chrysin and 6-hydroxyflavone

Topics: Animals; Cattle; Flavonoids; Glycosylation; Hemoglobins; Ligands; Molecular Docking Simulation; Protein Binding; Protein Conformation

The influence of glucose on the interaction between flavonoids and plasma proteins from healthy humans (HPPs) was investigated. Glucose affected the flavonoid-protein interactions depending upon their structures. Glucose significantly reduced the affinities of HPPs for 6-hydroxyflavone by 10.72 times, slightly weakened the affinities of HPPs for quercetin, 7-hydroxyflavone, and kaempferol, and hardly affected the affinities of HPPs for myricetin, chrysin, and 3,7-dihydroxyflavone on the first day. However, glucose obviously enhanced the affinities of HPPs for 3-hydroxyflavone, luteolin, and apigenin. Glucose significantly weakened the binding affinities of HPPs for chrysin, kaempferol, quercetin, and myricetin by 6.17, 7.94, 14.12, and 112.2 times, when kept at 37 °C under air conditions for 14 days, and the binding affinities of HPPs for 7-hydroxyflavone, luteolin, 3,7-dihydroxyflavone, 3-hydroxyflavone, and 6-hydroxyflavone were slightly decreased by 1.35-, 1.58-, 1.58-, 1.9-, and 2.4-fold. The binding affinity between apigenin and HPP was hardly influenced. Glucose weakened the binding affinities of HPPs for hydroxyflavonoids. The differences between log K(a)(absence) and log K(a)(presence) were bigger for the more lipophilic hydroxyflavonoids, and more lipophilic hydroxyflavonoids are easily affected by glucose, when kept at 37 °C under air conditions for 14 days. These flavonoids with lower hydrogen donor/acceptor numbers prefer to stably interact with HPPs in the presence of glucose. However, other flavonoids with high hydrogen donor/acceptor numbers (multi-hydroxyl flavonoids) were apt to reduce their affinities with HPPs in the presence of glucose.

Topics: Adult; Apigenin; Binding Sites; Binding, Competitive; Blood Glucose; Blood Proteins; Diet; Dietary Supplements; Flavonoids; Glucose; Humans; Hydrogen Bonding; Kaempferols; Luteolin

5,7-Dihydroxyflavone (chrysin) (1) when fermented with fungal cultures, Aspergillus alliaceous (ATCC 10060), Beauveria bassiana (ATCC 13144) and Absidia glauco (ATCC 22752) gave mainly 4'-hydroxychrysin (4), chrysin 7-O-beta-D-4-O-methylglucopyranoside (5) and chrysin 7-sulfate (6), respectively. Mucore ramannianus (ATCC 9628), however, transformed chrysin into six metabolites: 4'-hydroxy-3'-methoxychrysin (chrysoeriol) (7), 4'-hydroxychrysin (apigenin) (4) 3',4'-dihydroxychrysin (luteolin) (8), 3'-methoxychrysin 4'-O-alpha-D-6-deoxyallopyranoside (9), chrysin 4'-O-alpha-D-6-deoxyallopyranoside (10), and luteolin 3'-sulfate (11). Cultures of A. alliaceous (ATCC 10060) and B. bassiana (ATCC 13144) metabolized 5-hydroxyflavone (2) into 5,4'-dihydroxyflavone (12) and 4'-hydroxyflavone 5-O-beta-D-4-O-methylglucopyranoside (13), respectively. 6-Hydroxyflavone (3) was transformed into 6-hydroxyflavanone (14), flavone 3-O-beta-D-4-O-methylglucopyranoside (15) and (+/-)-flavanone 6-O-beta-D-4-O-methylglucopyranoside (16) by cultures of Beauveria bassiana (ATCC 13144). The structures of the metabolic products were elucidated by means of spectroscopic data. The significance of the metabolites as antioxidants in relation to their structure is briefly discussed.

Topics: Antioxidants; Flavonoids; Fungi; Hydrolysis; Magnetic Resonance Spectroscopy; Molecular Conformation; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Infrared