50376-43-7

Upstream product

• 10236-47-2 naringin 
• 10236-47-2 naringin 

Downstream Products

• 4192-90-9 4'-(β-D-glucopyranosyloxy)-2',4”,6'-trihydroxydihydrochalcone 
• 60-82-2 3-(4-Hydroxy-phenyl)-1-(2,4,6-trihydroxy-phenyl)-propan-1-on 
• 10236-47-2 naringin 
• 18916-17-1 [4-[[2-O-(6-deoxy-L-mannopyranosyl)-D-glucopyranosyl]oxy]-2,6-dihydroxyphenyl]-3-(4-hydroxyphenyl)-1-propanone 
• 58001-41-5 4′,5,7‐trihydroxyflavanone‐7‐rhamnoglucoside 

Relevant academic research and scientific papers

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

The pH-rate profile for the title reaction has been determined and accounted for in terms of contributions from the various ionised species.The effect of ionisation of a chalcone 4-OH group on rate of cyclisation is quantitatively accommodated for the first time.The rate data have been used to calculate the position of the equilibrium and its rate of attainment as a function of pH, and this information should be general value for optimising conditions for synthesis of 2',4,6'-trihydroxychalcones by ring-opening 4',5-dihydroxyflavones.

Enthalpy-entropy compensation effect in the chalcone formation from naringin in water-ethanol mixtures

The isomerisation equilibrium between the flavanone and chalcone forms of the naturally occurring flavonoid naringin (7-rhamnoglucosyl-4′,5-dihydroxyflavanone) has been studied in water-ethanol mixtures in the presence of NaOH. The variation of the observed pseudo-first order rate constant for the equilibrium reaction, kobs, and the equilibrium composition were determined as a function of the base concentration (-4.0 w ≤ 1.00) of the solvent mixture. The variation of the ring opening kop, and the cyclisation kcy, rate constants with the base concentration and solvent composition indicated that the isomerisation reaction is mediated by a carbanion intermediate. The temperature effect on kop and kcy showed that only the activation enthalpy and entropy changes for the ring-opening reaction, ΔHop? and ΔSop?, were dependent on the solvent composition. In fact, a good linear correlation of a plot of ΔHop? vs. ΔSop?, indicate the existence of an enthalpy-entropy compensation effect. This result was associated with changes in the balance of hydrogen-bonding interactions between the intermediate carbanion and its solvation sphere as solvent composition was modified.