Flavonoids and their glycosides are abundant in many plant-based foods. The (de)glycosylation of flavonoids by retaining glycoside hydrolases has recently attracted much interest in basic and applied research, including the possibility of altering the glycosylation pattern of flavonoids. Research in this area is driven by significant differences in physicochemical, organoleptic, and bioactive properties between flavonoid aglycones and their glycosylated counterparts. While many flavonoid glycosides are present in nature at low levels, some occur in substantial quantities, making them readily available low-cost glycosyl donors for transglycosylations. Retaining glycosidases can be used to synthesize natural and novel glycosides, which serve as standards for bioactivity experiments and analyses, using flavonoid glycosides as glycosyl donors. Engineered glycosidases also prove valuable for the synthesis of flavonoid glycosides using chemically synthesized activated glycosyl donors. This review outlines the bioactivities of flavonoids and their glycosides and highlights the applications of retaining glycosidases in the context of flavonoid glycosides, acting as substrates, products, or glycosyl donors in deglycosylation or transglycosylation reactions.

• Klíčová slova
• Glucosidase, Glycoside hydrolase, Glycosyl donor, Glycosynthase, Hydrolysis, Rutinosidase, Transglycosylation,
• MeSH
• flavonoidy * chemie   MeSH
• glykosidhydrolasy * metabolismus   MeSH
• glykosidy chemie   MeSH
• glykosylace MeSH
• katalýza MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• flavonoidy * MeSH
• glykosidhydrolasy * MeSH
• glykosidy MeSH

Background: Oxidative stress is a key factor in the pathophysiology of many diseases. This study aimed to verify the antioxidant activity of selected plant phenolics in cell-based assays and determine their direct or indirect effects. Methods: The cellular antioxidant assay (CAA) assay was employed for direct scavenging assays. In the indirect approach, the influence of each test substance on the gene and protein expression and activity of selected antioxidant enzymes was observed. One assay also dealt with activation of the Nrf2-ARE pathway. The overall effect of each compound was measured using a glucose oxidative stress protection assay. Results: Among the test compounds, acteoside showed the highest direct scavenging activity and no effect on the expression of antioxidant enzymes. It increased only the activity of catalase. Diplacone was less active in direct antioxidant assays but positively affected enzyme expression and catalase activity. Morusin showed no antioxidant activity in the CAA assay. Similarly, pomiferin had only mild antioxidant activity and proved rather cytotoxic. Conclusions: Of the four selected phenolics, only acteoside and diplacone demonstrated antioxidant effects in cell-based assays.

• Klíčová slova
• CAA, Nrf2-ARE, antioxidants, catalase, glucose toxicity, plant phenolics, superoxide dismutase,
• MeSH
• antioxidační responzivní elementy MeSH
• antioxidancia chemie   farmakologie   MeSH
• antitumorózní látky chemie   farmakologie   MeSH
• biologické markery MeSH
• exprese genu MeSH
• faktor 2 související s NF-E2 genetika   metabolismus   MeSH
• fenoly chemie   farmakologie   MeSH
• glukosa MeSH
• lidé MeSH
• molekulární struktura MeSH
• oxidační stres MeSH
• rostlinné extrakty chemie   farmakologie   MeSH
• superoxid dismutáza 1 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia MeSH
• antitumorózní látky MeSH
• biologické markery MeSH
• faktor 2 související s NF-E2 MeSH
• fenoly MeSH
• glukosa MeSH
• NFE2L2 protein, human MeSH Prohlížeč
• rostlinné extrakty MeSH
• SOD1 protein, human MeSH Prohlížeč
• superoxid dismutáza 1 MeSH

The stilbenoids, a group of naturally occurring phenolic compounds, are found in a variety of plants, including some berries that are used as food or for medicinal purposes. They are known to be beneficial for human health as anti-inflammatory, chemopreventive, and antioxidative agents. We have investigated a group of 19 stilbenoid substances in vitro using a cellular model of THP-1 macrophage-like cells and pyocyanin-induced oxidative stress to evaluate their antioxidant or pro-oxidant properties. Then we have determined any effects that they might have on the expression of the enzymes catalase, glutathione peroxidase, and heme oxygenase-1, and their effects on the activation of Nrf2. The experimental results showed that these stilbenoids could affect the formation of reactive oxygen species in a cellular model, producing either an antioxidative or pro-oxidative effect, depending on the structure pinostilbene (2) worked as a pro-oxidant and also decreased expression of catalase in the cell culture. Piceatannol (4) had shown reactive oxygen species (ROS) scavenging activity, whereas isorhapontigenin (18) had a mild direct antioxidant effect and activated Nrf2-antioxidant response element (ARE) system and elevated expression of Nrf2 and catalase. Their effects shown on cells in vitro warrant their further study in vivo.

• Klíčová slova
• Nrf2, antioxidant, macrophages, pro-oxidant, pyocyanin, stilbenoid,
• MeSH
• antioxidační responzivní elementy účinky léků   MeSH
• antioxidancia chemie   farmakologie   MeSH
• buňky Hep G2 MeSH
• faktor 2 související s NF-E2 genetika   MeSH
• lidé MeSH
• peroxidace lipidů účinky léků   MeSH
• pyokyanin chemie   MeSH
• stilbeny chemie   farmakologie   MeSH
• thiobarbituráty chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• faktor 2 související s NF-E2 MeSH
• NFE2L2 protein, human MeSH Prohlížeč
• pyokyanin MeSH
• stilbeny MeSH
• thiobarbituráty MeSH
• thiobarbituric acid MeSH Prohlížeč