529-55-5Relevant articles and documents
Covalent Immobilization of Naringinase over Two-Dimensional 2D Zeolites and its Applications in a Continuous Process to Produce Citrus Flavonoids and for Debittering of Juices
Carceller, Jose Miguel,Martínez Galán, Julián Paul,Monti, Rubens,Bassan, Juliana Cristina,Filice, Marco,Yu, Jihong,Climent, María J.,Iborra, Sara,Corma, Avelino
, p. 4502 - 4511 (2020/06/08)
The crude naringinase from Penicillium decumbens and a purified naringinase with high α-L-rhamnosidase activity could be covalently immobilized on two-dimensional zeolite ITQ-2 after surface modification with glutaraldehyde. The influence of pH and temperature on the enzyme activity (in free and immobilized forms) as well as the thermal stability were determined using the specific substrate: p-nitrophenyl-alpha-L-rhamnopyranoside (Rha-pNP). The crude and purified naringinase supported on ITQ-2 were applied in the hydrolysis of naringin, giving the flavonoids naringenin and prunin respectively with a conversion '90 percent and excellent selectivity. The supported enzymes showed long term stability, being possible to perform up to 25 consecutive cycles without loss of activity, showing its high potential to produce the valuable citrus flavonoids prunin and naringenin. We have also succeeded in the application of the immobilized crude naringinase on ITQ-2 for debittering grapefruit juices in a continuous process that was maintained operating for 300 h, with excellent results.
Regioselective O-glycosylation of flavonoids by fungi Beauveria bassiana, Absidia coerulea and Absidia glauca
Sordon, Sandra,Pop?oński, Jaros?aw,Tronina, Tomasz,Huszcza, Ewa
, (2019/02/13)
In the present study, the species: Beauveria bassiana, Absidia coerulea and Absidia glauca were used in biotransformation of flavones (chrysin, apigenin, luteolin, diosmetin) and flavanones (pinocembrin, naringenin, eriodictyol, hesperetin). The Beauveria bassiana AM 278 strain catalyzed the methylglucose attachment reactions to the flavonoid molecule at positions C7 and C3′. The application of the Absidia genus (A. coerulea AM 93, A. glauca AM 177) as the biocatalyst resulted in the formation of glucosides with a sugar molecule present at C7 and C3′ positions of flavonoids skeleton. Nine of obtained products have not been previously reported in the literature.
Purification and characterization of an intracellular α-L-rhamnosidase from a newly isolated strain, Alternaria alternata SK37.001
Zhang, Tao,Yuan, Wenbo,Li, Mengli,Miao, Ming,Mu, Wanmeng
, p. 63 - 69 (2018/07/06)
A strain, Alternaria alternata SK37.001, which produces an intracellular α-L-rhamnosidase, was newly isolated from citrus orchard soil. The molecular mass of the enzyme was 66 kDa, as evaluated by SDS-PAGE and 135 kDa, as determined by gel filtration, which indicated that the enzyme is a dimer. The enzyme had a specific activity of 21.7 U mg?1 after step-by-step purification. The optimal pH and temperature were 5.5 and 60 °C, respectively. The enzyme was relatively stable at a pH of 4.0–8.0 and a temperature between 30 and 50 °C compared with other pH levels and temperatures investigated. The enzyme activity was accelerated by Ba2+ and Al3+ but inhibited by Ni2+, Cu2+ and Co2+, especially Ni2+. The kinetic parameters of Km and Vmax were 4.84 mM and 53.1 μmol mg?1 min?1, respectively. The α-L-rhamnosidase could hydrolyze quercitrin, naringin and neohesperidin, hesperidin and rutin rhamnose-containing glycosides but could not hydrolyze ginsenoside Rg2 or saiko-saponin C.
