Production Of Fine Chemicals Research Articles

SYNBIOCHEM-a SynBio foundry for the biosynthesis and sustainable production of fine and speciality chemicals.

The Manchester Synthetic Biology Research Centre (SYNBIOCHEM) is a foundry for the biosynthesis and sustainable production of fine and speciality chemicals. The Centre's integrated technology platforms provide a unique capability to facilitate predictable engineering of microbial bio-factories for chemicals production. An overview of these capabilities is described.

Estimation of Potential Capability of Natural Bitumens and High Viscosity Oils for Refining According to Fuel-Bitumen Scheme

According to different estimates, geological heavy oil and natural bitumens resources at the Tatarstan deposits make 1,5- 7 billion tons. On the territory of Tatarstan across all bituminous horizons about 450 deposits of natural bitumens have been found. One third of deposits of this raw materials existing in Russia fall on the share of Tatarstan. Natural bitumens are valuable material for production of fine chemicals that are used in different spheres of life activities. Natural bitumen is to a different extent oxidized high-viscosity oils of liquid, semi-liquid and hard texture with high content of sulfur, resins and asphaltenes. In contrast to oil, they are characterized by increased content of vanadium, nickel, molybdenum and significantly smaller content of gasoline and diesel fractions. Nevertheless, despite the works performed, no significant success has been achieved in production and processing of bitumens yet. This is mainly because of absence of the relevant equipment. It is necessary to accelerate development of bituminous deposits, creation of complexes with the use of high performance technologies and technical means for most complete extraction of this raw material from the earth and treatment thereof. Implementation thereof will create pre-requisites for commercial exploitation of natural bitumens deposits not only in Tatarstan but in other regions of the Russian Federation as well. To estimate the potential capability of natural bitumens and high viscosity oils it is necessary to perform detailed analysis aimed at determining the graphical charts of the true temperature curve, density, low-temperature, viscosity properties, fraction and hydrocarbon composition.

Metal-Free sp(2)-C-H Borylation as a Common Reactivity Pattern of Frustrated 2-Aminophenylboranes.

C-H borylation is a powerful and atom-efficient method for converting affordable and abundant chemicals into versatile organic reagents used in the production of fine chemicals and functional materials. Herein we report a facile C-H borylation of aromatic and olefinic C-H bonds with 2-aminophenylboranes. Computational and experimental studies reveal that the metal-free C-H insertion proceeds via a frustrated Lewis pair mechanism involving heterolytic splitting of the C-H bond by cooperative action of the amine and boryl groups. The adapted geometry of the reactive B and N centers results in an unprecedentently low kinetic barrier for both insertion into the sp(2)-C-H bond and intramolecular protonation of the sp(2)-C-B bond in 2-ammoniophenyl(aryl)- or -(alkenyl)borates. This common reactivity pattern serves as a platform for various catalytic reactions such as C-H borylation and hydrogenation of alkynes. In particular, we demonstrate that simple 2-aminopyridinium salts efficiently catalyze the C-H borylation of hetarenes with catecholborane. This reaction is presumably mediated by a borenium species isoelectronic to 2-aminophenylboranes.

Iron(III) porphyrin supported on S and N co-doped graphene quantum dot as an efficient photocatalyst for aerobic oxidation of alcohols under visible light irradiation

In this study, we report the synthesis and impressive performance of Fe(III)tetra(4-sulfonatophenyl)porphyrins (FeTSPP) supported on S and N co-doped graphene quantum dots (S, N: GQDs) as efficient, recyclable, and noble metal free heterogeneous photocatalyst for the selective aerobic oxidation of alcohols to the corresponding carbonyl compounds. It was found that FeTSPP@S, N: GQDs photocatalyst represents a novel chemical function for efficient visible light catalyzed aerobic alcohol oxidation with good conversions and selectivity in water as a green solvent at room temperature. We envision that FeTSPP@S, N: GQDs provide a promising candidate for the development of highly efficient, recyclable, and industrially applicable photocatalyst in fine chemical production with high activity.

Enhancing cytochrome P450-mediated conversions in P. pastoris through RAD52 over-expression and optimizing the cultivation conditions

Cytochrome P450 enzymes (CYPs) play an essential role in the biosynthesis of various natural compounds by catalyzing regio- and stereospecific hydroxylation reactions. Thus, CYP activities are of great interest in the production of fine chemicals, pharmaceutical compounds or flavors and fragrances. Industrial applicability of CYPs has driven extensive research efforts aimed at improving the performance of these enzymes to generate robust biocatalysts. Recently, our group has identified CYP-mediated hydroxylation of (+)-valencene as a major bottleneck in the biosynthesis of trans-nootkatol and (+)-nootkatone in Pichia pastoris. In the current study, we aimed at enhancing CYP-mediated (+)-valencene hydroxylation by over-expressing target genes identified through transcriptome analysis in P. pastoris. Strikingly, over-expression of the DNA repair and recombination gene RAD52 had a distinctly positive effect on trans-nootkatol formation. Combining RAD52 over-expression with optimization of whole-cell biotransformation conditions, i.e. optimized media composition and cultivation at higher pH value, enhanced trans-nootkatol production 5-fold compared to the initial strain and condition. These engineering approaches appear to be generally applicable for enhanced hydroxylation of hydrophobic compounds in P. pastoris as confirmed here for two additional membrane-attached CYPs, namely the limonene-3-hydroxylase from Mentha piperita and the human CYP2D6.

Semi-Rational Design of Geobacillus stearothermophilus L-Lactate Dehydrogenase to Access Various Chiral α-Hydroxy Acids.

Chiral α-hydroxy acids (AHAs) are rapidly becoming important synthetic building blocks, in particular for the production of pharmaceuticals and other fine chemicals. Chiral compounds of a variety of functionalities are now often derived using enzymes, and L-lactate dehydrogenase from the thermophilic organism Geobacillus stearothermophilus (bsLDH) has the potential to be employed for the industrial synthesis of chiral α-hydroxy acids. Despite the thorough characterization of this enzyme, generation of variants with high activity on non-natural substrates has remained difficult and therefore limits the use of bsLDH in industry. Here, we present the engineering of bsLDH using semi-rational design as a method of focusing screening in a small and smart library for novel biocatalysts. In this study, six mutant libraries were designed in an effort to expand the substrate range of bsLDH. The eight variants identified as having enhanced activity toward the selected α-keto acids belonged to the same library, which targeted two positions simultaneously. These new variants now may be useful biocatalysts for chiral synthesis of α-hydroxy acids.

Horticultural crops development: the importance of fine chemicals production from microbial enzymes

Economically important horticultural crops worldwide are being faced with the challenges of diseases, pests and the present changing climatic conditions. Research efforts to solve these problems are only focused on plant breeding and genetic engineering to create new hybrids, and pest management through the use of synthetic agrochemicals. Horticultural crops development using fine chemicals produced from microbial enzymes for production of non-toxic agrochemicals and other bioproducts need also to be considered as alternative option to synthetic agrochemicals. To this end, some of the microbial enzymes presently used for the production of fine chemicals that are very useful as building blocks for agroactive products are discussed here. Thus, this is to create awareness on the need to extend the application of these microbial fine chemicals to horticulture for a safe and environmentally-friendly bioprocesses and crop development.

Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes.

The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the “ene” reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. “Better-than-Nature” biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost.

Nitrogen-doped carbon supported iron oxide as efficient catalysts for chemoselective hydrogenation of nitroarenes

Chemoselective hydrogenation has been widely used in the production of fine chemicals, and developing heterogeneous catalysts with high activity and chemoselectivity is always a challenging topic.

Determination of Isotopic Abundance of <sup>13</sup>C/<sup>12</sup>C or <sup>2</sup>H/<sup>1</sup>H and <sup>18</sup>O/<sup>16</sup>O in Biofield Energy Treated 1-Chloro-3-Nitrobenzene (3-CNB) Using Gas Chromatography-Mass Spectrometry

1-Chloro-3-nitrobenzene (3-CNB) is an aromatic halo-amine compound used as chemical intermediate for the production of several fine chemicals like pharmaceuticals, dyes, agricultural chemicals, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, etc. The objective of the current research was to investigate the impact of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in 3-CNB using gas chromatography - mass spectrometry (GC-MS). The sample, 3-CNB was divided into two parts - one part was denoted as control and another part was referred as biofield energy treated sample that was treated with biofield energy (The Trivedi Effect®). T1, T2, T3, and T4 were represented to different time interval analysis of the biofield treated 3-CNB. The GC-MS spectra of the both control and biofield treated 3-CNB indicated the presence of molecular ion peak [M+] at m/z 157 (calculated 156.99 for C6H4ClNO2) along with same pattern of fragmentation. The relative intensities of the parent molecule and other fragmented ions of the biofield treated 3-CNB were improved as compared to the control 3-CNB. The percentage change of the isotopic abundance ratio of PM+1/PM was significantly increased in the biofield treated 3-CNB at T1, T2 and T3 by 11.62, 18.50, and 29.82%, respectively with respect to the control 3-CNB. Accordingly, the isotopic abundance ratio of PM+2/PM in the biofield treated 3-CNB at T2 and T3 was significantly improved by 15.22 and 35.09%, respectively as compared to the control sample. The isotopic abundance ratios of PM+1/PM and PM+2/PM in the biofield treated 3-CNB at T1 and T4 were changed as compared to the control sample. The percentage change of the isotopic abundance ratio of PM+3/PM was enhanced in the biofield treated 3-CNB at T1, T2, T3, and T4 by 4.67, 18.69, 31.31 and 6.08%, respectively as compared to the control 3-CNB. The isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in the biofield treated 3-CNB changed with the time. So, the biofield energy treated 3-CNB might exhibit the altered isotope effects such as altered physicochemical and thermal properties, binding energy, and the rate of the chemical reaction as compared to the control sample. The biofield energy treated 3-CNB might assist in designing for the synthesis of pharmaceuticals, agricultural chemicals, dyes, corrosion inhibitors and other several useful industrial chemicals.

A Toolbox of Diverse Promoters Related to Methanol Utilization: Functionally Verified Parts for Heterologous Pathway Expression in Pichia pastoris.

The heterologous expression of biosynthetic pathways for pharmaceutical or fine chemical production requires suitable expression hosts and vectors. In eukaryotes, the pathway flux is typically balanced by stoichiometric fine-tuning of reaction steps by varying the transcript levels of the genes involved. Regulated (inducible) promoters are desirable to allow a separation of pathway expression from cell growth. Ideally, the promoter sequences used should not be identical to avoid loss by recombination. The methylotrophic yeast Pichia pastoris is a commonly used protein production host, and single genes have been expressed at high levels using the methanol-inducible, strong, and tightly regulated promoter of the alcohol oxidase 1 gene (PAOX1). Here, we have studied the regulation of the P. pastoris methanol utilization (MUT) pathway to identify a useful set of promoters that (i) allow high coexpression and (ii) differ in DNA sequence to increase genetic stability. We noticed a pronounced involvement of the pentose phosphate pathway (PPP) and genes involved in the defense of reactive oxygen species (ROS), providing strong promoters that, in part, even outperform PAOX1 and offer novel regulatory profiles. We have applied these tightly regulated promoters together with novel terminators as useful tools for the expression of a heterologous biosynthetic pathway. With the synthetic biology toolbox presented here, P. pastoris is now equipped with one of the largest sets of strong and co-regulated promoters of any microbe, moving it from a protein production host to a general industrial biotechnology host.

ChemInform Abstract: Monomeric and Dimeric Oxido‐peroxido Tungsten(VI) Complexes in Catalytic and Stoichiometric Epoxidation

AbstractReview: 124 refs.

Characterisation of algicidal bacterial exometabolites against the lipid-accumulating diatom Skeletonema sp.

Microalgae are of increasing interest due to their occurrence in the environment as harmful algal blooms and as a source of biomass for the production of fine and bulk chemicals. A method for the low cost disruption of algal biomass for environmental remediation or bioprocessing is desirable. Naturally-occurring algal lytic agents from bacteria could provide a cost-effective and environmentally desirable solution. A screen for algal lytic agents against a range of marine microalgae has identified two strains of algicidal bacteria isolated from the coastal region of the Western English Channel. Both strains (designated EC-1 and EC-2) showed significant algicidal activity against Skeletonema sp. and were identified as members of Alteromonas sp. and Maribacter sp. respectively. Characterisation of the two bioactivities revealed that they are small extracellular metabolites displaying thermal and acid stability. Purification of the EC-1 activity to homogeneity and initial structural analysis has identified it as a putative peptide with a mass of 1266amu.

Process Development for the Production of (R)-(−)-Mandelic Acid by Recombinant Escherichia coli Cells Harboring Nitrilase from Burkholderia cenocepacia J2315

(R)-(−)-Mandelic acid is an important chiral building block that is widely used in pharmacy and the production of fine chemicals. A more advanced method for obtaining (R)-(−)-mandelic acid is direct hydrolysis of the corresponding racemic mandelonitrile. In order to develop a cost-effective process, a highly efficient enantioselective nitrilase BCJ2315 from Burkholderia cenocepacia J2315 was used for the biotransformation of mandelonitrile to (R)-(−)-mandelic acid. The recombinant Escherichia coli M15/BCJ2315 showed high substrate tolerance and could completely hydrolyze up to 250 mM of mandelonitrile. A fed-batch reaction was performed by periodically or continuously dosing the substrate into the reactor to alleviate substrate inhibition in a monophasic buffer system. Finally, the highest substrate loading (2.9 M) was achieved in the continuous fed batch reaction mode, giving (R)-(−)-mandelic acid at the highest concentration (2.3 M, 350 g/L) with 97.4% ee ever reported. The hydrolysis process was easily...

A water-forming NADH oxidase from Lactobacillus pentosus suitable for the regeneration of synthetic biomimetic cofactors.

The cell-free biocatalytic production of fine chemicals by oxidoreductases has continuously grown over the past years. Since especially dehydrogenases depend on the stoichiometric use of nicotinamide pyridine cofactors, an integrated efficient recycling system is crucial to allow process operation under economic conditions. Lately, the variety of cofactors for biocatalysis was broadened by the utilization of totally synthetic and cheap biomimetics. Though, to date the regeneration has been limited to chemical or electrochemical methods. Here, we report an enzymatic recycling by the flavoprotein NADH-oxidase from Lactobacillus pentosus (LpNox). Since this enzyme has not been described before, we first characterized it in regard to its optimal reaction parameters. We found that the heterologously overexpressed enzyme only contained 13% FAD. In vitro loading of the enzyme with FAD, resulted in a higher specific activity towards its natural cofactor NADH as well as different nicotinamide derived biomimetics. Apart from the enzymatic recycling, which gives water as a by-product by transferring four electrons onto oxygen, unbound FAD can also catalyze the oxidation of biomimetic cofactors. Here a two electron process takes place yielding H2O2 instead. The enzymatic and chemical recycling was compared in regard to reaction kinetics for the natural and biomimetic cofactors. With LpNox and FAD, two recycling strategies for biomimetic cofactors are described with either water or hydrogen peroxide as by-product.

Liquid–liquid extraction system with microstructured coiled flow inverter and other capillary setups for single-stage extraction applications

Process intensification via miniaturization has become an attractive research field for industry and R&D especially for the production of fine chemicals and pharmaceuticals due to enhanced mass and heat transport. Fabrication of helically coiled tubular devices (HCTDs) in micro-scale can further enhance the mass and heat transfer due to the formation of secondary flow profile at laminar flow. Liquid–liquid (L–L) mass transfer performance of different microstructured HCTDs were investigated for slug flow patterns. A complete microextraction system was constructed and characterized including a T-junction (T-mixer) for slug flow generation, HCTDs as residence time units (RTUs), and a continuously working in-line phase splitter for an instantaneous phase separation. RTUs were fabricated by using fluorinated ethylene propylene (FEP) tubes (ID=1mm). EFCE test system, namely, n-butyl acetate/acetone/water system was chosen as an extraction system for the mass transfer characterization. The total volumetric flow rate and the volumetric flow ratio of aqueous to organic phase were varied in the range of 1–8mLmin−1 and 0.5–2.0, respectively. Effects of residence time, flow ratio, and the generation of secondary flow profile, i.e. Dean vortices on L–L mass transfer were investigated and results were compared with straight capillaries. Results revealed that a certain type of HCTD, i.e. coiled flow inverter (CFI) offers higher extraction efficiencies up to 20% in comparison to straight capillaries at constant residence times. Additionally, it was found that for slug flow patterns, Dean vortices provide enhanced L–L mass transfer compared to Taylor vortices that occur in straight capillaries. A complete, continuously operated microextraction system was developed for single-stage applications, where very small liquid hold-ups and longer residence times are required due to slower mass transfer rates.

Enzymatic processes in alternative reaction media: a mini review

Biocatalysis is a growing field in the production of fine chemicals and will most probably increase its share in the future. Enzymatic reactions are carried out under mild conditions, i.e., non-toxic solvents, low temperature and pressure, which eliminates most environmental drawbacks associated with conventional production methods. The superiority of chemo-, regio- and enantioselectivity of enzymes exhibit significant advantages over conventional catalysts for production of fine chemicals, flavors, fragrances, agrochemicals and pharmaceuticals. Enzymes can function both in aqueous and non-aqueous solvents. As a result of the growing scientific and industrial interest towards green chemistry, green solvent systems, which are mainly water, supercritical fluids, ionic liquids, fluorinated solvents, and solvent-free systems have become more popular in biocatalysis. However, the activity and selectivity of an enzyme is heavily dependent on solvent properties. In this review, various green solvents were classified and some of their influential features on enzyme activity were discussed.

The centrifugal partition reactor, a novel intensified continuous reactor for liquid–liquid enzymatic reactions

Implementation of continuous processes for production of fine chemicals and pharmaceuticals is an efficient way for process intensification. This study aims at demonstrating the potential of a Centrifugal Partition Chromatography (CPC) apparatus as a novel type of intensified reactor (termed Centrifugal Partition Reactor, CPR) for biphasic (water-organic solvent) enzymatic reactions. The reaction of esterification of oleic acid with n-butanol catalyzed by the Rhizomucor miehei lipase was tested as the model reaction.The influence of rotation speed, flow rate, enzyme and substrate concentrations on esterification reaction were studied. The CPR proved to be efficient to generate sufficient interfacial area (weakly dependent of the flow rate) and sufficient residence time (30min) to achieve good conversion (85%). Also, increasing rotation speed of the CPR surprisingly decreased performances, probably due to very specific inner hydrodynamics. For a given configuration, the productivity of the CPR (40.5gh−1L−1) was found to be more favorable than the conventional batch process (21.6gh−1L−1). Steady state operation of the reactor at 22°C, (i.e., constant conversion at the output, see Fig. 8), was reached after about 2 residence times and lasted for 24h. After 24h, the output conversion slowly decreased due to the low intrinsic stability of the enzyme at room temperature.The promising results obtained in this study are a good incentive to promote the CPR as a competitive innovative technology for operating continuous two phase enzymatic reactions.

Reactive Chromatographic and Membrane Separations for the Production of (Bio)Pharmaceuticals and Fine Chemicals

Reactive Chromatographic and Membrane Separations for the Production of (Bio)Pharmaceuticals and Fine Chemicals

Production of fine chemicals by integrated photocatalytical degradation of alkali lignin solution in corrugated plate reactor and cyclic extraction technology

This paper presented a procedure which includes the photocatalytical degradation of alkali lignin solution in corrugated plate reactor and the recovery of degraded products in organic solvent with cyclic extraction. It was prepared a Fe–TiO2 thin film photocatalyst by dip-coating method successfully immobilized on the surface of copper corrugated plate. Lignin was dissolved in sodium hydroxide (0.5mol/L) solution and the concentration of lignin solution in range of 10–40g/L. Lignin was degraded on the surface of catalyst and over irradiation by ultraviolet (UV) lamp (power-21W with wavelength of 254nm). By GC–MS analysis, it confirmed that there were more than 20 kinds of compounds in degradation products of alkali lignin. In addition to this, some commercial value chemicals including 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP) were also observed.