Design of combined crosslinked enzyme aggregates (combi-CLEAs) of β-galactosidase and glucose isomerase for the one-pot production of fructose syrup from lactose

2019 ◽  
Vol 288 ◽  
pp. 102-107 ◽  
Author(s):  
Erick Araya ◽  
Paulina Urrutia ◽  
Oscar Romero ◽  
Andrés Illanes ◽  
Lorena Wilson
Keyword(s):  
One Pot ◽  
Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1167
Author(s):  
Pablo Silva ◽  
Vanessa Arancibia ◽  
Daniela Cid ◽  
Oscar Romero ◽  
Andrés Illanes ◽  
...  

One-pot systems are an interesting proposal to carry out multi-enzymatic reactions, though this strategy implies establishing an optimal balance between the activity and operability of the involved enzymes. This is crucial for enzymes with marked differences in their operational stability, such as one-pot production of lactofructose syrup from cheese whey permeate, which involves two enzymes—β-galactosidase (β-gal) and glucose isomerase (GI). The aim of this work was to study the behavior of one-pot sequential batch production of lactofructose syrup considering both enzymes immobilized individually, in order to evaluate and design a strategy of replacement of the catalysts according to their stabilities. To this end, the modelling and simulation of the process was carried out, considering simultaneously the kinetics of both reactions and the kinetics of inactivation of both enzymes. For the latter, it was also considered the modulating effect that sugars present in the medium may have on the stability of β-gal, which is the less stable enzyme. At the simulated reaction conditions of 40 °C, pH 7, and 0.46 (IUGI/IUβ-gal), the results showed that considering the stability of β-gal under non-reactive conditions, meaning in absence of the effect of modulation, it is necessary to carry out four replacements of β-gal for each cycle of use of GI. On the other hand, when considering the modulation caused by the sugars on the β-gal stability, the productivity increases up to 23% in the case of the highest modulation factor studied (η = 0.8). This work shows the feasibility of conducting a one-pot operation with immobilized enzymes of quite different operational stability, and that a proper strategy of biocatalyst replacement increases the productivity of the process.


2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>


2020 ◽  
Vol 24 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Zita Rádai ◽  
Réka Szabó ◽  
Áron Szigetvári ◽  
Nóra Zsuzsa Kiss ◽  
Zoltán Mucsi ◽  
...  

The phospha-Brook rearrangement of dialkyl 1-aryl-1-hydroxymethylphosphonates (HPs) to the corresponding benzyl phosphates (BPs) has been elaborated under solid-liquid phase transfer catalytic conditions. The best procedure involved the use of triethylbenzylammonium chloride as the catalyst and Cs2CO3 as the base in acetonitrile as the solvent at room temperature. The substrate dependence of the rearrangement has been studied, and the mechanism of the transformation under discussion was explored by quantum chemical calculations. The key intermediate is an oxaphosphirane. The one-pot version starting with the Pudovik reaction has also been developed. The conditions of this tandem transformation were the same, as those for the one-step HP→BP conversion.


2020 ◽  
Vol 24 (20) ◽  
pp. 2341-2355
Author(s):  
Thaipparambil Aneeja ◽  
Sankaran Radhika ◽  
Mohan Neetha ◽  
Gopinathan Anilkumar

One-pot syntheses are a simple, efficient and easy methodology, which are widely used for the synthesis of organic compounds. Imidazoline is a valuable heterocyclic moiety used as a synthetic intermediate, chiral auxiliary, chiral catalyst and a ligand for asymmetric catalysis. Imidazole is a fundamental unit of biomolecules that can be easily prepared from imidazolines. The one-pot method is an impressive approach to synthesize organic compounds as it minimizes the reaction time, separation procedures, and ecological impact. Many significant one-pot methods such as N-bromosuccinimide mediated reaction, ring-opening of tetrahydrofuran, triflic anhydrate mediated reaction, etc. were reported for imidazoline synthesis. This review describes an overview of the one-pot synthesis of imidazolines and covers literature up to 2020.


2018 ◽  
Vol 21 (4) ◽  
pp. 302-311
Author(s):  
Younes Ghalandarzehi ◽  
Mehdi Shahraki ◽  
Sayyed M. Habibi-Khorassani

Aim & Scope: The synthesis of highly substituted piperidine from the one-pot reaction between aromatic aldehydes, anilines and β-ketoesters in the presence of tartaric acid as a catalyst has been investigated in both methanol and ethanol media at ambient temperature. Different conditions of temperature and solvent were employed for calculating the thermodynamic parameters and obtaining an experimental approach to the kinetics and mechanism. Experiments were carried out under different temperature and solvent conditions. Material and Methods: Products were characterized by comparison of physical data with authentic samples and spectroscopic data (IR and NMR). Rate constants are presented as an average of several kinetic runs (at least 6-10) and are reproducible within ± 3%. The overall rate of reaction is followed by monitoring the absorbance changes of the products versus time on a Varian (Model Cary Bio- 300) UV-vis spectrophotometer with a 10 mm light-path cell. Results: The best result was achieved in the presence of 0.075 g (0.1 M) of catalyst and 5 mL methanol at ambient temperature. When the reaction was carried out under solvent-free conditions, the product was obtained in a moderate yield (25%). Methanol was optimized as a desirable solvent in the synthesis of piperidine, nevertheless, ethanol in a kinetic investigation had none effect on the enhancement of the reaction rate than methanol. Based on the spectral data, the overall order of the reaction followed the second order kinetics. The results showed that the first step of the reaction mechanism is a rate determining step. Conclusion: The use of tartaric acid has many advantages such as mild reaction conditions, simple and readily available precursors and inexpensive catalyst. The proposed mechanism was confirmed by experimental results and a steady state approximation.


2015 ◽  
Vol 12 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Prabhakar Rairala ◽  
Bandi Yadagiri ◽  
Rajashaker Bantu ◽  
Vijayacharan Guguloth ◽  
Lingaiah Nagarapu

Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shay Laps ◽  
Fatima Atamleh ◽  
Guy Kamnesky ◽  
Hao Sun ◽  
Ashraf Brik

AbstractDespite six decades of efforts to synthesize peptides and proteins bearing multiple disulfide bonds, this synthetic challenge remains an unsolved problem in most targets (e.g., knotted mini proteins). Here we show a de novo general synthetic strategy for the ultrafast, high-yielding formation of two and three disulfide bonds in peptides and proteins. We develop an approach based on the combination of a small molecule, ultraviolet-light, and palladium for chemo- and regio-selective activation of cysteine, which enables the one-pot formation of multiple disulfide bonds in various peptides and proteins. We prepare bioactive targets of high therapeutic potential, including conotoxin, RANTES, EETI-II, and plectasin peptides and the linaclotide drug. We anticipate that this strategy will be a game-changer in preparing millions of inaccessible targets for drug discovery.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lirong Zhang ◽  
Jingjing Zhang ◽  
Lixia Xu ◽  
Zijian Zhuang ◽  
Jingjin Liu ◽  
...  

Abstract Background Therapeutic tumor vaccine (TTV) that induces tumor-specific immunity has enormous potentials in tumor treatment, but high heterogeneity and poor immunogenicity of tumor seriously impair its clinical efficacy. Herein, a novel NIR responsive tumor vaccine in situ (HA-PDA@IQ/DOX HG) was prepared by integrating hyaluronic acid functionalized polydopamine nanoparticles (HA-PDA NPs) with immune adjuvants (Imiquimod, IQ) and doxorubicin (DOX) into thermal-sensitive hydrogel. Results HA-PDA@IQ NPs with high photothermal conversion efficiency (41.2%) and T1-relaxation efficiency were using HA as stabilizer by the one-pot oxidative polymerization. Then, HA-PDA@IQ loaded DOX via π-π stacking and mixed with thermal-sensitive hydrogel to form the HA-PDA@IQ/DOX HG. The hydrogel-confined delivery mode endowed HA-PDA@IQ/DOX NPs with multiple photothermal ablation performance once injection upon NIR irradiation due to the prolonged retention in tumor site. More importantly, this mode enabled HA-PDA@IQ/DOX NPs to promote the DC maturation, memory T cells in lymphatic node as well as cytotoxic T lymphocytes in spleen. Conclusion Taken together, the HA-PDA@IQ/DOX HG could be served as a theranostic tumor vaccine for complete photothermal ablation to trigger robust antitumor immune responses.


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