169 results on '"Ramesh N. Patel"'
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2. Biocatalytic Synthesis of Chiral Pharmaceutical Intermediates
- Author
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Ramesh N. Patel
- Subjects
biocatalysis ,chiral intermediates ,anticancer ,antihypertensive ,anti-infective ,enantioselective enzymatic de-protection ,Biotechnology ,TP248.13-248.65 ,Food processing and manufacture ,TP368-456 - Abstract
The production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. Chiral intermediates and fine chemicals are in high demand from both the pharmaceutical and agrochemical industries for the preparation of bulk drug substances and agricultural products. The enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivities has been demonstrated. In this article, biocatalytic processes are described for the synthesis of chiral pharmaceutical intermediates.
- Published
- 2004
3. Green Biocatalysis
- Author
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Ramesh N. Patel, Ramesh N. Patel and Ramesh N. Patel, Ramesh N. Patel
- Published
- 2016
4. Biocatalysis for synthesis of pharmaceuticals
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Ramesh N. Patel
- Subjects
Drug ,media_common.quotation_subject ,Clinical Biochemistry ,Molecular Conformation ,Pharmaceutical Science ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Drug Discovery ,Animals ,Humans ,Organic chemistry ,Molecular Biology ,media_common ,Pharmaceutical industry ,010405 organic chemistry ,Chemistry ,business.industry ,Organic Chemistry ,Enzymes ,0104 chemical sciences ,Pharmaceutical Preparations ,Biocatalysis ,Molecular Medicine ,Chirality (chemistry) ,business - Abstract
Chirality is a key factor in the safety and efficacy of many drug products and thus the production of single enantiomers of drug intermediates and drugs has become important and state of the art in the pharmaceutical industry. There has been an increasing awareness of the enormous potential of microorganisms and enzymes (biocatalysts) for the transformation of synthetic chemicals with high chemo-, regio- and enatioselectivities providing products in high yields and purity. In this article, biocatalytic processes are described for the synthesis of key chiral intermediates for development pharmaceuticals.
- Published
- 2018
5. CHAPTER 5. Bristol-Myers Squibb: Preparation of Chiral Intermediates for the Development of Drugs and APIs
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Ramesh N. Patel
- Subjects
Active ingredient ,Chemistry ,Biocatalysis ,Enantioselective synthesis ,Regioselectivity ,Organic chemistry ,Enantiomer ,Directed evolution ,Chemical reaction ,Chemical synthesis - Abstract
The production of single enantiomers of key chiral intermediates has become increasingly important for the development of drugs. Demand for chiral compounds continues to rise in the pharmaceutical industry due to federal regulations covering active pharmaceutical ingredients (APIs), and the recognition that enantiomers of a chiral compound could have dramatically different biological activities and toxicity. In this area, there are a number of advantages in using biocatalysis over chemical synthesis. Typically, enzyme-catalyzed reactions are highly enantioselective, regioselective and do not require protection and deprotection steps during synthesis. They can be carried out at ambient temperature, atmospheric pressure in aqueous systems, and are often regarded as green processes that avoid the use of more extreme conditions used in chemical reactions which could cause undesirable side reactions. Microbial cells and enzymes (biocatalysts) can be immobilized and reused for many cycles, and enzymes are generally over-expressed in suitable hosts such as Escherichia coli to make enzymatic processes economically efficient, safer and cheaper. The preparation of thermostable, pH stable, organic solvent tolerant and highly active biocatalysts towards substrates by random and site-directed mutagenesis by directed evolution has led to the production of novel biocatalysts to be used under desired process conditions. This chapter describes the synthesis of key intermediates for the synthesis of APIS by biocatalysis at Bristol-Myers Squibb to provide sustainable, energy efficient and economical processes.
- Published
- 2017
6. Enzymatic Reduction of Adamantanones to Chiral Adamantanol Intermediates for the Synthesis of 11-β-Hydroxysteroid Dehydrogenase Inhibitors
- Author
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Animesh Goswami, Ramesh N. Patel, Zhiwei Guo, Xiang-Yang Ye, Steven L. Goldberg, Ronald L. Hanson, Jeffrey A. Robl, and Thomas P. Tully
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chemistry.chemical_classification ,chemistry.chemical_compound ,Acetic acid ,Enzyme ,Ketone ,Chemistry ,Stereochemistry ,Organic Chemistry ,Organic chemistry ,Alcohol ,Physical and Theoretical Chemistry ,11 β hydroxysteroid dehydrogenase - Abstract
An enzymatic reduction process was developed to convert the ketone 2-(6-oxo-2-phenyladamantan-2-yl)acetic acid to the chiral alcohol 2-((2S, 6S)-6-hydroxy-2-phenyladamantan-2-yl)acetic acid and to ...
- Published
- 2014
7. Green Biocatalysis
- Author
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Ramesh N. Patel and Ramesh N. Patel
- Subjects
- Biocatalysis, Enzymes--Biotechnology, Green chemistry
- Abstract
Green Biocatalysis presents an exciting green technology that uses mild and safe processes with high regioselectivity and enantioselectivity. Bioprocesses are carried out under ambient temperature and atmospheric pressure in aqueous conditions that do not require any protection and deprotection steps to shorten the synthetic process, offering waste prevention and using renewable resources. Drawing on the knowledge of over 70 internationally renowned experts in the field of biotechnology, Green Biocatalysis discusses a variety of case studies with emphases on process R&D and scale-up of enzymatic processes to catalyze different types of reactions. Random and directed evolution under process conditions to generate novel highly stable and active enzymes is described at length. This book features: A comprehensive review of green bioprocesses and application of enzymes in preparation of key compounds for pharmaceutical, fine chemical, agrochemical, cosmetic, flavor, and fragrance industries using diverse enzymatic reactions Discussion of the development of efficient and stable novel biocatalysts under process conditions by random and directed evolution and their applications for the development of environmentally friendly, efficient, economical, and sustainable green processes to get desired products in high yields and enantiopurity The most recent technological advances in enzymatic and microbial transformations and cuttingedge topics such as directed evolution by gene shuffling and enzyme engineering to improve biocatalysts With over 3000 references and 800 figures, tables, equations, and drawings, Green Biocatalysis is an excellent resource for biochemists, organic chemists, medicinal chemists, chemical engineers, microbiologists, pharmaceutical chemists, and undergraduate and graduate students in the aforementioned disciplines.
- Published
- 2016
8. Enzymes for the removal of N-carbobenzyloxy protecting groups from N-carbobenzyloxy-d- and l-amino acids
- Author
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Linda N. Chu, Venkata B. Nanduri, Ramesh N. Patel, and Animesh Goswami
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chemistry.chemical_classification ,Sphingomonas paucimobilis ,biology ,Process Chemistry and Technology ,Bioengineering ,medicine.disease_cause ,biology.organism_classification ,Biochemistry ,Burkholderia phenazinium ,Catalysis ,Enzyme assay ,Amino acid ,Hydrolysis ,Enzyme ,chemistry ,Enzymatic hydrolysis ,medicine ,biology.protein ,Escherichia coli - Abstract
Biocatalytic processes to selectively hydrolyze the N-carbobenzyloxy (CBz) group from CBz-protected d - or l -amino acids have been developed. The substrate specificities of the CBz-deprotecting enzymes from Burkholderia phenazinium SC 16530, and Sphingomonas paucimobilis expressed into Escherichia coli SC 16501 were evaluated on CBz-protected amino acids and structurally related compounds. Modifications of various structural components and their effects on enzyme activity and enantioselectivity provided a greater understanding of the two CBz-deprotecting enzymes.
- Published
- 2013
9. Pharmaceutical Intermediates by Biocatalysis: From Fundamental Science to Industrial Applications
- Author
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Ramesh N. Patel
- Subjects
Active ingredient ,chemistry.chemical_compound ,chemistry ,Drug development ,010405 organic chemistry ,Biocatalysis ,Boceprevir ,Organic chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Published
- 2016
10. Green Biocatalysis
- Author
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Ramesh N. Patel
- Subjects
Chemistry ,Biocatalysis ,Nanotechnology - Published
- 2016
11. Green Processes for the Synthesis of Chiral Intermediates for the Development of Drugs
- Author
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Ramesh N. Patel
- Subjects
Drug synthesis ,010405 organic chemistry ,Biocatalysis ,Stereochemistry ,Chemistry ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences - Published
- 2016
12. Applications of Biocatalysis for Pharmaceuticals and Chemicals
- Author
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Ramesh N. Patel
- Subjects
Drug ,Chemistry ,Biocatalysis ,business.industry ,media_common.quotation_subject ,Enantioselective synthesis ,Organic chemistry ,Biochemical engineering ,business ,media_common ,Pharmaceutical industry - Abstract
Chirality is a key factor in the safety and efficacy of many drug products and thus producing single enantiomers of drug intermediates and drugs has become increasingly important in the pharmaceutical industry. There has been an increasing awareness of the enormous potential of microorganisms and enzymes derived from them for the transformation of synthetic chemicals with high chemo-, regio-, and enatioselectivities. In this article, biocatalytic processes are described for the synthesis of key chiral intermediates for development of pharmaceuticals and fine chemicals.
- Published
- 2016
13. List of Contributors
- Author
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Samantha K. Au, Andreas S. Bommarius, Chen Cao, Pere Clapés, Rodrigo O.M.A. de Souza, Brent D. Feske, Michael J. Fink, Animesh Goswami, Gideon Grogan, Harald Gröger, Jonathan Groover, Melissa L.E. Gutarra, Romas Kazlauskas, Tomoko Matsuda, Marko D. Mihovilovic, Leandro S.M. Miranda, Thomas S. Moody, Ramesh N. Patel, Laila Roper, J. David Rozzell, Florian Rudroff, and Jon D. Stewart
- Published
- 2016
14. Biocatalysis: Synthesis of Key Intermediates for Development of Pharmaceuticals
- Author
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Ramesh N. Patel
- Subjects
business.industry ,Chemistry ,Enantioselective synthesis ,General Chemistry ,Enzymatic process ,Directed evolution ,Desymmetrization ,Catalysis ,Process conditions ,Biocatalysis ,Organic chemistry ,Chirality (chemistry) ,business ,Pharmaceutical industry - Abstract
Chirality is a key factor for the safety and efficacy of many drug products. The production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. There has been an enormous potential of microorganisms and enzymes derived from there for the transformation of synthetic chemicals with high chemo-, regio-, and enatioselectivities. Recent development in the area of directed evolution has led screen mutants under process conditions to increase activity and selectivity of biocatalysts, thus making the enzymatic process highly efficient and economically feasible. In this review, chemoenzymatic processes are described for the synthesis of chiral intermediates for the development of pharmaceuticals.
- Published
- 2011
15. Enzymatic Preparation of an (S)-Amino Acid from a Racemic Amino Acid
- Author
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Animesh Goswami, Ronald L. Hanson, Ramesh N. Patel, Thomas P. Tully, Yijun Chen, Iqbal Gill, Michael A. Montana, William L. Parker, and Steven L. Goldberg
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chemistry.chemical_classification ,biology ,Stereochemistry ,Organic Chemistry ,Dehydrogenase ,Formate dehydrogenase ,biology.organism_classification ,Reductive amination ,Cofactor ,Amino acid ,chemistry.chemical_compound ,Propanoic acid ,chemistry ,biology.protein ,Formate ,Physical and Theoretical Chemistry ,Sporosarcina ureae - Abstract
The (S)-amino acid, (S)-2-amino-3-(6-o-tolylpyridin-3-yl)propanoic acid (3), is a key intermediate needed for synthesis of an antidiabetic drug candidate. Three enzymatic routes to 3 were explored. (S)-Amino acid 3 could be prepared in 73% isolated yield with 99.9% ee from racemic amino acid 1 using (R)-amino acid oxidase from Trigonopsis variabilis expressed in Escherichia coli in combination with an (S)-aminotransferase using (S)-aspartate as amino donor. The (S)-aminotransferase was purified from a soil organism identified as Burkholderia sp. and cloned and expressed in E. coli. (S)-Amino acid 3 with 100% ee was also prepared in 68% solution yield and 54% isolated yield from 1 using recombinant (R)-amino acid oxidase from T. variabilis and an (S)-amino acid dehydrogenase from Sporosarcina ureae. The cofactor NADH required for the reductive amination reaction was regenerated using formate and formate dehydrogenase. The chemoenzymatic dynamic resolution of 1 by (R)-selective oxidation with Celite-immobil...
- Published
- 2010
16. Hydroxylation of l-proline to cis-3-hydroxy-l-proline by recombinant Escherichia coli expressing a synthetic l-proline-3-hydroxylase gene
- Author
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Animesh Goswami, Robert M. Johnston, Mark Liu, Ramesh N. Patel, Steven L. Goldberg, and Linda N. Chu
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chemistry.chemical_classification ,Bioengineering ,Biology ,medicine.disease_cause ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biochemistry ,Streptomyces ,law.invention ,Hydroxylation ,Hydroxyproline ,chemistry.chemical_compound ,Enzyme ,chemistry ,Biotransformation ,law ,Recombinant DNA ,medicine ,Proline ,Escherichia coli ,Biotechnology - Abstract
A synthetic gene encoding a Streptomyces l -proline-3-hydroxylase was constructed and used to produce the hydroxylase protein in recombinant Escherichia coli. A fermentation process for growth of this recombinant E. coli for enzyme production was scaled-up to 250 L. A biotransformation process was developed using cell suspensions of the recombinant E. coli and subsequently scaled-up to 10 L for conversion of l -proline to cis-3-hydroxy- l -proline. A reaction yield of 85 M% and d.e. of 99.9% was obtained for cis-3-hydroxy- l -proline.
- Published
- 2009
17. Synthesis of ethyl-(3R,5S)-dihydroxy-6-benzyloxyhexanoates via diastereo- and enantioselective microbial reduction: Cloning and expression of ketoreductase III from Acinetobacter sp. SC 13874
- Author
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Steve Chen, Ramesh N. Patel, Zhiwei Guo, Steven L. Goldberg, and Animesh Goswami
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biology ,Stereochemistry ,Enantioselective synthesis ,Diastereomer ,Bioengineering ,Acinetobacter ,medicine.disease_cause ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biochemistry ,law.invention ,Biocatalysis ,law ,Yield (chemistry) ,medicine ,Recombinant DNA ,Enantiomeric excess ,Escherichia coli ,Biotechnology - Abstract
Previously we have demonstrated the reduction of ethyl and t-butyl diketoesters 1 to the corresponding syn-(3R,5S)-dihydroxy esters 2a by Acinetobacter sp. 13874. The syn-(3R,5S)-dihydroxy ester 2a was obtained with an enantiomeric excess (e.e.) of 99% and a diastereomeric excess (de) of 63%. In this report, we identified a gene encoding desired ketoreductase III which catalyzed the diastereoselective reduction of diketoesters 1 to syn-(3R,5S)-dihydroxy esters 2a and describe cloning and expression of ketoreductase III into Escherichia coli. Cells or extracts of recombinant E. coli efficiently reduced the diketoester 1 to the corresponding syn-(3R,5S)-dihydroxy ester 2a in 99.3% yield, 100% e.e., and 99.8% de.
- Published
- 2008
18. Enzymatic Preparation of a <scp>d</scp>-Amino Acid from a Racemic Amino Acid or Keto Acid
- Author
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Steven L. Goldberg, Robert M. Johnston, William L. Parker, Michael A. Montana, Ronald L. Hanson, Thomas P. Tully, Ramesh N. Patel, and Brian L. Davis
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Alanine ,chemistry.chemical_classification ,Stereochemistry ,Organic Chemistry ,medicine.disease_cause ,Formate dehydrogenase ,Amino acid ,chemistry.chemical_compound ,Propanoic acid ,Enzyme ,chemistry ,Biochemistry ,Lactate dehydrogenase ,medicine ,Formate ,Physical and Theoretical Chemistry ,Escherichia coli - Abstract
The d-amino acid (R)-2-amino-3-(7-methyl-1 H-indazol-5-yl)propanoic acid (3) is a key intermediate needed for synthesis of a drug candidate compound. Enzymatic routes to 3 were explored. d-Amino acid 3 was prepared in 68% isolated yield with >99% ee from racemic amino acid 1 using l-amino acid deaminase from Proteus mirabilis expressed in Escherichia coli in combination with a commercially available d-transaminase using d-alanine as amino donor. The d-enantiomer was also prepared in 79% isolated yield with >99% ee from the corresponding keto acid 2 using the d-transaminase with racemic alanine as the amino donor. The rate and yield of this reaction could be accelerated by addition of lactate dehydrogenase (with NAD, formate and formate dehydrogenase to regenerate NADH) to remove the inhibitory pyruvate produced during the reaction. A d-transaminase was purified from a soil organism identified as Bacillus thuringiensis and cloned and expressed in E. coli. The d-transaminase was very effective for the prepa...
- Published
- 2008
19. Preparation of (R)-Amines from Racemic Amines with an (S)-Amine Transaminase fromBacillus megaterium
- Author
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Steven L. Goldberg, Thomas P. Tully, Ronald L. Hanson, Ramesh N. Patel, Yijun Chen, Michael A. Montana, Brian L. Davis, and William L. Parker
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chemistry.chemical_classification ,biology ,Chemistry ,Transamination ,Stereochemistry ,fungi ,General Chemistry ,biology.organism_classification ,Cofactor ,Transaminase ,Enzyme catalysis ,Amino acid ,chemistry.chemical_compound ,biology.protein ,Amine gas treating ,Pyridoxal phosphate ,Bacillus megaterium - Abstract
Screening was carried out to identify strains useful for the preparation of (R)-1-cyclopropylethylamine and (R)-sec-butylamine by resolution of the racemic amines with an (S)-specific transaminase. Several Bacillus megaterium strains from our culture collection as well as several soil isolates were found to have the desired activity for the resolution of the racemic amines to give the (R)-enantiomers. Using an extract of the best strain, Bacillus megaterium SC6394, the reaction was shown to be a transamination requiring pyruvate as amino acceptor and pyridoxal phosphate as a cofactor. Initial batches of both amines were produced using whole cells of Bacillus megaterium SC6394. The transaminase was purified to homogeneity to obtain N-terminal as well as internal amino acid sequences. The sequences were used to design polymerase chain reaction (PCR) primers to enable cloning and expression of the transaminase in E. coli SC16578. In contrast to the original B. megaterium process, pH control and aeration were not required for the resolution of sec-butylamine and an excess of pyruvate was not consumed by the recombinant cells. The resolution of sec-butylamine (0.68 M) using whole cells of E. coli SC16578 was scaled up to give (R)-sec-butylamine⋅1/2 H2SO4 in 46.6% isolated yield with 99.2% ee. An alternative isolation procedure was also used to isolate (R)-sec-butylamine as the free base.
- Published
- 2008
20. Synthesis of chiral pharmaceutical intermediates by biocatalysis
- Author
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Ramesh N. Patel
- Subjects
chemistry.chemical_classification ,Lactol ,Stereochemistry ,Synthon ,Diol ,Epoxide ,Chemical synthesis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Biotransformation ,Biocatalysis ,Materials Chemistry ,Organic chemistry ,Physical and Theoretical Chemistry ,Lactone - Abstract
Chiral intermediates were prepared by biocatalytic processes for the chemical synthesis of four pharmaceutical drug candidates. These include: (i) the microbial reduction of 3,5-dioxo-6-(benzyloxy) hexanoic ethyl ester to (3S,5R)-dihydroxy-6-(benzyloxy) hexanoic acid ethyl ester, an intermediate for a new anticholesterol drug; (ii) synthesis of (2R,3S)-(-)-N-benzoyl-3-phenyl isoserine ethyl ester, a taxol side-chain synthon; (iii) the microbial oxygenation of 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile to the corresponding (3S,4S) epoxide and (3S,4R)-trans diol, intermediates for synthesis of potassium channel opener; (iv) the biotransformation of (exo,exo)-7-oxabicyclo [2.2.1] heptane-2,3-dimethanol to the corresponding chiral lactol and lactone, intermediates for thromboxane A2 antagonist.
- Published
- 2008
21. Chemo-enzymatic synthesis of pharmaceutical intermediates
- Author
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Ramesh N. Patel
- Subjects
Drug ,Biocatalysis ,business.industry ,Chemistry ,media_common.quotation_subject ,Drug Discovery ,Organic chemistry ,Chemo enzymatic ,Enantiomer ,business ,Chirality (chemistry) ,Pharmaceutical industry ,media_common - Abstract
Chirality is a key factor in the safety and efficacy of many drug products and, thus, the production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. There has been an increasing awareness of the enormous potential of microorganisms and enzymes derived therefrom for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivities. In this article, some selected enzymatic processes are described for the synthesis of chiral intermediates for pharmaceuticals.
- Published
- 2008
22. Enzymatic resolution of methyl (1RS)-N-tBoc-6-hydroxy-3,4-dihydro-1H-isoquinoline-1-carboxylate by Seaprose S
- Author
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Ellen K. Kick, Yufeng Wang, Kate Richlin-Zack, Wu Yang, Ramesh N. Patel, and Iqbal Gill
- Subjects
chemistry.chemical_classification ,Resolution (mass spectrometry) ,Stereochemistry ,Organic Chemistry ,Enantioselective synthesis ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Hydrolysis ,Enzyme ,chemistry ,Yield (chemistry) ,Potency ,Carboxylate ,Physical and Theoretical Chemistry ,Isoquinoline - Abstract
An efficient biocatalytic process has been developed for the resolution of methyl (1 RS )- N - t Boc-6-hydroxy-3,4-dihydro-1 H -isoquinoline-1-carboxylate rac - 1 by means of Seaprose S-mediated enantioselective hydrolysis to afford (1 S )- 2 and (1 R )- 1 in 87% and 93% isolated yield, 101% and 96% potency, and ee >99.8% and >99.5%, respectively.
- Published
- 2007
23. Preparation of an Amino Acid Intermediate for the Dipeptidyl Peptidase IV Inhibitor, Saxagliptin, using a Modified Phenylalanine Dehydrogenase
- Author
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David B. Brzozowski, Ronald L. Hanson, Michael K. Wong, Dana L Cazzulino, Steven L. Goldberg, Thomas P. Tully, Truc Chi Vu, Ramesh N. Patel, William L. Parker, and Olav Lyngberg
- Subjects
chemistry.chemical_classification ,biology ,General Chemistry ,Nicotinamide adenine dinucleotide ,Formate dehydrogenase ,biology.organism_classification ,Dipeptidyl peptidase ,Pichia pastoris ,Amino acid ,Phenylalanine dehydrogenase ,chemistry.chemical_compound ,chemistry ,Biochemistry ,NAD+ kinase ,Branched-chain alpha-keto acid dehydrogenase complex - Abstract
The non-proteinogenic amino acid 2-(3-hydroxy-1-adamantyl)-(2S)-aminoethanoic acid [2, (S)-3-hydroxyadamantylglycine], is a key intermediate required for the synthesis of Saxagliptin, a dipeptidyl peptidase IV inhibitor under development for treatment of type 2 diabetes mellitus. Keto acid 2-(3-hydroxy-1-adamantyl)-2-oxoethanoic acid (1) was converted to (S)-3-hydroxyadamantylglycine by reductive amination using a phenylalanine dehydrogenase from Thermoactinomyces intermedius expressed in a modified form in Pichia pastoris or Escherichia coli. NAD (nicotinamide adenine dinucleotide) produced during the reaction was recycled to NADH (reduced form of nicotinamide adenine dinucleotide) using formate dehydrogenase. Pichia pastoris produces an endogenous formate dehydrogenase when grown on methanol, and the corresponding gene was cloned and expressed in E. coli. The modified phenylalanine dehydrogenase contains two amino acid changes at the C-terminus and a 12-amino acid extension of the C-terminus. The modified enzyme is more effective with keto acid 1 than the wild-type enzyme, but less effective with the natural substrate, phenylpyruvate. Production of multi-kg batches was originally carried out with extracts of Pichia pastoris expressing the modified phenylalanine dehydrogenase from Thermoactinomyces intermedius and endogenous formate dehydrogenase, and further scaled up using a preparation of the two enzymes expressed in E. coli.
- Published
- 2007
24. Enantioselective enzymatic acylation of 1-(3′-bromophenyl)ethylamine
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Iqbal I. Gill, Jagbandhu Das, and Ramesh N. Patel
- Subjects
Inorganic Chemistry ,Acylation ,chemistry.chemical_classification ,chemistry.chemical_compound ,Enzyme ,Chemistry ,Stereochemistry ,Yield (chemistry) ,Organic Chemistry ,Enantioselective synthesis ,Physical and Theoretical Chemistry ,Ethylamine ,Catalysis - Abstract
An efficient biocatalytic process has been developed for the resolution of 1-(3′-bromophenyl)ethylamine ( RS )- 1 by way of enantioselective lipase-mediated ( R )-selective acylation with ethyl 2-methoxyacetate to afford ( S )-amine ( S )- 1 and ( R )-2″-methoxyacetamide (( R )- 2 ) in 91–95% and 90–92% isolated yield, respectively, and both with >99% ee.
- Published
- 2007
25. Enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione: Cloning and expression of reductases
- Author
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Ramesh N. Patel, Linda Chu, Robert M. Johnston, Steven L. Goldberg, and Venkata B. Nanduri
- Subjects
Gel electrophoresis ,biology ,Stereochemistry ,Bioengineering ,Dehydrogenase ,Reductase ,medicine.disease_cause ,Formate dehydrogenase ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biochemistry ,Cofactor ,Pseudomonas putida ,chemistry.chemical_compound ,chemistry ,medicine ,biology.protein ,Sodium dodecyl sulfate ,Escherichia coli ,Biotechnology - Abstract
The enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione (1) to either of the corresponding (S)- and (R)-6-hydroxy-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-diones (2 and 3, respectively) is described. The NADP+-dependent (R)-reductase (RHBR) which catalyzes the reduction of 6-ketobuspirone (1) to (R)-6-hydroxybuspirone (3) was purified to homogeneity from cell extracts of Hansenula polymorpha SC 13845. The subunit molecular weight of the enzyme is 35,000 kDa based on sodium dodecyl sulfate gel electrophoresis and the molecular weight of the enzyme is 37,000 kDa as estimated by gel filtration chromatography. (R)-reductase from H. polymorpha was cloned and expressed in Escherichia coli. To regenerate the cofactor NADPH required for reduction we have cloned and expressed the glucose-6-phosphate dehydrogenase gene from Saccharomyces cerevisiae in E. coli. The NAD+-dependent (S)-reductase (SHBR) which catalyzes the reduction of 6-ketobuspirone (1) to (S)-6-hydroxybuspirone (2) was purified to homogeneity from cell extracts of Pseudomonas putida SC 16269. The subunit molecular weight of the enzyme is 25,000 kDa based on sodium dodecyl sulfate gel electrophoresis. The (S)-reductase from P. putida was cloned and expressed in E. coli. To regenerate the cofactor NADH required for reduction we have cloned and expressed the formate dehydrogenase gene from Pichia pastoris in E. coli. Recombinant E. coli expressing (S)-reductase and (R)-reductase catalyzed the reduction of 1 to (S)-6-hyroxybuspirone (2) and (R)-6-hyroxybuspirone (3), respectively, in >98% yield and >99.9% e.e.
- Published
- 2006
26. Stereospecific microbial reduction of ethyl 1-benzyl-3-oxo-piperidine-4-carboxylate
- Author
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Richard M. Corbett, Animesh Goswami, Zhiwei Guo, Ramesh N. Patel, and Bharat P. Patel
- Subjects
biology ,Organic Chemistry ,Diastereomer ,Pichia methanolica ,biology.organism_classification ,Candida parapsilosis ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Stereospecificity ,chemistry ,Organic chemistry ,Piperidine ,Carboxylate ,Physical and Theoretical Chemistry ,Enantiomeric excess - Abstract
Microbial reduction of ethyl 1-benzyl-3-oxo-piperidine-4-carboxylate by the majority of evaluated microorganisms gave the ethyl cis-(3R,4R)-1-benzyl-3R-hydroxy-piperidine-4R-carboxylate as the major product in high diastereo- and enantioselectivities. The 3R,4R-hydroxy ester was produced in 97.4% diastereomeric excess (de) and 99.8% enantiomeric excess (ee) by Candida parapsilosis SC16347, while 99.5% de and 98.2% ee were obtained from reduction by Pichia methanolica SC16415. A few of the evaluated microorganisms gave 10–40% of the ethyl trans-(3R,4S)-1-benzyl-3R-hydroxy-piperidine-4S-carboxylate as the minor product.
- Published
- 2006
27. Biocatalysis: Synthesis of Chiral Intermediates for Pharmaceuticals
- Author
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Ramesh N. Patel
- Subjects
Biocatalysis ,Chemistry ,Organic Chemistry ,Organic chemistry - Published
- 2006
28. Synthesis of ethyl and t-butyl (3R,5S)-dihydroxy-6-benzyloxy hexanoates via diastereo- and enantioselective microbial reduction
- Author
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Yijun Chen, Ramesh N. Patel, Animesh Goswami, Ronald L. Hanson, and Zhiwei Guo
- Subjects
biology ,Chemistry ,Stereochemistry ,Organic Chemistry ,Enantioselective synthesis ,Diastereomer ,Reductase ,Acinetobacter ,biology.organism_classification ,Catalysis ,Yeast ,Inorganic Chemistry ,Acinetobacter sp ,Hexanoates ,Physical and Theoretical Chemistry ,Enantiomeric excess - Abstract
Previously we have demonstrated the reduction of ethyl diketoester 4 to the corresponding dihydroxy ester 6a by Acinetobacter sp. SC13874. Recently we screened more than 100 cultures for microbial reduction of both the ethyl and t-butyl diketoesters 4 and 5. Most yeast cultures showed a preference for reduction at the C-3 with low enantioselectivity. Among the three Acinetobacter strains screened, Acinetobacter sp. SC13874 reduced both compounds 4 and 5 to the corresponding (3R)- and (5S)-monohydroxy compounds. Monohydroxy compounds were isolated and their absolute configurations determined. (3R)- and (5S)-Monohydroxy compounds were reduced further to the corresponding dihydroxy esters 6a and 8a to provide alternate routes for the synthesis of compounds 14a and 16a, potential intermediates for the synthesis of HMG-CoA reductase inhibitors. Cell suspensions of Acinetobacter sp. SC13874 reduced the ethyl diketoester 4 to a mixture of desired syn and undesired anti diastereomers. The desired syn-(3R,5S)-dihydroxy ester 6a was obtained with an enantiomeric excess (ee) of 99% and a diastereomeric excess (de) of 63%. Cell suspensions reduced the t-butyl diketoester 5 to a mixture of mono- and dihydroxy esters with the dihydroxy ester showing an ee of 87% and de of 51% for the desired syn-(3R,5S)-dihydroxy ester 8a. Three different ketoreductases were purified to homogeneity, and their biochemical properties compared. Reductase I only catalyzes the reduction of ethyl diketoester 4 to its monohydroxy products 10 and 11, whereas reductase II catalyzes the formation of dihydroxy products 6 and 7 from monohydroxy substrates 10 and 11. A third reductase (III) was identified, which catalyzes the reduction of diketoester 4 to syn-(3R,5S)-dihydroxy ester 6a.
- Published
- 2006
29. Biocatalytic ammonolysis of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester: Preparation of an intermediate to the dipeptidyl peptidase IV inhibitor Saxagliptin
- Author
-
Iqbal Gill and Ramesh N. Patel
- Subjects
Nitrogen ,Dipeptidyl Peptidase 4 ,Clinical Biochemistry ,Triacylglycerol lipase ,Pharmaceutical Science ,Adamantane ,Saxagliptin ,Biochemistry ,Chemical synthesis ,Catalysis ,Dipeptidyl peptidase ,Fungal Proteins ,Calcium Chloride ,chemistry.chemical_compound ,Ammonia ,Amide ,Drug Discovery ,Sodium Hydroxide ,Organic chemistry ,Dicarboxylic Acids ,Pyrroles ,Enzyme Inhibitors ,Molecular Biology ,Pyrrole ,chemistry.chemical_classification ,Ethane ,Ethanol ,Molecular Structure ,Chemistry ,Organic Chemistry ,Asbestos ,Esters ,Stereoisomerism ,Dipeptides ,Lipase ,General Medicine ,Carbon Dioxide ,Dicarboxylic acid ,Yield (chemistry) ,Molecular Medicine ,Ammonium carbamate ,Carbamates ,Biotechnology - Abstract
An efficient biocatalytic method has been developed for the conversion of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester (1) into the corresponding amide (5S)-5-aminocarbonyl-4,5-dihydro-1H-pyrrole-1-carboxylic acid, 1-(1,1-dimethylethyl)ester (2), which is a critical intermediate in the synthesis of the dipeptidyl peptidase IV (DPP4) inhibitor Saxagliptin (3). Candida antartica lipase B mediates ammonolysis of the ester with ammonium carbamate as ammonia donor to yield up to 71% of the amide. The inclusion of Ascarite and calcium chloride as adsorbents for carbon dioxide and ethanol byproducts, respectively, increases the yield to 98%, thereby offering an efficient and practical alternative to chemical routes which yield 57-64%.
- Published
- 2006
30. Preparation of a chiral synthon for an HBV inhibitor: enzymatic asymmetric hydrolysis of (1α,2β,3α)-2-(benzyloxymethyl)cyclopent-4-ene-1,3-diol diacetate and enzymatic asymmetric acetylation of (1α,2β,3α)-2-(benzyloxymethyl)cyclopent-4-ene-1,3-diol
- Author
-
Jing Liang, Yadagiri Pendri, Ramesh N. Patel, Amit Banerjee, Chung-Pin Chen, and Richard H. Mueller
- Subjects
biology ,Stereochemistry ,Organic Chemistry ,Diol ,Enantioselective synthesis ,Catalysis ,Inorganic Chemistry ,Acylation ,Isopropenyl acetate ,chemistry.chemical_compound ,Hydrolysis ,chemistry ,biology.protein ,Physical and Theoretical Chemistry ,Lipase ,Enantiomeric excess ,Ene reaction - Abstract
Enantioselective asymmetric hydrolysis of (1α,2β,3α)-2-(benzyloxymethyl)-cyclopent-4-ene-1,3-diol diacetate 1 to the corresponding (+)-monoacetate 2 was carried out using lipase PS-30 from Pseudomonas cepacia or pancreatin. A reaction yield of 85 M % with an enantiomeric excess (ee) of 98% was obtained. Using pancreatin, a reaction yield of 75 M % with an ee of 98.5% was obtained. Asymmetric acetylation of (1α,2β,3α)-2-(benzyloxymethyl)-cyclopent-4-ene-1,3-diol 3 to the corresponding (−)-monoacetate 4 was carried out using lipase PS-30 with isopropenyl acetate as the acylating agent. A reaction yield of 80 M % with an ee of 98% was obtained for (−)-monoacetate 4 .
- Published
- 2006
31. Enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione
- Author
-
Jianqing Li, Linda Chu, Venkata B. Nanduri, Atul S. Kotnis, William L. Parker, Richard H. Mueller, Ramesh N. Patel, and Mark Liu
- Subjects
Inorganic Chemistry ,Reduction (complexity) ,chemistry.chemical_compound ,chemistry ,Organic Chemistry ,Enantioselective synthesis ,Organic chemistry ,Decane ,Physical and Theoretical Chemistry ,Catalysis - Abstract
The enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione 1 to either of the corresponding (R)- or (S)-6-hydroxy-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-diones 2 and 3 is described.
- Published
- 2005
32. Preparation of (R)- and (S)-6-hydroxybuspirone by enzymatic resolution or hydroxylation
- Author
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Ronald L. Hanson, Ramesh N. Patel, William L. Parker, David B. Brzozowski, Atul S. Kotnis, Mark Liu, and Thomas P. Tully
- Subjects
chemistry.chemical_classification ,Stereochemistry ,Organic Chemistry ,Catalysis ,Amino acid ,Inorganic Chemistry ,Hydroxylation ,chemistry.chemical_compound ,Hydrolysis ,Enzyme ,chemistry ,Yield (chemistry) ,Acid hydrolysis ,Physical and Theoretical Chemistry ,Enantiomer ,Active metabolite - Abstract
6-Hydroxybuspirone is an active metabolite of the antianxiety drug buspirone. The (R)- and (S)-enantiomers of 6-hydroxybuspirone were prepared using an enzymatic resolution process. l -Amino acid acylase from Aspergillus melleus (Amano Acylase 30000) was used to hydrolyze racemic 6-acetoxybuspirone to (S)-6-hydroxybuspirone in 95% ee after 45% conversion. The remaining (R)-6-acetoxybuspirone with 88% ee was converted to (R)-6-hydroxybuspirone by acid hydrolysis. The ee of both enantiomers could be improved to 99% by crystallization as a metastable polymorph. (S)-6-Hydroxybuspirone was also obtained in 88% ee and 14.5% yield by hydroxylation of buspirone using Streptomyces antibioticus ATCC 14890.
- Published
- 2005
33. Purification and Cloning of a Ketoreductase used for the Preparation of Chiral Alcohols
- Author
-
Thomas P. Tully, Ronald L. Hanson, Steven L. Goldberg, Ramesh N. Patel, and Animesh Goswami
- Subjects
Cloning ,chemistry.chemical_classification ,Ketone ,biology ,Organic Chemistry ,Saccharomyces cerevisiae ,Dehydrogenase ,biology.organism_classification ,Catalysis ,Amino acid ,Enzyme catalysis ,law.invention ,Enzyme ,Biochemistry ,chemistry ,law ,Recombinant DNA - Abstract
The synthesis of the leading candidate compound in an anticancer program required (S)-2-chloro-1-(3-chlorophenyl)-ethanol as an intermediate. Other possible candidate compounds used analogues of the S-alcohol. Of 119 microbial cultures screened for reduction of the corresponding ketone to the S-alcohol, Hansenula polymorpha ATCC 58401 (73.8% ee) and Rhodococcus globerulus ATCC 21505 (71.8% ee) had the highest enantioselectivity for producing the desired alcohol. A ketoreductase from Hansenula polymorpha, after purification to homogeneity, gave the S-alcohol with 100% ee. Amino acid sequences from the purified enzyme were used to design PCR primers for cloning the ketoreductase. The cloned ketoreductase required NADP(H), had a subunit molecular weight of 29,220 and a native molecular weight of 88,000. The cloned ketoreductase was expressed in E. coli together with a cloned glucose 6-phosphate dehydrogenase from Saccharomyces cerevisiae to allow regeneration of the NADPH required by the ketoreductase. An extract of E. coli containing the two recombinant enzymes was used to reduce 2-chloro-1-(3-chloro-4-fluorophenyl)-ethanone and two related ketones to the corresponding S-alcohols. Intact E. coli cells provided with glucose were used to prepare (S)-2-chloro-1-(3-chloro-4-fluorophenyl)-ethanol in 89% yield with 100% ee.
- Published
- 2005
34. Enzymatic resolution of sec-butylamine
- Author
-
Ramesh N. Patel, William L. Parker, Zhiwei Guo, and Animesh Goswami
- Subjects
biology ,Butylamine ,organic chemicals ,Organic Chemistry ,Ether ,biology.organism_classification ,Catalysis ,Inorganic Chemistry ,Acylation ,chemistry.chemical_compound ,chemistry ,Ethyl decanoate ,sec-Butylamine ,biology.protein ,Organic chemistry ,Candida antarctica ,Physical and Theoretical Chemistry ,Lipase ,Enantiomeric excess - Abstract
Resolution of (±)- sec -butylamine by Candida antarctica lipase provided a very low enantiomeric excess of the residual amine when either ethyl or vinyl butyrate was used as the acylating agent. The enantiomeric excess was increased by using ethyl esters of long chain fatty acids. The rate of the reaction was increased by using methyl t -butyl ether as a solvent. ( S )- sec -Butylamine of very high enantiomeric excess was obtained by C. antarctica lipase catalyzed acylation with ethyl decanoate in methyl t -butyl ether.
- Published
- 2005
35. Enantioselective microbial reduction of substituted acetophenones
- Author
-
Prasad J Siva, Linda Chu, Mary Jo Donovan, Ronald F Eiring, Robert J. Johnston, Richard H. Mueller, Ramesh N. Patel, Zhongping Shi, Junying Fan, Animesh Goswami, Brent Nielsen, Ambarish K. Singh, Kwok Y Wang, Dana L Cazzulino, Steven L. Goldberg, Weixuan He, and Venkata B. Nanduri
- Subjects
biology ,Stereochemistry ,Chemistry ,Organic Chemistry ,Enantioselective synthesis ,Pichia methanolica ,Reductase ,Rhodotorula ,biology.organism_classification ,Saccharomyces ,Catalysis ,Inorganic Chemistry ,Yield (chemistry) ,Organic chemistry ,Physical and Theoretical Chemistry ,Enantiomeric excess ,Pichia - Abstract
The chiral intermediate ( S )-1-(2′-bromo-4′-fluoro phenyl)ethanol 2 was prepared by the enantioselective microbial reduction of 2-bromo-4-fluoro acetophenone 1 . Organisms from genus Candida , Hansenula , Pichia , Rhodotorula , Saccharomyces , Sphingomonas and Baker's yeast reduced 1 to 2 in >90% yield and 99% enantiomeric excess (ee). In an alternative approach, the enantioselective microbial reductions of methyl, ethyl, and tert -butyl 4-(2′-acetyl-5′-fluorophenyl) butanoates 3 , 5 , and 7 , respectively, were demonstrated using strains of Candida and Pichia . Reaction yields of 40–53% and ee's of 90–99% were obtained for the corresponding ( S )-hydroxy esters 4 , 6 , and 8 . The reductase, which catalyzed the enantioselective reduction of ketoesters was purified to homogeneity from cell extracts of Pichia methanolica SC 13825. It was cloned and expressed in Escherichia coli with recombinant cultures used for the enantioselective reduction of keto methyl ester 3 to the corresponding ( S )-hydroxy methyl ester 4 . On a preparative scale, a reaction yield of 98% and an ee of 99% was obtained.
- Published
- 2004
36. Cloning and expression of a novel enantioselective N-carbobenzyloxy-cleaving enzyme
- Author
-
Robert J. Johnston, Ramesh N. Patel, Steven L. Goldberg, and Venkata B. Nanduri
- Subjects
Cloning ,chemistry.chemical_classification ,Sphingomonas paucimobilis ,biology ,Bioengineering ,Molecular cloning ,biology.organism_classification ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Biochemistry ,DNA sequencing ,Enzyme ,chemistry ,Gene expression ,medicine ,Gene ,Escherichia coli ,Biotechnology - Abstract
A novel enantioselective N-carbobenzyloxy (Cbz)-cleaving enzyme was purified to homogeneity from Sphingomonas paucimobilis SC 16113. The gene encoding the protein has been identified and its complete DNA sequence was determined. The Cbz-cleaving enzyme was expressed in Escherichia coli.
- Published
- 2004
37. Enzymatic preparation of (3R)-cis-3-acetyloxy-4-(1,1-dimethylethyl)-2-azetidinone: a side-chain synthon for an orally active taxane
- Author
-
Ramesh N. Patel, Jeffrey M. Howell, Joydeep Kant, Serge Benoit, and Rama Chidambaram
- Subjects
Taxane ,biology ,Chemistry ,Stereochemistry ,Organic Chemistry ,Synthon ,Enantioselective synthesis ,Semisynthesis ,Catalysis ,Inorganic Chemistry ,Enzymatic hydrolysis ,biology.protein ,Side chain ,Organic chemistry ,Physical and Theoretical Chemistry ,Lipase ,Enantiomer - Abstract
The chiral intermediate (3R)-cis-3-acetyloxy-4-(1,1-dimethylethyl)-2-azetidinone 2 was prepared for the semi-synthesis of the new taxane 5, an orally active anticancer compound. The enantioselective enzymatic hydrolysis of cis-3-acetyloxy-4-(1,1-dimethylethyl)-2-azetidinone 1 to the corresponding undesired (S)-alcohol 3 and unreacted desired 2 was carried out using immobilized lipase PS-30 or BMS lipase. Reaction yields of >48% and enantiomeric excesses of >99% were obtained for the desired 2. Acetoxy β-lactam 2 was converted to hydroxy β-lactam 4 for use in the semisynthesis of 5.
- Published
- 2003
38. Diastereoselective microbial reduction of (S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester
- Author
-
Richard H. Mueller, Linda Chu, and Ramesh N. Patel
- Subjects
biology ,Stereochemistry ,Organic Chemistry ,Diastereomer ,Total synthesis ,Brevibacterium ,Alcohol ,biology.organism_classification ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Carbamic acid ,chemistry ,Yield (chemistry) ,Physical and Theoretical Chemistry ,Enantiomeric excess ,Rhodococcus - Abstract
The chiral intermediate (1S,2R)-[3-chloro-2-hydroxy-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester 2a was prepared for the total synthesis of the HIV protease inhibitor Atazanavir. The diastereoselective reduction of (1S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl] carbamic acid, 1,1-dimethyl-ethyl ester 1 was carried out using microbial cultures among, which Rhodococcus, Brevibacterium, and Hansenula strains reduced 1 to 2a. Three strains of Rhodococcus gave >90% yield. A diastereomeric purity of >98% and enantiomeric excess of >99.3% were obtained for alcohol 2a.
- Published
- 2003
39. Microbial / Enzymatic Synthesis of Chiral Intermediates for Pharmaceuticals: Case Studies from BMS
- Author
-
Ramesh N. Patel
- Subjects
Chemistry ,Organic Chemistry ,Enzymatic synthesis ,Combinatorial chemistry - Published
- 2003
40. Enantioselective Enzymatic Cleavage of N-Benzyloxycarbonyl Groups
- Author
-
Ramesh N. Patel, Amit Banerjee, David B. Brzozowski, Clyde G. McNamee, and Venkata B. Nanduri
- Subjects
chemistry.chemical_classification ,Sphingomonas paucimobilis ,biology ,Stereochemistry ,Protein subunit ,Cell ,Enantioselective synthesis ,General Chemistry ,Enzymatic process ,biology.organism_classification ,Amino acid ,medicine.anatomical_structure ,Enzyme ,Biochemistry ,chemistry ,Biocatalysis ,medicine - Abstract
A new enzymatic process for the enantioselective cleavage of N-benzyloxycarbonyl (Cbz) groups from protected amino acids and related compounds has been developed. The Cbz-deprotecting enzyme was isolated from cell extracts of Sphingomonas paucimobilis SC 16113 and purified to homogeneity. The purified protein has a molecular weight of 155,000 daltons and a subunit size of 44,000 daltons.
- Published
- 2003
41. Enzymatic synthesis of chiral intermediates for pharmaceuticals
- Author
-
Robert J. Johnston, Ramesh N. Patel, Ronald L. Hanson, Jeffrey M. Howell, Amit Banerjee, Rapheal Ko, Mary-Jo Donovan, Animesh Goswami, Dana L Cazzulino, Steven L. Goldberg, David B. Brzozowski, Venkata B. Nanduri, and Thomas P. Tully
- Subjects
chemistry.chemical_classification ,Chemistry, Pharmaceutical ,Receptors, Melatonin ,Receptors, Cytoplasmic and Nuclear ,Adrenergic beta-3 Receptor Agonists ,Receptors, Cell Surface ,Stereoisomerism ,Bioengineering ,Adrenergic beta-Agonists ,Enzymatic synthesis ,Applied Microbiology and Biotechnology ,Bulk drug ,Melatonin receptor ,Enzymes ,Enzyme ,chemistry ,Biocatalysis ,Organic chemistry ,Antihypertensive Agents ,Biotransformation ,Biotechnology - Abstract
There has been an increasing awareness of the enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enatioselective manner. Chiral intermediates are in high demand by pharmaceutical industries for the preparation bulk drug substances. In this review article, microbial/enzymatic processes for the synthesis of chiral intermediates for antihypertensive drugs, melatonin receptor agonists, and beta3-receptor receptor agonists are described.
- Published
- 2003
42. Microbial/enzymatic synthesis of chiral intermediates for pharmaceuticals
- Author
-
Ramesh N. Patel
- Subjects
chemistry.chemical_classification ,Drug ,business.industry ,media_common.quotation_subject ,Bioengineering ,Enzymatic synthesis ,Applied Microbiology and Biotechnology ,Biochemistry ,Bulk drug ,Enzyme ,chemistry ,Biotransformation ,Biocatalysis ,Organic chemistry ,business ,Biotechnology ,Pharmaceutical industry ,media_common - Abstract
There has been an increasing awareness of the enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enatioselective manner. Chiral intermediates and fine chemicals are in high demand both from pharmaceutical and agrochemical industries for the preparation bulk drug substances and agricultural products. In this review article, microbial/enzymatic processes have been described for the synthesis of chiral intermediates for anticancer drugs, antiviral agents, β3-receptor agonists, antihypertensive drugs, melatonin receptor agonists, anticholesterol drugs, and anti-Alzheimer’s drugs.
- Published
- 2002
43. Hydroxylation of Mutilin by Streptomyces griseus and Cunninghamella echinulata
- Author
-
Laporte Thomas L, Ramesh N. Patel, Ronald L. Hanson, David B. Brzozowski, Dane M. Springer, and James A. Matson
- Subjects
Hydroxylation ,chemistry.chemical_compound ,biology ,Biotransformation ,Chemistry ,Stereochemistry ,Organic Chemistry ,Ms analysis ,Physical and Theoretical Chemistry ,biology.organism_classification ,Streptomyces griseus ,Pleuromutilin ,Cunninghamella echinulata - Abstract
Biotransformation of mutilin and pleuromutilin by microbial cultures was investigated to provide a source of 8-hydroxymutilin or 8-hydroxypleuromutilin. LC/MS analysis of culture broths showed that...
- Published
- 2002
44. Enantioselective microbial reduction of 2-oxo-2-(1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethyl-6′-naphthalenyl)acetic acid and its ethyl ester
- Author
-
Joydeep Kant, Linda Chu, Ramakrishna Chidambaram, Ramesh N. Patel, and Jason Zhu
- Subjects
biology ,Stereochemistry ,Organic Chemistry ,Enantioselective synthesis ,Alcohol ,biology.organism_classification ,Catalysis ,Inorganic Chemistry ,Aureobasidium pullulans ,chemistry.chemical_compound ,Acetic acid ,Retinoic acid receptor ,chemistry ,Yield (chemistry) ,Physical and Theoretical Chemistry ,Enantiomeric excess ,Benzoic acid - Abstract
The chiral ester ethyl (2 R )-hydroxy-2-(1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethyl-6′-naphthalenyl) acetate 2 and the corresponding acid 4 were prepared as intermediates in the synthesis of the retinoic acid receptor gamma-specific agonist ( R )-3-fluoro-4-[[hydroxy(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)acetyl]amino]benzoic acid 7 . Enantioselective reduction of ethyl 2-oxo-2-(1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethyl-6′naphthalenyl)acetate 1 to alcohol 2 was carried out using Aureobasidium pullulans SC 13849 in 98% yield and with an enantiomeric excess (e.e.) of 96%. Among microorganisms screened for the reduction of 2-oxo-2-(1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethyl-6′-naphthalenyl)acetic acid 3 to hydroxy acid 4 , Candida maltosa SC 16112 and two strains of Candida utilis (SC 13983, SC 13984) gave reaction yields of >53% with e.e.s of >96%.
- Published
- 2002
45. Enzymatic Synthesis of Chiral Intermediates for Drug Development
- Author
-
Ramesh N. Patel
- Subjects
chemistry.chemical_compound ,chemistry ,Biocatalysis ,Stereochemistry ,Lactol ,Acetal ,Enantioselective synthesis ,Epoxide ,General Chemistry ,Enantiomer ,Epoxide hydrolase ,Kinetic resolution - Abstract
Chirality is a key factor in the efficacy of many drug products and thus the production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. Biocatalysis is now accepted as a one of key methodologies for the preparation of chiral drug intermediates and fine chemicals. The biocatalytic production of several key intermediates in the synthesis of antihypertensive, anticholesterol, anti-Alzheimer’s, β3-receptor agonist, HIV-protease inhibitor, and other pharmaceuticals is described. These includes (1) the synthesis of L-6-hydroxynorleucine from racemic 6-hydroxynorleucine, (2) the enzymatic synthesis of (S)-allysine ethylene acetal by reductive deamination using phenylalanine dehydrogenase, (3) the synthesis of [4S-(4a,7a,10ab)]-1-octahydro-5-oxo-4-{[(phenylmethoxy)carbonyl]-amino}-7H-pyrido-[2,1-b][1,3]thiazepine-7-carboxylic acid (BMS-199541–01) by enzymatic oxidation process using L-lysine-ϵ-aminotransferase, (4) the enzymatic synthesis of the lactol [3aS-(3aα,4α,7α,7aα)]-hexahydro-4,7-epoxyisobenzofuran-1(3H)-ol and corresponding lactone, (5) the microbial synthesis of (3R-cis)-1,3,4,5-tetrahydro-3-hydroxy-4-(4-methoxyphenyl)-6-(trifluoromethyl)-2H-1-benzazepin-2-one, (6) the microbial oxygenation of 6-cyano-2,2-dimethyl-2H-1-benzopyran to the corresponding chiral epoxide and (+)-trans diol, (7) the enantioselective microbial reductions of N-[4-(2-chloroacetyl)phenyl]methanesulfonamide and (4-benzyloxy-3-methanesulfonylamino)-2'-bromoacetophenone to the corresponding (R)-alcohols, (8) the enzymatic resolution of racemic α-methyl phenylalanine amides by amidase, (9) the enantioselective hydrolysis of diethyl methyl-(4-methoxyphenyl)-propanedioate by lipase PS-30, (10) the enantioselective microbial reduction of methyl 4-chloro-3-oxobutanoate, (11) the enzymatic synthesis of ethyl (3S,5R)-dihydroxy-6-(benzyloxy)hexanoate, (12) the enantioselective hydrolysis of racemic epoxide 1-{2',3'-dihydrobenzo[b]furan-4'-yl}-1,2-oxirane by epoxide hydrolase, (13) the biocatalytic dynamic kinetic resolution of R,S-1-{2',3'-dihydrobenzo[b]furan-4'-yl}-ethane-1,2-diol, and (13) the diastereoselective microbial reduction of (1S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl]carbamic acid 1,1-dimethylethyl ester. 1 Introduction 2 Antihypertensive Drugs 3 Thromboxane A2 Antagonists 4 Calcium Channel Blocking Drugs 5 Potassium Channel Openers 6 Antiarrhythmic Agents 7 β3-Receptor Agonists 8 Anticholesterol Drugs 9 Microbial Resolution10 Anti-Alzheimer Drugs11 HIV Protease Inhibitors12 Conclusion
- Published
- 2001
46. Chemical and Enzymatic Resolution of (R,S)-N-(tert-Butoxycarbonyl)-3-hydroxymethylpiperidine
- Author
-
Jeffrey M. Howell, Maxime Soumeillant, K. David Mirfakhrae, Truc Chi Vu, and David R. Kronenthal, Shankar Swaminathan, Xinhua Qian, Xuebao Wang, Edward Y. Hua, Bin Zheng, Animesh Goswami, Fernando Quiroz, and Ramesh N. Patel
- Subjects
chemistry.chemical_classification ,Base (chemistry) ,biology ,Chemistry ,Organic Chemistry ,Succinic anhydride ,Medicinal chemistry ,Acylation ,Hydrolysis ,chemistry.chemical_compound ,Stereospecificity ,Yield (chemistry) ,biology.protein ,Organic chemistry ,Physical and Theoretical Chemistry ,Lipase ,Enantiomeric excess - Abstract
(S)-N-(tert-Butoxycarbonyl)-3-hydroxymethylpiperidine 1 was made from (R,S)-3-hydroxymethylpiperidine 2 via fractional crystallization of the corresponding l(−)-dibenzoyl tartarate salt 3 followed by hydrolysis and acylation. Lipase from Pseudomonas cepacia was found to be the best enzyme for the stereospecific resolution of (R,S)-N-(tert-butoxycarbonyl)-3-hydroxymethylpiperidine 4. (S)-N-(tert-Butoxycarbonyl)-3-hydroxymethylpiperidine 1 was obtained in 16% yield and >95% enantiomeric excess (ee) by hydrolysis of (R,S)-acetate 5 by lipase PS from Pseudomonas cepacia. Lipase PS-catalyzed esterification of the (R,S)-N-(tert-butoxycarbonyl)-3-hydroxymethylpiperidine 4 with succinic anhydride provided the S-hemisuccinate ester 6, which could be easily separated and hydrolyzed by base to the (S)-N-(tert-butoxycarbonyl)-3-hydroxymethylpiperidine 1. The yield and ee could be improved greatly by repetition of the process. Using the repeated esterification procedure (S)-N-(tert-butoxycarbonyl)-3-hydroxymethylpiper...
- Published
- 2001
47. Enzymatic synthesis of chiral intermediates for Omapatrilat, an antihypertensive drug
- Author
-
Ramesh N. Patel
- Subjects
D-Amino-Acid Oxidase ,Pyridines ,Thiazepines ,Stereochemistry ,L-Lysine 6-Transaminase ,Norleucine ,Lysine ,Hydantoin ,Bioengineering ,Reductive amination ,Chemical synthesis ,Pichia ,chemistry.chemical_compound ,Bioreactors ,Glutamate Dehydrogenase ,Escherichia coli ,Organic chemistry ,Enantiomeric excess ,Molecular Biology ,Antihypertensive Agents ,Transaminases ,Dipeptide ,Stereoisomerism ,Recombinant Proteins ,Enzymes ,Phenylalanine dehydrogenase ,chemistry ,Fermentation ,Amino Acid Oxidoreductases ,Biotechnology - Abstract
Biocatalytic processes were used to prepare chiral intermediates required for the synthesis of Omapatrilat 1 by three different routes. The synthesis and enzymatic conversion of 2-keto-6-hydroxyhexanoic acid 3 to L-6-hydroxynorleucine 2 was demonstrated by reductive amination using beef liver glutamate dehydrogenase. To avoid the lengthy chemical synthesis of the ketoacid 3, a second route was developed to prepare the ketoacid by treatment of racemic 6-hydroxy norleucine [readily available from hydrolysis of 5-(4-hydroxybutyl) hydantoin 4] with D-amino acid oxidase from porcine kidney or Trigonopsis variabilis followed by reductive amination to convert the mixture completely to L-6-hydroxynorleucine in 98% yield and 99% enantiomeric excess (e.e.). The enzymatic synthesis of (S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (allysine ethylene acetal, 5) was demonstrated using phenylalanine dehydrogenase (PDH) from T. intermedius. Phenylalanine dehydrogenase was cloned and overexpressed in Escherichia coli and Pichia pastoris. Using PDH from E. coli or P. pastoris, the enzymatic process was scale-up to prepare kg quantity of allysine ethylene acetal 5. The reaction yields of >94% and e.e. of >98% were obtained for allysine ethylene acetal 5. An enzymatic process was developed for the synthesis of [4S-(4a,7a,10ab)]1-octahydro-5-oxo-4 [[(phenylmethoxy)carbonyl]amino]-7H-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid [BMS-199541-01]. The enzymatic oxidation of the epsilon-amino group of lysine in the dipeptide dimer N(2)-[N[[(phenyl-methoxy)carbonyl] L-homocysteinyl] L-lysine)-1,1-disulphide [BMS-201391-01] to produce BMS-199541-01 using a novel L-lysine epsilon-aminotransferase (LAT) from Sphingomonas paucimobilis SC 16113 was demonstrated. This enzyme was overexpressed in E. coli and a process was developed using the recombinant enzyme.
- Published
- 2001
48. Biochemical approaches to the synthesis of ethyl 5-(s)-hydroxyhexanoate and 5-(s)-hydroxyhexanenitrile
- Author
-
Laporte Thomas L, John M. Wasylyk, Ronald L. Hanson, Ramesh N. Patel, Animesh Goswami, Kishta Katipally, Hyei-Jha Chung, and Venkata B. Nanduri
- Subjects
biology ,Chemistry ,Stereochemistry ,Bioengineering ,Alcohol ,Enzymatic synthesis ,Pichia methanolica ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biochemistry ,chemistry.chemical_compound ,Hydrolysis ,Succinylation ,Enzymatic hydrolysis ,Yield (chemistry) ,Enantiomeric excess ,Biotechnology - Abstract
Three different biochemical approaches were used for the synthesis of ethyl 5-(S)-hydroxyhexanoate 1 and 5-(S)-hydroxyhexanenitrile 2. In the first approach, ethyl 5-oxo-hexanoate 3 and 5-oxo-hexanenitrile 4 were reduced by Pichia methanolica (SC 16116) to the corresponding (S)-alcohols, ethyl (S)-5-hydroxyhexanoate 1 and 5-(S)-hydroxyhexanenitrile 2, with an 80–90% yield and >95% enantiomeric excess (e.e). In the second approach, racemic 5-hydroxyhexanenitrile 5 was resolved by enzymatic succinylation, leading to the formation of (R)-5-hydroxyhexanenitrile hemisuccinate and leaving the desired alcohol 5-(S)-hydroxyhexanenitrile 2 with a yield of 34% (50% maximum yield) and >99% e.e. In the third approach, enzymatic hydrolysis of racemic 5-acetoxy hexanenitrile 6 resulted in the hydrolysis of the R-isomer to provide 5-(R)-hydroxyhexanenitrile, leaving 5-(S)-acetoxyhexanenitrile 7 with a 42% yield (50% maximum yield) and >99% e.e.
- Published
- 2001
49. Asymmetric acyloin condensation catalysed by phenylpyruvate decarboxylase. Part 2: Substrate specificity and purification of the enzyme
- Author
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Ramesh N. Patel, Venkata B. Nanduri, Animesh Goswami, and Zhiwei Guo
- Subjects
chemistry.chemical_classification ,Phenylpyruvate decarboxylase ,Chemistry ,Acyloin condensation ,Organic Chemistry ,Size-exclusion chromatography ,Acetaldehyde ,Substrate (chemistry) ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Enzyme ,Yield (chemistry) ,Organic chemistry ,Physical and Theoretical Chemistry ,Polyacrylamide gel electrophoresis - Abstract
Phenylpyruvate decarboxylase from Achromobacter eurydice was used to catalyse the asymmetric acyloin condensation of phenylpyruvate 1 with various aldehydes 2 to produce optically active acyloins PhCH2COCH(OH)R 3. The specific activity of the phenylpyruvate decarboxylase enzyme was increased by a factor of 332 after its purification. The molecular weight of the purified enzyme was shown to be 150 kDa by gel filtration chromatography, while SDS gel electrophoresis showed two sub-units with molecular weights of 90 and 40 kDa. The acyloin condensation yield decreased with increasing chain length for straight chain aliphatic aldehydes from 76% for acetaldehyde to 24% for valeraldehyde. The e.e.s of the acyloin products were 87–98%. Low yields of acyloin products were obtained with chloroacetaldehyde (13%) and glycoaldehyde (16%). Indole-3-pyruvate was a substrate of the enzyme and provided acyloin condensation product 3-hydroxy-1-(3-indolyl)-2-butanone 5 with acetaldehyde in 19% yield, while benzoylformate was not a substrate for the enzyme.
- Published
- 2001
50. ENZYMATIC PREPARATION OF CHIRAL PHARMACEUTICAL INTERMEDIATES BY LIPASES*
- Author
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Ramesh N. Patel
- Subjects
chemistry.chemical_classification ,Liposome ,Enzyme ,chemistry ,Pharmaceutical Science ,Receptor ,Small molecule ,Combinatorial chemistry ,Macromolecule - Abstract
Currently, much attention has been focused on the interaction of small molecules with biological macromolecules. The search for selective enzyme inhibitors and receptor agonists or antagonists is o...
- Published
- 2001
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