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Tek Chand Bhalla - One of the best experts on this subject based on the ideXlab platform.
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nocardia globerula nhb 2 nitrilase catalysed biotransformation of 4 cyanopyridine to isonicotinic acid
AMB Express, 2012Co-Authors: Nitya Nand Sharma, Monica Sharma, Tek Chand BhallaAbstract:Isonicotinic acid (INA) is an important pyridine derivative used in the manufacture of isoniazid (antituberculosatic drug) and other pharmaceutically important drugs. Nitrilase catalysed processes for the synthesis of pharmaceutically important acids from their corresponding nitriles are promising alternative over the cumbersome, hazardous, and energy demanding chemical processes. Nitrilase of Nocardia globerula NHB-2 (NitNHB2) is expressed in presence of isobutyronitrile in the growth medium (1.0% glucose, 0.5% peptone, 0.3% beef extract, and 0.1 % yeast extract, pH 7.5). NitNHB2 hydrolyses 4-cyanopyridine (4-CP) to INA without accumulation of isonicotinamide, which is common in the reaction catalysed via fungal nitrilases. The NitNHB2 suffers from substrate inhibition effect and hydrolysing activity up to 250 mM 4-CP was recorded. Complete conversion of 200 mM 4-CP to INA was achieved in 40 min using resting cell concentration corresponding to 10 U mL-1 nitrilase activity in the reaction. Substrate inhibition effect in the fed batch reaction (200 mM substrate feed/40min) led to formation of only 729 mM INA. In a fed batch reaction (100 mM 4-CP/20min), substrate inhibition effect was encountered after 7th feed and a total of 958 mM INA was produced in 400 min. The fed batch reaction scaled up to 1 L and 100% hydrolysis of 700 mM of 4-CP to INA at 35°C achieved in 140 min. The rate of INA production was 21.1 g h-1 mgDCW-1. This is the fastest biotransformation process ever reported for INA production with time and space productivity of 36 g L-1 h-1 using a bacterial nitrilase.
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an improved nitrilase mediated bioprocess for synthesis of nicotinic acid from 3 cyanopyridine with hyperinduced nocardia globerula nhb 2
Journal of Industrial Microbiology & Biotechnology, 2011Co-Authors: Nitya Nand Sharma, Monica Sharma, Tek Chand BhallaAbstract:Nitrilase of Nocardia globerula NHB-2 was induced by short-chain aliphatic nitriles (valeronitrile > isobutyronitrile > butyronitrile > propionitrile) and exhibited activity towards aromatic nitriles (benzonitrile > 3-cyanopyridine > 4-cyanopyridine > m-tolunitrile > p-tolunitrile). Hyperinduction of nitrilase (6.67 U mgDCW−1, 18.7 U mL−1) was achieved in short incubation time (30 h, 30°C) through multiple feeding of isobutyronitrile in the growth medium. The nitrilase of this organism exhibits both substrate and product inhibition effects. In a fed batch reaction at 1 L scale using hyperinduced resting cells corresponding to 10 U mL−1 nitrilase activity (1.5 mgDCW mL−1), a total of 123.11 g nicotinic acid was produced at a rate of 24 g h−1 gDCW−1.
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Generation of mutant of Rhodococcus rhodochrous PA-34 through chemical mutagenesis for hyperproduction of nitrile hydratase.
Acta microbiologica et immunologica Hungarica, 2010Co-Authors: Amit Pratush, Amit Seth, Tek Chand BhallaAbstract:Rhodococcus rhodochrous PA-34 has been reported to produce nitrile hydratase enzyme that converts 3-cyanopyridine to nicotinamide. A mutant of R. rhodochrous PA-34 was generated through chemical mutagenesis using N-methyl-N-nitro-N-nitrosoguanidine (MNNG) that exhibited 2 times higher nitrile hydratase activity as compared to wild strain. The reaction conditions using resting cells of this mutant strain for the conversion of nicotinamide were optimized. Under the optimized reaction conditions the mutant strain exhibited maximum nitrile hydratase activity [7.8 U/mgdcm (milligram dry cell mass)] at 55 °C in 0.3 M potassium phosphate buffer (pH 5.5).
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nocardia globerula nhb 2 bench scale production of nicotinic acid
Process Biochemistry, 2006Co-Authors: Nitya Nand Sharma, Monica Sharma, Harish Kumar, Tek Chand BhallaAbstract:Abstract The intracellular nitrilase of Nocardia globerula NHB-2 induced by propionitrile catalyses the hydrolysis of 3-cyanopyridine to nicotinic acid without detectable formation of nicotinamide. N. globerula NHB-2 showed highest conversion rate at 40 mM 3-cyanopyridine, in 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5) containing 5 mM 2-mercaptoethanol. In 1 l fed-batch reaction, containing 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5), 4.2 g resting cells (dry weight), at 35 °C, 400 rpm, a total of 1 mol of 3-cyanopyridine added at feed rate of 0.12 mol h −1 was converted to nicotinic acid (98.6%) in 9 h. The rate of nicotinic acid production was 26 mmol h −1 g −1 DW.
Ren-gen Xiong - One of the best experts on this subject based on the ideXlab platform.
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heterometallic tetrazole coordination polymer formed through 2 3 cycloaddition reaction between inorganic complexes in the presence of lewis acid
Crystal Growth & Design, 2007Co-Authors: Yunzhi Tang, Ren-gen Xiong, Guoxi Wang, Qiong Ye, Rongxin YuanAbstract:The two in situ 2 + 3 intermolecular cycloaddition reactions between inorganic complexes bis(3-cyanopyrdine)copper(II)azide (A) offer homometallic and heterometallic 3D novel tetrazole coordination polymers, (3-C5H4N-CN4)2Cu(I)2 (1) and (3-C5H4N-CN4)Cu(I)Cd(II)Cl2 (2), respectively, in the presence of Lewis acid CuCl2 and CdCl2 in which A is used to replace the organic cyano group and NaN3 during Sharplessʼs tetrazole synthesis. Their interesting luminescent properties are reported.
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isolation and crystallographic characterization of a solid precipitate intermediate in the preparation of 5 substituted 1h tetrazoles from nitrile in water
Inorganic Chemistry, 2003Co-Authors: Lizhong Wang, Hong Zhao, Xi-sen Wang, Zhirong Qu, Ren-gen XiongAbstract:The reactions of 2-, 3-, and 4-cyanopyridine with NaN3 in the presence of H2O and Lewis acid (ZnCl2) afford discrete monomer, (2-PTZ)2Zn(H2O)2 (1), 3D diamondoid-like network (3-PTZ)2Zn (2), and 2D layered network (4-PTZ)Zn(OH)(H2O) (3), respectively (PTZ = 5-(pyridyl)tetrazolato).Their solid state structures and natures give new insight into the Sharpless reaction of 5-substituted 1H-tetrazole. Interestingly, 2 crystallizes in a noncentrosymmetric space group and its powdered sample is second-harmonic generation active.
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isolation and crystallographic characterization of a solid precipitate intermediate in the preparation of 5 substituted 1h tetrazoles from nitrile in water
Inorganic Chemistry, 2003Co-Authors: Lizhong Wang, Hong Zhao, Xi-sen Wang, Ren-gen Xiong, Ziling XueAbstract:The reactions of 2-, 3-, and 4-cyanopyridine with NaN3 in the presence of H2O and Lewis acid (ZnCl2) afford discrete monomer, (2-PTZ)2Zn(H2O)2 (1), 3D diamondoid-like network (3-PTZ)2Zn (2), and 2D...
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novel acentric metal organic coordination polymers from hydrothermal reactions involving in situ ligand synthesis
Angewandte Chemie, 2002Co-Authors: Ren-gen Xiong, Hong Zhao, Xiang Xue, Xiaozeng You, Brendan F Abrahams, Ziling XueAbstract:The pyridyltetrazolate ligand formed in situ from NaN3 and 3-cyanopyridine in the presence of ZnCl2 or CdCl2 in water affords acentric (1) or chiral (2) coordination polymers, respectively. The corresponding reaction of ZnCl2 with 4-cyanopyridine gives acentric 3 (not shown). Compounds 1-3 are second harmonic generation active.
Nitya Nand Sharma - One of the best experts on this subject based on the ideXlab platform.
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nocardia globerula nhb 2 nitrilase catalysed biotransformation of 4 cyanopyridine to isonicotinic acid
AMB Express, 2012Co-Authors: Nitya Nand Sharma, Monica Sharma, Tek Chand BhallaAbstract:Isonicotinic acid (INA) is an important pyridine derivative used in the manufacture of isoniazid (antituberculosatic drug) and other pharmaceutically important drugs. Nitrilase catalysed processes for the synthesis of pharmaceutically important acids from their corresponding nitriles are promising alternative over the cumbersome, hazardous, and energy demanding chemical processes. Nitrilase of Nocardia globerula NHB-2 (NitNHB2) is expressed in presence of isobutyronitrile in the growth medium (1.0% glucose, 0.5% peptone, 0.3% beef extract, and 0.1 % yeast extract, pH 7.5). NitNHB2 hydrolyses 4-cyanopyridine (4-CP) to INA without accumulation of isonicotinamide, which is common in the reaction catalysed via fungal nitrilases. The NitNHB2 suffers from substrate inhibition effect and hydrolysing activity up to 250 mM 4-CP was recorded. Complete conversion of 200 mM 4-CP to INA was achieved in 40 min using resting cell concentration corresponding to 10 U mL-1 nitrilase activity in the reaction. Substrate inhibition effect in the fed batch reaction (200 mM substrate feed/40min) led to formation of only 729 mM INA. In a fed batch reaction (100 mM 4-CP/20min), substrate inhibition effect was encountered after 7th feed and a total of 958 mM INA was produced in 400 min. The fed batch reaction scaled up to 1 L and 100% hydrolysis of 700 mM of 4-CP to INA at 35°C achieved in 140 min. The rate of INA production was 21.1 g h-1 mgDCW-1. This is the fastest biotransformation process ever reported for INA production with time and space productivity of 36 g L-1 h-1 using a bacterial nitrilase.
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an improved nitrilase mediated bioprocess for synthesis of nicotinic acid from 3 cyanopyridine with hyperinduced nocardia globerula nhb 2
Journal of Industrial Microbiology & Biotechnology, 2011Co-Authors: Nitya Nand Sharma, Monica Sharma, Tek Chand BhallaAbstract:Nitrilase of Nocardia globerula NHB-2 was induced by short-chain aliphatic nitriles (valeronitrile > isobutyronitrile > butyronitrile > propionitrile) and exhibited activity towards aromatic nitriles (benzonitrile > 3-cyanopyridine > 4-cyanopyridine > m-tolunitrile > p-tolunitrile). Hyperinduction of nitrilase (6.67 U mgDCW−1, 18.7 U mL−1) was achieved in short incubation time (30 h, 30°C) through multiple feeding of isobutyronitrile in the growth medium. The nitrilase of this organism exhibits both substrate and product inhibition effects. In a fed batch reaction at 1 L scale using hyperinduced resting cells corresponding to 10 U mL−1 nitrilase activity (1.5 mgDCW mL−1), a total of 123.11 g nicotinic acid was produced at a rate of 24 g h−1 gDCW−1.
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nocardia globerula nhb 2 bench scale production of nicotinic acid
Process Biochemistry, 2006Co-Authors: Nitya Nand Sharma, Monica Sharma, Harish Kumar, Tek Chand BhallaAbstract:Abstract The intracellular nitrilase of Nocardia globerula NHB-2 induced by propionitrile catalyses the hydrolysis of 3-cyanopyridine to nicotinic acid without detectable formation of nicotinamide. N. globerula NHB-2 showed highest conversion rate at 40 mM 3-cyanopyridine, in 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5) containing 5 mM 2-mercaptoethanol. In 1 l fed-batch reaction, containing 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5), 4.2 g resting cells (dry weight), at 35 °C, 400 rpm, a total of 1 mol of 3-cyanopyridine added at feed rate of 0.12 mol h −1 was converted to nicotinic acid (98.6%) in 9 h. The rate of nicotinic acid production was 26 mmol h −1 g −1 DW.
Mandana Yaghoobi - One of the best experts on this subject based on the ideXlab platform.
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a concise and versatile synthesis of 2 amino 3 cyanopyridine derivatives in 2 2 2 trifluoroethanol
ChemInform, 2013Co-Authors: Samad Khaksar, Mandana YaghoobiAbstract:Trifluoroethanol is found to be an efficient and easily recoverable solvent for the synthesis of pyridine derivatives (IV)/(VI) via one-pot four-component condensation of aldehydes, ketones, malononitrile and NH4OAc.
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a concise and versatile synthesis of 2 amino 3 cyanopyridine derivatives in 2 2 2 trifluoroethanol
Journal of Fluorine Chemistry, 2012Co-Authors: Samad Khaksar, Mandana YaghoobiAbstract:Abstract Trifluoroethanol (TFE) is found to be an efficient and recyclable medium in promoting one-pot, four-component coupling reactions of aldehydes, ketones, malononitrile, and ammonium acetate to afford the corresponding 2-amino-3-cyanopyridine derivatives in high yields. The solvent (TFE) can be readily separated from reaction products and recovered in excellent purity for direct reuse.
Monica Sharma - One of the best experts on this subject based on the ideXlab platform.
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nocardia globerula nhb 2 nitrilase catalysed biotransformation of 4 cyanopyridine to isonicotinic acid
AMB Express, 2012Co-Authors: Nitya Nand Sharma, Monica Sharma, Tek Chand BhallaAbstract:Isonicotinic acid (INA) is an important pyridine derivative used in the manufacture of isoniazid (antituberculosatic drug) and other pharmaceutically important drugs. Nitrilase catalysed processes for the synthesis of pharmaceutically important acids from their corresponding nitriles are promising alternative over the cumbersome, hazardous, and energy demanding chemical processes. Nitrilase of Nocardia globerula NHB-2 (NitNHB2) is expressed in presence of isobutyronitrile in the growth medium (1.0% glucose, 0.5% peptone, 0.3% beef extract, and 0.1 % yeast extract, pH 7.5). NitNHB2 hydrolyses 4-cyanopyridine (4-CP) to INA without accumulation of isonicotinamide, which is common in the reaction catalysed via fungal nitrilases. The NitNHB2 suffers from substrate inhibition effect and hydrolysing activity up to 250 mM 4-CP was recorded. Complete conversion of 200 mM 4-CP to INA was achieved in 40 min using resting cell concentration corresponding to 10 U mL-1 nitrilase activity in the reaction. Substrate inhibition effect in the fed batch reaction (200 mM substrate feed/40min) led to formation of only 729 mM INA. In a fed batch reaction (100 mM 4-CP/20min), substrate inhibition effect was encountered after 7th feed and a total of 958 mM INA was produced in 400 min. The fed batch reaction scaled up to 1 L and 100% hydrolysis of 700 mM of 4-CP to INA at 35°C achieved in 140 min. The rate of INA production was 21.1 g h-1 mgDCW-1. This is the fastest biotransformation process ever reported for INA production with time and space productivity of 36 g L-1 h-1 using a bacterial nitrilase.
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an improved nitrilase mediated bioprocess for synthesis of nicotinic acid from 3 cyanopyridine with hyperinduced nocardia globerula nhb 2
Journal of Industrial Microbiology & Biotechnology, 2011Co-Authors: Nitya Nand Sharma, Monica Sharma, Tek Chand BhallaAbstract:Nitrilase of Nocardia globerula NHB-2 was induced by short-chain aliphatic nitriles (valeronitrile > isobutyronitrile > butyronitrile > propionitrile) and exhibited activity towards aromatic nitriles (benzonitrile > 3-cyanopyridine > 4-cyanopyridine > m-tolunitrile > p-tolunitrile). Hyperinduction of nitrilase (6.67 U mgDCW−1, 18.7 U mL−1) was achieved in short incubation time (30 h, 30°C) through multiple feeding of isobutyronitrile in the growth medium. The nitrilase of this organism exhibits both substrate and product inhibition effects. In a fed batch reaction at 1 L scale using hyperinduced resting cells corresponding to 10 U mL−1 nitrilase activity (1.5 mgDCW mL−1), a total of 123.11 g nicotinic acid was produced at a rate of 24 g h−1 gDCW−1.
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nocardia globerula nhb 2 bench scale production of nicotinic acid
Process Biochemistry, 2006Co-Authors: Nitya Nand Sharma, Monica Sharma, Harish Kumar, Tek Chand BhallaAbstract:Abstract The intracellular nitrilase of Nocardia globerula NHB-2 induced by propionitrile catalyses the hydrolysis of 3-cyanopyridine to nicotinic acid without detectable formation of nicotinamide. N. globerula NHB-2 showed highest conversion rate at 40 mM 3-cyanopyridine, in 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5) containing 5 mM 2-mercaptoethanol. In 1 l fed-batch reaction, containing 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5), 4.2 g resting cells (dry weight), at 35 °C, 400 rpm, a total of 1 mol of 3-cyanopyridine added at feed rate of 0.12 mol h −1 was converted to nicotinic acid (98.6%) in 9 h. The rate of nicotinic acid production was 26 mmol h −1 g −1 DW.