SYNTHESIS AND CYTOTOXIC ACTIVITY OF 1,2,3-TRIAZOLE DERIVATIVES OF EUGENOL

Eugenol is an aromatic compound found in several plant species. It presents important biological activities including cytotoxicity. In this paper, it is described the synthesis and the evaluation of the cytotoxic activity of eugenol derivatives bearing 1,2,3-triazole functionalities. Eugenol, extracted via hydrodistillation from dried flower buds of Eugenia caryophyllata (=Syzygium aromaticum), was submitted to alkylation reactions to afford two terminal alkynes in good yields. The key reaction involved in the preparation of eugenol derivatives corresponded to the Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC), between alkynylated eugenol derivatives and different benzyl azides. The evaluation of the cytotoxicity of twenty seven synthesized derivatives against HL60 leukemia cell line revealed that at 100 µmol L-1, five of them, namely 4-((4-allyl-2-methoxyphenoxy)methyl)-1-(3-bromobenzyl)-1H-1,2,3-triazole (6n), 4-(3-(4-allyl-2-methoxyphenoxy)propyl)-1-benzyl-1H-1,2,3-triazole (7a), 4-(3-(4-allyl-2-methoxyphenoxy)propyl)-1-(4-chlorobenzyl)-1H-1,2,3-triazole (7c), 4-(3-(4-allyl-2-methoxyphenoxy)propyl)-1-(4-iodobenzyl)-1H-1,2,3-triazole (7e) and 4-(3-(4-allyl-2-methoxyphenoxy)propyl)-1-(3-bromobenzyl)-1H-1,2,3-triazole (7m), were capable of significantly decreasing cell viability. These most active triazolic derivatives were also evaluated against B16F10 melanoma and Nalm6 leukemia cell lines. While only compound 7a was active against the former, compounds 6n, 7a, and 7m displayed activity against the latter. Derivative 7a was active against all cell lines. It is believed that eugenol derivatives bearing triazole functionalities may represent a scaffold to be explored toward the development of new agents against cancer.