134003-04-6Relevant articles and documents
Efficient synthesis of the intermediate of abacavir and carbovir using a novel (+)-γ-lactamase as a catalyst
Gao, Shuaihua,Zhu, Shaozhou,Huang, Rong,Lu, Yingxiu,Zheng, Guojun
, p. 3878 - 3881 (2015)
Abstract The enantiomers of 2-azabicyclo[2.2.1]hept-5-en-3-one (γ-lactam) are key chiral synthons in the synthesis of antiviral drugs such as carbovir and abacavir. (+)-γ-Lactamase can be used as a catalyst in the enzymatic preparation of optically pure (-)-γ-lactam. Here, a (+)-γ-lactamase discovered from Bradyrhizobium japonicum USDA 6 by sequence-structure guided genome mining was cloned, purified and characterized. The enzyme possesses a significant catalytic activity towards γ-lactam. The active site of the (+)-γ-lactamase was studied by homologous modeling and molecular docking, and the accuracy of the prediction was confirmed by site-specific mutagenesis. The (+)-γ-lactamase reveals the great practical potential as an enzymatic method for the efficient production of carbocyclic nucleosides of pharmaceutical interest.
Novel screening methods - The key to cloning commercially successful biocatalysts
Taylor, Stephen J. C.,Brown, Rob C.,Keene, Phil A.,Taylor, Ian N.
, p. 2163 - 2168 (1999)
Providing sufficient biocatalyst to support the demands of multi tonne product supply can be problematical. Here we describe how screening for and cloning a γ-lactamase overcame biocatalyst supply issues, and greatly improved the actual biocatalytic process. The isolation of an expressing γ- lactamase clone from a gene library necessitated a combination of classical molecular biology techniques together with innovative screening methods to identify a functional clone. Once isolated the enzyme was characterised with regard to its process performance and proved to be active at 500 g L-1 substrate. Further development of the recombinant fermentation and downstream processing has resulted in the ability to produce sufficient biocatalyst from one 500 l fermentation to resolve 5 metric tonnes of (±)-lactam, whilst simplifying the process chemistry greatly.
Chemical preparation method of 2-azabicyclo [2.2.1] hept-5-ene-3-one with optical activity
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Paragraph 0023; 0029-0031; 0041; 0047-0049; 0059; 0065-0067, (2020/05/08)
The invention discloses a chemical preparation method of 2-azabicyclo [2.2.1] hept-5-ene-3-one with optical activity. The chemical preparation method comprises the following steps: racemic 2-azabicyclo [2.2.1] hept-5-ene-3-one which is easily available on the market is used as a raw material and is subjected to chemical resolution to obtain (+/-) 4-aminocyclopent-2-ene-1-carboxylic acid methyl ester with optical activity, (+/-) 4-aminocyclopent-2-ene-1-carboxylic acid is prepared by hydrolysis, and the (+/-) 4-aminocyclopent-2-ene-1-carboxylic acid is subjected to intramolecular condensation to obtain the 2-azabicyclo [2.2.1] hept-5-ene-3-one with optical activity. The method has the advantages that the use of an enzyme fermentation method is avoided, the repeatability is good, and the yield is high.
Method for synthesizing (1R,4S)-1-amino-4-hydroxymethyl-2-cyclopentene hydrochloride
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Paragraph 0017; 0018, (2017/07/23)
The invention relates to a method for synthesizing (1R,4S)-1-amino-4-hydroxymethyl-2-cyclopentene hydrochloride. According to the method, the reaction conditions are mild, (1S,4R)-(-)-2-azabicyalo[2,2,1]hepta-5-alkene-3-ketone is directly used, (1R,4S)-1-amino-4-hydroxymethyl-2-cyclopentene hydrochloride is obtained through the reactions of hydrolysis and reducing, the yield is high, and the optical purity is high.
