This investigation examined the deracemisation of chiral amines via a cyclic oxidation and reduction sequence. The deracemisation relies on the combination of monoamine oxidase enzyme to perform an enantioselective oxidation of a single enantiomer of a racemic amine substrate to the imine. The imine is subsequently reduced back to the amine. Cycles of oxidation and reduction are required to produce high yields and enantiomeric excess. Directed evolution was used to screen for monoamine oxidase variants that showed superior activity towards novel secondary amine substrates. The specificity and enantioselectivity of the identified variants was examined. The optimised monoamine oxidases variant was used in the preparative deracemisation of secondary amine substrates in either whole cell or purified protein immobilised on resin. Various reducing agents were examined to identify those that showed the fastest rate of imine reduction under deracemisation conditions in order to minimise imine hydrolysis.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:642610 |
Date | January 2005 |
Creators | Carr, Reuben |
Publisher | University of Edinburgh |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | http://hdl.handle.net/1842/13323 |
Page generated in 0.0017 seconds