Extensive screening for a robust producer of α-L-rhamnosidase activity from well-defined strains of filamentous fungi, including multifactorial optimization (inducers, cultivation conditions) was accomplished. Enzyme production of the optimal producer Aspergillus terreus (non-toxigenic) was scaled up to 50L. α-L-Rhamnosidase, which was fully characterized, proved to be thermo- and alkali-tolerant, thus enabling effective operation at 70°C and pH 8.0. These conditions allow for a very high substrate (rutin) load up to 100-300 g/L, thus enabling very high volumetric productivity of the reaction product quercetin-3-β-D-glucopyranoside (isoquercitrin). Here, a novel concept of "immobilised substrate" is used. Isoquercitrin is a highly effective and biocompatible antioxidant with strong anti-inflammatory activities. Rutin biotransformation was optimized and scaled up to ca 10 kg production and thus the robustness of the large-scale production was demonstrated. Isoquercitrin can be produced to a very high purity (98%) in multikilogram amounts, without any quercetin and directly applicable in nutraceuticals.

Institute of Microbiology Center for Biocatalysis and Biotransformation Academy of Sciences of the Czech Republic Prague Czech Republic

References provided by Crossref.org

Antioxidative effect of dietary flavonoid isoquercitrin on human ovarian granulosa cells HGL5 in vitro

Two fungal flavonoid-specific glucosidases/rutinosidases for rutin hydrolysis and rutinoside synthesis under homogeneous and heterogeneous reaction conditions

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"Sweet Flavonoids": Glycosidase-Catalyzed Modifications

Synthesis and Antiradical Activity of Isoquercitrin Esters with Aromatic Acids and Their Homologues

Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties