INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Aspergillus genus as a source of new catalysts for sulfide oxidation
Autor/es:
MARÍA L. MASCOTTI; ALEJANDRO A. ORDEN; FABRICIO R. BISOGNO; GONZALO DE GONZALO; MARCELA KURINA-SANZ
Revista:
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 82 p. 32 - 36
ISSN:
1381-1177
Resumen:
This work extends the present knowledge about the ability of filamentous fungi to selectively transform
sulfur-containing compounds. Here, it has been demonstrated that several species of the Aspergillus
genus are able to perform chemo- and stereoselective oxidation of organic sulfides. Two substrates
were chosen as models, the aliphatic cyclohexyl(methyl)sulfide and the alkyl aryl sulfide, thioanisole.
All the tested strains showed the ability to oxidize cyclohexyl(methyl)sulfide, whereas most of them
oxidized thioanisole. In all cases R-stereoselectivity was observed and full chemoselectivity was verified
since no sulfone was detected. Several biotransformation parameters such as the employment of
growing or resting cell, different head-space volumes, age of the cultures, bio-reaction times and biocatalyst/
substrate ratios resulted crucial in the optimization of the processes. Thus, when using isopropyl
alcohol as co-solvent in growing cell systems, chemo- and stereoselectivity could be modulated. Among
the studied strains, Aspergillus japonicus ICFC 744/11 was found to be a promising whole cell biocatalyst
to prepare enantioenriched sulfoxides since after optimization, either conversion and optical purity of
(R)-cyclohexyl(methyl)sulfoxide were excellent (c: 100%, ee > 99%).