The kinetics and mechanism, and the equilibrium position as a function of pH, of the isomerisation of naringin and the 4′-rhamnoglucoside of 2′,4,4′,6′-tetrahydroxychalcone

Chiral separation of diastereomeric flavanone‐7‐O‐glycosides in citrus by capillary electrophoresis

“…1). Flavanones with a free hydroxy group at this position (glycosides of naringenin and eriodictyol) racemize easier than with a methoxy group (glycosides of hesperetin and isosakuranetin) [6].…”

Thermal Inactivation and Product Inhibition ofAspergillus terreusCECT 2663 α-L-Rhamnosidase and Their Role on Hydrolysis of Naringin Solutions

“…These ‰avonoids can be transformed to chalcones in the basic medium used for p-nitrophenol measurement in the test of activity, 12) being a possible source of interference due to the production of color at 400 nm. 17) However, after dilution, this interference was only of the order of 5z of the p-nitrophenol absorbance and was easily corrected by subtracting the value of the control. Activity after the hydrolysis in presence of naringin was also measured using membrane-centrifuge concentrators, which separate the enzyme from the main part of low molecular weight substrate and products.…”

Stereospecific high-performance liquid chromatographic analysis of eriodictyol in urine

“…Eriodictyol contains a free hydroxyl group in the carbon 4 , which increases its potential to racemize easier than other flavanones with a methoxy group on that position such as hesperetin and isosakuranetin [11]. Therefore, the racemization process of eriodictyol under heated 25% methanol was studied.…”

“…It has been previously reported that flavanones such as eriodictyol can racemize depending on the substituted functional groups around the stereogenic center [10]. Furthermore, flavanones with a free hydroxyl group in the carbon 4 such as naringenin and eriodictyol have the potential to racemize easier than flavanones with a methoxy group on that position such as hesperetin and isosakuranetin [11]. The racemization process reaches an equilibrium between the two antipodes and is facilitated with by high temperatures, moisture, solvent, and pH, among other factors [10].…”