Synthesis and evaluation as antitumor agents of 1,4-naphthohydroquinone derivatives conjugated with amino acids and purines.

We report on the synthesis of two series of 1,4-naphthohydroquinone derivatives conjugated with amino acids (Gly, Ala, Phe, and Glu) and with substituted purines linked by an aliphatic chain. The compounds were obtained through Diels-Alder cycloaddition between myrcene and 1,4-benzoquinone and evaluated in vitro for their cytotoxicity (GI50 ) against cultured human cancer cells of A-549 lung carcinoma, HT-29 colon adenocarcinoma, and MCF-7 breast carcinoma. The GI50 values found for some hydroquinone-amino acid and hydroquinone-purine hybrids against MCF-7 are in an activity range comparable to that of the reference drug doxorubicin.