Interactions between bioactive ferulic acid and fumed silica by UV–vis spectroscopy, FT-IR, TPD MS investigation and quantum chemical methods

Recovery of hydroxycinnamic acids from renewable resources by adsorption on zeolites

“…It results from the protonation or dissociation of the hydroxyl groups (SiOH and AlOH). Thus complexes are probably formed involving silanol and aluminol sites of zeolite and hydroxyl and carboxyl groups of the phenolic compound [31][32]. At pKa 2 > pH > pKa 1 , the compound is mainly in the form of negatively charged carboxylate ions and at pH > pKa 2 the form of negatively charged phenolate ion is added.…”

Thermal transformations of biologically active derivatives of cinnamic acid by TPD MS investigation

“…The TPD MS experiments were performed on a MX-7304A monopole mass spectrometer (Sumy, Ukraine) with electron impact ionization adapted for thermodesorption measurements as described earlier [17,18]. A typical TPD MS test comprised placing the samples of 0.1-2 mg weight on the bottom of a molybdenumquartz ampoule, its evacuating to ∼5 × 10 −5 Pa at ∼20 • C and the sample heating at a rate of 0.15 • C/s up to ∼750 • C. The volatile pyrolysis products passed through a high-vacuum valve into the ionization chamber of the mass-spectrometer, where they were ionized and fragmented by electron impact.…”

“…In the previous works [17,18] we have reported the TPD MS study of the cinnamic and ferulic acid interaction with fumed silica. Several decomposition pathways of these acids on silica surface were found.…”

A TPD‐MS study of the interaction of coumarins and their heterocyclic derivatives with a surface of fumed silica and nanosized oxides CeO2/SiO2, TiO2/SiO2, Al2O3/SiO2

“…[27] For example, some derivatives of another natural oxygen heterocycles γ -pyrones and chromones [28 -30] and biologically active substituted cinnamic acids have been lately studied. [31,32] Despite the importance of the gathered empirical evidence, the development of complex drugs demands more detailed information about the interactions in the adsorbed state, the structure of surface complexes and their mechanism of formation. Such information could be obtained from the analysis of TPD-MS data.…”

“…Such information could be obtained from the analysis of TPD-MS data. [31,32] Of special interest would be the application of this technique to the elucidation of the binding mechanisms of coumarins on the silica surface.…”