A novel cascade catalysis for one-pot enzymatically modified isoquercitrin (EMIQ) conversion from rutin and sucrose using rationally designed gradient temperature control.

Enzymatically modified isoquercitrin (EMIQ) is a glyco-chemically modified flavonoid exhibiting notably high biological activity, such as antioxidant, anti-inflammatory and anti-allergic properties. However, the utilization of expensive substrates such as isoquercitrin and cyclodextrin in the conventional approach has hindered the industrial-scale production of EMIQ due to high cost and low yields. Hence, the development of a cost-effective and efficient method is crucial for the biological synthesis of EMIQ. In this study, a natural cascade catalytic reaction system was constructed with α -L-rhamnosidase and amylosucrase using the inexpensive substrates rutin and sucrose. Additionally, a novel approach integrating gradient temperature regulation into biological cascade reactions was implemented. Under the optimal conditions, the rutin conversion reached a remarkable 95.39% at 24 h. Meanwhile, the productivity of quercetin-3- O -tetraglucoside with the best bioavailability reached an impressive 41.69%. This study presents promising prospects for future mass production of EMIQ directly prepared from rutin and sucrose. [Display omitted] • A novel cascade strategy was constructed to produce EMIQ from inexpensive substrates. • Amylosucrase with sucrose as a substrate was used to further reduce the production cost. • Gradient temperature control was innovatively integrated into the biological cascade reaction. • The conversion rate of IQ-G3 with the best bioavailability reached an impressive 41.69%. • The industrial production of EMIQ with rutin and sucrose as materials has good potential. [ABSTRACT FROM AUTHOR]