Quinone methides (QM) are important intermediates in the chemistry and photochemistry of phenols that have received significant attention in the last 10 years due to their biological activity. Several classes of anticancer drugs base their action on methabolic formation of QMs that alkylate DNA. One of the methods to generate QMs relies on photochemical reaction of dehydration of hydroxy-substituted benzocarbinols. We became interested in photochemical formation of QMs substituted with bulky adamantyl substituents that have longer lifetimes than the corresponding non-substituted analogues, and therefore higher selectivity in the reactions with nucleophiles, rendering them applicable for biological systems.1 Photochemical reactivity of several classes of phenols 1 and 2, 1-3 and naphthols 34 were conducted wherein QMs were characterized by laser flash photolysis. In addition, antiproliferative investigation was carried out on three cancer cell lines in the presence of compounds, with and without exposure to light. We have shown that irradiation of cells treated with adamantyl derivative of 4-hydroxybiphenyl or 2-naphthol induce stronger antiproliferative activity than the nonirradiated samples, in accordance with the transient formation of QMs.3, 4 |