title: Enzyme-assisted preparation of D-tert.-leucine.
abstract: Optically pure D-tert.-leucine was obtained by the enzymatic hydrolysis of (+/-)-N-acetyl-tert. leucine chloroethyl ester after about 50% conversion, this being catalyzed by a protease from Bacillus licheniformis (Alcalase), and subsequent acidic saponification of the recovered ester. Among the methyl, ethyl, octyl, chloroethyl and trichloroethyl esters, the chloroethyl ester exhibited the highest rate of hydrolysis.
authors.affiliation: Novartis Pharma AG, Core Technology Area, Basel, Switzerland. kurt.laumen@pharma.novartis.com
authors.forename: K
authors.initials: K
authors.lastname: Laumen
authors.forename: O
authors.initials: O
authors.lastname: Ghisalba
authors.forename: K
authors.initials: K
authors.lastname: Auer
mesh_terms: D001407:Bacillus / Q000201:enzymology; D001671:Biochemistry / Q000379:methods*; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D007930:Leucine / Q000138:chemical synthesis* / Q000378:metabolism / Q000031:analogs & derivatives; D013381:Subtilisins / Q000737:chemistry / Q000378:metabolism; D014633:Valine / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000378:metabolism
chemical_list: C089871:2-amino-3,3-dimethylbutanoic acid; D010450:Endopeptidases; D013381:Subtilisins; D007930:Leucine; D014633:Valine