- Regioselectivity of Cobalamin-Dependent Methyltransferase Can Be Tuned by Reaction Conditions and Substrate
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Regioselective reactions represent a significant challenge for organic chemistry. Here the regioselective methylation of a single hydroxy group of 4-substituted catechols was investigated employing the cobalamin-dependent methyltransferase from Desulfitobacterium hafniense. Catechols substituted in position four were methylated either in meta- or para-position to the substituent depending whether the substituent was polar or apolar. While the biocatalytic cobalamin dependent methylation was meta-selective with 4-substituted catechols bearing hydrophilic groups, it was para-selective for hydrophobic substituents. Furthermore, the presence of water miscible co-solvents had a clear improving influence, whereby THF turned out to enable the formation of a single regioisomer in selected cases. Finally, it was found that also the pH led to an enhancement of regioselectivity for the cases investigated.
- Pompei, Simona,Grimm, Christopher,Farnberger, Judith E.,Schober, Lukas,Kroutil, Wolfgang
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p. 5977 - 5983
(2020/10/06)
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- BIOISPIRED PROTEASOME ACTIVATORS WITH ANTIAGEING ACTIVITY
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The present invention relates to novel bio-inspired hybrid compounds of formula I which act as proteasome activators and exhibit anti-ageing activity, as well as methods for their synthesis. These hybrid compounds combine the structural features of hydroxytyrosol and the natural antioxidant vitamin E or its bioisosteres in one molecular scaffold. The compounds of formula I, which include structural proteasome activators (activation by stereochemical interaction), can be used in the production of anti-ageing products, such as cosmetic preparations. Additionally, they can be used in conditions and diseases where the proteasome is down-regulated, as well as proteasome-activation control compounds.
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- HYDROXYTYROSOL ETHERS
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The invention relates to hydroxytyrosol ethers derived from fatty alcohols and phenolic compounds of olive oil and the salts, solvates and hydrates thereof, which have an affinity for type 1 cannabinoid receptors (CB1) and which can: prevent the oxidation of low-density lipoprotein (LDL); and modulate the actions regulated by said receptor, such as inducing satiety, controlling intake and reducing body fat.
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Paragraph 0122; 0123; 0124
(2013/10/22)
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- HYDROXYTYROSOL ETHERS
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Hydroxytyrosol ethers. The invention relates to hydroxytyrosol ethers derived from fatty alcohols and phenolic compounds of olive oil and the salts, solvates and hydrates thereof, which have an affinity for type 1 cannabinoid receptors (CB1) and which can: prevent the oxidation of low-density lipoprotein (LDL); and modulate the actions regulated by said receptor, such as inducing satiety, controlling intake and reducing body fat.
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Paragraph 0086-0088
(2014/01/07)
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- Unsaturated fatty alcohol derivatives of olive oil phenolic compounds with potential low-density lipoprotein (LDL) antioxidant and antiobesity properties
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A new route for the synthesis of fatty alcohol derivatives of hydroxytyrosol and other olive oil phenolic compounds was developed to allow the preparation of unsaturated derivatives. The biological activity of synthesized compounds was evaluated. Most of the compounds presented a significant antioxidant activity on low-density lipoprotein (LDL) particles. The activity of the tested products was significantly influenced by the number and position of unsaturations as well as modifications on the polar head of the synthesized compounds. Some of them presented modulation of food intake in rats and, due to their molecular similarity with CB1 endogenous ligands, the endocannabinoid system and PPAR-α were also evaluated as potential targets. The pharmacodynamics could not be totally explained by CB1 and PPAR-α receptor interactions because only two of the four compounds with biological activity showed a CB1 activity and all of them presented low PPAR-α affinity, not justifying its whole in vivo activity. The hydroxytyrosol linoleylether (7) increased LDL resistance to oxidation with a capacity similar to that of hydroxytyrosol and was the most active in vivo compound with a hypophagic effect comparable to that of oleoylethanolamine. We consider that this compound could be a good lead compound for future drug development in obesity treatments.
- Cotrim, Bruno Almeida,Joglar, Jesus,Rojas, M. Jesus L.,Del Olmo, Juan Manuel Decara,MacIas-Gonzalez, Manuel,Cuevas, Miguel Romero,Fito, Montserrat,Munoz-Aguayo, Daniel,Covas Planells, Maria Isabel,Farre, Magi,Rodriguez De Fonseca, Fernando,De La Torre, Rafael
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experimental part
p. 1067 - 1074
(2012/06/16)
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- Bifunctional catechol based linkers for modification of TiO2 surfaces
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Bifunctional linkers for modification of TiO2 nanoparticles were prepared containing a catechol group for TiO2 surface attachment and a maleimide and alkyne group for Michael addition and Cu catalysed Huisgen cycloaddition respectively. Peptide and fluorophore functionalised TiO 2 NPs were prepared, different purification methodologies were explored and conjugates were characterized using a range of methods.
- Geiseler, Bianca,Fruk, Ljiljana
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p. 735 - 741
(2012/04/04)
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- High-yielding preparation of a stable precursor of hydroxytyrosol by total synthesis and from the natural glycoside oleuropein
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The unprecedented acetonide of the antioxidant hydroxytyrosol has been synthesized by a two-step high-yielding procedure and found to be both purifiable by chromatography and stable over a wide pH range. The protection stabilizes hydroxytyrosol against oxidation, thereby allowing long-term storage. The protection can quantitatively be removed, under nonaqueous conditions, to afford pure hydroxytyrosol suitable for use as an additive in food and cosmetic preparations. Extension of the same methodology to the natural and easily accessible glycoside oleuropein, followed by saponification of the resulting complex mixture of acetonides, allowed hydroxytyrosol acetonide to be recovered in high yield. This constitutes a new interesting methodology to obtain the antioxidant hydroxytyrosol.
- Gambacorta, Augusto,Tofani, Daniela,Bernini, Roberta,Migliorini, Antonella
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p. 3386 - 3391
(2008/02/07)
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