β-Glucosidase from tartary buckwheat immobilization on bifunctionalized nano-magnetic iron oxide and its application in tea soup for aroma and flavonoid aglycone enhancement

β-Glucosidase (BG) was immobilized on the surface of bifunctionalized nano-magnetic iron oxide with silica and amine groups (Fe3O4@SiO2-NH2).

In vitro study on the antitumor activity of Tanacetum vulgare L. extracts

The major nonvolatile compounds derived from extracts and fractions from Tanacetum vulgare L. flowers were determined by LC–HRMS. Major compounds in the crude extract were determined to be: six hydroxycinnamoyl quinic acids with 4,5-dicaffeoylquinic acid and twelve flavonoids and their derivatives, six of which were in the form of flavonoid-O-glucuronides. Generally, the major flavonoid aglycone in tansy was luteolin. Extracts and fractions were tested under in vitro conditions in nine cell lines - one control non-tumorogenic and eight tumor lines, whereby antitumor activity was observed after 72 hours of incubation with the aforementioned substances as determined by an MTT assay. The obtained results show the highest selectivity index for the ethyl acetate extract from Flores Tanaceti (EAFT) and for the ethyl acetate fraction of the crude extract (EACE). EAFT extract was found to exert the highest antitumor effect, followed by EACE. From the above results it becomes evident that ethyl acetate extracts of T. vulgare contain substances with high selective activity against tumor cells.

Interaction of Chrysin and Its Main Conjugated Metabolites Chrysin-7-Sulfate and Chrysin-7-Glucuronide with Serum Albumin

Chrysin (5,7-dihydroxyflavone) is a flavonoid aglycone, which is found in nature and in several dietary supplements. During the biotransformation of chrysin, its conjugated metabolites chrysin-7-sulfate (C7S) and chrysin-7-glucuronide (C7G) are formed. Despite the fact that these conjugates appear in the circulation at much higher concentrations than chrysin, their interactions with serum albumin have not been reported. In this study, the complex formation of chrysin, C7S, and C7G with human (HSA) and bovine (BSA) serum albumins was investigated employing fluorescence spectroscopic, ultrafiltration, and modeling studies. Our major observations/conclusions are as follows: (1) Compared to chrysin, C7S binds with a threefold higher affinity to HSA, while C7G binds with a threefold lower affinity; (2) the albumin-binding of chrysin, C7S, and C7G did not show any large species differences regarding HSA and BSA; (3) tested flavonoids likely occupy Sudlow’s Site I in HSA; (4) C7S causes significant displacement of Sudlow’s Site I ligands, exerting an even stronger displacing ability than the parent compound chrysin. Considering the above-listed observations, the high intake of chrysin (e.g., through the consumption of dietary supplements with high chrysin contents) may interfere with the albumin-binding of several drugs, mainly due to the strong interaction of C7S with HSA.

Nomenclature of flavonoids (IUPAC Recommendations 2017)

Flavonoid structures, found in nature or obtained by synthesis, may be very complex. These Recommendations provide a guide for flavonoid aglycone names. This will also allow the construction of the names for their polyglycosylated species with clarity and conciseness. A joint working party of IUPAC/IUBMB members has prepared these recommendations, which establish rules for the general nomenclature of flavonoids, providing examples of acceptable trivial names, and names derived from trivial names, together with semi-systematic and fully systematic names that follow the published IUPAC recommendations.

Naringenin ameliorates renal and platelet purinergic signalling alterations in high-cholesterol fed rats through the suppression of ROS and NF-κB signaling pathways

The in vivo protective effect of Naringenin (NGEN), a natural flavonoid aglycone of naringin, against the mitochondrial dysfunction and oxidative stress induced by high cholesterol levels in the renal tissue.

The use of ionic liquid as a mobile phase modifier in analytical supercritical fluid chromatography for the separation of flavonoids

This paper presents a method that the uses ionic liquids (ILs) as a mobile phase modifier in supercritical fluid chromatography (SFC) for flavonoid aglycone analysis, significantly improving the resolution and changing the selectivity.