Complex of Burkholderia cepacia lipase with transition state analogue of 1-phenoxy-2-acetoxybutane - Biocatalytic, structural and modelling study

In a series of four racemic phenoxyalkyl-alkyl carbinols, 1-phenoxy-2-hydro xybutane (1) is enantioselectively acetylated by Burkholderia cepacia (form erly Pseudomonas cepacia) lipase with an E value greater than or equal to 2 00, whereas for the other three racemates E was found to be less than or eq ual to4. To explain the high preference of B. cepacia lipase for (R)-(+)-1, a precursor of its transition state analogue with a tetrahedral P-atom, (R PSP)-O-(2R)-(1-phenoxybut-2-yl)-methylphosphonic acid chloride was prepared and crystallized in complex with B. cepacia lipase. The X-ray structure of the complex was determined, allowing to compare the conformation of the in hibitor with results of molecular modelling.