Glycosylation of Quercetin by Selected Entomopathogenic Filamentous Fungi and Prediction of Its Products’ Bioactivity

Abstract

Quercetin is the most abundant flavonoid in food products, including berries, apples, cauliflower, tea, cabbage, nuts, onions, red wine and fruit juices. It exhibits various biological activities and is used for medical applications, such as treating allergic, inflammatory and metabolic disorders, ophthalmic and cardiovascular diseases, and arthritis. However, its low water solubility may limit quercetin’s therapeutic potential. One method of increasing the solubility of active compounds is their coupling to polar molecules, such as sugars. The attachment of a glucose unit impacts the stability and solubility of flavonoids and often determines their bioavailability and bioactivity. Entomopathogenic fungi are biocatalysts well known for their ability to attach glucose and its 4-O-methyl derivative to bioactive compounds, including flavonoids. We investigated the ability of cultures of entomopathogenic fungi belonging to Beauveria, Isaria, Metapochonia, Lecanicillium and Metarhizium genera to biotransform quercetin. Three major glycosylation products were detected: (1), 7-O-β-D-(4″-O-methylglucopyranosyl)-quercetin, (2) 3-O-β-D-(4″-O-methylglucopyranosyl)-quercetin and (3) 3-O-β-D-(glucopyranosyl)-quercetin. The results show evident variability of the biotransformation process, both between strains of the tested biocatalysts from different species and between strains of the same species. Pharmacokinetic and pharmacodynamic properties of the obtained compounds were predicted with the use of cheminformatics tools. The study showed that the obtained compounds may have applications as effective modulators of intestinal flora and may be stronger hepato-, cardio- and vasoprotectants and free radical scavengers than quercetin.

Biotransformation of Δ1-Progesterone Using Selected Entomopathogenic Filamentous Fungi and Prediction of Its Products’ Bioactivity

“…Due to the large number of compounds formed, attempts to isolate them were not pursued. Nevertheless, the obtained result indicates that the tested biocatalyst produces a multitude of enzymes capable of transforming steroid compounds and indicates the possibility of using this strain in the biocatalysis of various bioactive compounds; e.g., in our previous work, we described the effective glycosylation of quercetin by Isaria tenuipes MU35 [ 52 ]. It was also proven that a strain of this species is capable of an effective metabolism of zearalenone and, similar to the two representatives of this genus more popular in biocatalysis ( I. fumosorosea , I. farinosa ), multienzymatic transformations of the used substrate were observed [ 41 ].…”

“…The microorganisms Beauveria bassiana KCh J1.5, B. caledonica KCh J3.3, Isaria farinosa KCh KW 1.1 and I. fumosorosea KCh J2, and Metarhizium robertsii MU4 and Isaria tenuipes MU35 were obtained from the collection of the Department of Food Chemistry and Biocatalysts, at the Wrocław University of Environmental and Life Sciences (Wrocław, Poland) and the collection of the Institute of Plant Genetics, at the Polish Academy of Sciences (Poznań, Poland). Isolation and identification procedures were described in our previous papers [ 36 , 52 , 86 ].…”

Quercetin, a Flavonoid with Great Pharmacological Capacity

“…Quercetin consists of five hydroxyl groups ( Figure 2 ), which determine the biological activity of the compound [ 2 , 12 ]. Naturally, quercetin is distributed in the form of derivatives, either in glycosidic form, mainly attached to the C-3 carbon with glucose, rhamnose, and rutinose, or linked to others, and it is very rarely distributed as an aglycone [ 13 ]. On the other hand, quercetin in its aglycone form is a bright lemon-yellow powder, insoluble in water but soluble in alcohol and lipids.…”

Metabolic Engineering of Corynebacterium glutamicum for the Production of Flavonoids and Stilbenoids

“…It usually is more soluble, more stable, and more functional compared to their aglycones [67]. Furthermore, some research has demonstrated that the glycosylation of flavonoids had shown higher antioxidant activities; stronger hepato-, cardio-, and vasoprotectant behavior; and free radical scavengers than aglycone [68,69].…”