Complexation of hydroxytyrosol with β-cyclodextrins. An efficient photoprotection

López-García, María Ángeles; López, Óscar; Maya, Inés; Fernández-Bolaños, José G.

doi:10.1016/j.tet.2010.08.009

Cited by 29 publications

(18 citation statements)

References 21 publications

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“…1B). A symmetrical curve with a maximum at r = 0.5 evidenced the formation of a complex having a 1:1 stoichiometry in accordance with literature data (López-García et al, 2010). Fig.…”

Section: Stoichiometry and Association Constants Determinationsupporting

confidence: 91%

Characterization of hydroxytyrosol-β-cyclodextrin complexes in solution and in the solid state, a potential bioactive ingredient

Malapert

Reboul

Tourbin

et al. 2019

LWT

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This study focused for the first time on characterizing the inclusion complexes between β-cyclodextrin (β-CD) and hydroxytyrosol (HT) in the solid state. In solution, HT and β-CD are able to form a 1:1 inclusion complex with an association constant of 33.2 ± 3.7 M-1. In the solid state, the inclusion complexes prepared by freezedrying and spray-drying of an equimolar mixture of both partners were characterized and compared by 13 C NMR and SEM. After dissolution, their free radical-scavenging ability was also determined by UV-visible spectroscopy. The results show that β-CD and drying processes have no effect on the efficiency of HT to reduce the DPPH radical. The solid state 13 C NMR data provided information on the spatial proximity between β-CD and HT and suggest the formation of inclusion complexes for both drying processes compared to the physical mix. However, the morphology of the solids obtained was significantly different, as spherical particles were formed by spraydrying while freeze-drying only provided irregular shapes.

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“…1B). A symmetrical curve with a maximum at r = 0.5 evidenced the formation of a complex having a 1:1 stoichiometry in accordance with literature data (López-García et al, 2010). Fig.…”

Section: Stoichiometry and Association Constants Determinationsupporting

confidence: 91%

Characterization of hydroxytyrosol-β-cyclodextrin complexes in solution and in the solid state, a potential bioactive ingredient

Malapert

Reboul

Tourbin

et al. 2019

LWT

View full text Add to dashboard Cite

show abstract

“…The stoichiometries, the association constants and the geometry of the complexes have been determined by NMR techniques. The stoichiometries of both complexes are 1:1 and the association constants are 93±7 M -1 for HT/ -CD complex and 43±1 M -1 for HT/HP--CD complex (López-García et al, 2010). In both cases, the insertion of the catechol moiety took place by directing the hydroxyalkyl chain to the primary rim.…”

Section: Complexation Of Hydroxytyrosol With β-Cyclodextrinsmentioning

confidence: 95%

“…The complexation of hydroxytyrosol with commercially-available -cyclodextrin ( -CD) (López-García et al, 2010;Rescifina et al 2010) and hydroxypropyl--cyclodextrin (HP--CD) (López-García et al, 2010) in aqueous solutions has been studied. The stoichiometries, the association constants and the geometry of the complexes have been determined by NMR techniques.…”

Section: Complexation Of Hydroxytyrosol With β-Cyclodextrinsmentioning

confidence: 99%

“…For equimolecular mixtures of HT and -CD at 1.2 mM, the observed degradation after 24 h and 48 h is similar to the degradation found for HT at the same concentration and time (entries 4 and 5) showing no protection at 24 h and only a slight protection after 48 h. However, using 1:4 mixtures of HT (1.2 mM) and -CD (4.8 mM), a remarkable reduction of the degradation rate was observed when compared with pure HT. In this way, the complexation of HT with cyclodextrins might enhance stability, improve its performance as antioxidant and extend its storage life (López-García et al, 2010 Table 2. Effect of the encapsulation of HT on its photostability…”

Section: Complexation Of Hydroxytyrosol With β-Cyclodextrinsmentioning

confidence: 99%

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Biological Properties of Hydroxytyrosol and Its Derivatives

Fernandez‐Bolanos¹,

López²,

López-García³

et al. 2012

Olive Oil - Constituents, Quality, Health Properties and Bioconversions

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“…6). This may be a result of low hydroxytyrosol stability under the process conditions and its partial splitting (López-García et al, 2010) or the formation of by-products.…”

Section: -Phenylethanol Hydroxylationmentioning

confidence: 99%

Biotransformation of 1- and 2-phenylethanol to products of high value via redox reactions

Głąb¹,

Szmigiel-Merena²,

Brzezińska-Rodak³

et al. 2016

bta

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The aim of this research was to conduct biotransformation of phenolic compounds, prochiral ketone acetophenone into optically pure (R)-and (S)-1-phenylethanol and 2-phenylethanol into tyrosol and hydroxytyrosol. For acetophenone reduction reaction, the biocatalysts of choice were cyanobacteria, phototrophic microorganisms with biocatalytic potential that have not yet been fully discovered. For the hydroxylation reaction of 2-phenylethanol, instead of using vital Aspergillus niger cells, the reaction was carried out using the spores. As a result, high conversion rates were obtained (79.6%) for the reduction reaction performed by photobiocatalyst Nodularia sphaerocarpa, although the enantioselectivity was moderate (enantiomeric excess, ee 48%). The reaction carried out by cyanobacterium Leptolyngbya foveolarum yielded 25.7%, but with high enantioselectivity of (S)-1-phenylethanol 95% ee was received. It has also been proven that the acetophenone reduction did not depend on the light regime. For aromatic ring hydroxylation, several modifications of the conditions of biooxidation were introduced to maximize the effectiveness; the addition of glucose into the reaction medium gave the best results. As a result, new methods of bioconversion of phenylethyl alcohol have been developed, leading to the formation of desired products: 1-phenylethanol, tyrosol, and hydroxytyrosol antioxidants, compounds of utilitarian meaning.

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Complexation of hydroxytyrosol with β-cyclodextrins. An efficient photoprotection

Cited by 29 publications

References 21 publications

Characterization of hydroxytyrosol-β-cyclodextrin complexes in solution and in the solid state, a potential bioactive ingredient

Characterization of hydroxytyrosol-β-cyclodextrin complexes in solution and in the solid state, a potential bioactive ingredient

Biological Properties of Hydroxytyrosol and Its Derivatives

Biotransformation of 1- and 2-phenylethanol to products of high value via redox reactions

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