Enzymatic resolution of antidepressant drug precursors in an undergraduate laboratory

Publicado online: novembro 13, 2014

Quim. Nova, Vol. 38, No. 2, 285-287, 2015

Educação http://dx.doi.org/10.5935/0100-4042.20140306

*e-mail: nmtl@tecnico.ulisboa.pt

ENZYMATIC RESOLUTION OF ANTIDEPRESSANT DRUG PRECURSORS IN AN UNDERGRADUATE LABORATORY

Luís M. R. Solanoa and Nuno M. T. Lourençob,* a Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal b Departamento de Bioengenharia, Instituto de Biotecnologia e Bioengenharia, Instituto Superior Técnico, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal

Recebido em 07/07/2014; aceito em 17/09/2014; publicado na web em 13/11/2014

The use of biocatalysts in synthetic chemistry is a conventional methodology for preparing enantiomerically enriched compounds. Despite this fact, the number of experiments in chemical teaching laboratories that demonstrate the potential of enzymes in synthetic organic chemistry is limited. We describe a laboratory experiment in which students synthesized a chiral secondary alcohol that can be used in the preparation of antidepressant drugs. This experiment was conducted by individual students as part of a Drug Synthesis course held at the Pharmacy Faculty, Lisbon University. This laboratory experiment requires six laboratory periods, each lasting four hours. During the first four laboratory periods, students synthesized and characterized a racemic ester using nuclear magnetic resonance spectroscopy and gas chromatography. During the last two laboratory periods, they performed enzymatic hydrolysis resolution of the racemic ester using Candida antarctica lipase B to yield enantiomerically enriched secondary alcohol. Students successfully prepared the racemic ester with a 70%-81% overall yield in three steps. The enzymatic hydrolysis afforded (R)- secondary alcohol with good enantioselectivity (90%–95%) and reasonable yields (10%–19%). In these experiments, students were exposed to theoretical and practical concepts of aromatic acylation, ketone reduction, esterification, and enzymatic hydrolysis. Keywords: sec-alcohols; esters; lípase; enantiomers; resolution.

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