechins of green tea polyphenols (GTPs) with numerous potential bioactivities, which have wide application prospects in the fields of medicine and functional foods. In this study, a new method using macroporous resin and crystallization was established to separate and purify EGCG and ECG. Two resins with high adsorption and desorption capacities for EGCG and ECG were screened through static adsorption/desorption tests, and the LX-20B resin was selected through column chromatography due to its best separation effect. Moreover, the column separation parameters of LX-20B resin (sample amount, ethanol elution concentration, elution volume, and elution flow rate) were optimized. After resin purification, the EGCG and ECG purity were 70.08 ± 2.55% and 74.97 ± 2.66%, respectively, and the recovery rates were 68.07 ± 2.43% and 74.28 ± 2.24%, respectively. After crystallization, the EGCG purity reached 95.87 ± 0.89%, with a total recovery rate of 58.66%, and the ECG purity reached 95.55 ± 1.30%, with a total recovery rate of 62.45%. The separation efficiency of the resin showed no significant change after 6 cycles. These results show the proposed method to be a simple, eco-friendly, and cost-effective separation method for the industrial separation and purification of EGCG and ECG from GTPs.

18.
Int J Biol Macromol ; 164: 1927-1938, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32795575

RESUMO

This study aimed to reveal the interaction and inhibitory mechanisms of tangeretin (TAN), nobiletin (NBT), and their acidic hydroxylated forms, 5-demethyltangeretin (5-DT) and 5-demethylnobiletin (5-DN) on porcine pancreatic lipase (PPL) using spectroscopic techniques and molecular dynamics (MD) simulation. PPL inhibition assay showed that the inhibitory activity of NBT (IC50 value of 3.60 ± 0.19 µM) was superior to those of three polymethoxylated flavones (PMFs), indicating it may be related to the methoxy groups at the 3'-position in its molecular structure. Inhibition kinetic analyses demonstrated that the inhibition types of the 4 PMFs were consistent with the mixed inhibition model, which agreed well with the results from the ultraviolet-visible (UV-Vis) spectroscopy, Circular dichroism (CD), fluorescence spectroscopy, molecular docking, and MD simulation that PMFs could bind to the PPL catalytic site and non-catalytic site, affecting the normal spatial conformation of PPL and weakening its ability to decompose the substrate. All these findings suggest that PMFs are a kind of natural lipase inhibitors, and NBT has the potential as a lipase inhibition precursor because of its unique flavone skeleton structure.


Assuntos
Citrus/química , Flavonas/farmacologia , Lipase/metabolismo , Extratos Vegetais/farmacologia , Animais , Frutas/química , Cinética , Simulação de Acoplamento Molecular/métodos , Simulação de Dinâmica Molecular , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Suínos
19.
ChemSusChem ; 13(4): 827-837, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31782967

RESUMO

A precursor-engineering strategy coupled with a microwave molten-salt process (PE-MWMS) is developed to synthesize graphitic carbon nitride (g-C3 N4 ) with an isotype triazine/heptazine-based g-C3 N4 heterojunction as a photocatalyst for the hydrogen evolution reaction (HER) under visible light illumination. Four hybrid precursor combinations-thiourea/melamine, thiourea/dicyandiamide, urea/melamine, and urea/dicyandiamide-are used to synthesize g-C3 N4 heterojunctions by the PE-MWMS process. Control experiments indicate that the precursor components and microwave treatment have a great effect on the HER performance of the g-C3 N4 samples. Samples synthesized with the optimal molar ratios of thiourea/melamine (2:1), thiourea/dicyandiamide (2:1), urea/melamine (3:1), and urea/dicyandiamide (3:1), exhibit the highest HER rates of 3135, 2519, 2844, and 2565 µmol g-1 h-1 , respectively. The amounts of heptazine and triazine units in the g-C3 N4 samples can be easily adjusted by changing the ratios of the hybrid precursors and play a decisive role in improving the photocatalytic HER activity. Because of the unique composition and microstructure, the efficient separation of electron-hole pairs, the broadened photo-absorption edges, and the narrowed band gaps, the as-obtained triazine/heptazine-based g-C3 N4 nanostructures exhibit promising activity for HER application.

20.
J Food Biochem ; 44(12): e13536, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33103275

RESUMO

There is a growing interest in screening α-amylase inhibitors from natural products for application in the development of new antidiabetic drugs or functional foods. In this study, a structure-based virtual screening was applied to rapidly identify the α-amylase inhibitors from medicine food homology (MFH) plants. Similarity search, docking & scoring were used for further filter small molecules. As a result, 21 corresponding potential α-amylase inhibitors from MFH plants were obtained. And, six polyphenol compounds (curcumin, procyanidins, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), hesperidin, and puerarin) were highlighted for further verification after a thorough assessment of the classification of hit molecules as well as docking scores. The results of the enzyme inhibition test showed that ECG, EGCG, and procyanidins had the better binding ability of α-amylase among these six polyphenols. The Ki values of ECG, EGCG, and procyanidins on α-amylase were 0.70, 1.68, and 0.24, respectively. The CD spectra results indicated that the three polyphenols can cause conformational changes in α-amylase. PRACTICAL APPLICATIONS: A structure-based virtual screening method for rapid identifying α-amylase inhibitors from MFH plants was developed successfully in this study. These findings suggested that natural polyphenols such as ECG, EGCG, and procyanidins may be a potential inhibitor of α-amylase which could be used as a nutrient supplement for the prevention of diabetes mellitus or can be further used in the development of hypoglycemic drugs. At the same time, it can provide theoretical guidance for the better utilization and development of medicine food homology plants containing these potential α-amylase inhibitors. Moreover, this work may provide ideas and references for the screening of other target protein inhibitors.


Assuntos
Plantas Comestíveis , alfa-Amilases , Hipoglicemiantes , Extratos Vegetais/farmacologia , Polifenóis
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