Influence of a 4′-substituent on the efficiency of flavonol-based fluorescent indicators of β-glycosidase activity

Abstract

This article presents novel fluorescent probes, based on the excited-state intramolecular proton transfer (ESIPT) phenomenon and flavonols, sensitive to the action of specific glycosidases. 4’-Substituted flavonols were synthesized, using various...

Binding interactions of hydrophobically-modified flavonols with β-glucosidase: fluorescence spectroscopy and molecular modelling study

“…2-Aryl-3-hydroxy-4 H -chromen-4-ones 2a–f were synthesized by the following method. For the synthesis of the target 2-aryl-3-hydroxy-4 H -chromen-4-ones 2a–f , we used the one-pot optimized method 27 without obtaining and additional purification of the corresponding intermediate unsaturated ketones. The synthesis of unsaturated ketones 1a–f described elsewhere.…”

Progress and Achievements in Glycosylation of Flavonoids

“…Also, in the synthesis of glycosides of flavonoids, oxidized forms are used, particularly bromides and chlorides of esters of glucuronic acid (Needs and Williamson, 2001;Reszka et al, 2020), as well as 2-acetamido-2-deoxy glucosides (Ngameni et al, 2008;Cao et al, 2018;Reszka et al, 2020). It should be noted that acetamides form final products with a higher yield than other donors of glycosidic groups-from 70-80% (Hörhammer et al, 1966) up to 92% (Reszka et al, 2020), respectively. The use of 2-acetamido-2-deoxy glucosides and glucuronides allows further chemical modification of glycosidic residues after removing the protective groups.…”

“…Despite the presence of protective groups, some of the glycosyl bromides undergo hydrolysis, which is why the glycosylation reaction in some cases must be carried out in additionally dehydrated solvents and the presence of a water adsorbent, for example, molecular sieves (Needs and Williamson, 2001;Smith et al, 2006;Mei et al, 2015). Moreover, some authors note the appearance in the reaction mixture of side products-glycals (Needs and Williamson, 2001;Reszka et al, 2020).…”

“…To increase the yield of the final product, instead of KOH, NaOH (Zhu et al, 2006) and also less alkaline agents -Na 2 CO 3 (Mughal et al, 2018) or K 2 CO 3 (Semeniuchenko et al, 2009;Serdiuk et al, 2016;Reszka et al, 2020) began to be used. The yield of flavonols-glycosides with donors of glycoside groups, uronates, and 2-acetamides was 40-95%.…”

Visual Sensing of β-Glucosidase From Intestinal Fungus in the Generation of Cytotoxic Icarisid II

“…While, enzymatic fluorescent probes have been widely used to sense biological enzymes, exhibiting the advantages of high sensitivity, high selectivity and facilitate in vivo/in vitro imaging (Feng, et al, 2021;Li, et al, 2020;Liu, et al, 2021;Ning, et al, 2019;Tian, et al, 2021;Yan, et al, 2022;Zhang, et al, 2021). Using the excited-state intramolecular proton transfer (ESIPT) phenomenon, flavonol derivatives have been used as fluorescent indicators for β-Glc activity (Reszka, et al, 2020). However, an enzymatic activatable long wavelength fluorescent probe is still desirable for the sensing and determination of intestinal β-Glc.…”