Immobilized heterologous Rhizopus oryzae lipase as an efficient catalyst in the acetylation of cortexolone

PAULA G. QUINTANA; MARINA GUILLEN; MARZIA MARCIELLO; FRANCISCO VALERO; JOSÉ PALOMO; ALICIA BALDESSARI

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2012 p. 4306 - 4312

1434-193X

The enzymatic preparation of a monoacetyl derivative of the corticosteroid cortexolone, through a transesterification reaction, is described. The heterologous Rhizopus oryzae lipase, immobilized on three different supports proved to be an efficient catalyst in the acylation reaction using a complex substrate such as cortexolone. The immobilization of the enzyme on Lewatit1600 resin at pH 7 and 25ºC was the best choice to catalyze the acetylation reaction. The influence of various reaction parameters, such as nature of the acetylating agent, acetylating agent: substrate ratio, enzyme: substrate ratio, solvent and temperature, was evaluated. Using the response surface methodology and a central composite rotatable design, the specific yield of acetylated cortexolone was optimized by means of the study of the effect of enzyme:substrate ratio and acylating:substrate ratio. The ratios of 5 (E/S) and 31.6 (A/S) were predicted as the optimal values to reach the maximum specific yield of 1.59 mmol P/ mmol A∙g E. The mild reaction conditions and low environmental impact make the biocatalytic procedure a convenient way to prepare the reported derivative of this biologically active steroid.