INIQUI   05448
INSTITUTO DE INVESTIGACIONES PARA LA INDUSTRIA QUIMICA
Unidad Ejecutora - UE
artículos
Título:
Synthesis of rutinosides and rutinose by reverse hydrolysis catalyzed by fungal alpha-L-rhamnosidases
Autor/es:
MARÍA RITA MARTEARENA; MIRTA ELIZABETH DAZ; GUILLERMO VON ELLENRIEDER
Revista:
BIOCATALYSIS AND BIOTRANSFORMATION
Editorial:
Taylor & Francis
Referencias:
Lugar: Londres; Año: 2008 vol. 26 p. 177 - 185
ISSN:
1024-2422
Resumen:
The synthesis of a-L-rhamnosyl(1-6)-b-D-glucosides (rutinosides) and a-L-rhamnosyl(1-6)-b-D-glucose (rutinose) catalyzed by several fungal a-L-rhamnosidases was studied by the reverse hydrolysis reaction between rhamnose plus  naringenin 7-b-D-glucoside (prunin) and rhamnose plus glucose, respectively. The products of the reaction were determined by HPLC chromatography with some available standards. As expected the major product of the prunin rhamnosylation was always narirutin (naringenin-7-b-D-rutinoside), which was originated from the glycosylation of the primary alcoholic group of the glucoside. Whereas Aspergillus terreus, Penicillium decumbens and Penicillium ulaiense a-L-rhamnosidases gave other minor derivatives besides narirutin, two commercial Aspergillus niger enzymes synthesized it as the unique reaction product. Initial rate kinetics of the narirutin synthesis catalyzed by the purified A. niger a-L-rhamnosidase did not permit to distinguish between sequential and ping pong mechanisms, but it showed a strong inhibition by the substrate L-rhamnose. The equations derived for a competitive inhibition together with a non-exclusive inhibition by this substrate, fitted at best the kinetic experimental data. When glucose was rhamnosylated by the A. niger enzyme, other two minor products were originated together with the disaccharide rutinose. The conditions for obtaining maximum yield for rutinose synthesis were determined.