Synthesis of high added value compounds through catalytic oxidation of 2‐phenylethanol: A Kinetic study

Abstract

An effective procedure was developed to produce high‐value added phenolic compounds through the conversion of 2‐phenylethanol (2‐PhEt) by using acid‐activated clays KSF for the hydrogen peroxide. Owing to KSF's ability to catalyze a variety of complex oxidations, it was likely to convert 2‐PhEt to hydroxytyrosol (HTY) and tyrosol (TY) derivatives. The analyses of catalytic solution revealed that the optimum conditions, giving a higher concentration of oxidation products such as HTY, were as follows: 2‐PhEt concentration 10−2 mol/L, the hydrogen peroxide concentration 5.05 × 10−2 and 0.6 g L–1 of KSF clays . The yield during the conversion reaction into HTY was around 25%. All compounds in the reaction mixture were identified by mass spectrophotometry using a LC‐MS apparatus. HTY, TY, meta‐tyrosol and ortho‐tyrosol were the major compounds. The antioxidant activity was realized by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) method. In fact, it is revealed that the strongest inhibition percentage (PI = 96) was detected with the increase in the concentration of HTY. The approach proposed in the present work presents an environment friendly method.

Study on the Effect of Climate Changes on the Composition and Quality Parameters of Virgin Olive Oil “Zalmati” Harvested at Three Consecutive Crop Seasons: Chemometric Discrimination

“…Subsequently, the lowest IC 50 values (5.07 mg/mL), which specified higher antioxidant potentials, were observed for the samples harvested in the last development stage of maturity (MI = 4.17). This is possibly due to the important radical inhibition caused by the high concentration of total phenols, principally oleuropein aglycone and hydroxytyrosol …”

“…This is possibly due to the important radical inhibition caused by the high concentration of total phenols, principally oleuropein aglycone and hydroxytyrosol. 29 …”

“…This is possibly due to the important radical inhibition caused by the high concentration of total phenols, principally oleuropein aglycone and hydroxytyrosol. 29 Table 1 shows the variability between the values of oxidative stability of the studied oils. These values ranged between a maximum of 9.56 h for MI = 9.17 in the season 2020/2021 and a minimum of 3.31 h (for MI = 5.56 in the season 2020/202.…”

Production of biologically active hydroxytyrosol rich extract via catalytic conversion of tyrosol

“…In fact, using a higher concentration of H 2 O 2 acts as a quencher ( eqn (4) , (5) , therefore, low content of hydroxy radical concentration. 25 H 2 O 2 + ˙OH → HO 2 ˙ + H 2 O HO 2 ˙ + ˙OH → H 2 O + O 2 …”

Chemometric Analysis and Physicochemical Composition of Foreign and Tunisian Olive Oil: Consumer Preferences

“…Angerosa and coworkers [19] found that polyphenols contributed to the characterization of walnut husk, bitter and pungent characteristics. Moreover, it was reported that the stimuli that are mainly responsible for bitter and pungent attributes are tyrosol, hydroxytyrosol, and the aglycones that contain them, arising from glycosides naturally occurring in olive fruits [11,19,20].…”