Solubilities of Cinnamic Acid Esters in Organic Solvents

Abstract

The solubilities of three cinnamic acid esters, namely, methyl ferulate, methyl p-coumarate, and methyl sinapate, have been measured in tert-butanol, tert-pentanol, ethyl acetate, and n-hexane, at the temperature range of (303.15 to 321.15) K. It is shown that tert-pentanol is the best solvent for methyl p-coumarate and methyl ferulate and ethyl acetate for methyl sinapate, while the nonpolar n-hexane is the worst solvent. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of the three esters have been calculated. To better understand the solubilization process, the melting temperatures and the enthalpies of fusion of the three esters were determined by differential scanning calorimetry. Finally, successful correlation of the experimental data was achieved with the UNIQUAC and the nonrandom twoliquid (NRTL) activity coefficient models.

Solubility of daidzin in different organic solvents and (ethyl alcohol+water) mixed solvents

“…Especially, D diss H o for tetrahydrofuran (77.1998 kJ Á mol À1 ) is much larger than that for other solvents, which may be due to the facts that (i) more energy is required for overcoming the cohesive force of the solute and the solvent in the dissolution process, and (ii) the solubility increases quickly at high temperatures which also indicates a strong temperature dependence of solubility [26]. The similar phenomena with anomalously large D diss H o are also reported in the literature [27,28]. However, there is also a stronger entropic effect (i.e., more positive D diss S o values) for the (daidzin + tetrahydrofuran) mixture.…”

Stability of Omega-3 LC-PUFA-rich Photoautotrophic Microalgal Oils Compared to Commercially Available Omega-3 LC-PUFA Oils

“…51 Moreover, carotenoids are particularly good at protecting against 1 O 2 mediated photo-oxidation, a type of oxidation that will not take place in this setup due to the use of amber vials. Because the solubility of phenolic compounds was shown to be a lot smaller in hexane than in alcohols, 52 it is expected that they are more abundant in the HI than in the H oils, thus possibly explaining the higher oxidative stability of the HI compared to the H oils. A second possible explanation is the higher GL and PL content in the HI oil compared to H oil (Table 1).…”

Molecular Distillation of Lavender Supercritical Extracts: Physicochemical and Antimicrobial Characterization of Feedstocks and Assessment of Distillates Enriched with Oxygenated Fragrance Components

“…Similar structures could be responsible for some minor features in the second heat thermal analysis of L-Pl-E found at 75 °C ( Figure 3 ). However, further increase of melting properties was supposed to be affected by the addition of methoxy substituent on the phenol ring, and such behavior was observed for p -coumaric acid esters, i.e., methyl ferulate and methyl sinapate, showing fusion points of 62 and 88 °C, respectively [ 54 ]. This might support the similarity between the highest melting fractions of L-Bg-E (81 °C) and carnauba wax (83 °C) in terms of carboxylic acid constituents ( Figure 4 ).…”