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1.
Acta Pharmacol Sin ; 45(2): 422-435, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37816856

RESUMO

Extracellular regulated protein kinases 1/2 (ERK1/2) are key members of multiple signaling pathways, including the ErbB axis. Ectopic ERK1/2 activation contributes to various types of cancer, especially drug resistance to inhibitors of RTK, RAF and MEK, and specific ERK1/2 inhibitors are scarce. In this study, we identified a potential novel covalent ERK inhibitor, Laxiflorin B, which is a herbal compound with anticancer activity. However, Laxiflorin B is present at low levels in herbs; therefore, we adopted a semi-synthetic process for the efficient production of Laxiflorin B to improve the yield. Laxiflorin B induced mitochondria-mediated apoptosis via BAD activation in non-small-cell lung cancer (NSCLC) cells, especially in EGFR mutant subtypes. Transcriptomic analysis suggested that Laxiflorin B inhibits amphiregulin (AREG) and epiregulin (EREG) expression through ERK inhibition, and suppressed the activation of their receptors, ErbBs, via a positive feedback loop. Moreover, mass spectrometry analysis combined with computer simulation revealed that Laxiflorin B binds covalently to Cys-183 in the ATP-binding pocket of ERK1 via the D-ring, and Cys-178 of ERK1 through non-inhibitory binding of the A-ring. In a NSCLC tumor xenograft model in nude mice, Laxiflorin B also exhibited strong tumor suppressive effects with low toxicity and AREG and EREG were identified as biomarkers of Laxiflorin B efficacy. Finally, Laxiflorin B-4, a C-6 analog of Laxiflorin B, exhibited higher binding affinity for ERK1/2 and stronger tumor suppression. These findings provide a new approach to tumor inhibition using natural anticancer compounds.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Camundongos , Animais , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Receptores ErbB , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Sistema de Sinalização das MAP Quinases , Camundongos Nus , Simulação por Computador , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Mutação , Linhagem Celular Tumoral
2.
Artigo em Inglês | MEDLINE | ID: mdl-38232715

RESUMO

OBJECTIVES: To identify an optimal magnetic resonance imaging (MRI)-based classification for the severity of adenomyosis and explore the factors associated with disease severity (dysmenorrhea or menorrhagia). DESIGN AND PARTICIPANTS: Several classifications based on MRI have been proposed, and their phenotypes are reported to be associated with the severity of adenomyosis. However, a consensus classification based on MRI findings has not yet been reached. Our study was designed to retrospectively analyze data from a cohort of patients in the Affiliated Nanchong Central Hospital of North Sichuan Medical College from June 2017 to December 2021 before focused ultrasound ablation surgery (FUAS), to identify the optimal classification of adenomyosis severity from different classification criteria and explore factors associated with the presence of symptoms. METHODS: The proportions of disease severity among different classification groups were compared to obtain the one generating the most considerable chi-square value, which was identified as the optimal classification for informing disease severity. A logistic regression model was constructed to explore factors associated with disease severity. RESULTS: Classification of Kobayashi H (classification 4) concerning the affected areas and size (volumes of lesions) was recognized as the optimal one, which identified dysmenorrhea (χ2=18.550, p-value=0.002) and menorrhagia (χ2=15.060, p-value=0.010) secondary to adenomyosis. For volumes of uterine wall <2/3, the dysmenorrhea rate in subtype-4 was higher than that in subtype-1 (χ2=4.114, p-value=0.043), and the dysmenorrhea rate in subtype-5 was higher than that in subtype-2 (χ2=4.357, p-value=0.037). Age (OR=0.899, 95%CI=0.810~0.997, p-value=0.044) and external phenotype (OR=3.588, 95%CI=CI 1.018~12.643, p-value=0.047) were associated with dysmenorrhea. Concerning volumes of uterine wall ≥2/3, the menorrhagia rate in subtype-3 remarkably increased compared with that in subtype-6 (χ2=9.776, p-value=0.002), and internal phenotype was identified as an independent factor associated with menorrhagia (OR=1.706, 95%CI=1.131~2.573, p-value=0.011). LIMITATIONS: Patients in our study were all included before FUAS, which limited our result interpretation for the general patient population. CONCLUSIONS: MRI-based classification 4 is identified as an optimal classification for informing the severity of adenomyosis. The phenotype of classification is the main characteristic associated with disease severity.

3.
Perfusion ; : 2676591231180997, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37290065

RESUMO

BACKGROUND: Cardiopulmonary bypass (CPB) causes coagulation disorders after surgery. This study aimed to compare the coagulation parameters after congenital cardiac surgery with miniaturised CPB (MCPB) versus conventional CPB (CCPB). METHODS: We gathered information about children who underwent cardiac surgery between 1/1/2016 and 12/31/2019. Using propensity score-matched data, we compared the coagulation parameters and postoperative outcomes of the MCPB and CCPB groups. RESULTS: A total of 496 patients (327 with MCPB, 169 withCCPB) underwent congenital cardiac surgery, and 160 matched pairs in each group were enrolled in the analysis. Compared with CCPB children, MCPB children had a lowermean prothrombin time (14.9 ± 2.0 vs 16.4 ± 4.1; p < 0.001)and international normalised ratio (1.3 ± 0.2 vs. 1.4 ± 0.3; p < 0.001), but higher thrombin time (23.4 ± 20.4 vs 18.2 ± 4.4; p = 0.002). The CCPB group had greaterperioperative changes inprothrombin time, international normalised ratio, fibrinogen, and antithrombin III activity (all p < 0.01) but lower perioperative changesin thrombin time (p = 0.001) thanthe MCPB group. Ultra-fasttrack extubation and blood transfusionrates, postoperative blood loss, and intensive care unitlength of stay were considerably decreased in the MCPB group. There were no considerable intergroup differences in the activated partial thromboplastin time or platelet count. CONCLUSIONS: Compared with CCPB, MCPB was associated with lower coagulation changes and better early outcomes, including shorter intensive care unit stay and less postoperative blood loss.

4.
J Microencapsul ; 40(6): 456-474, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37249352

RESUMO

AIMS: To evaluate the potential applications of soy protein-glucan-catechin (SGC) complexes prepared with different ultrasound times in stabilising high internal phase Pickering emulsion (HIPPE) and delivering curcumin. METHODS: The SGC complexes were characterised by particle size, morphology, zeta potential, Fourier transform infra-red, and fluorescence spectroscopy. Formation and stability of curcumin emulsions were monitored by droplet size, microstructure, rheological property, lipid oxidation, and in vitro digestion. RESULTS: Short-time ultrasound-induced complexes (SGC-U15) exhibited a small size and wettability of ∼82.5°. The chemical stability and bioaccessibility of curcumin was greatly improved by SGC-U15-stabilised HIPPEs, even after 70 days of storage, heating at 100 °C for 30 min, ultraviolet irradiation for 120 min, and in vitro digestion, owing to the formation of elastic gel-like structure at the oil/water interfaces. CONCLUSION: Our findings may contribute to the design of emulsion-based delivery systems using ultrasound-induced protein-polysaccharide-polyphenol complexes.


Assuntos
Catequina , Curcumina , Nanopartículas , beta-Glucanas , Emulsões , Proteínas de Soja
5.
Plant Foods Hum Nutr ; 76(4): 419-426, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32857283

RESUMO

The objective of this study was to evaluate the fermentation characteristics of proteins from diverse sources by human gut microbiota. Cereal proteins (rice and oat), red meat proteins (pork and beef), chicken protein and casein were selected as the substrates for simulated gastrointestinal digestion (SGID), and human faecal samples were collected from healthy donors as the inoculum of fermentation. In this study, we further analyzed the correlations of amino acids (AA) compositions, fermentation productions and gut microbiota. As the results, the animal protein groups had higher degree of hydrolysis (DH) after digestion and higher levels of ammonia nitrogen (NH3-N) after fermentation than cereal proteins. The pH value of fermentation liquid declined as proteins were added during fermentation. Cereal protein groups promoted the gut microbiota to produce more short chain fatty acids (SCFAs) with the high proportion of acetate, propionate and butyrate by lowering the pH than red meat proteins. The abundance of Firmicutes at phylum level in cereal protein groups was lower than red meat proteins after fermentation. The cereal protein groups enhanced the growth of Bacteroides spp. and Bifidobacterium spp. while red meat proteins stimulated the growth of Peptoclostridium spp.. Taken together, our research implies that cereal proteins have better fermentation characters than red meat proteins.


Assuntos
Microbioma Gastrointestinal , Animais , Bovinos , Proteínas Alimentares , Ácidos Graxos Voláteis , Fezes , Fermentação , Humanos
7.
J Sep Sci ; 37(7): 782-91, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24478185

RESUMO

A new method combining the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method with ultra high performance liquid chromatography and ESI quadrupole Orbitrap high-resolution MS was developed for the highly accurate and sensitive screening of 69 dyes in wines. Response surface methodology was employed to optimize the QuEChERS sample preparation method for the determination of 69 different analytes in wines for the first time. After optimization, the maximum predicted recovery was 99.48% rate for canacert indigo carmine under the optimized conditions of 10 mL acetonitrile, 1.45 g sodium acetate, 107 mg primary secondary amine, and 96 mg C18 . For the matrices studied, the recovery rates of the other 68 compounds ranged from 87.2-107.4%, with coefficient of variation < 6.4%. The mass accuracy typically obtained is routinely better than 1.6 ppm and only needed to be calibrated once a week. The LODs for the analytes are in the range 1-1000 µg/kg. This method has been successfully applied on screening of dyes in commercial wines, and it is very useful for the fast screening of different food additives.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Corantes/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Vinho/análise
8.
Angew Chem Int Ed Engl ; 53(42): 11294-7, 2014 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-25159722

RESUMO

A highly diastereoselective and practical biomimetic total synthesis of (±)-basiliolide B has been achieved through the study of the two proposed biosynthetic pathways (O-methylation and O-acylation) for the unprecedented 7-methoxy-4,5-dihydro-3H-oxepin-2-one (C ring). The synthesis featured a cyclopropanation/ring opening strategy for establishing the stereogenic centers at C8 and C9, a biomimetic 2-pyrone Diels-Alder cycloaddition for the synthesis of the ABD ring system, and finally a highly efficient biomimetic intramolecular O-acylation for the C ring formation. This result provides an important perspective on the biosynthetic origin of the unprecedented 7-membered acyl ketene acetal moiety of the C ring.


Assuntos
Pironas/síntese química , Acilação , Biomimética , Reação de Cicloadição , Pironas/química , Estereoisomerismo
9.
Food Res Int ; 186: 114340, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729695

RESUMO

Fruits are essential sources of nutrients in our daily diet; however, their spoilage is often intensified by mechanical damage and the ethylene phytohormone, resulting in significant economic losses and exacerbating hunger issues. To address these challenges, this study presented a straightforward in situ synthesis protocol for producing Z/SOPPU foam, a 3D porous-structured fruit packaging. This innovative packaging material offered advanced ethylene-adsorbing and cushioning capabilities achieved through stirring, heating, and standing treatments. The results demonstrated that the Z/SOPPU foam, with its porous structure, served as an excellent packaging material for fruits, maintaining the intact appearance of tomatoes even after being thrown 72 times from a height of 1.5 m. Additionally, it exhibited desirable hydrophobicity (contact angle of 114.31 ± 0.82°), degradability (2.73 ± 0.88 % per 4 weeks), and efficient ethylene adsorption (adsorption rate of 13.2 ± 1.7 mg/m3/h). These remarkable characteristics could be attributed to the unique 3D micron-porous configuration, consisting of soybean oil polyol polyurethane foam for mechanical strain cushioning and zein for enhanced ethylene adsorption efficiency. Overall, this research offers an effective and original approach to the rational design and fabrication of advanced bio-based fruit packaging.


Assuntos
Etilenos , Embalagem de Alimentos , Frutas , Poliuretanos , Óleo de Soja , Zeína , Etilenos/química , Poliuretanos/química , Embalagem de Alimentos/métodos , Porosidade , Frutas/química , Óleo de Soja/química , Zeína/química , Adsorção , Polímeros/química , Solanum lycopersicum/química , Interações Hidrofóbicas e Hidrofílicas
10.
Chem Commun (Camb) ; 60(24): 3217-3225, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38436212

RESUMO

High-throughput continuous flow technology has emerged as a revolutionary approach in chemical synthesis, offering accelerated experimentation and improved efficiency. With the aid of process analytical technology and automation, this system not only enables rapid optimisation of reaction conditions at the millimole to the picomole scale, but also facilitates automated scale-up synthesis. It can even achieve the self-planning and self-synthesis of small drug molecules with artificial intelligence incorporated in the system. The versatility of the system is highlighted by its compatibility with both electrochemistry and photochemistry, and its significant applications in organic synthesis and drug discovery. This highlight summarises its recent developments and applications, emphasising its significant impact on advancing research across multiple disciplines.

11.
Int J Biol Macromol ; 267(Pt 1): 131522, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38614175

RESUMO

Glutinous sorghum grains were soaked (60-80 °C, 2-8 h) to explore the effects of soaking, an essential step in industrial processing of brewing, on starch. As the soaking temperature increased, the peak viscosity and crystallinity of starch gradually decreased, while the enzymatic hydrolysis rate and storage modulus first increased and then decreased. At 70 °C, the content of amylose, the enzymatic hydrolysis rate of starch, and the final viscosity first increase and then decrease with the increase of soaking time, reaching their maximum at 6 h, increased by 53.1 %, 11.0 %, and 10.4 %, respectively, as compared with the non-soaked sample. At 80 °C (4 h), the laser confocal microscopy images showed a network structure formed between the denatured protein chains and the leached-out amylose chains. The molecular weights of starch before and after soaking were all in the range of 3.82-8.98 × 107 g/mol. Since 70 °C is lower than that of starch gelatinization and protein denaturation, when soaking for 6 h, the enzymatic hydrolysis rate of starch is the highest, and the growth of miscellaneous bacteria is inhibited, which is beneficial for subsequent processing technology. The result provides a theoretical basis for the intelligent control of glutinous sorghum brewing.


Assuntos
Amilose , Fenômenos Químicos , Sorghum , Amido , Sorghum/química , Amido/química , Hidrólise , Amilose/química , Viscosidade , Grão Comestível/química , Temperatura , Peso Molecular
12.
Org Lett ; 26(27): 5844-5849, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38950387

RESUMO

We have developed a highly regio-, diastereo-, and enantioselective Cu-catalyzed desymmetrization of inert meso-diethers using Grignard reagents. Moreover, previous inaccessible sterically hindered organometallic reagents are realized in the reaction with broad secondary alkyl Grignard reagents. Finally, detailed control experiments and density functional theory calculations revealed the desymmetrization of meso-diethers exploits a direct anti-SN2' pathway, in the absence of an in situ-generated allyl bromine intermediate. The following oxidative addition is the crucial rate-determining and enantioselectivity-determining step.

13.
Chem Sci ; 15(22): 8280-8294, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38846404

RESUMO

The synthesis of enantiomerically pure compounds is a pivotal subject in the field of chemistry, with enantioselective catalysis currently standing as the primary approach for delivering specific enantiomers. Among these strategies, Cu-catalyzed asymmetric allylic substitution (AAS) is significant and irreplaceable, especially when it comes to the use of non-stabilized nucleophiles (pK a > 25). Although Cu-catalyzed AAS of prochiral substrates has also been widely developed, methodologies involving racemic/meso substrates are highly desirable, as the substrates undergo dynamic processes to give single enantiomer products. Inspired by the pioneering work of the Alexakis, Feringa and Gennari groups, Cu-catalyzed AAS has been continuously employed in deracemization and desymmetrization processes for the synthesis of enantiomerically enriched products. In this review, we mainly focus on the developments of Cu-catalyzed AAS with racemic/meso substrates over the past two decades, providing an explicit outline of the ligands employed, the scope of nucleophiles, the underlying dynamic processes and their practical applications.

14.
Meat Sci ; 217: 109614, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39089084

RESUMO

This study investigated the effects of the application of glycine (Gly) and Pediococcus pentosaceus R1(Pp), alone or in combination, on the physicochemical properties, oxidative stability, and taste quality of Harbin dry sausages. The results demonstrated that after nine days of fermentation, the Gly + Pp group exhibited significantly (P < 0.05) lower moisture content (19.04%), water activity (0.686), and pH (4.78) values, alongside notably (P < 0.05) higher lactic acid bacteria count (8.11 log CFU/g sausage) and redness value (17.2), compared to the other three groups (P < 0.05). In addition, the dry sausages in the Gly + Pp group exhibited the lowest peroxide value (0.34 meq/kg sausage), thiobarbituric acid reactive substances (0.46 MAD/kg sausage), and protein carbonyl content (1.26 nmol/kg protein) during fermentation, followed by the Gly group, Pp group, and control group. Electronic tongue (e-tongue) and sensory evaluations revealed that the combined treatment with P. pentosaceus R1 and Gly resulted in superior taste characteristics. Besides, partial least squares regression (PLSR) analysis illustrated that the taste qualities characterized using the e-tongue were accordant with the sensory evaluation consequences, and total free amino acids (FAAs) and organic acids contributed to the dry sausages' taste properties. In conclusion, the combined application of Gly and P. pentosaceus R1 enhanced the physicochemical properties, oxidative stability, and taste profile of Harbin dry sausages.


Assuntos
Fermentação , Glicina , Produtos da Carne , Pediococcus pentosaceus , Paladar , Produtos da Carne/análise , Produtos da Carne/microbiologia , Glicina/farmacologia , Animais , Humanos , Suínos , Concentração de Íons de Hidrogênio , Oxirredução , Probióticos , Masculino , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Adulto , Nariz Eletrônico , Feminino
15.
Chem Sci ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39297002

RESUMO

Various prenylated indoline alkaloids with diverse biological activities, including (-)-debromoflustramine B with significant butyrylcholinesterase inhibitory activity, could be synthesized by dearomative prenylation reactions of tryptophan derivatives. However, previously reported dearomative prenylations were limited to batch reactions at the milligram scale, requiring multistep reactions and complex post-processing to obtain the desired natural products. The more efficient synthesis of alkaloids remains challenging, as does the recovery of expensive catalysts. Herein, we developed a chiral heterogeneous Pd nanoparticle (NP) catalyst supported on a polymer, which produces indoline alkaloids in high yields with excellent enantioselectivities. Additionally, the first gram-scale four-step continuous-flow total synthesis of (-)-debromoflustramine B was successfully achieved with this chiral Pd heterogeneous catalyst, requiring only a simple post-processing step.

16.
Ultrason Sonochem ; 111: 107067, 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39288593

RESUMO

Zein-based films exhibit high efficiency in ethylene adsorption. However, its brittleness limits the practical applications. To address this issue, this study synergizes the plasticizing effects of high-intensity ultrasound (HIU) and castor oil (CO) to reduce the brittleness of zein-based films. The plasticizing mechanism was demonstrated through the formation of new intermolecular hydrogen bonds and electrostatic interactions, as evidenced by fourier transform infrared spectroscopy (FTIR) and zeta potential measurements. The tensile strength of 6 % CO-zein film increased eightfold. Additionally, the freshness of mangoes stored with 6 % CO-zein film significantly improved, extending their shelf life from 5 days to 15 days. Therefore, this study investigated the synergistic plasticization of zein-based films through the addition of CO, based on HIU. It also provides a theoretical basis for fruit packaging.

17.
Food Chem ; 461: 140884, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39167951

RESUMO

This study investigated the effects of sodium pyrophosphate (SPP) and catechin (C) on the in vitro enzymatic digestion of oxidatively damaged myofibrillar protein (MP) gel. The results indicated that SPP increased the ß-sheet content and the gastric digestibility of the MP gel, while C hindered the transition from α-helix to ß-sheet structure, leading to decreased digestibility. Notably, neither compound significantly affected intestinal digestibility. Furthermore, SPP and C significantly enhanced the antioxidant activity of MP gel digestion products. Notably, their synergistic hydrolysis products, simulating both gastric and gastrointestinal stages, chelated 91.4 % and 89.1 % of Fe2+ and scavenged 59.4 % and 77.6 % of hydroxyl radicals, respectively. Moreover, the final digestion products of the MP gel treated with SPP and C exhibited the highest content of negatively charged amino acids and absolute Zeta potential values. Overall, this study demonstrated that incorporating SPP and C could positively impact the digestion of oxidatively damaged MP gels.


Assuntos
Catequina , Digestão , Difosfatos , Géis , Hidrólise , Difosfatos/química , Difosfatos/metabolismo , Catequina/química , Catequina/metabolismo , Géis/química , Animais , Oxirredução , Proteínas Musculares/química , Proteínas Musculares/metabolismo , Miofibrilas/química , Miofibrilas/metabolismo , Antioxidantes/química
18.
Elife ; 132024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38896455

RESUMO

Microbes strongly affect invasive plant growth. However, how phyllosphere and rhizosphere soil microbes distinctively affect seedling mortality and growth of invaders across ontogeny under varying soil nutrient levels remains unclear. In this study, we used the invader Ageratina adenophora to evaluate these effects. We found that higher proportions of potential pathogens were detected in core microbial taxa in leaf litter than rhizosphere soil and thus leaf inoculation had more adverse effects on seed germination and seedling survival than soil inoculation. Microbial inoculation at different growth stages altered the microbial community and functions of seedlings, and earlier inoculation had a more adverse effect on seedling survival and growth. The soil nutrient level did not affect microbe-mediated seedling growth and the relative abundance of the microbial community and functions involved in seedling growth. The effects of some microbial genera on seedling survival are distinct from those on growth. Moreover, the A. adenophora seedling-killing effects of fungal strains isolated from dead seedlings by non-sterile leaf inoculation exhibited significant phylogenetic signals, by which strains of Allophoma and Alternaria generally caused high seedling mortality. Our study stresses the essential role of A. adenophora litter microbes in population establishment by regulating seedling density and growth.


Assuntos
Ageratina , Folhas de Planta , Rizosfera , Plântula , Microbiologia do Solo , Ageratina/microbiologia , Plântula/microbiologia , Plântula/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Folhas de Planta/crescimento & desenvolvimento , Microbiota , Espécies Introduzidas , Germinação
19.
Food Chem ; 444: 138541, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38330601

RESUMO

The effects of resonant acoustic mixing (RAM) with different treatment times (0, 5, 10, 15, 20 and 30 min) on the structural and emulsifying properties of pea protein isolate (PPI) were investigated for the first time. Increasing the RAM treatment time from 0 to 20 min decreased the α-helix/ß-sheet ratio and particle size of the PPI samples by 37.84 % and 46.44 %, respectively, accompanied by an increase in solubility from 54.79 % to 71.80 % (P < 0.05). Consequently, the emulsifying activity index of PPI (from 10.45 m2/g to 14.2 m2/g) and the physical stability of RAM-PPI emulsions were effectively enhanced, which was confirmed by the small and uniformly distributed oil droplets in the micrographs of the emulsions. However, excessive RAM treatment (30 min) diminished the effectiveness of the aforementioned improvements. Therefore, obviously enhanced solubility and emulsifying properties of PPI can be attained through proper RAM treatment (15-20 min).


Assuntos
Proteínas de Ervilha , Emulsões/química , Acústica , Solubilidade , Tamanho da Partícula , Emulsificantes/química
20.
Chem Sci ; 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39246375

RESUMO

A novel Ir-catalyzed asymmetric hydrogenation protocol for the synthesis of chiral tetrahydroquinoxaline (THQ) derivatives has been developed. By simply adjusting the reaction solvent, both enantiomers of mono-substituted chiral THQs could be selectively obtained in high yields with excellent enantioselectivities (toluene/dioxane: up to 93% yield and 98% ee (R); EtOH: up to 83% yield and 93% ee (S)). For 2,3-disubstituted chiral THQs, the cis-hydrogenation products were obtained with up to 95% yield, 20 : 1 dr, and 94% ee. Remarkably, this methodology was also applicable under continuous flow conditions, yielding gram-scale products with comparable yields and enantioselectivities (dioxane: 91% yield and 93% ee (R); EtOH: 90% yield and 87% ee (S)). Unlike previously reported Ir-catalyzed asymmetric hydrogenation protocols, this system exhibited a significant improvement as it required no additional additives. Furthermore, comprehensive mechanistic studies including deuterium-labeling experiments, control experiments, kinetic studies, and density functional theory (DFT) calculations were conducted to reveal the underlying mechanism of enantioselectivities for both enantiomers.

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