Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.258
Filtrar
1.
Molecules ; 29(8)2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38675593

RESUMO

Rare sugars are known for their ability to suppress postprandial blood glucose levels. Therefore, oligosaccharides and disaccharides derived from rare sugars could potentially serve as functional sweeteners. A disaccharide [α-d-allopyranosyl-(1→2)-ß-d-psicofuranoside] mimicking sucrose was synthesized from rare monosaccharides D-allose and D-psicose. Glycosylation using the intermolecular aglycon delivery (IAD) method was employed to selectively form 1,2-cis α-glycosidic linkages of the allopyranose residues. Moreover, ß-selective psicofuranosylation was performed using a psicofuranosyl acceptor with 1,3,4,6-tetra-O-benzoyl groups. This is the first report on the synthesis of non-reducing disaccharides comprising only rare d-sugars by IAD using protected ketose as a unique acceptor; additionally, this approach is expected to be applicable to the synthesis of functional sweeteners.


Assuntos
Dissacarídeos , Frutose , Glucose , Sacarose , Dissacarídeos/química , Dissacarídeos/síntese química , Sacarose/química , Glicosilação , Edulcorantes/química
2.
Food Chem ; 449: 139180, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38579650

RESUMO

Maple syrup, a popular natural sweetener has a high content of sucrose, whose consumption is linked to different health issues such as obesity and diabetes. Hence, within this paper, the conversion of sucrose to prebiotics (fructo-oligosaccharides, FOS) was proposed as a promising approach to obtaining a healthier, value-added product. Enzymatic conversion was optimized with respect to key experimental factors, and thereafter derived immobilized preparation of fructosyltransferase (FTase) from Pectinex® Ultra SP-L (FTase-epoxy Purolite, 255 IU/g support) was successfully utilized to produce novel functional product in ten consecutive reaction cycles. The product, obtained under optimal conditions (60 °C, 7.65 IU/mL, 12 h), resulted in 56.0% FOS, 16.7% sucrose, and 27.3% monosaccharides of total carbohydrates, leading to a 1.6-fold reduction in caloric content. The obtained products` prebiotic potential toward the probiotic strain Lactobacillus plantarum 299v was demonstrated. The changes in physico-chemical and sensorial characteristics were esteemed as negligible.


Assuntos
Acer , Proteínas de Bactérias , Hexosiltransferases , Oligossacarídeos , Prebióticos , Sacarose , Prebióticos/análise , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Hexosiltransferases/metabolismo , Hexosiltransferases/química , Sacarose/metabolismo , Sacarose/química , Acer/química , Acer/metabolismo , Lactobacillus plantarum/metabolismo , Lactobacillus plantarum/enzimologia , Lactobacillus plantarum/química , Biocatálise , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo
3.
Chem Biodivers ; 21(5): e202400302, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38454878

RESUMO

This study isolated pure compounds from Canna edulis aerial parts and assessed their antiplatelet and anticoagulant potential. Structural elucidation resulted in the identification of two new compounds: caneduloside A (1) and caneduloside B (2), and eleven known compounds: 6'-acetyl-3,6,2'-tri-p-coumaroyl sucrose (3), 6'-acetyl-3,6,2'-triferuloyl sucrose (4), tiliroside (5), afzelin (6), quercitrin (7), 2-hydroxycinnamaldehyde (8), cinnamic acid (9), 3,4-dimethoxycinnamic acid (10), dehydrovomifoliol (11), 4-hydroxy-3,5-dimethoxybenzaldehyde (12), and (S)-(-)-rosmarinic acid (13). Compounds 3, 4, 6-9, 13 were previously reported for antithrombotic properties. Hence, antithrombotic tests were conducted for 1, 2, 5, 10-12. All tested compounds demonstrated a dose-dependent antiaggregatory effect, and 10 and 12 were the most potent for both ADP and collagen activators. Additionally, 10 and 12 showed anticoagulant effects, with prolonged prothrombin time and activated partial thromboplastin time. The new compound 1 displayed antiplatelet and anticoagulant activity, while 2 mildly inhibited platelet aggregation. C. edulis is a potential source for developing antithrombotic agents.


Assuntos
Anticoagulantes , Componentes Aéreos da Planta , Inibidores da Agregação Plaquetária , Sacarose , Anticoagulantes/farmacologia , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/isolamento & purificação , Sacarose/química , Sacarose/farmacologia , Sacarose/metabolismo , Componentes Aéreos da Planta/química , Componentes Aéreos da Planta/metabolismo , Humanos , Ésteres/química , Ésteres/farmacologia , Ésteres/isolamento & purificação , Agregação Plaquetária/efeitos dos fármacos , Myristicaceae/química , Relação Dose-Resposta a Droga , Estrutura Molecular , Relação Estrutura-Atividade , Animais
4.
Eur J Pharm Biopharm ; 198: 114269, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38527635

RESUMO

Sucrose esters (SEs) have great potential in the field of nucleic acid delivery due to their unique physical and chemical properties and good biosafety. However, the mechanism of the effect of SEs structure on delivery efficiency has not been studied. The liposomes containing peptide lipids and SEs were constructed, and the effects of SEs on the interaction between the liposomes and DNA were studied. The addition of SEs affects the binding rate of liposomes to DNA, and the binding rate gradually decreases with the increase of SEs' carbon chain length. SEs also affect the binding site and affinity of liposomes to DNA, promoting the aggregation of lipids to form liposomes, where DNA wraps around or compresses inside the liposomes, allowing it to compress DNA without damaging the DNA structure. COL-6, which is composed of sucrose laurate, exhibits the optimal affinity for DNA, and SE promotes the formation of ordered membrane structure and enhances membrane stability, so that COL-6 exhibits a balance between rigidity and flexibility, and thus exhibits the highest delivery efficiency of DNA among these formulations. This work provides theoretical foundations for the application of SE in gene delivery and guides for the rational design of delivery systems.


Assuntos
Ésteres , Lipossomos , Lipossomos/química , Ésteres/química , DNA/metabolismo , Sacarose/química , Lipídeos/química
5.
Mol Pharm ; 21(5): 2555-2564, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38551918

RESUMO

Poloxamer 188 (P188) was hypothesized to be a dual functional excipient, (i) a stabilizer in frozen solution to prevent ice-surface-induced protein destabilization and (ii) a bulking agent to provide elegant lyophiles. Based on X-ray diffractometry and differential scanning calorimetry, sucrose, in a concentration-dependent manner, inhibited P188 crystallization during freeze-drying, while trehalose had no such effect. The recovery of lactate dehydrogenase (LDH), the model protein, was evaluated after reconstitution. While low LDH recovery (∼60%) was observed in the lyophiles prepared with P188, the addition of sugar improved the activity recovery to >85%. The secondary structure of LDH in the freeze-dried samples was assessed using infrared spectroscopy, and only moderate structural changes were observed in the lyophiles formulated with P188 and sugar. Thus, P188 can be a promising dual functional excipient in freeze-dried protein formulations. However, P188 alone does not function as a lyoprotectant and needs to be used in combination with a sugar.


Assuntos
Varredura Diferencial de Calorimetria , Excipientes , Liofilização , Poloxâmero , Trealose , Liofilização/métodos , Poloxâmero/química , Excipientes/química , Trealose/química , Varredura Diferencial de Calorimetria/métodos , Sacarose/química , Difração de Raios X , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/química , Cristalização/métodos , Química Farmacêutica/métodos , Proteínas/química , Composição de Medicamentos/métodos , Congelamento
6.
J Agric Food Chem ; 72(10): 5439-5451, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38412221

RESUMO

Increasing hydrogen peroxide (H2O2)-based systems have been developed to degrade various polysaccharides due to the presence of highly reactive free radicals, but published degradation mechanisms are still limited. Therefore, this study aimed to clarify the degradation mechanism of six typical glucosidic bonds from different disaccharides in an ultraviolet (UV)/H2O2 system. The results showed that the H2O2 concentration, disaccharide concentration, and radiation intensity were important factors affecting pseudo-first-order kinetic constants. Hydroxyl radical, superoxide radical, and UV alone contributed 58.37, 18.52, and 19.17% to degradation, respectively. The apparent degradation rates ranked in the order of cellobiose ≈ lactose > trehalose ≈ isomaltose > turanose > sucrose ≈ maltose. The reaction pathways were then deduced after identifying their degradation products. According to quantum chemical calculations, the cleavage of α-glycosidic bonds was more kinetically unfavorable than that of ß-glycosidic bonds. Additionally, the order of apparent degradation rates depended on the energy barriers for the formation of disaccharide-based alkoxyl radicals. Moreover, energy barriers for homolytic scissions of glucosidic C1-O or C7-O sites of these alkoxyl radicals ranked in the sequence: α-(1 → 2) ≈ α-(1 → 3) < α-(1 → 4) < ß-(1 → 4) < α-(1 → 6) < α-(1 → 1) glucosidic bonds. This study helps to explain the mechanisms of carbohydrate degradation by free radicals.


Assuntos
Álcoois , Peróxido de Hidrogênio , Poluentes Químicos da Água , Peróxido de Hidrogênio/química , Glucosídeos , Dissacarídeos/química , Maltose/metabolismo , Sacarose/química , Raios Ultravioleta , Oxirredução , Cinética , Poluentes Químicos da Água/química
7.
Int J Pharm ; 652: 123803, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38218506

RESUMO

This paper explores how vacuum foam-drying of a protein is influenced by formulation parameters by investigating the foam structure, physical properties of the foam, and the stability of the protein. Recombinant human bile salt-stimulated lipase was used as a model of a protein drug. The stability of the lipase was evaluated through activity measurements. Two disaccharides (sucrose and trehalose), strongly tending to an amorphous form, were used as matrix formers, and the physical properties were assessed through residual water content, glass transition temperature, and crystalline state. Moreover, some formulations included surfactants with different sizes and structures of the head group. The alkyl chain length was kept constant to only investigate the impact of the surfactant head group, in the presence of the lipase, on the foamability and surface coverage of the lipase. The study demonstrated that the lipase allowed for a dry, solid foam with a foam overrun of up to 2600 %. The wall thickness of the dry, solid foam was estimated to be 20-50 µm. Clear differences between sucrose and trehalose as matrix former were identified. The lipase showed no tendency to lose activity because of the drying and rehydration, despite a proportion of the lipase covering the surfaces of the dry material.


Assuntos
Sacarose , Trealose , Humanos , Liofilização , Trealose/química , Vácuo , Estabilidade de Medicamentos , Sacarose/química , Tensoativos/química , Lipase
8.
J Phys Chem B ; 128(3): 676-683, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38197901

RESUMO

Addition of sugars such as sucrose to aqueous protein solutions generally stabilizes proteins against thermal denaturation by preferential exclusion of sugars from proteins (preferential hydration of proteins). In this study, we investigated the effect of sucralose, a chlorinated sucrose derivative, on protein stability and preferential solvation. Circular dichroism and small-angle X-ray scattering measurements showed that sucrose increased the denaturation temperature of myoglobin and was preferentially excluded from the protein, whereas sucralose decreased the denaturation temperature of myoglobin and was preferentially adsorbed to the protein. No clear evidence was obtained for the indirect effects of sucralose on protein destabilization via the structure and properties of solvent water from the physicochemical properties (mass density, sound velocity, viscosity, and osmolality) of aqueous sucralose solutions; therefore, we concluded that a direct protein-sucralose interaction induced protein destabilization.


Assuntos
Mioglobina , Água , Água/química , Mioglobina/química , Solventes/química , Sacarose/química , Desnaturação Proteica
9.
Food Chem ; 442: 138406, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38219571

RESUMO

The present study aimed to elucidate the pathway of pigment formation and identify the source of antioxidant activity during sugar smoking. Building upon previous research, this investigation replicated the sucrose cleavage process involved in sugar-smoking through model reactions to obtain distinct model reaction products. The products were analyzed using various techniques such as ultraviolet-visible spectrometry, Fourier-transform infrared spectroscopy, high-performance liquid chromatography, and high-performance liquid chromatography-tandem mass spectrometry. The findings revealed that the pyrolysis of sucrose at 330 °C yielded glucose and fructose, with fructose pyrolysis producing significantly more 5-HMF than glucose. Moreover, the antioxidant capacity of 5-HMF was found to make a substantial contribution. The primary source of 5-HMF was identified as fructose resulting from the cleavage of sucrose at 330 °C, while the primary pathway for the formation of the sugar-smoking pigment 5-GGMF was attributed to the intermolecular dehydration of 5-HMF and glucose at 150 °C.


Assuntos
Antioxidantes , Açúcares , Carboidratos/química , Glucose/química , Sacarose/química , Frutose/química , Fumar , Furaldeído/química
10.
Eur J Pharm Sci ; 192: 106625, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37918545

RESUMO

Saccharides are a popular group of stabilizers in liquid, frozen and freeze dried protein formulations. The current work reviewed the stabilization mechanisms of three groups of saccharides: (i) Disaccharides, specifically sucrose and trehalose; (ii) cyclodextrins (CDs), a class of cyclic oligosaccharides; and (iii) dextrans, a class of polysaccharides. Compared to sucrose, trehalose exhibits a more pronounced preferential exclusion effect in liquid protein formulations, due to its stronger interaction with water molecules. However, trehalose obtains higher phase separation and crystallization propensity in frozen solutions, resulting in the loss of its stabilization function. In lyophilized formulations, sucrose has a higher crystallization propensity. Besides, its glass matrix is less homogeneous than that of trehalose, thus undermining its lyoprotectant function. Nevertheless, the hygroscopic nature of trehalose may result in high water absorption upon storage. Among all the CDs, the ß form is believed to have stronger interactions with proteins than the α- and γ-CDs. However, the stabilization effect, brought about by CD-protein interactions, is case-by-case - in some examples, such interactions can promote protein destabilization. The stabilization effect of hydroxypropyl-ß-cyclodextrin (HPßCD) has been extensively studied. Due to its amphiphilic nature, it can act as a surface-active agent in preventing interfacial stresses. Besides, it is a dual functional excipient in freeze dried formulations, acting as an amorphous bulking agent and lyoprotectant. Finally, dextrans, when combined with sucrose or trehalose, can be used to produce stable freeze dried protein formulations. A strong stabilization effect can be realized by low molecular weight dextrans. However, the terminal glucose in dextrans yields protein glycation, which warrants extra caution during formulation development.


Assuntos
Ciclodextrinas , Trealose , Trealose/química , Sacarose/química , Ciclodextrinas/química , Dextranos/química , Excipientes/química , Água/química , Liofilização
11.
Molecules ; 28(23)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38067437

RESUMO

(1) Background: DA-Gelucire® 50/13-based solid lipid nanoparticles (SLNs) administering the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) have been prepared by us in view of a possible application for Parkinson's disease (PD) treatment. To develop powders constituted by such SLNs for nasal administration, herein, two different agents, namely sucrose and methyl-ß-cyclodextrin (Me-ß-CD), were evaluated as cryoprotectants. (2) Methods: SLNs were prepared following the melt homogenization method, and their physicochemical features were investigated by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). (3) Results: SLN size and zeta potential values changed according to the type of cryoprotectant and the morphological features investigated by SEM showed that the SLN samples after lyophilization appear as folded sheets with rough surfaces. On the other hand, the AFM visualization of the SLNs showed that their morphology consists of round-shaped particles before and after freeze-drying. XPS showed that when sucrose or Me-ß-CD were not detected on the surface (because they were not allocated on the surface or completely absent in the formulation), then a DA surfacing was observed. In vitro release studies in Simulated Nasal Fluid evidenced that DA release, but not the GSE one, occurred from all the cryoprotected formulations. Finally, sucrose increased the physical stability of SLNs better than Me-ß-CD, whereas RPMI 2650 cell viability was unaffected by SLN-sucrose and slightly reduced by SLN-Me-ß-CD. (4) Conclusions: Sucrose can be considered a promising excipient, eliciting cryoprotection of the investigated SLNs, leading to a powder nasal pharmaceutical dosage form suitable to be handled by PD patients.


Assuntos
Extrato de Sementes de Uva , Nanopartículas , Humanos , Extrato de Sementes de Uva/farmacologia , Dopamina , Pós , Nanopartículas/química , Crioprotetores , Liofilização/métodos , Sacarose/química , Tamanho da Partícula
12.
Virus Res ; 336: 199213, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37657509

RESUMO

The Orf virus (ORFV) is a promising candidate for vector vaccines as well as for immunomodulatory and oncolytic therapies. However, few publications are available on its infectivity degradation or on suitable additives for prolonging its viral stability. In this study, the non-supplemented ORFV itself showed a very high stability at storage temperatures up to 28 °C, with a linear titer loss of 0.10 log infectious particles per day at 4 °C over a period of five weeks. To prolong this inherent stability, thirty additives, i.e., detergents, sugars, proteins, salts, and buffers as well as amino acids, were tested for their time- and temperature-dependent influence on the ORFV infectivity. A stabilizing effect on the infectivity was identified for the addition of all tested proteins, i.e., gelatine, bovine serum albumin, and recombinant human serum albumin (rHSA), of several sugars, i.e., mannitol, galactose, sucrose, and trehalose, of amino acids, i.e., arginine and proline, of the detergent Pluronic F68, and of the salt Na2SO4. The infectivity preservation was especially pronounced for proteins in liquid and frozen formulations, sugars in frozen state, and arginine und Pluronic in liquid formulations at high storage temperatures (37 °C). The addition of 1% rHSA with and without 5% sucrose was evaluated as a very stable formulation with a high safety profile and economic validity at storage temperatures up to 28 °C. At increased temperatures, the supplementation with 200 mM arginine performed better than with rHSA. In summary, this comprehensive data provides different options for a stable ORFV formulation, considering temperature, storage time, economic aspects, and downstream processing integrity.


Assuntos
Excipientes , Proteínas , Humanos , Excipientes/química , Liofilização , Sacarose/química , Açúcares , Aminoácidos , Arginina/química
13.
Mol Pharm ; 20(9): 4664-4675, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37555640

RESUMO

The freeze-drying of proteins, along with excipients, offers a solution for increasing the shelf-life of protein pharmaceuticals. Using differential scanning calorimetry, thermogravimetric analysis, sorption calorimetry, and synchrotron small-angle X-ray scattering (SAXS), we have characterized the properties at low (re)hydration levels of the protein lysozyme, which was freeze-dried together with the excipient sucrose. We observe that the residual moisture content in these samples increases with the addition of lysozyme. This results from an increase in equilibrium water content with lysozyme concentration at constant water activity. Furthermore, we also observed an increase in the glass transition temperature (Tg) of the mixtures with increasing lysozyme concentration. Analysis of the heat capacity step of the mixtures indicates that lysozyme does not participate in the glass transition of the sucrose matrix; as a result, the observed increase in the Tg of the mixtures is the consequence of the confinement of the amorphous sucrose domains in the interstitial space between the lysozyme molecules. Sorption calorimetry experiments demonstrate that the hydration behavior of this formulation is similar to that of the pure amorphous sucrose, while the presence of lysozyme only shifts the sucrose transitions. SAXS analysis of amorphous lysozyme-sucrose mixtures and unfolding of lysozyme in this environment show that prior to unfolding, the size and shape of lysozyme in a solid sucrose matrix are consistent with its native state in an aqueous solution. The results obtained from our study will provide a better understanding of the low hydration behavior of protein-excipient mixtures and support the improved formulation of biologics.


Assuntos
Muramidase , Vitrificação , Muramidase/química , Sacarose/química , Água/química , Excipientes/química , Espalhamento a Baixo Ângulo , Difração de Raios X , Proteínas/química , Varredura Diferencial de Calorimetria , Liofilização/métodos
14.
Phys Chem Chem Phys ; 25(32): 21215-21226, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37534799

RESUMO

Disaccharides are well known to be efficient stabilizers of proteins, for example in the case of lyophilization or cryopreservation. However, although all disaccharides seem to exhibit bioprotective and stabilizing properties, it is clear that trehalose is generally superior compared to other disaccharides. The aim of this study was to understand this by comparing how the structural and dynamical properties of aqueous trehalose and sucrose solutions influence the protein myoglobin (Mb). The structural studies were based on neutron and X-ray diffraction in combination with empirical potential structure refinement (EPSR) modeling, whereas the dynamical studies were based on quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations. The results show that the overall differences in the structure and dynamics of the two systems are small, but nevertheless there are some important differences which may explain the superior stabilizing effects of trehalose. It was found that in both systems the protein is preferentially hydrated by water, but that this effect is more pronounced for trehalose, i.e. trehalose forms less hydrogen bonds to the protein surface than sucrose. Furthermore, the rotational motion around dihedrals between the two glucose rings of trehalose is slower than in the case of the dihedrals between the glucose and fructose rings of sucrose. This leads to a less perturbed protein structure in the case of trehalose. The observations indicate that an aqueous environment closest to the protein molecules is beneficial for an efficient bioprotective solution.


Assuntos
Sacarose , Trealose , Trealose/química , Sacarose/química , Dissacarídeos/química , Proteínas , Água/química , Glucose
15.
Mol Pharm ; 20(9): 4587-4596, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37535010

RESUMO

The phase behavior of poloxamer 188 (P188) in aqueous solutions, characterized by differential scanning calorimetry (DSC) and synchrotron X-ray diffractometry, revealed solute crystallization during both freezing and thawing. Sucrose and trehalose inhibited P188 crystallization during freeze-thawing (FT). While trehalose inhibited P188 crystallization only during cooling, sucrose completely suppressed P188 crystallization during both cooling and heating. Lactate dehydrogenase (LDH) served as a model protein to evaluate the stabilizing effect of P188. The ability of P188, over a concentration range of 0.003-0.800% w/v, to prevent LDH (10 µg/mL) destabilization was evaluated. After five FT cycles, the aggregation behavior (by dynamic light scattering) and activity recovery were evaluated. While LDH alone was sensitive to interfacial stress, P188 at concentrations of ≥0.100% w/v stabilized the protein. However, as the surfactant concentration decreased, protein aggregation after FT increased. The addition of sugar (1.0% w/v; sucrose or trehalose) improved the stabilizing function of P188 at lower concentrations (≤0.010% w/v), possibly due to the inhibition of surfactant crystallization. Based on a comparison with the stabilization effect of polysorbate (both 20 and 80), it was evident that P188 could be a promising alternative surfactant in frozen protein formulations. However, when the surfactant concentration is low, the potential for P188 crystallization and the consequent compromise in its functionality warrant careful consideration.


Assuntos
Gelo , Poloxâmero , Congelamento , Trealose/química , Proteínas , L-Lactato Desidrogenase/química , Tensoativos , Sacarose/química , Liofilização , Varredura Diferencial de Calorimetria
16.
J Agric Food Chem ; 71(33): 12549-12557, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37552844

RESUMO

Nucleotide sugars are essential precursors for carbohydrate synthesis but are in scarce supply. Uridine diphosphate (UDP)-glucose is a core building block in nucleotide sugar preparation, making its efficient synthesis critical. Here, a process for producing valuable UDP-glucose and functional mannose from sucrose was established and improved via a semirational sucrose synthase (SuSy) design and the accurate D-mannose isomerase (MIase) cascade. Engineered SuSy exhibited enzyme activity 2.2-fold greater than that of the WT. The structural analysis identified a latch-hinge combination as the hotspot for enhancing enzyme activity. Coupling MIase, process optimization, and reaction kinetic analysis revealed that MIase addition during the high-speed UDP-glucose synthesis phase distinctly accelerated the entire process. The simultaneous triggering of enzyme modules halved the reaction time and significantly increased the UDP-glucose yield. A maximum UDP-glucose yield of 83%, space-time yield of 70 g/L/h, and mannose yield of 32% were achieved. This novel and efficient strategy for sucrose value-added exploitation has industrial promise.


Assuntos
Uridina Difosfato Glucose , Uridina Difosfato Glucose/química , Uridina Difosfato Glucose/metabolismo , Sacarose/química , Sacarose/metabolismo , Mutação , Cinética , Modelos Moleculares , Manose/química , Manose/metabolismo , Estrutura Terciária de Proteína
17.
Appl Microbiol Biotechnol ; 107(20): 6205-6217, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37642718

RESUMO

Naringin found in citrus fruits is a flavanone glycoside with numerous biological activities. However, the bitterness, low water-solubility, and low bioavailability of naringin are the main issues limiting its use in the pharmaceutical and nutraceutical industries. Herein, a glucansucrase from isolated Leuconostoc citreum NY87 was used for trans-α-glucosylattion of naringin by using sucrose as substrate. Two naringin glucosides (O-α-D-glucosyl-(1'''' → 6″) naringin (compound 1) and 4'-O-α-D-glucosyl naringin (compound 2)) were purified and determined their structures by nuclear magnetic resonance. The optimization condition for the synthesis of compound 1 was obtained at 10 mM naringin, 200 mM sucrose, and 337.5 mU/mL at 28 °C for 24 h by response surface methodology method. Compound 1 and compound 2 showed 1896- and 3272 times higher water solubility than naringin. Furthermore, the bitterness via the human bitter taste receptor TAS2R39 displayed that compound 1 was reduced 2.9 times bitterness compared with naringin, while compound 2 did not express bitterness at 1 mM. Both compounds expressed higher neuroprotective effects than naringin on human neuroblastoma SH-SY5Y cells treated with 5 mM scopolamine based on cell viability and cortisol content. Compound 1 reduced acetylcholinesterase activity more than naringin and compound 2. These results indicate that naringin glucosides could be utilized as functional material in the nutraceutical and pharmaceutical industries. KEY POINTS: • A novel O-α-D-glucosyl-(1 → 6) naringin was synthesized using glucansucrase from L. citreum NY87. • Naringin glucosides improved water-solubility and neuroprotective effects on SH-SY5Y cells. • Naringin glucosides showed a decrease in bitterness on bitter taste receptor 39.


Assuntos
Flavanonas , Neuroblastoma , Fármacos Neuroprotetores , Humanos , Fármacos Neuroprotetores/farmacologia , Solubilidade , Acetilcolinesterase , Flavanonas/farmacologia , Sacarose/química , Glucosídeos/farmacologia , Glucosídeos/química , Água , Receptores de Superfície Celular
18.
Biosci Biotechnol Biochem ; 87(10): 1169-1182, 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37491698

RESUMO

Inulin, ß-(2→1)-fructan, is a beneficial polysaccharide used as a functional food ingredient. Microbial inulosucrases (ISs), catalyzing ß-(2→1)-transfructosylation, produce ß-(2→1)-fructan from sucrose. In this study, we identified a new IS (NdIS) from the soil isolate, Neobacillus drentensis 57N. Sequence analysis revealed that, like other Bacillaceae ISs, NdIS consists of a glycoside hydrolase family 68 domain and shares most of the 1-kestose-binding residues of the archaeal IS, InuHj. Native and recombinant NdIS were characterized. NdIS is a homotetramer. It does not require calcium for activity. High performance liquid chromatography and 13C-nuclear magnetic resonance indicated that NdIS catalyzed the hydrolysis and ß-(2→1)-transfructosylation of sucrose to synthesize ß-(2→1)-fructan with chain lengths of 42 or more residues. The rate dependence on sucrose concentration followed hydrolysis-transglycosylation kinetics, and a 50% transglycosylation ratio was obtained at 344 m m sucrose. These results suggest that transfructosylation from sucrose to ß-(2→1)-fructan occurs predominantly to elongate the fructan chain because sucrose is an unfavorable acceptor.


Assuntos
Frutanos , Sacarose , Frutanos/química , Sacarose/química , Hidrólise , Inulina
19.
Int J Biol Macromol ; 244: 125442, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37330087

RESUMO

The catalytic product of levansucrase from Bacillus subtilis (SacB) is mainly composed of 10 % high molecular weight levan (HMW, ~2000 kDa) and 90 % low molecular weight levan (LMW, ~7000 Da). In order to achieve efficient production of food hydrocolloid, high molecular weight levan (HMW), with the help of molecular dynamics simulation software, a protein self-assembly element, Dex-GBD, was found and fused with the C-terminus of SacB to construct a novel fusion enzyme, SacB-GBD. The product distribution of SacB-GBD was reversed compared with SacB, and the proportion of HMW in the total polysaccharide was significantly increased to >95 %. We then confirmed that the self-assembly was responsible for the reversal of the SacB-GBD product distribution by the simultaneous modulation of SacB-GBD particle size and product distribution by SDS. The hydrophobic effect may be the main driver of self-assembly as analyzed by molecular simulations and hydrophobicity determination. Our study provides an enzyme source for the industrial production of HMW and provides a new theoretical basis for guiding the molecular modification of levansucrase towards the size of the catalytic product.


Assuntos
Hexosiltransferases , Sacarose , Sacarose/química , Oligossacarídeos/metabolismo , Peso Molecular , Hexosiltransferases/química , Frutanos/química , Bacillus subtilis
20.
Molecules ; 28(12)2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37375320

RESUMO

Twenty-four new phenylpropanoid esters of sucrose, phanerosides A-X (1-24), were isolated from an EtOH extract of the rattans of Phanera championii Benth. (Fabaceae). Their structures were elucidated on the basis of comprehensive spectroscopic data analysis. A wide range of structural analogues were presented due to the different numbers and positions of acetyl substituents and the structures of phenylpropanoid moieties. Phenylpropanoid esters of sucrose were isolated from the Fabaceae family for the first time. Biologically, the inhibitory effects of compounds 6 and 21 on NO production in LPS-induced BV-2 microglial cells were better than that of the positive control, with IC50 values of 6.7 and 5.2 µM, respectively. The antioxidant activity assay showed that compounds 5, 15, 17, and 24 displayed moderate DPPH radical scavenging activity, with IC50 values ranging from 34.9 to 43.9 µM.


Assuntos
Bauhinia , Sacarose , Sacarose/química , Ésteres/química , Antioxidantes/farmacologia , Antioxidantes/química , Estrutura Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...