High-yielding preparation of a stable precursor of hydroxytyrosol by total synthesis and from the natural glycoside oleuropein.
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
A
Dipartimento di Ingegneria Meccanica e Industriale, Università degli studi Roma Tre, via della Vasca Navale 79, 00146 Roma, Italy. gambacor@uniroma3.it
Tofani
Daniela
D
Bernini
Roberta
R
Migliorini
Antonella
A
D000975:Antioxidants / Q000138:chemical synthesis*; D004355:Drug Stability; D005503:Food Additives; D057888:Iridoid Glucosides; D039823:Iridoids; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D011714:Pyrans / Q000737:chemistry*
D000975:Antioxidants; D005503:Food Additives; D057888:Iridoid Glucosides; D039823:Iridoids; D011714:Pyrans; C005975:3,4-dihydroxyphenylethanol; C002769:oleuropein; D010626:Phenylethyl Alcohol