Protective Activity of Hydroxytyrosol Metabolites on Erythrocyte Oxidative-Induced Hemolysis
摘要:
The capacity of important hydroxytyrosol metabolites (homovanillyl alcohol, hydroxytyrosol acetate, homovanillyl alcohol acetate, hydroxytyrosol 3' and 4'-O-glucuronides, and homovanillyl alcohol 4'-O-glucuronide) to protect red blood cells (RBCs) from oxidative injury induced by the radical initiator 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH) or by the natural radical initiator H2O2 was evaluated. In the presence of AAPH, all compounds showed to protect RBCs from hemolysis in a dose-dependent manner, exccept for the homovanillyl alcohol glucuronide, with the order of activity being at 20 mu M hydroxytyrosol > hydroxytyrosol glucuronides = hydroxytyrosol acetate = homovanillyl alcohol = homovanillyl acetate > homovanillyl alcohol glucuronide. At 10 mu M, hydroxytyrosol, hydroxytyrosol acetate, and hydroxytyrosol glucuronides still protected hemoglobine from oxidation and from morphological RBC changes. In the presence of H2O2, hydroxytyrosol showed to significantly protect RBCs from oxidative hemolysis in a dose-dependent manner, but the hydroxytyrosol glucuronides showed only a limited protection that was independent of the concentration used.
Biocatalyzed Synthesis and Structural Characterization of Monoglucuronides of Hydroxytyrosol, Tyrosol, Homovanillic Alcohol, and 3-(4′-Hydroxyphenyl)propanol
作者:Olha Khymenets、Jesús Joglar、Pere Clapés、Teodor Parella、María-Isabel Covas、Rafael de la Torre
DOI:10.1002/adsc.200606221
日期:2006.10
The biocatalytic synthesis and purification of O-β-D-monoglucuronide conjugates of hydroxytyrosol, tyrosol, homovanillicalcohol, and 3-(4′-hydroxyphenyl)propanol, using porcine liver microsomes, are described here. The glucuronides were synthesized, analyzed and separated by HPLC-UV, identified by HPLC-MS, and their structures unequivocally established by NMR techniques. The outcome of the glucuronidation
A concise synthesis of glucuronide metabolites of urolithin-B, resveratrol, and hydroxytyrosol
作者:Ricardo Lucas、David Alcantara、Juan Carlos Morales
DOI:10.1016/j.carres.2009.05.016
日期:2009.7
A simple and direct strategy to chemically synthesize O-beta-D-glucuronides of urolithin-B 4, resveratrol 5, and the corresponding hydroxytyrosol derivatives 6, 7 (as a regioisomeric mixture), and 8 is described. The critical glycosylation step has been optimized using a structurally simple phenol, urolithin-B, by modification of several reaction parameters (solvent, promoter, and glucuronide donor). Very high yields have been obtained in the first synthesis of the O-beta-D-glucuronide of urolithin-B 4. Extension of these reaction conditions was used for the synthesis of resveratrol-3-O-glucuronide 5 where a higher yield than previously reported was obtained by using the much more common trichloroacetimidate glucuronide donor. Finally, three O-beta-D-glucuronides of hydroxytyrosol 6, 7, and 8 have been synthesized for the first time using chemical synthesis. (C) 2009 Elsevier Ltd. All rights reserved.
Protective Activity of Hydroxytyrosol Metabolites on Erythrocyte Oxidative-Induced Hemolysis
The capacity of important hydroxytyrosol metabolites (homovanillyl alcohol, hydroxytyrosol acetate, homovanillyl alcohol acetate, hydroxytyrosol 3' and 4'-O-glucuronides, and homovanillyl alcohol 4'-O-glucuronide) to protect red blood cells (RBCs) from oxidative injury induced by the radical initiator 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH) or by the natural radical initiator H2O2 was evaluated. In the presence of AAPH, all compounds showed to protect RBCs from hemolysis in a dose-dependent manner, exccept for the homovanillyl alcohol glucuronide, with the order of activity being at 20 mu M hydroxytyrosol > hydroxytyrosol glucuronides = hydroxytyrosol acetate = homovanillyl alcohol = homovanillyl acetate > homovanillyl alcohol glucuronide. At 10 mu M, hydroxytyrosol, hydroxytyrosol acetate, and hydroxytyrosol glucuronides still protected hemoglobine from oxidation and from morphological RBC changes. In the presence of H2O2, hydroxytyrosol showed to significantly protect RBCs from oxidative hemolysis in a dose-dependent manner, but the hydroxytyrosol glucuronides showed only a limited protection that was independent of the concentration used.