Solubility of Quercetin in Water + Methanol and Water + Ethanol from (292.8 to 333.8) K

Abstract

The solubilities of quercetin in water + methanol and water + ethanol mixtures were measured over the temperature range of (292.8 to 333.8) K. The concentrations of quercetin in different solvent mixtures were analyzed by the UV/vis spectrophotometric method. The experimental solubility data were correlated with the modified Apelblat equation. The calculated solubilities show good agreement with the experimental solubility data.

Optimization of Quercetin Extraction from Green Tea ( Camellia sinensis ) Using Central Composite Design, and the Pharmacological Activity of the Extract

“…The quercetin yield significantly increased when the concentrations were higher than 80 % (v/v). This was expected, because quercetin is a flavonoid poorly soluble in water, but better soluble in alcoholic solutions 39 In Figure 7, a normal probability plot is presented. The normal probability plot is basically a plot of the ordered observations from a sample against the corresponding percentage points from the standard normal distribution.…”

On the solubility of quercetin

“…1 we compare predicted and observed [2] solubilities in water-ethanol mixtures, and also our fitted value of log Cw with the experimental values in Table 1. As might be expected, our predicted solubilities in the water-ethanol system are in good agreement with the experimental solubilities [2] at large vol % ethanol, but diverge considerably as the proportion of water increases. Our suggested value for log Cw is about in the mid-range of the various recorded solubilities in water.…”

“…A value for the water-octanol partition coefficient of quercetin, log P(oct) = 2.06, is available [16], Althans et al [1] have determined the solubility in ethanol and Razmara et al [2] the solubility in methanol at 298 K. Then use of Cw allows log P(ethanol) and log P(methanol) to be deduced, and use of Kw allows log K values for gas to ethanol partition and gas to methanol partition to be deduced. In addition, we have equations on the lines of Eq.…”

Detection of Some Types of Bacteria in Patients with Kidney Stones and the Use of Corn Silk Extracts to Effectively Inhibit the Urease Enzyme in Klebsiella Species

“…In our study, because of the re-adsorption of the extracted solutes, a lower flavonoid yield was found when the particle size was smaller than 0.4mm. Hence, a particle size of 0.4 mm was selected for subsequent tests (Razmara et al, 2010). …”