scholarly journals Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

2019 ◽  
Vol 15 ◽  
pp. 60-66 ◽  
Author(s):  
Antonella Petri ◽  
Valeria Colonna ◽  
Oreste Piccolo

Chiral N-heterocyclic molecules and in particular compounds with an amino functional group such as 3-aminopiperidine are valuable intermediates for the production of a large number of bioactive compounds with pharmacological properties. In this paper, the synthesis of both enantiomers of 3-amino-1-Boc-piperidine by amination of the prochiral precursor 1-Boc-3-piperidone using immobilized ω-transaminases (TAs-IMB), isopropylamine as amine donor and pyridoxal-5’-phosphate (PLP) as cofactor is described. Compared to other methods, the present approach affords the target compound in just one step with high yield and high enantiomeric excess starting from a commercial substrate. The reaction was carried out by using different commercially available immobilized enzymes, evaluating the catalytic activity and the enantioselectivity under different experimental conditions. Re-use of the most efficient enzyme was performed both in batch and in a semi-continuous system. The selected biocatalyst showed good stability under the reaction conditions providing consistent results in terms of conversion and enantiomeric excess after several cycles. The reported results may be of practical interest in view of the development of this sustainable approach to an industrial scale.

2020 ◽  
Vol 17 (8) ◽  
pp. 628-630
Author(s):  
Vu Binh Duong ◽  
Pham Van Hien ◽  
Tran Thai Ngoc ◽  
Phan Dinh Chau ◽  
Tran Khac Vu

A simple and practical method for the synthesis on a large scale of altretamine (1), a wellknown antitumor drug, has been successfully developed. The synthesis method involves the conversion of cyanuric chloride (2) into altretamine (1) by dimethylamination of 2 with an aqueous solution of 40% dimethylamine and potassium hydroxide in 1, -dioxan 4in one step to give altretamine (1) in high yield.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1502
Author(s):  
Johannes M. Parikka ◽  
Karolina Sokołowska ◽  
Nemanja Markešević ◽  
J. Jussi Toppari

The predictable nature of deoxyribonucleic acid (DNA) interactions enables assembly of DNA into almost any arbitrary shape with programmable features of nanometer precision. The recent progress of DNA nanotechnology has allowed production of an even wider gamut of possible shapes with high-yield and error-free assembly processes. Most of these structures are, however, limited in size to a nanometer scale. To overcome this limitation, a plethora of studies has been carried out to form larger structures using DNA assemblies as building blocks or tiles. Therefore, DNA tiles have become one of the most widely used building blocks for engineering large, intricate structures with nanometer precision. To create even larger assemblies with highly organized patterns, scientists have developed a variety of structural design principles and assembly methods. This review first summarizes currently available DNA tile toolboxes and the basic principles of lattice formation and hierarchical self-assembly using DNA tiles. Special emphasis is given to the forces involved in the assembly process in liquid-liquid and at solid-liquid interfaces, and how to master them to reach the optimum balance between the involved interactions for successful self-assembly. In addition, we focus on the recent approaches that have shown great potential for the controlled immobilization and positioning of DNA nanostructures on different surfaces. The ability to position DNA objects in a controllable manner on technologically relevant surfaces is one step forward towards the integration of DNA-based materials into nanoelectronic and sensor devices.


2014 ◽  
Vol 2 (36) ◽  
pp. 7477-7481 ◽  
Author(s):  
Xinwei Dong ◽  
Yanjie Su ◽  
Huijuan Geng ◽  
Zhongli Li ◽  
Chao Yang ◽  
...  

N-doped CDs can be obtained directly with high yield by pyrolyzing ethanolamine in air within just 7 minutes with the assistance of hydrogen peroxide.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Madhab Kumar Sen ◽  
Kateřina Hamouzová ◽  
Pavlina Košnarová ◽  
Amit Roy ◽  
Josef Soukup

AbstractBromus sterilis is an annual weedy grass, causing high yield losses in winter cereals. Frequent use of herbicides had led to the evolution of herbicide resistance in this species. Mechanisms underlying herbicide resistance in B. sterilis must be uncovered because this problem is becoming a global threat. qRT-PCR and the next-generation sequencing technologies can elucidate the resistance mechanisms. Although qRT-PCR can calculate precise fold changes, its preciseness depends on the expression of reference genes. Regardless of stable expression in any given condition, no gene can act as a universal reference gene. Hence, it is necessary to identify the suitable reference gene for each species. To our knowledge, there are no reports on the suitable reference gene in any brome species so far. Thus, in this paper, the stability of eight genes was evaluated using qRT-PCR experiments followed by expression stability ranking via five most commonly used software for reference gene selection. Our findings suggest using a combination of 18S rRNA and ACCase to normalise the qRT-PCR data in B. sterilis. Besides, reference genes are also recommended for different experimental conditions. The present study outcomes will facilitate future molecular work in B. sterilis and other related grass species.


2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Maryam Mikhak

AbstractNanostructured zinc titanate (NZT) was synthesized in high yield via a one-step and template-free sol-gel route. The prepared nanocomposite exhibited good size uniformity and regularity. The enhanced photocatalytic activity of the NZT was evaluated in the degradation and mineralization of Indocorn Brilliant Red (M5B) under metal halide lamp irradiation. The effects of different parameters such as pH of the solution, and initial dye concentration on photodegradation of M5B were analyzed. The degradation of M5B follows pseudo-first order kinetics according to the Langmuir-Hinshelwood model. The experimental results showed that the initial concentration of azo dye in the dye mixture greatly affected the degradation efficiency. At M5B concentrations of 10 mg/L, the optimum conditions for the highest degradation efficiency (94%) of azo dye were a photocatalyst dosage of 0.01 g/L and an initial solution pH of 9. This study provided new insight into the design and preparation of nanomaterial demonstrated an excellent ability to remove organic pollutants in wastewater.


2005 ◽  
Vol 52 (3) ◽  
pp. 703-711 ◽  
Author(s):  
Jochen Urthaler ◽  
Wolfgang Buchinger ◽  
Roman Necina

Gene therapy and genetic vaccines promise to revolutionize the treatment of inherited and acquired diseases. Since viral vectors are generally associated with numerous disadvantages when applied to humans, the administration of naked DNA, or DNA packed into lipo- or polyplexes emerge as viable alternatives. To satisfy the increasing demand for pharmaceutical grade plasmids we developed a novel economic downstream process which overcomes the bottlenecks of common lab-scale techniques and meets all regulatory requirements. After cell lysis by an in-house developed gentle, automated continuous system the sequence of hydrophobic interaction, anion exchange and size exclusion chromatography guarantees the separation of impurities as well as undesired plasmid isoforms. After the consecutive chromatography steps, adjustment of concentration and final filtration are carried out. The final process was proven to be generally applicable and can be used from early clinical phases to market-supply. It is scaleable and free of animal-derived substances, detergents (except lysis) and organic solvents. The process delivers high-purity plasmid DNA of homogeneities up to 98% supercoiled form at a high yield in any desired final buffer.


2020 ◽  
Author(s):  
Brian J Wang ◽  
Matthew Duncton

<div> <p>The azetidine group is frequently encountered within contemporary medicinal chemistry where it is viewed as a privileged structure. However, the introduction of an azetidine can be synthetically challenging. Herein, a straight-forward one step synthesis of azetidine-3-amines, starting from a bench stable, commercial material is presented. The reaction tolerates functional groups commonly encountered in biological-, medicinal- and agro-chemistry, and proceeds in moderate-to-high yield with secondary amines, and moderate-to-low yield with primary amines. The methodology compares favorably to recent alternative procedures and can be utilized in “any-stage” functionalization, including late-stage azetidinylation of approved drugs and other compounds with pharmacological activity.</p> </div>


2020 ◽  
Vol 312 ◽  
pp. 154-159
Author(s):  
Alexander Yuryevich Mironenko ◽  
Mikhail Tutov ◽  
Alexander Konstantinovich Chepak ◽  
Eugeny Mitsai ◽  
Alexander A. Sergeev ◽  
...  

Direct laser processing of various materials with nano- and femtosecond (fs) laser pulses is known to be a facile and inexpensive technology for fabrication of various surface morphologies. Since ultrafast deposition of the laser energy to target material typically creates unique experimental conditions with extremely high pressure and temperature, we hypothesized that carrying out this process in anhydrous non-oxidizing environment containing functionalizing agent (fluorophore with vinyl functional group) will allow one-step fabrication and subsequent functionalization of the surface of high-n material. In this paper, we demonstrate successful implementation of this idea by fabricating high-spatial-frequency laser-induced periodic surface structures (LIPSS) via direct fs-pulse ablation of bulk crystalline Si wafer immersed in solution of N-vinylcarbazole in toluene. Laser processing with linearly polarized fs-laser pulses was found to produce LIPSS with a characteristic period around 100 nm functionalized with N-vinylcarbazole molecules via photo-activated hydrosililation reaction. The unique LIPSS with hierarchical roughness and remarkable light trapping performance functionalized with sensory fluorophore show high sensitivity due to implementation of surface enhanced fluorescence effect. By using N-vinylcarbazole as functionalizing agent we demonstrate one-step fabrication of high-performance sensor for detecting nitrobenzene in water with a detection limit of 40 nM.


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