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1.
Phytochemistry ; 195: 113073, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34974412

RESUMEN

Six flavonoids, namely, three undescribed biflavonoids, one undescribed 8-aryl flavonoid, and two known compounds, were isolated from Selaginella tamariscina (P.Beauv.) Spring. The structures and absolute configurations of those undescribed compounds were established by NMR spectroscopy data, HRESIMS analyses and electronic circular dichroism (ECD) analyses. In addition, all the isolates were evaluated for their hypoglycemic activity in HepG2 cells. Involvenflavone H, I, and J significantly increased glucose consumption in both normal and insulin-resistant HepG2 cells. Interestingly, these three compounds can effectively upregulate the protein expression of glucokinase (GCK) and adenylate cyclases (ADCYs). These results suggested that involvenflavone H, I, and J (especially involvenflavone J) may have potent hypoglycemic activity, which also provided promising molecular targets for the treatment of diabetes.


Asunto(s)
Selaginellaceae , Flavonoides/farmacología , Hipoglucemiantes/farmacología , Insulina , Estructura Molecular
2.
J Asian Nat Prod Res ; 24(1): 76-87, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34937462

RESUMEN

Renal fibrosis is a critical pathological process lead to a progressive loss of renal function. Jolkinolide B (JB) is a natural compound with anti-inflammatory activity from Euphorbia fischeriana Steud. The study evaluated the effect of JB on renal fibrosis in mice with unilateral ureteral obstruction (UUO). The results showed that JB could decrease renal fibrotic area, reduce phosphorylation of NF-κB p65 and the release of TNF-α, IL-6 and IL-1ß, restore the expression of vementin, α-SMA and E-cadherin, as well as TGF-ß1 and p-smad2/3. In conclusion, JB might reduce renal fibrosis by inhibiting inflammation induced by NF-κB pathway and EMT mediated by TGF-ß1/Smad pathway.


Asunto(s)
Obstrucción Ureteral , Animales , Antiinflamatorios/farmacología , Diterpenos , Transición Epitelial-Mesenquimal , Fibrosis , Riñón/patología , Ratones , Estructura Molecular , Transducción de Señal , Factor de Crecimiento Transformador beta1/farmacología , Factor de Crecimiento Transformador beta1/uso terapéutico , Obstrucción Ureteral/tratamiento farmacológico , Obstrucción Ureteral/patología
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120259, 2022 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-34388428

RESUMEN

Diabetes mellitus (DM) is associated with a high incidence of morbidity and mortality which, in many cases, is derived from the progressive kidney dysfunction due to diabetic nephropathy (DN). In this study, synchrotron-Fourier-transform infrared (SR-FTIR) microspectroscopy was used to identify molecular changes in the lipid and protein regions in the plasma of patients with different stages of DN (mild, moderate, severe and end-stage), and patients with type 2 diabetes mellitus (T2DM) without DN. Our results revealed different conformational changes in the proteins secondary structure between DN stages, and between DN and T2DM groups illustrated by peak shifts and intensity alterations. End-stage DN showed the highest CH2/CH3 ratio and intensity of the carbonyl group in protein-carbonyl region compared to other DN stages indicating high level of unsaturation and lipid peroxidation and oxidation conditions. Moreover, end-stage DN group was characterized by a decrease in amide I and amide II absorption signals which reflected a sign of hypoalbuminemia. When compared to T2DM, DN group demonstrated a higher oxidation state as confirmed via the high intensity of the carbonyl group and the high level of malondialdehyde. The current study highlights the promising role of SR-FTIR microspectroscopy as a new sensitive analytical approach that can be used to provide better understanding of the pathophysiology of DN, and guide the development of new preventive therapies and treatments.


Asunto(s)
Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/diagnóstico , Humanos , Estructura Molecular , Plasma , Sincrotrones
4.
Food Chem ; 368: 130806, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34399184

RESUMEN

The objective of this study was to compare the in vitro digestibility of different buckwheat and wheat starch cultivars and establish the relationship between digestibility and structure of buckwheat starch. Structure of starches were analyzed with size exclusion chromatography and fluorophore-assisted capillary electrophoresis. Results showed that the amylose content of Tartary buckwheat starch (TBS) and common buckwheat starch (CBS) was 3-4% lower than that of wheat starch. However, no significant difference in the digestibility was found between them. The fast digestion rate coefficient of TBS was negatively correlated with the amount of long amylopectin chains (24 < DP ≤ 36), and the total digested starch percentage of CBS was negatively correlated with the amount of medium-long amylopectin chains (13 < DP ≤ 24). This suggests that the digestibility of fully gelatinized starch had no association with the botanical sources but may be more influenced by starch structure.


Asunto(s)
Fagopyrum , Almidón , Amilopectina , Amilosa , Estructura Molecular , Triticum
5.
Food Chem ; 369: 130876, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34455332

RESUMEN

In-depth molecular structure and properties of cassava-derived resistant maltodextrins (RMDs) were determined. Cassava starch was dextrinized with 0.04% or 0.06% HCl at 120 °C for 60-180 min to obtain resistant dextrins (RDs), which were further hydrolyzed by α-amylase to produce RMDs. Prolonging dextrinization duration decreased proportion of α-1,4 linkages and α-/ß-reducing ends but increased fraction of indigestible α-/ß-1,6, ß-1,4, ß-1,2 linkages, degree of branching (DB), degree of polymerization, relative molecular weight, and total dietary fiber (TDF) content of the RMDs. Moreover, RMDs had greater proportion of ß-glycosidic linkages, α-/ß-reducing end, DB, TDF, and low molecular weight dietary fiber (LMWDF) content than their RD counterparts. Potential prebiotic activity score was higher in RMDs with abundant LMWDF fraction but low DB. Slight difference in the glass transition temperature of maximally freeze-concentrated unfrozen phase (Tg') and unfrozen water content was found among RMDs. However, RMDs had lower Tg' than their RD counterparts.


Asunto(s)
Manihot , Estructura Molecular , Polisacáridos , Almidón
6.
Phys Chem Chem Phys ; 24(2): 861-874, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34908073

RESUMEN

Src homology-2 domain-containing protein tyrosine phosphatase 1 (SHP1) is mainly restricted to hematopoietic and epithelial cells and widely accepted as a convergent node for oncogenic cell-signaling cascades. The development of efficient methods for rapidly tracing and inhibiting the SHP1 activity in complex biological systems is of considerable significance for advancing the integration of diagnosis and treatment of the related disease. With this aim, we designed and synthesized five 2-phenyl-1,3,4-thiadiazole derivatives (PT2, PT5, PT8, PT9 and PT10) here based on the reported SHP1 inhibitors (PT1, PT3, PT4, PT6 and PT7). The photophysical properties and inhibitory activities of these 2-phenyl-1,3,4-thiadiazole derivatives (PT1-PT10) against SHP1 were thoroughly studied from the theoretical simulation and experimental application aspects. The representative compound PT10 exhibited a larger quantum yield than the other molecules because of the smaller geometric relaxation and reorganization energy of the excited state, which was consistent with the results from the fluorescence experiments in organic solvents. In addition, PT10 showed a selective fluorescence response for SHP1 activity and low cytotoxicity in HeLa cells. Lastly, it indicated the potential application in two-photon cell fluorescence imaging in the future according to the calculated excellent two-photon absorption properties. In this contribution, firstly, we offered the fluorescent and activated molecule PT10 against SHP1, which achieved the integration of visualization and inhibitory activity of SHP1 preliminarily at the enzyme molecular level.


Asunto(s)
Teoría Funcional de la Densidad , Inhibidores Enzimáticos/farmacología , Proteína Tirosina Fosfatasa no Receptora Tipo 6/antagonistas & inhibidores , Tiadiazoles/farmacología , Inhibidores Enzimáticos/química , Células HeLa , Humanos , Estructura Molecular , Proteína Tirosina Fosfatasa no Receptora Tipo 6/metabolismo , Tiadiazoles/química
7.
Phys Chem Chem Phys ; 24(2): 687-696, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34927643

RESUMEN

Enzymatic hydrolysis by phosphotriesterase (PTE) is one of the most effective ways of degrading organophosphorus pesticides, but the catalytic efficiency depends on the structural features of substrates. Here the enzymatic degradation of diazinon (DIN) and diazoxon (DON), characterized by PS and PO, respectively, have been investigated by QM/MM calculations and MM MD simulations. Our calculations demonstrate that the hydrolysis of DON (with PO) is inevitably initiated by the nucleophilic attack of the bridging-OH- on the phosphorus center, while for DIN (with PS), we proposed a new degradation mechanism, initiated by the nucleophilic attack of the Znα-bound water molecule, for its low-energy pathway. For both DIN and DON, the hydrolytic reaction is predicted to be the rate-limiting step, with energy barriers of 18.5 and 17.7 kcal mol-1, respectively. The transportation of substrates to the active site, the release of the leaving group and the degraded product are generally verified to be favorable by MD simulations via umbrella sampling, both thermodynamically and dynamically. The side-chain residues Phe132, Leu271 and Tyr309 play the gate-switching role to manipulate substrate delivery and product release. In comparison with the DON-enzyme system, the degraded product of DIN is more easily released from the active site. These new findings will contribute to the comprehensive understanding of the enzymatic degradation of toxic organophosphorus compounds by PTE.


Asunto(s)
Teoría Funcional de la Densidad , Simulación de Dinámica Molecular , Compuestos Organofosforados/metabolismo , Plaguicidas/metabolismo , Hidrolasas de Triéster Fosfórico/metabolismo , Estructura Molecular , Compuestos Organofosforados/química , Plaguicidas/química , Hidrolasas de Triéster Fosfórico/química
8.
Chem Commun (Camb) ; 58(3): 343-382, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34904599

RESUMEN

2-Aminopyridine is a simple, low molecular weight and perfectly functionalised moiety known for the synthesis of diverse biological molecules. Many pharmaceutical companies across the globe aim to synthesise low-molecular weight molecules for use as pharmacophores against various biological targets. 2-Aminopyridine can serve as a perfect locomotive in the synthesis and pulling of such molecules towards respective pharmacological goals. The major advantage of this moiety is its simple design, which can be used to produce single products with minimum side reactions. Moreover, the exact weight of synthesised compounds is low, which enables facile identification of toxicity-causing metabolites in drug discovery programmes. This manuscript is a quick review of such pharmacophores derived from 2-aminopyridine.


Asunto(s)
Aminopiridinas/química , Descubrimiento de Drogas , Aminopiridinas/síntesis química , Estructura Molecular
9.
Chem Commun (Camb) ; 58(4): 569-572, 2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-34913054

RESUMEN

In this study, we report on a bi-metal organic framework, MOF-919 (Fe-Cu), capable of bifunctional-enzyme mimicking activity with oxidase- and peroxidase-like activities. The catalytic activities were examined by using o-phenylenediamine (OPD) as a chromogenic substrate to study oxidase- and peroxidase-like mimetics. Based on our findings, we developed a simple epinephrine colorimetric biosensor with a broad linear range (1-100 µM) and a low detection limit (0.298 µM). This approach provides evidence for transition metal-based pristine bi-metallic MOFs capable of reproducing both oxidase-peroxidase properties, which could be applied as new nanosensors.


Asunto(s)
Cobre/metabolismo , Hierro/metabolismo , Estructuras Metalorgánicas/metabolismo , Oxidorreductasas/metabolismo , Peroxidasa/metabolismo , Fenilendiaminas/análisis , Biocatálisis , Técnicas Biosensibles , Colorimetría , Cobre/química , Hierro/química , Estructuras Metalorgánicas/química , Estructura Molecular , Oxidorreductasas/química , Peroxidasa/química , Fenilendiaminas/metabolismo
10.
Chem Commun (Camb) ; 58(4): 573-576, 2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-34913446

RESUMEN

Fluorophores with different emission wavelengths were efficiently quenched by a tert-butyl terminated tetrazylmethyl group and activated by an isonitrile-tetrazine click-to-release reaction. Nucleic acid templated chemistry significantly accelerated this bioorthogonal cleavage. Moreover, two mutually orthogonal fluorogenic cleavage reactions were simultaneously conducted in live cells for the first time.


Asunto(s)
Compuestos Aza/química , Derivados del Benceno/química , Colorantes Fluorescentes/química , Nitrilos/química , Imagen Óptica , Línea Celular Tumoral , Humanos , Estructura Molecular
11.
J Hazard Mater ; 423(Pt A): 127040, 2022 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-34474366

RESUMEN

Osmotic membrane bioreactors (OMBRs) have been applied to enhance removal of antibiotics, however, information on the effects of molecular structures on the behavior of antibiotics is still lacking. Herein, adsorption kinetics, transformation pathways, and membrane rejection mechanisms of OMBRs were investigated by adding two typical antibiotics (i.e., sulfadiazine, SDZ, and tetracycline hydrochloride, TC-HCl). 80.70-91.12% of TC-HCl was removed by adsorption and biodegradation, while 17.50-75.14% of SDZ was removed by membrane rejection; this depended on its concentration due to reduced electrostatic interactions and hydrophobic adsorption. The adsorption capacity of TC-HCl (i.e., 1.34±0.01 mg/g) was significantly higher than that of SDZ (i.e., 0.18±0.03 mg/g) due to enhanced π-π interactions, hydrogen bonding and improved electrostatic interactions. The abundant production of polysaccharide-like substances from TC-HCl biodegradation contributed to microbial metabolism and thus enhanced microbial function during TC-HCl biotransformation. The primary degradation pathways were determined by microbial function analysis, and the primary intermediates from TC-HCl degradation were less toxic than those from SDZ degradation due to the different reactions of amino groups. These results and the corresponding mechanism provide a theoretical foundation for the further development of OMBR technology for highly efficient treatment of antibiotic wastewater.


Asunto(s)
Antibacterianos , Reactores Biológicos , Estructura Molecular , Ósmosis , Sulfadiazina
12.
Phytochemistry ; 193: 112975, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34649046

RESUMEN

In this study, the popular food and medicinal herb Ophiopogon japonicus was investigated alongside a 70% ethanol extract of its rhizomes, revealing twenty-three steroidal glycosides with four undescribed steroidal saponins, named ophiopogonols A-D. Among them, ophiopogonols A-B are two unusual spirostanols with a rearranged A/B ring system (5/7/6/5/5/6 ring system) that have not previously been identified in plants. The chemical structures of all isolated steroidal glycosides were elucidated by comprehensive analysis through chemical methods, HRESIMS, and NMR spectroscopy. Further, putative biosynthetic pathways for ophiopogonols A-B were proposed. In addition, based on traditional applications of O. japonicus, cytotoxic effects of the isolates were evaluated using human large cell lung carcinoma cells (NCI-H460 cells). Sprengerinin C displayed a remarkable cytotoxic effect with IC50 values of 2.1 ± 0.8 µM by inducing apoptosis and G2/M phase cycle arrest in the NCI-H460 cell line.


Asunto(s)
Ophiopogon , Saponinas , Espirostanos , Glicósidos , Estructura Molecular , Rizoma , Saponinas/farmacología , Espirostanos/farmacología
13.
Phytochemistry ; 193: 112981, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34653910

RESUMEN

In this research, twenty aromatic and branched aliphatic polyketides, including seven previously undescribed butenolide derivatives, piterriones A-G and one known analogue, along with twelve known altenusin derivatives, were isolated from the isopod-associated fungus Pidoplitchkoviella terricola. Their structures were elucidated by analysis of NMR (1D and 2D) and mass spectrometry data, and their absolute configurations were determined by Mosher's method, microscale derivatization, and comparison of their specific rotations and ECD spectra. Dihydroaltenuene B exhibited mushroom tyrosinase inhibitory activity with an IC50 value of 38.33 ± 1.59 µM, which was comparable to that of the positive control, kojic acid (IC50 = 39.72 ± 1.34 µM). A molecular-docking study disclosed the hydrogen bonding interactions between the 3-OH and 4'-OH of dihydroaltenuene B and the His244, Met280 and Gly281 residues of tyrosinase.


Asunto(s)
Ascomicetos , Isópodos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/farmacología , Animales , Estructura Molecular
14.
Phytochemistry ; 193: 112979, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34653911

RESUMEN

In the course of our continuing search for biologically active compounds from medicinal sources, we further investigated the aqueous extract of Metapanax delavayi (Franch.) J. Wen & Frodin (Araliaceae) leaves. Five undescribed terpene glycosides, liangwanosides B-F referring to two megastigmane glycosides, one monoterpene glycoside, and two sesquiterpene glycosides, together with seven known compounds were isolated. Their chemical structures were elucidated by detailed spectroscopy (1D/2D NMR), HRESIMS data analysis, hydrolysis, and comparison of experimental and calculated electronic circular dichroism (ECD) data. The biological evaluation of benign prostate hyperplasia (BPH) inhibition revealed that some compounds, including liangwanosides B-D, benzyl-O-α-L-rhamnopyranosyl-(1 â†’ 6)-ß-D-glucopyranoside, methyl 2-O-ß-D-glucopyranosylbenzoate, and 3,4-dihydroxybenzaldehyde, exhibited moderate inhibitory activity against BPH-1 cells with inhibition rates ranging from 13.8% to 23.8% at 100 µM. Among them, liangwanoside B showed the comparable effect to positive control (finasteride) at 100 µM, and its possible mechanism was then explored by molecular docking studies.


Asunto(s)
Araliaceae , Hiperplasia Prostática , Glicósidos/farmacología , Simulación del Acoplamiento Molecular , Estructura Molecular , Hojas de la Planta , Hiperplasia Prostática/tratamiento farmacológico
15.
Phytochemistry ; 193: 112973, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34656025

RESUMEN

Ten previously undescribed cassane diterpenoids, cassabonducins A-J, and eleven known compounds were isolated from the seeds of Caesalpinia bonduc. The structures of the undescribed compounds were elucidated by extensive analysis of spectroscopic data (IR, HRESIMS, and 1H, 13C and 2D NMR) and their absolute configurations were determined by the ECD data and single-crystal X-ray diffraction analysis. ε-Caesalpin-Ⅶ was obtained from natural resources for the first time. Cassabonducin A possessed noteworthy inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages with IC50 value of 6.12 µM. Cassabonducin D and neocaesalpin N showed moderate α-glucosidase inhibition at the concentration of 50 µM with inhibitory capacities of 47.17% and 43.83%, respectively.


Asunto(s)
Caesalpinia , Diterpenos , Diterpenos/farmacología , Espectroscopía de Resonancia Magnética , Estructura Molecular , Óxido Nítrico , Semillas , alfa-Glucosidasas
16.
Food Chem ; 371: 131046, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34537614

RESUMEN

To investigate the 3D printability of surimi from golden pompano, the rheological properties, protein molecular structure, and 3D printability of food inks from every step of surimi processing were measured, and their correlations were analysed. The results showed that surimi from chopping (surimi-C), chopping with salt (surimi-CS) and setting (surimi-S) were suitable for 3D printing, among which surimi-CS had the best shape fidelity. The clustering analysis of variables revealed that the yield stress and AF could be used as indexes to characterize extrusion and deposition behaviour of surimi, respectively. The accuracy of 3D printing was affected by the extrusion property of the food ink, which was controlled by the ionic bond content. The stability of 3D printing was affected by the self-supporting capacity of the food ink, which was controlled by the hydrogen bond and hydrophobic interaction contents. The results provided theoretical guidance for developing 3D printing of surimi ingredients.


Asunto(s)
Tinta , Impresión Tridimensional , Animales , Peces , Estructura Molecular , Reología
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120396, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34592685

RESUMEN

Water activity is an important phenomenon not yet explained in terms of water molecular structure. This paper aims to find the relationship between the water activity and water molecular structure of the rice germ, based on its spectral pattern which can be measured using non-destructive technology. Aquaphotomics near-infrared spectroscopy was used to study rice germ stored at different levels of water activity and atmosphere. The findings show that state of the rice germ is governed by the water activity upon storage, which is defined by the structure of water within germ matrix. The structure of water can be described solely by the absorbance spectral pattern at the following absorbance bands: proton hydrates, hydration shells and water vapor (1364, 1375 and 1382 nm), trapped water (1392 nm), free water (1410 nm), hydration water (1425 nm), adsorbed water (1455 nm), non-bonded hydroxyl (1436 nm) and bound water (1520 nm).


Asunto(s)
Oryza , Espectroscopía Infrarroja Corta , Biomarcadores , Estructura Molecular , Preservación Biológica
18.
J Colloid Interface Sci ; 607(Pt 2): 1754-1761, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34598032

RESUMEN

Saponins like ß-escin exhibit an unusually high surface activity paired with a remarkable surface rheology which makes them as biosurfactants highly interesting for applications in soft matter colloids and at interfaces. We have applied vibrational sum-frequency generation (SFG) to study ß-escin adsorption layers at the air-water interface as a function of electrolyte pH and compare the results from SFG spectroscopy to complementary experiments that have addressed the surface tension and the surface dilational rheology. SFG spectra of ß-escin modified air-water interfaces demonstrate that the SFG intensity of OH stretching vibrations from interfacial water molecules is a function of pH and dramatically increases when the pH is increased from acidic to basic conditions and reaches a plateau at a solution pH of > 6. These changes are attributable to the interfacial charging state and to the deprotonation of the carboxylic acid group of ß-escin. Thus, the change in OH intensity provides qualitative information on the degree of protonation of this group at the air-water interface. At pH < 4 the air-water interface is dominated by the charge neutral form of ß-escin, while at pH > 6 its carboxylic acid group is fully deprotonated and, consequently, the interface is highly charged. These observations are corroborated by the change in equilibrium surface tension which is qualitatively similar to the change in OH intensity as seen in the SFG spectra. Further, once the surface layer is charge neutral, the surface elasticity drastically increases. This can be attributed to a change in prevailing intermolecular interactions that change from dominating repulsive electrostatic interactions at high pH, to dominating attractive interactions, such as hydrophobic and dispersive interactions, as well as, hydrogen bonding at low pH values. In addition to the clear changes in OH intensity from interfacial H2O, the SFG spectra exhibit drastic changes in the CH bands from interfacial ß-escin which we relate to differences in the net molecular orientation. This orientation change is driven by tighter packing of ß-escin adsorption layers when the ß-escin moiety is in its charge neutral form (pH < 4).


Asunto(s)
Escina , Agua , Concentración de Iones de Hidrógeno , Estructura Molecular , Tensión Superficial
19.
J Colloid Interface Sci ; 607(Pt 2): 1805-1812, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34600344

RESUMEN

Shear thickening fluids (STFs) have been the research focus for decades because of the prospect as a damping ingredient. However, their inherent liquid character confines their practical applications. In this work, inspired by the assembly engineering, novel gelatinous shear thickening fluids (GSTFs) are fabricated by integrating low molecular weight gelators (LMWGs) into STFs and investigated by rheological experiments. The results show that the apparent performances of GSTFs are determined by the LMWGs content. LMWGs inside GSTFs can assemble into three-dimensional network that can constraint the flowability of liquid molecular and their content dominate the density and strength of assembly network. At a moderate content, GSTFs exhibit desired properties with restricted quasi-static flowability and almost undamaged dynamic shear thickening character. While a higher content will disappear shear thickening and a lower content cannot gelate STFs. Besides, three different LMWGs are employed to gelate STFs and all they can gelate STFs in spite of the distinct minimum gelation concentration, indicating the universality for GSTFs preparation and the superiority of a reasonable molecular structure of LMWGs. Further, the temperature sweep experiments suggest that GSTFs can endure higher temperature without flowing due to its higher gel-sol transition temperature. Basing on these advanced mechanical properties, we believe that the GSTFs with more expected characters have significance for the study of non-Newtonian fluids and will broaden the special application field of STFs.


Asunto(s)
Reología , Estructura Molecular , Peso Molecular , Temperatura
20.
Food Chem ; 371: 131194, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34600364

RESUMEN

Styrian pumpkin seed oil is a conditioned green-colored oil renowned for nutty smell and taste. Due to α-linolenic acid (ALA) contents below 1% of total fatty acids and the prospect of nutritional health claims based on its potential oxidation products, we investigated the fate of ALA and product oxylipins in the course of down-stream processing of seeds and in oils. Lipidomic analyses with Lipid Data Analyzer 2.8.1 revealed: Processing did not change (1) main fatty acid composition in the oils, (2) amounts of triacylglycerol species, (3) structures of triacylglycerol molecular species containing ALA. (4) Minor precursor ALA in fresh Styrian and normal pumpkins produced 6 product phytoprostanes in either cultivar, quantitatively more in the latter. (5) In oil samples 7 phytoprostanes and 2 phytofurans were detected. The latter two are specific for their presence in pumpkin seed oils, of note, quantitatively more in conditioned oils than in cold-pressed native oils.


Asunto(s)
Cucurbita , Ácidos Grasos , Lipidómica , Estructura Molecular , Oxilipinas , Aceites Vegetales , Semillas , Triglicéridos , Ácido alfa-Linolénico
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