An expedient synthesis of 2,5-dihydroxytyrosol and studies on its effects on cell growth inhibition

Many antioxidant molecules are described to have an oxidant activity causing cell damages. Some dietary phytophenols, in spite of their beneficial effects, have been found to promote lipid peroxidation and DNA breaks. Hydroxytyrosol, a phytophenol extracted from olive oil and wine, has been found to act as an antioxidant. Furthermore it also inhibits the growth of several bacteria and fungi. During recent studies on the synthesis of antioxidant polyphenols from tyrosol, a phenol recovered in high amount from olive oil wastes, we prepared 2,4,5-trihydroxy-(2-hydroxyethyl)-phenol (2,5-dihydroxytyrosol). We observed its biological effect on cultured human and bacterial cells showing that its toxic activity is more potent than tyrosol and hydroxytyrosol resulting toxicity at 5 mu M whereas its parent molecules are toxic at a dose of about 100 mu M.