Premium
Biocatalyzed Synthesis and Structural Characterization of Monoglucuronides of Hydroxytyrosol, Tyrosol, Homovanillic Alcohol, and 3‐(4′‐Hydroxyphenyl)propanol
Author(s) -
Khymenets Olha,
Joglar Jesús,
Clapés Pere,
Parella Teodor,
Covas MaríaIsabel,
de la Torre Rafael
Publication year - 2006
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200606221
Subject(s) - tyrosol , chemistry , hydroxytyrosol , glucuronidation , alcohol , microsome , chromatography , organic chemistry , biotransformation , high performance liquid chromatography , phenols , enzyme , polyphenol , antioxidant
The biocatalytic synthesis and purification of O ‐β‐ D ‐monoglucuronide conjugates of hydroxytyrosol, tyrosol, homovanillic alcohol, 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 reaction depends on the structure of the phenolic compounds. Thus, the glucuronidation of hydroxytyrosol, biocatalyzed with porcine liver microsomes, proceeded exclusively on the phenolic hydroxy groups. The regioselectivity was similar to that observed for human and rat liver microsomes, the 4′‐hydroxy position being more favorable than the 3′‐hydroxy one. In the case of tyrosol, homovanillic alcohol, and hydroxyphenylpropanol, two products were formed during microsomal glucuronidation: a major one, the phenolic O ‐β‐ D ‐glucuronidated derivative and, a minor one, the O ‐β‐ D ‐glucuronidated aliphatic alcohol.