betadex and 3-4-dihydroxyphenylethanol

Polysaccharide substrates loaded with antioxidant and antimicrobial compounds, effectively protected by cyclodextrin moieties, can be a long-lasting solution to confer certain properties to fabrics, paper and other materials. β-Cyclodextrin was attached to α-cellulose, bleached pulp and starch by a two-step esterification with a tetracarboxylic acid. The resulting derivatives were characterized by spectroscopy, thermal degradation analysis and capability of phenolphthalein inclusion. The carriers, containing between 89 and 171 μmol of β-cyclodextrin per gram, were loaded with carvacrol, cuminaldehyde, cinnamaldehyde and hydroxytyrosol. From a stoichiometric addition, the percentage of compound retained ranged from 49% (hydroxytyrosol in pulp-cyclodextrin) to 92% (carvacrol in starch-cyclodextrin). Finally, the release rate to aqueous ethanol was measured over eight days and fitted to kinetic models. From the analysis of the mean dissolution time, it can be concluded that inserting β-cyclodextrin units enhanced the long-term holding of phenolic active compounds in carbohydrate matrices.

Topics: Acrolein; Antioxidants; Benzaldehydes; beta-Cyclodextrins; Butanes; Carboxylic Acids; Cellulose; Cross-Linking Reagents; Cymenes; Drug Liberation; Kinetics; Phenols; Phenylethyl Alcohol; Starch

The extraction of phenolic compounds from olive mill wastes is important, not only to avoid environmental damages, but also because of the intrinsic value of those biophenols, well-known for their high antioxidant potential and health benefits. This study focuses on tyrosol (Tyr) and hydroxytyrosol (HT), two of the main phenolic compounds found in olive mill wastes. A new, simple, and eco-friendly extraction process for the removal of phenolic compounds from aqueous solutions using native β-cyclodextrin (β-CD) in the solid state has been developed. Several β-CD/biophenol molar ratios and biophenol concentrations were investigated, in order to maintain β-CD mostly in the solid state while optimizing the extraction yield and the loading capacity of the sorbent. The extraction efficiencies of Tyr and HT were up to 61%, with a total solid recovery higher than 90% using an initial concentration of 100 mM biophenol and 10 molar equivalents of β-CD. The photochemical stability of the complexes thus obtained was estimated from ∆E*ab curve vs. illumination time. The results obtained showed that the phenols encapsulated into solid β-CD are protected against photodegradation. The powder obtained could be directly developed as a safe-grade food supplement. This simple eco-friendly process could be used for extracting valuable biophenols from olive mill wastewater.

Topics: Antioxidants; beta-Cyclodextrins; Dietary Supplements; Olea; Olive Oil; Phenylethyl Alcohol; Plant Extracts; Wastewater

Hydroxytyrosol bioaccessibility and absorption by the intestinal cells were studied using an in vitro digestion model and Caco-2 TC7 monolayers cells in culture in the presence and absence of β-cyclodextrin and foods. Hydroxytyrosol was either provided as a pure standard or in an alperujo powder. The presence of foods significantly decreased hydroxytyrosol bioaccessibility and absorption (-20 and -10%, respectively), while β-cyclodextrin had no effect. Moreover, the presence of other compounds from alperujo in the intestinal compartment reduced hydroxytyrosol absorption by Caco-2 cells compared to pure standard (-60%). The final bioavailability of hydroxytyrosol, defined as its quantity at the basolateral side of cultured cell monolayers compared to the initial amount in the test meal, was 6.9 ± 0.4, 31.1 ± 1.1, and 40.9 ± 1.5% when hydroxytyrosol was from alperujo or a standard administered with or without food, respectively. Our results show that conversely to foods, β-cyclodextrin does not alter hydroxytyrosol bioavailability.

Topics: beta-Cyclodextrins; Biological Availability; Caco-2 Cells; Digestion; Drug Carriers; Drug Delivery Systems; Humans; Intestinal Absorption; Models, Biological; Olea; Phenylethyl Alcohol; Plant Extracts; Waste Products

Olives and olive oil, a key food type of the Mediterranean diets, are packed with various important polyphenols including oleuropein (OLE), hydroxytyrosol (HTY) and tyrosol (TYR). OLE and HTY are highly powerful antioxidants and play a prime role in the therapeutics of free radical-related diseases. Their molecular stabilities and antioxidant properties can be improved by cyclodextrin (CD) encapsulation. Here, we present a systematic investigation on the inclusion complexes of β-CD-TYR (1), β-CD-HTY (2) and β-CD-OLE (3) by combined single-crystal structure determination, DFT complete-geometry optimization and DPPH antioxidant assay. X-ray analysis and DFT calculation reveal the preference of inclusion geometry with deep protrusion of the aromatic ring moieties of TYR, HTY and OLE from the β-CD O6-H-side, and the common host-guest stabilization scheme via intermolecular O-H⋯O hydrogen bonding interactions. No polyphenol OH group is shielded in the β-CD cavity, in contrast to the structures of β-CD-tea catechins complexes. The established host-guest O-H⋯O hydrogen bonds help to elevate antioxidant capacities of the olive polyphenols upon β-CD encapsulation. The order of antioxidant activity 2 >3 ≫ 1 based on the DPPH measurement is in fair agreement with their relative thermodynamic stabilities derived from DFT calculation.

Topics: beta-Cyclodextrins; Crystallography, X-Ray; Free Radical Scavengers; Hydrogen Bonding; Iridoid Glucosides; Iridoids; Models, Chemical; Molecular Structure; Phenylethyl Alcohol; Quantum Theory; Structure-Activity Relationship; Thermodynamics

Alperujo-a two-phase olive mill waste that is composed of olive vegetation water and solid skin, pulp, and seed fragments - is a highly valuable olive by-product due to its high content in phenolic compounds. In this study, we assessed whether β-cyclodextrin (β-CD), which is used to extract and protect alpejuro phenolic compounds (hydroxytyrosol-

Topics: Antioxidants; beta-Cyclodextrins; Biological Availability; Caco-2 Cells; Caffeic Acids; Coumaric Acids; Glucosides; Humans; Olea; Phenols; Phenylethyl Alcohol; Plant Extracts; Propionates

Although the separation efficiency of capillary electrophoresis (CE) is much higher than that of other chromatographic methods, it is sometimes difficult to adequately separate the complex ingredients in biological samples. This article describes how one effective and simple way to develop the separation efficiency in CE is to add some modifiers to the running buffer. The suitable running buffer modifier β-cyclodextrin (β-CD) was explored to fast and completely separate four phenylethanoid glycosides and aglycones (homovanillyl alcohol, hydroxytyrosol, 3,4-dimethoxycinnamic acid, and caffeic acid) in Lamiophlomis rotata (Lr) and Cistanche by capillary zone electrophoresis with ultraviolet (UV) detection. It was found that when β-CD was used as running buffer modifier, a baseline separation of the four analytes could be accomplished in less than 20 min and the detection limits were as low as 10(-3) mg L(-1). Other factors affecting the CE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage, and sample injection time, were investigated extensively. Under the optimal conditions, a successful practical application on the determination of Lr and Cistanche samples confirmed the validity and practicability of this method.

Topics: beta-Cyclodextrins; Buffers; Caffeic Acids; Cinnamates; Cistanche; Electrophoresis, Capillary; Glycosides; Hydrogen-Ion Concentration; Lamiaceae; Limit of Detection; Phenylethyl Alcohol