scholarly journals Designing Modular Cell-free Systems for Tunable Biotransformation of l-phenylalanine to Aromatic Compounds

2021 ◽  
Vol 9 ◽  
Author(s):  
Chen Yang ◽  
Yushi Liu ◽  
Wan-Qiu Liu ◽  
Changzhu Wu ◽  
Jian Li
Keyword(s):  
Aromatic Compounds ◽  
Value Added ◽  
Resource Limitation ◽  
Biosynthetic Pathways ◽  
One Pot ◽  
Conversion Rates ◽  
The One ◽  
Free Modules ◽  
Enzymatic Pathways

Cell-free systems have been used to synthesize chemicals by reconstitution of in vitro expressed enzymes. However, coexpression of multiple enzymes to reconstitute long enzymatic pathways is often problematic due to resource limitation/competition (e.g., energy) in the one-pot cell-free reactions. To address this limitation, here we aim to design a modular, cell-free platform to construct long biosynthetic pathways for tunable synthesis of value-added aromatic compounds, using (S)-1-phenyl-1,2-ethanediol ((S)-PED) and 2-phenylethanol (2-PE) as models. Initially, all enzymes involved in the biosynthetic pathways were individually expressed by an E. coli-based cell-free protein synthesis (CFPS) system and their catalytic activities were confirmed. Then, three sets of enzymes were coexpressed in three cell-free modules and each with the ability to complete a partial pathway. Finally, the full biosynthetic pathways were reconstituted by mixing two related modules to synthesize (S)-PED and 2-PE, respectively. After optimization, the final conversion rates for (S)-PED and 2-PE reached 100 and 82.5%, respectively, based on the starting substrate of l-phenylalanine. We anticipate that the modular cell-free approach will make a possible efficient and high-yielding biosynthesis of value-added chemicals.

scholarly journals One-Pot Ionic Liquid-Mediated Bioprocess for Pretreatment and Enzymatic Hydrolysis of Rice Straw with Ionic Liquid-Tolerance Bacterial Cellulase

2022 ◽  
Vol 9 (1) ◽  
pp. 17
Author(s):  
Malinee Sriariyanun ◽  
Nichaphat Kitiborwornkul ◽  
Prapakorn Tantayotai ◽  
Kittipong Rattanaporn ◽  
Pau-Loke Show
Keyword(s):  
Ionic Liquid ◽  
Saline Soil ◽  
Enzymatic Saccharification ◽  
Value Added ◽  
Specific Enzyme ◽  
One Pot ◽  
The One ◽  
Hydrolysis Of ◽  
Bacterial Cellulase ◽  
Value Added Products

Ionic liquid (IL) pretreatment of lignocellulose is an efficient method for the enhancement of enzymatic saccharification. However, the remaining residues of ILs deactivate cellulase, therefore making intensive biomass washing after pretreatment necessary. This study aimed to develop the one-pot process combining IL pretreatment and enzymatic saccharification by using low-toxic choline acetate ([Ch][OAc]) and IL-tolerant bacterial cellulases. Crude cellulases produced from saline soil inhabited Bacillus sp. CBD2 and Brevibacillus sp. CBD3 were tested under the influence of 0.5–2.0 M [Ch][OAc], which showed that their activities retained at more than 95%. However, [Ch][OAc] had toxicity to CBD2 and CBD3 cultures, in which only 32.85% and 12.88% were alive at 0.5 M [Ch][OAc]. Based on the specific enzyme activities, the sugar amounts produced from one-pot processes using 1 mg of CBD2 and CBD3 were higher than that of Celluclast 1.5 L by 2.0 and 4.5 times, respectively, suggesting their potential for further application in the biorefining process of value-added products.

PTSA-Catalyzed One Pot Domino Synthesis of Dihydropyrido[2,3-d]pyrimidine Derivatives and their Antimicrobial Activity

2021 ◽  
Vol 6 (3) ◽  
pp. 222-227
Author(s):  
Krishna A. Bhensdadia ◽  
Prakash L. Kalavadiya ◽  
Nilam H. Lalavani ◽  
Shipra H. Baluja
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Pyrimidine Derivatives ◽  
One Pot ◽  
In Vitro Antimicrobial Activity ◽  
Aryl Aldehydes ◽  
Three Component Reaction ◽  
The One

A novel series of dihydropyrido[2,3-d]pyrimidine derivatives were synthesized by multicomponent domino cyclization via the one-pot three component reaction of 6-amino uracil, substituted aryl aldehydes and N-methyl-1-(methylthio)-2-nitroethenamine in the presence of PTSA 10 mol% as a catalyst. The structures of these synthesized compounds were characterized by spectral analysis. Further the synthesized compounds screened for in vitro antimicrobial activity. Among all the compounds, compound 4b containing flouro substitution exhibited good inhibition against the tested species.

scholarly journals Microwave Assisted One Pot Synthesis of Tetrazole Based 3-hydroxy-4H-chromen-4-ones by modified Algar-Flynn-Oyamada reaction and their Antimicrobial activity

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
ASHOK DONGAMANTI ◽  
Nagaraju Nalaparaju ◽  
Sarasija Madderla ◽  
Vijaya Lakshmi Bommidi
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Klebsiella Pneumonia ◽  
Good Activity ◽  
One Pot ◽  
Microwave Assisted ◽  
One Pot Synthesis ◽  
Antimicrobial Studies ◽  
The One

In the present work, we report the one pot synthesis of tetrazole based 3-hydroxy-4H-chromen-4-ones 3(a-g) from  4-(1H-tetrazol-5-yl)benzaldehyde and 2-hydroxy acetophenone using KOH and H2O2 by modified Algar-Flynn-Oyamada reaction under conventional and microwave irradiation conditions. In this technique, flavonols are synthesized without isolating chalcones, in good yields. All the synthesized compounds were characterized by IR, NMR, MS and elemental. All newly synthesized compounds were screened for their in-vitro antimicrobial activity against strains such as Staphylococcus aurous, Bacillus subtilis, Klebsiella pneumonia, Escherichia coli, Aspergillus Niger, Aspergillus flavus, and Fusarium oxysporum. The results of antimicrobial studies revealed that most of the compounds exhibit good activity.

scholarly journals Outer membrane vesicles catabolize lignin-derived aromatic compounds in Pseudomonas putida KT2440

2020 ◽  
Vol 117 (17) ◽  
pp. 9302-9310 ◽  
Author(s):  
Davinia Salvachúa ◽  
Allison Z. Werner ◽  
Isabel Pardo ◽  
Martyna Michalska ◽  
Brenna A. Black ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Outer Membrane ◽  
Aromatic Compounds ◽  
Value Added ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Pseudomonas Putida Kt2440 ◽  
Rich Media

Lignin is an abundant and recalcitrant component of plant cell walls. While lignin degradation in nature is typically attributed to fungi, growing evidence suggests that bacteria also catabolize this complex biopolymer. However, the spatiotemporal mechanisms for lignin catabolism remain unclear. Improved understanding of this biological process would aid in our collective knowledge of both carbon cycling and microbial strategies to valorize lignin to value-added compounds. Here, we examine lignin modifications and the exoproteome of three aromatic–catabolic bacteria: Pseudomonas putida KT2440, Rhodoccocus jostii RHA1, and Amycolatopsis sp. ATCC 39116. P. putida cultivation in lignin-rich media is characterized by an abundant exoproteome that is dynamically and selectively packaged into outer membrane vesicles (OMVs). Interestingly, many enzymes known to exhibit activity toward lignin-derived aromatic compounds are enriched in OMVs from early to late stationary phase, corresponding to the shift from bioavailable carbon to oligomeric lignin as a carbon source. In vivo and in vitro experiments demonstrate that enzymes contained in the OMVs are active and catabolize aromatic compounds. Taken together, this work supports OMV-mediated catabolism of lignin-derived aromatic compounds as an extracellular strategy for nutrient acquisition by soil bacteria and suggests that OMVs could potentially be useful tools for synthetic biology and biotechnological applications.

scholarly journals Biosynthesis of Commodity Chemicals From Oil Palm Empty Fruit Bunch Lignin

2021 ◽  
Vol 12 ◽  
Author(s):  
Tat-Ming Lo ◽  
In Young Hwang ◽  
Han-Saem Cho ◽  
Raissa Eka Fedora ◽  
Si Hui Chng ◽  
...  
Keyword(s):  
Oil Palm ◽  
Aromatic Compounds ◽  
Levulinic Acid ◽  
Agricultural Waste ◽  
Value Added ◽  
One Pot ◽  
Empty Fruit Bunches ◽  
Commodity Chemicals ◽  
Commercially Important ◽  
Derivatives Of

Lignin is one of the most abundant natural resources that can be exploited for the bioproduction of value-added commodity chemicals. Oil palm empty fruit bunches (OPEFBs), byproducts of palm oil production, are abundant lignocellulosic biomass but largely used for energy and regarded as waste. Pretreatment of OPEFB lignin can yield a mixture of aromatic compounds that can potentially serve as substrates to produce commercially important chemicals. However, separation of the mixture into desired individual substrates is required, which involves expensive steps that undermine the utility of OPEFB lignin. Here, we report successful engineering of microbial hosts that can directly utilize heterogeneous mixtures derived from OPEFB lignin to produce commodity chemicals, adipic acid and levulinic acid. Furthermore, the corresponding bioconversion pathway was placed under a genetic controller to autonomously activate the conversion process as the cells are fed with a depolymerized OPEFB lignin mixture. This study demonstrates a simple, one-pot biosynthesis approach that directly utilizes derivatives of agricultural waste to produce commodity chemicals.

scholarly journals Three Multi-Components Reaction: Synthesis and X-Ray Single-Crystal of Hydroacridinone-Based Hydrazino-S-Triazine Derivative as a New Class of Urease Inhibitor

Crystals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Assem Barakat ◽  
Saied M. Soliman ◽  
Ayman El-Faham ◽  
M. Ali ◽  
Abdullah Mohammed Al-Majid ◽  
...  
Keyword(s):  
Structural Features ◽  
Acetohydroxamic Acid ◽  
Orthorhombic Crystal System ◽  
Orthorhombic Crystal ◽  
One Pot ◽  
X Ray ◽  
New Class ◽  
Hirshfeld Surfaces ◽  
The One

The one-pot fashion of three multi-component reaction provides the desired hydroacridinone-based hydrazino-s-triazine scaffold 4. Compound 4 was crystallized in an orthorhombic crystal system and Pbca space group with a = 11.6271(2) Å, b = 18.2018(4) Å, c = 32.4721(6) Å, and α = β = γ = 90° with one formula unit per asymmetric unit and eight molecules per unit cell. Additionally, structural features, Hirshfeld surfaces, and DFT studies were also investigated. Its packing in the crystal is controlled by H…H (63.4%), O…H (12.7%), Cl…H (7.2%), N…H (4.7%), and C…H (10.2%) contacts, where the O…H and Cl…H contacts were found the strongest. In vitro urease inhibition evaluation showed that the hydroacridinone-based hydrazino-s-triazine is more active (IC50 = 17.9 ± 0.47 µM) than the standard acetohydroxamic acid (IC50 = 20.3 ± 0.43 µM).

One-Pot Approach for SNAr Reaction of Fluoroaromatic Compounds with Cyclopropanol

Synlett ◽  
2019 ◽  
Vol 30 (08) ◽  
pp. 982-986
Author(s):  
Hao Jin ◽  
Zhuo Gao ◽  
Shaodong Zhou ◽  
Chao Qian
Keyword(s):  
Aromatic Compounds ◽  
Substitution Reaction ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
One Pot ◽  
Mild Conditions ◽  
Snar Reaction ◽  
Novel Method ◽  
The One ◽  
Application Scope

A novel method for preparing aromatic compounds containing cyclopropoxy via nucleophilic aromatic substitution reaction (SNAr) of fluoroaromatic compounds with cyclopropanol under relatively mild conditions is presented. As compared to the approaches reported previously for preparing 1-(cyclopropyloxy)-2-nitrobenzene, the one proposed in this work is simplified without sacrificing the yields: When the reaction was performed at 75 °C with Cs2CO3 as the base and DMF as solvent, after 6 h the yield was up to 90%. Finally, various fluoroaromatic compounds were employed as substrates for a test that proves a wide application scope of the method.

scholarly journals Assessment of the Arterial Input Curve for [99mTc]-d,l-HM-PAO by Rapid Octanol Extraction

1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S23-S30 ◽  
Author(s):  
Allan R. Andersen ◽  
Hans Friberg ◽  
Niels A. Lassen ◽  
K. Kristensen ◽  
Rudi D. Neirinckx
Keyword(s):  
Rapid Method ◽  
Half Life ◽  
Quantitative Measurements ◽  
Arterial Blood ◽  
Conversion Rates ◽  
Low Levels ◽  
Blood Cell And Plasma ◽  
The One

The in vitro conversion of the lipophilic molecule [99mTc]– d,l-hexamethylpropyleneamine oxime ([99mTc]– d,l-HM-PAO) to a hydrophilic form was studied in saline, plasma, and blood at 37°C by paper chromatography and by octanol extraction. The octanol:saline ratio was 79.9. From this value and the corresponding octanol: plasma and octanol:blood partitioning values, an estimate of the transport of the lipophilic compound by various components of blood was made: 20% is carried in hemoglobin, 53% by the plasma proteins and 27% by the water phases of the red blood cell and plasma. Octanol extraction provided a rapid method for measuring the radiochemical purity (RCP) of lipophilic [99mTc]– d,l-HM-PAO. In saline, the RCP declined with a half-life of more than 1 h. In human plasma and whole blood, the conversion of [99mTc]– d,l-HM-PAO was biexponential due to the differences in the conversion rates of the d and l isomeric forms. The initial half-life representing the conversion rate of the l form was 1.7 min in blood and 1.4 min in plasma, while the conversion half-life of the d form was 7.4 and 24.4 min, respectively. In vivo, the RCP of arterial blood sampled after an i.v. bolus injection showed an initial peak value of 75% (68–79%) during the initial, first passage of the bolus. It declined to approximately 35% (29–40%) after 1.5 min and reached very low levels (about 1%) at 6 to 10 min. Quantitative measurements of cerebral blood flow using [99mTc]– d,l-HM-PAO necessitates a rapid method for RCP determination in arterial blood such as the one described here.

scholarly journals Development of a Cofactor Balanced, Multi Enzymatic Cascade Reaction for the Simultaneous Production of L-Alanine and L-Serine from 2-Keto-3-deoxy-gluconate

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Benjamin Begander ◽  
Anna Huber ◽  
Josef Sperl ◽  
Volker Sieber
Keyword(s):  
Enzymatic Reaction ◽  
Value Added ◽  
Thermostable Enzymes ◽  
One Pot ◽  
Major Drawback ◽  
Significant Group ◽  
Cofactor Recycling ◽  
Sugar Degradation ◽  
The One ◽  
Reaction Cascades

Enzymatic reaction cascades represent a powerful tool to convert biogenic resources into valuable chemicals for fuel and commodity markets. Sugars and their breakdown products constitute a significant group of possible substrates for such biocatalytic conversion strategies to value-added products. However, one major drawback of sugar cascades is the need for cofactor recycling without using additional enzymes and/or creating unwanted by-products. Here, we describe a novel, multi-enzymatic reaction cascade for the one-pot simultaneous synthesis of L-alanine and L-serine, using the sugar degradation product 2-keto-3-deoxygluconate and ammonium as precursors. To pursue this aim, we used four different, thermostable enzymes, while the necessary cofactor NADH is recycled entirely self-sufficiently. Buffer and pH optimisation in combination with an enzyme titration study yielded an optimised production of 21.3 +/− 1.0 mM L-alanine and 8.9 +/− 0.4 mM L-serine in one pot after 21 h.

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