35455-20-0

Upstream product

• 16652-37-2 3-fluoroalanine 
• 36369-37-6 (2S)-2-benzyloxycarbonylamino-3-fluoropropionic acid 
• 312-84-5 D-Serine 
• 338-69-2 D-Alanine 
• 433-48-7 fluoropyruvic acid 
• 618-36-0 rac-methylbenzylamine 
• 18099-45-1 diborane 
• 76312-98-6 3-fluoro-D-alanine methyl ester 

Relevant academic research and scientific papers

ω-Transaminase-catalyzed asymmetric synthesis of unnatural amino acids using isopropylamine as an amino donor

Isopropylamine is an ideal amino donor for reductive amination of carbonyl compounds by ω-transaminase (ω-TA) owing to its cheapness and high volatility of a ketone product. Here we developed asymmetric synthesis of unnatural amino acids via ω-TA-catalyzed amino group transfer between α-keto acids and isopropylamine.

Characterization of d-amino acid aminotransferase from Lactobacillus salivarius

We searched a UniProt database of lactic acid bacteria in an effort to identify d-amino acid metabolizing enzymes other than alanine racemase. We found a d-amino acid aminotransferase (d-AAT) homologous gene (UniProt ID: Q1WRM6) in the genome of Lactobacillus salivarius. The gene was then expressed in Escherichia coli, and its product exhibited transaminase activity between d-alanine and α-ketoglutarate. This is the first characterization of a d-AAT from a lactic acid bacterium. L. salivarius d-AAT is a homodimer that uses pyridoxal-5′-phosphate (PLP) as a cofactor; it contains 0.91 molecules of PLP per subunit. Maximum activity was seen at a temperature of 60 °C and a pH of 6.0. However, the enzyme lost no activity when incubated for 30 min at 30 °C and pH 5.5 to 9.5, and retained half its activity when incubated at pH 4.5 or 11.0 under the same conditions. Double reciprocal plots of the initial velocity and d-alanine concentrations in the presence of several fixed concentrations of α-ketoglutarate gave a series of parallel lines, which is consistent with a Ping-Pong mechanism. The Km values for d-alanine and α-ketoglutarate were 1.05 and 3.78 mM, respectively. With this enzyme, d-allo-isoleucine exhibited greater relative activity than d-alanine as the amino donor, while α-ketobutylate, glyoxylate and indole-3-pyruvate were all more preferable amino acceptors than α-ketoglutarate. The substrate specificity of L. salivarius d-AAT thus differs greatly from those of the other d-AATs so far reported.

Thermodynamics and kinetic aspects involved in the enzymatic resolution of (R,S)-3-fluoroalanine in a coupled system of redox reactions catalyzed by dehydrogenases

Two systems of redox enzymatic reactions were tested, looking forward to the preparation of (S)-3-fluoroalanine, a potent antibiotic, by kinetic resolution of rac-3-fluoroalanine. This starting material was the main substrate for the deaminative oxidation reaction catalyzed by L-alanine dehydrogenase (L-AlaDH) in the presence of NAD+. One system was formed by coupling this reaction (main reaction) to the reduction of 3-fluoropyruvate (a cascade system) produced in the main reaction catalyzed by L-lactate dehydrogenase (L-LDH) in the presence of NADH, also formed in the main reaction. This system, that was able to achieve 92% of conversion, allows the accumulation of NH 4+, one of the secondary products of the main reaction. The other coupled redox system involved the coupling to the L-AlaDH reaction to the aminative reduction reaction of α-ketoglutarate in the presence of NADH and NH4+ (both side products of the main reaction) catalyzed by L-glutamate dehydrogenase (L-GluDH), that allows accumulation of 3-fluoropyruvate. With this system, the extent of the reaction in the coupled system was only 22%. This big difference in the efficiency of both systems was identified as being the result of a different potency of the products that accumulates in both systems, acting as inhibitors of L-AlaDH. It was demonstrated that 3-fluoropyruvate is a much stronger inhibitor of L-AlaDH than NH4+. This fact, and not thermodynamic considerations, explains the results obtained with both systems.

Kinetic aspects involved in the simultaneous enzymatic synthesis of (S)-3-fluoroalanine and (R)-3-fluorolactic acid

Desaminative oxidation of rac -3-fluoroalanine (rac-1) catalyzed by l-alanine dehydrogenase (l-ALADH) was studied by means of initial rate experiments both in the presence and in the absence of a product. Estimates of kinetic parameters of the reaction were obtained. The reaction mechanism is the sequential ordered BiTer mechanism with inhibition by excess of (S)-3-fluoroalanine. This kinetic study was the basis for the development of a couple enzymatic system for the simultaneous synthesis of (S)-3-fluoroalanine (1a) and (R)-3-fluorolactic acid (3) with l-ALADH and l-lactate dehydrogenase using rac-1 and NAD+. Analysis of isolated products revealed 1a in 60% yield and 86% ee and 3 in 80% yield and over 99% ee. Compounds 1a and 3 represent chiral building blocks for the synthesis of several products with pharmacological activity. The presence of the fluorine atom in the substrate causes a better interaction of it in the active site of the enzyme.

Simultaneous enzymatic synthesis of (S)-3-fluoroalanine and (R)-3-fluorolactic acid

A coupled enzymatic system for the simultaneous synthesis of (S)-3-fluoroalanine (1a) and (R)-3-fluorolactic acid (3) with L-alanine dehydrogenase (L-AlaDH) from Bacillus subtilis and rabbit muscle L-lactate dehydrogenase (L-LDH) using rac-1 and NAD+ is described. Analysis of isolated products of the laboratory preparative scale process revealed 1a in 60% yield and 88% ee and 3 in 80% yield and over 99% ee. The compounds 1a and 3 represent chiral building blocks for the synthesis of several products with pharmacological activity. Copyright (C) 2000 Elsevier Science Ltd.

Stereoselective synthesis of the antibacterial 3-fluoro-D-alanine

The wide spectrum antibacterial 3-fluoro-D-alanine (S)-9 has been stereoselectively synthesized via 'chiral sulfoxide chemistry'. Key steps are the azidation of the α-fluoro α'-sulfinyl alcohol (2S,R(S))-1 under Mitsunobu conditions and the one-pot transf

SYNTHESIS AND ENZYMATIC CLEAVAGE OF D,L-3-FLUOROALANINE

The action of bromine trifluoride on methyl 2,3-dibromopropionate in the presence of stannic chloride gives a high yield of methyl 2-bromo-3-fluoropropionate.Under the conditions of phase-transfer catalysis the product gave a 3-fluoro-2-azido ester, and reduction of the latter with hydrogen in the presence of Pd/C gave 3-fluoroalanine methyl ester.Enzymatic cleavage of N-BOC-3-fluoro-D,L-alanine methyl ester with papain took place stereospecifically, and N-BOC-3-fluoro-L-alanine was isolated with an almost quantitative yield.

α-Keto aldehydes as enhancing agents of gastro-intestinal drug absorption

A method and drug form enhancing the absorption of a rectally or orally administered drug from the rectal compartment into the blood stream of a warm blooded animal. The method includes the steps of preparing a drug form capable of being rectally and orally administered. The drug form comprises a therapeutically effective unit dosage amount of a selected drug of the type which is capable of being absorbed into the blood stream from the gastrointestinal area and an α-keto aldehyde or salts thereof being present in the drug form in a sufficient amount to be effective in enhancing the drug absorption rate, when administering the drug form to warm blooded animals.

Processes for asymmetric conversion of 3-fluoro-L-alanine and 2-deutero-3-fluoro-L-alanine to their D-isomers

3-Fluoro-L-alanine is transformed by asymmetric conversion, via an intermediate L-2-(halo)-3-fluoropropionic acid, to 3-fluoro-D-alanine. The 3-fluoro-D-alanine thus obtained is a potent antibacterial agent.