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:
Año: 2006
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.